Fabrication and characterization of 3D printing filaments based on PMMA/ZrO2 hybrid nanocomposites .... 47 Trang 5 ABBREVIATIONS Abbreviations Definition 3D 3 Dimensions 3DP 3-Dimension
OVERVIEW
Three-dimensional (3D) printing technology and 3D printing
Three-dimensional (3D) printing technology has emerged as a highly appealing research area for scientists in recent years, enabling the creation of intricate objects and products The journey of 3D printing began in 1984 when Charles W Hull invented the first stereolithography apparatus (SLA) by successfully producing a teacup, marking a significant milestone in this innovative field.
1 by himself, and the related patent on stereolithography was issued on August
In 1984, a 3D Printing Corporation was co-founded, leading to significant advancements in the field Notable inventions include Selective Sintering (SS) developed by Carl R Deckard at the University of Texas in 1986, and the laminated manufacturing method created by Michael Feygin and colleagues at Helisys, Inc in 1988 In 1989, Scott S Crump introduced Fused Deposition Modelling (FDM) at Stratasys, Inc Additionally, Emanuel M Sachs and his team at the Massachusetts Institute of Technology pioneered three-dimensional printing techniques that utilize a binding agent and colored ink injected onto a bed of powdered material, similar to a conventional ink-jet printer.
There are numerous 3D printing techniques available today, with the most popular being powder bed fusion (PBF) methods such as selective laser sintering (SLS) and selective laser melting (SLM), along with 3D inkjet printing (3D JP) and photochemical embossing (SLG) Additionally, layered fusion printing techniques, including fused filament fabrication (FFF) and fused deposition modeling (FDM), are also widely utilized.
Three-dimensional (3D) printing technology is extensively utilized across various industries, including automotive, construction, medical equipment, and healthcare Additionally, it plays a significant role in the art sector by enabling the creation of unique objects and jewelry, while in the electronics industry, it is employed for manufacturing intricate components.
This article explores the synthesis and characterization of poly(methyl methacrylate)-zirconia (PMMA-ZrO2) nanocomposite materials, emphasizing their application in 3D printing of complex structures The advancements in 3D printing technology are highlighted, showcasing its growing relevance across various sectors, including education, military, and aerospace.
Table 1.1: Several of 3D printing techniques [5]
3DB Three-dimensional bioplotter DCM Direct composite manufacturing
3DP Three-dimensional printing DIPC Direct inkjet printing of ceramics
AF Additive fabrication DLC Direct laser casting
AM Additive manufacturing MD Material deposition
BM Biomanufacturing MEM Melted extrusion manufacturing LPD Laser powder deposition SL Stereolithography
LPF Laser powder fusion SS Selective Sintering LPS Liquid-phase sintering SLA Stereolithography apparatus
(cutting) FDC Fused deposition of ceramics
LMF Laser metal forming FFEF Freeze-form extrusion fabrication LRF Laser rapid forming FLM Fused layer modeling
LS Laser sintering FFF Fused filament fabrication
JP Jet prototyping (injection) FDM Fused deposition modeling Figure 1.2 displays the state of the use rate of 3D printing materials with thermoplastics (65%), metal (36%), thermoset resins (29%), sandstone (15%)
The report indicates a growing trend in the use of metallic materials, while polymers, particularly thermoplastics and thermosetting resins, continue to dominate the market According to Statista, polylactic acid (PLA) is the most prevalent polymer, accounting for 33% of usage, followed by acrylonitrile butadiene styrene copolymer (ABS) at 14% and thermosetting resin at 9%.
FDM (Fused Deposition Modeling) or FFF (Fused Filament Fabrication) is a 3D printing technique where thermoplastic filament is melted and extruded in layers to create the desired shape on the print bed The thermoplastic properties of polymer filaments enable them to melt during the printing process and solidify at room temperature once printing is complete Key factors such as the thickness and width of each monolayer, along with their orientation, play a crucial role in determining the quality and precision of the final printed object.
The study focuses on the synthesis and characterization of poly(methyl methacrylate) zirconia (PMMA-ZrO2) nanocomposite materials for use in 3D printing filaments Key factors influencing the mechanical properties of 3D printed products include the air gap between layers and the deformation of the products, which can lead to decreased mechanical performance The advantages of filamentous thermoplastic polymers in 3D printing include ease of processing, cost-effectiveness, and reduced material usage Research has shown that incorporating fiber reinforcement can significantly enhance the mechanical properties of polymers; however, challenges such as microfiber orientation, bonding with the polymer matrix, and air gaps persist in polymer composite 3D printing The FFM/FDM 3D printing technique is favored for creating products from polymer blends and composites due to its simplicity and compatibility with traditional polymer processing Despite the potential of polymer materials in 3D printing, studies remain limited, primarily focusing on composition trends, printer testing, and basic 3D printing techniques, with most outputs being prototypes rather than functional products.
Figure 1.2: (a): Types of 3D printing materials 3D printing; (b): Percentage of common polymers used for 3D printing in the world
Selective laser melting (SLM) 3D printing involves evenly distributing a thin layer of metal powder onto a build plate A focused laser selectively heats designated areas of the powder bed, melting it to form solid layers This process is repeated layer by layer until the final model is completed, allowing for the recovery of any residual powder for future use.
This research focuses on the synthesis and characterization of poly(methyl methacrylate) zirconia (PMMA-ZrO2) nanocomposite materials, which are designed for 3D printing applications The study highlights the unique properties of these materials and their potential for use in various advanced manufacturing processes The final products may require additional processing stages to enhance their performance and applicability.
Introduction to polymer nanocomposite materials
Polymer nanocomposites are advanced materials that consist of a polymer matrix combined with inorganic nanoscale fillers, enhancing both rigidity and thermal stability while maintaining the flexibility and processability of organic polymers These composites leverage the unique properties of nanofillers, resulting in significantly improved performance characteristics compared to traditional composites A key advantage of polymer nanocomposites is the increased interfacial area due to the small size of the fillers, which contributes to their superior mechanical and thermal properties.
A hybrid nanocomposite is a material created by integrating inorganic nanoparticles into a macroscopic organic matrix These nanocomposites can be categorized into three types: binary hybrid nanocomposites, which consist of two components with one nanomaterial; ternary hybrid nanocomposites, which include three components with one at the nanoscale; and multiple hybrid nanocomposites, featuring more than three components, with at least one in the nanoscale Notably, a polymer nanocomposite is a specific type of hybrid nanocomposite where the organic matrix is substituted with a polymer matrix.
In this method, all ingredients and polymers are continuously stirred in a common solvent to create a homogeneous solution This solution is then poured onto a flat glass plate or Petri dish, allowing the solvent to evaporate completely, after which the dried membrane is peeled off from the glass support Alternatively, a thin selective layer can be deposited on a microporous substrate, which may take the form of a flat sheet, hollow fiber, or tubular shape.
Poly methyl methacylate (PMMA)
In in-situ polymerization, it is crucial to disperse nanoparticles in the monomer solution before the polymerization process to achieve optimal interaction at the interface and ensure effective polymer formation This is essential because inorganic particles often phase separate and settle quickly from the organic phase To enhance nanoparticle dispersion, organic modification techniques can be employed Additionally, various methods, including the application of heat and the use of suitable initiators, can facilitate the polymerization process.
This method has number of advantages in relation to the other methods since it is a simple method, no solvent is required, environmentally friendly
[33], especially it is a common method used in industrial application [33] [34]
The dispersion of nanoparticles plays a crucial role in the melt extrusion process due to the tendency for agglomeration It is essential to maintain sufficiently high temperatures and heat energy during this method For certain biopolymers and natural polymers, the degradation temperatures are alarmingly close to their processing temperatures To prevent polymer degradation during fabrication, it is vital to minimize processing time while ensuring adequate time for proper nanoparticle dispersion.
Ultrasonication-assisted solution mixing is a popular method for producing polymer nanocomposites This technique utilizes ultrasound waves with frequencies ranging from 2 × 10^4 to 10^9 Hz to effectively disperse nanoparticles within a polymer solution By dissolving both the nanoparticles and polymer in a solvent, ultrasound enhances the distribution of nanofillers throughout the polymer matrix The final polymer nanocomposites are formed by evaporating the solvent, resulting in a well-integrated material.
1.3 Poly methyl methacrylate (PMMA) 1.3.1 Structure and general properties
Poly methyl methacrylate (PMMA), commonly referred to as acrylic resin or Plexiglas, is a significant thermoplastic polymer characterized by its transparent and colorless properties This versatile material has a vitrification temperature range of 100 to 130°C, making it suitable for various applications.
The study focuses on the synthesis and characterization of poly(methyl methacrylate)-zirconia (PMMA-ZrO2) nanocomposite materials, which are promising for 3D printing applications This material exhibits a density of approximately 1.2 g/cm³ at room temperature and melts between 130°C and 200°C, depending on its molecular weight and isomer form PMMA-ZrO2 demonstrates low water absorption at 0.3% and moisture absorption at equilibrium ranging from 0.3% to 0.33%, with linear shrinkage mold values between 0.003 and 0.0065 cm/cm Notably, PMMA is highly resistant to UV light, showcases excellent thermal stability, and can withstand temperatures from -70°C to 100°C Additionally, it possesses remarkable optical properties with a refractive index of 1.49, making it a vital component in bone cement due to its biocompatibility with human and animal tissues.
PMMA exhibits a high Young's modulus, low elongation at break, and excellent scratch resistance It demonstrates good chemical resistance, remaining largely unaffected by most laboratory aqueous solutions However, PMMA has limited resistance to chlorinated and aromatic hydrocarbons, as well as esters and ketones.
Nghiên cứu chế tạo và đặc trưng tính chất của vật liệu nanocompozit poly(methyl methacrylat) zirconia (PMMA-ZrO2) lai ghép hữu cơ có ứng dụng trong in 3D dạng rắn Vật liệu này hứa hẹn mang lại những ưu điểm vượt trội trong công nghệ in 3D, nhờ vào sự kết hợp giữa tính linh hoạt của PMMA và độ cứng của zirconia Các đặc tính cơ học và hóa học của vật liệu sẽ được phân tích để đánh giá khả năng ứng dụng trong sản xuất các sản phẩm phức tạp và chất lượng cao.
PMMA can exist in three types of tacticities: isotactic, syndiotactic, and atactic The synthesis of pure PMMA in these forms can be achieved through methods such as control/living radical polymerization, reversible addition-fragmentation chain transfer (RAFT), and anionic polymerization, depending on the careful selection of initiator, solvent, and monomer concentration The amorphous characteristics of PMMA are influenced by its tacticity, ranked as isotactic < atactic < syndiotactic, with corresponding glass transition temperatures (Tg) of 55°C < 120°C.
PMMA, or polymethyl methacrylate, is a synthetic polymer derived from the monomer methyl methacrylate (MMA), which has the molecular formula C5H8O2 This colorless liquid has a density of 0.94 g/cm³, a boiling point of 101°C, a melting point of -48°C, and a viscosity of 0.6 cP at 20°C As an ester, methyl methacrylate readily reacts with other esters and alkalis, and its C=C double bond facilitates polymerization to form PMMA The presence of methyl (CH3) groups in the polymer structure prevents tight crystallization and allows for free rotation around C-C bonds, resulting in a hard plastic PMMA boasts excellent visible light transmission and maintains its properties over time, even when exposed to ultraviolet radiation and weathering, making it an ideal glass substitute.
Poly (methyl methacrylate) (PMMA) can be synthesized through various methods, with the primary polymerization techniques including bulk, solution, emulsion, and suspension polymerizations Additionally, advanced PMMA polymerization technologies are prominent in basic research, featuring techniques such as controlled radical polymerization (CRP), reversible addition fragmentation chain transfer polymerization (RAFT), nitroxide-mediated radical polymerization (NMP), and atom transfer radical polymerization (ATRP).
Bulk polymerization is an efficient and cost-effective process that utilizes only a monomer and an initiator, eliminating the need for solvents This polymerization method can be initiated through heat or light, resulting in an increase in viscosity as the reaction progresses, ultimately transforming the mixture into a solid state.
Nghiên cứu chế tạo và đặc trưng tính chất của vật liệu nanocompozit poly(methyl methacrylat) zirconia (PMMA-ZrO2) là một lĩnh vực quan trọng trong ứng dụng in 3D dạng rắn Vật liệu này kết hợp các đặc tính ưu việt của PMMA và zirconia, mang lại khả năng chịu lực tốt và độ bền cao Việc phát triển PMMA-ZrO2 không chỉ mở rộng khả năng ứng dụng trong công nghiệp mà còn cải thiện hiệu suất của các sản phẩm in 3D, đáp ứng nhu cầu ngày càng cao trong lĩnh vực chế tạo hiện đại.
The solution polymerization method offers several benefits, including being environmentally friendly when utilizing less toxic solvents and minimizing localized heat generation However, it also presents challenges, such as potential side reactions between the solvent and monomers that can decrease the average molecular weight of the resulting polymer Additionally, the process requires the recovery of the solvent and separation of the polymer from it at the conclusion of polymerization.
Emulsion polymerization is a key industrial process that begins with essential components such as monomers, initiators, and surfactants The primary function of emulsifiers is to lower the surface tension between the aqueous phases of the monomers, thereby improving the emulsification process When water-insoluble monomers are introduced, some will diffuse into the micelles while others remain suspended in the solvent Common initiators used in this process include peroxide and hydroperoxide compounds.
Polymerization occurs within micelles, leading to their growth as monomers from the aqueous solution are added, replenished by the dissolution of monomer droplets This process continues until free radicals diffuse into the micelle, resulting in termination and the formation of polymer molecules As polymerization progresses, the size of these polymer molecules gradually increases, while the process also generates multiple polymer droplets within the polymer particles.
Zirconia (ZrO 2 )
Zirconia, or Zirconium(IV) oxide (ZrO2), is a white crystalline solid found in nature as the mineral Baddeleyite, which features a monoclinic crystalline structure Often referred to as "ceramic steel," zirconia is chemically inert and is recognized as one of the best restorative materials in medicine due to its outstanding mechanical properties.
Zirconia, recognized for its exceptional hardness and toughness at room temperature, is the most robust ceramic material However, during high-temperature phase transitions, zirconia can undergo significant volume changes, complicating the production of stable products during sintering This necessitates the stabilization of zirconia to enhance its performance.
Partially stabilized zirconia (PSZ) is renowned for its outstanding physical, mechanical, electrical, chemical, thermal, and bioactive properties This makes PSZ a preferred choice for applications such as thermal barrier coatings, refractories, oxygen-permeating membranes, and dental and bone implants, thanks to its exceptional mechanical strength and resemblance to natural teeth.
Nghiên cứu chế tạo và đặc trưng tính chất của vật liệu nanocompozit poly(methyl methacrylat) zirconia (PMMA-ZrO2) lai ghép hữu cơ được thực hiện nhằm ứng dụng làm vật liệu in 3D dạng rắn Vật liệu này hứa hẹn mang lại những ưu điểm vượt trội trong công nghệ in 3D, kết hợp giữa tính linh hoạt của PMMA và độ cứng của zirconia, tạo ra sản phẩm có độ bền và tính chất cơ lý tốt Kết quả nghiên cứu sẽ đóng góp vào việc phát triển các vật liệu mới cho ngành công nghiệp in 3D, mở ra nhiều cơ hội ứng dụng trong thực tiễn.
Zirconium dioxide is known highly resistant to cracking (including further development of cracks) and mechanical stress Table 1.2 is the other outstanding mechanical property of zirconia:
Table 1.2: Mechanical properties of zirconia [53]
Elastic modulus 100 – 250 GPa at 20ºC
Flexural strength 180 – 1000 MPa at 20ºC
Tensile strength 330 MPa at 20ºC
High temperature resistance and expansion:
Zirconium dioxide is widely known for its high resistance to heat with a melting point and thermal expansion coefficient are 2700ºC and 1.08×10-5 K -
Zirconia has diverse applications in refractories and high-temperature industries due to its varying melting points across different temperature-dependent forms Table 1.3 illustrates these temperature ranges for zirconia, highlighting its significance in industrial processes.
Table 1.3: High temperature resistance and expansion [53]
Zirconia’s temperature-dependent form Melting point
In its tetragonal form, zirconia can experience a phase change that leads to internal stresses and crack formation To mitigate this issue, stabilizers like yttria are incorporated, resulting in a more stable variant known as yttria partially stabilized zirconia (or yttria tetragonal zirconia polycrystalline).
“Zirconium dioxide has a thermal conductivity of 2 W/(m.K), which makes it perfect for situations where heat needs to be contained” [53]
“The substance is chemically inert and unreactive, which works in industries that make use of several chemicals during processing Nevertheless,
Researchers have investigated the synthesis and characterization of poly(methyl methacrylate) zirconia (PMMA-ZrO2) nanocomposite materials, which have potential applications as 3D printing inks Notably, the compound is soluble in concentrated acids, including sulfuric and hydrofluoric acid, as reported in previous studies.
Zirconium dioxide can exist in three distinct phases—monoclinic, tetragonal, and cubic—depending on the temperature during its production This versatility in its structural forms allows zirconium dioxide to be utilized across various industries and applications.
Zirconia is created through thermal treatment, known as thermal dissociation, but producing it in its pure form can lead to sudden phase changes that may result in cracks or fractures To maintain structural integrity, stabilizers like magnesium oxide, yttrium oxide, and calcium oxide are often added This thermal process is commonly referred to as dry calcination Additionally, zirconia can be synthesized by decomposing zircon through fusion with compounds such as calcium carbonate, calcium oxide, sodium carbonate, magnesium oxide, and sodium hydroxide.
Chlorination of zircon generates zirconia through the calcination of zirconium tetrachloride at approximately 900ºC, yielding commercial-grade zirconia Alternatively, zirconium tetrachloride can be dissolved in water to create crystallized zirconyl chloride, which is subsequently thermally treated at high temperatures to produce high-purity zirconia.
- Ceramics: Thank to the mechanical strength, resistance of zirconium dioxide and high hardness factor of zirconia, so it becomes a suitable component for ceramic manufacturing
Zirconium dioxide is a key refractory material known for its exceptional thermal resistance, making it essential in the production of crucibles, furnaces, and other high-heat applications It enhances the fireproof properties of ceramics, including refractory bricks and armor plates Additionally, zirconia is utilized in the creation of siloxide glass when combined with melted quartz, resulting in a harder and more stress-resistant glass compared to traditional quartz opaque glass Furthermore, zirconia can be combined with aluminum oxide for use in components within the steel casting process.
- Thermal barrier coating: With the compound’s low thermal conductivity and high heat resistance of zirconium dioxide it is applied as a coating for jet
This article explores the synthesis and properties of poly(methyl methacrylate)-zirconia (PMMA-ZrO2) nanocomposite materials, particularly their application in 3D printing of solid engine components subjected to high temperatures Numerous studies have validated the efficacy of zirconium dioxide in thermal barrier coating applications, highlighting the importance of proper and uniform material application for optimal performance.
Zirconia is a widely used material in the dental industry, particularly for dental restorations such as bridges, crowns, feldspar porcelain veneers, and prostheses, due to its excellent biocompatibility, aesthetic appeal, and robust mechanical properties Additionally, yttria-stabilized zirconium dioxide plays a crucial role in the creation of durable zirconia crowns.
- Abrasive material and scratch resistant: Zirconia is being used as an abrasive material because of its elevated mechanical stability and abrasion resistance
Cubic zirconia has emerged as a popular and affordable alternative to diamonds in the jewelry industry, offering exceptional durability and a striking visual similarity to natural diamonds Unlike diamonds, cubic zirconia features distinctive cutting lines and possesses optical flawlessness, appearing completely colorless to the naked eye While often referred to as a diamond imitation, cubic zirconia differs chemically from natural diamonds, making it a unique choice for jewelry such as cubic zirconia rings and earrings.
The research status on 3D filaments from PMMA and its composites
While polymers and thermoset resins have been extensively researched in 3D printing, PMMA and curing acrylic resins remain underexplored Literature indicates that studies on common polymers like PLA, ABS, and PA significantly outnumber those on PMMA, and research on epoxy resins surpasses that of acrylic resins PMMA, characterized by its hardness and high melting point, presents challenges such as shrinkage when used in printing Consequently, researchers have increasingly focused on developing polymer blends and composites from acrylic resins to enhance their usability in various applications.
Polzin C et al [59] studied 3D printing materials based on polymer blend PMMA/polyethylmethacrylate (PEMA) The powder material was a mixture of
50 àm average particle size and a little amount of benzoyl peroxide (BPO)
This study explores the synthesis and characterization of poly(methyl methacrylate)-zirconia (PMMA-ZrO2) nanocomposite materials for 3D printing applications The binding liquid used in the process was a blend of hexane-1-ol, 2-ethylhexyl acetate, and hexyl acetate A VX500-type 3D printer from Voxeljet Technology GmbH was employed, with a resolution of 64 µm, 102 µm, and 150 µm for the x, y, and z axes, respectively The powder layer thickness was set at 150 µm, and ink droplets were adjusted to 90 µg After completing each xy plane, the powder cavity was lowered, and a new layer was applied Testing revealed that the tensile strength (TS) of the 3D printed products was 2.91 MPa, with an elastic modulus (YM) of 233 MPa Notably, heat-curing the samples with epoxy resin enhanced the mechanical properties, resulting in a TS of 26 MPa and a YM of 1990 MPa.
Roca A et al [27] highlighted the challenges of using PMMA as a tissue culture material without surface treatment They developed poly(MMA-co-BMA)-polyethyleneglycol diacrylate (PEG-DA) frame materials utilizing MMA, BMA, and PEGDA as curative agents, along with the photoinitiator ethyl-2,4,6-trimethylbenzoyl-phenylphosphinate (TPO), and cured the mixture using a UV lamp at a wavelength of 365 nm for 60 minutes The study revealed that variations in BMA and PEGDA content significantly affected the mechanical properties of the resulting films Cytotoxicity tests confirmed that the membranes met the requirements for cell culture, leading the authors to recommend the use of SLS 3D printing technology to fabricate cell and tissue culture membranes from this innovative material.
Wagner A et al [10] developed a 3D inkjet formulation designed to create lightweight, porous objects directly during the printing process, eliminating the need for foaming treatment steps used in traditional 3D printing techniques The ink, composed of acrylic modified with a blowing agent (BA), was characterized by its viscosity, the decomposition of the foaming agent, and the ultraviolet (UV) polymerization of the base ink The acrylic foaming ink was produced by dissolving BA agents in liquid acrylic resin (PEG-600-diacrylate, PEG600DA) along with other additives Upon exposure to UV irradiation and heat, photopolymerization and gas generation occurred simultaneously, resulting in the formation of acrylic polymer foam material, making this ink suitable for Polyjet™ applications.
Nghiên cứu này tập trung vào việc chế tạo và xác định các đặc trưng tính chất của vật liệu nanocompozit poly(methyl methacrylat) zirconia (PMMA-ZrO2) lai ghép hữu cơ, với ứng dụng chính trong in 3D dạng rắn Vật liệu này hứa hẹn mang lại những cải tiến vượt trội về độ bền và tính năng sử dụng trong các lĩnh vực công nghiệp và y tế Việc phát triển PMMA-ZrO2 không chỉ giúp tối ưu hóa quy trình sản xuất mà còn nâng cao chất lượng sản phẩm cuối cùng, mở ra nhiều cơ hội mới trong công nghệ in 3D.
In Vietnam, 3D printing technology is being utilized across various scientific fields, including medicine, fine arts, fashion, architecture, mechanics, and education Numerous companies are investing in this innovative technology, and researchers have published studies providing an overview of its applications Notably, authors Nguyen Xuan Chanh, Tran Minh Tam, and Nguyen Manh Quan offered introductory reports on 3D printing techniques and their applications, although they did not specifically address the technology's use in Vietnam A summary report by Dr Hoang Xuan Tung, Huynh Huu Nghi, and Vo Hong Ky from the Science and Technology Information and Statistics Center in Ho Chi Minh City analyzed trends and future applications of 3D printing, highlighting its implementation at the Faculty of 3D Printing Technology at Vietnam National University, Ho Chi Minh City, where modern 3D printers are being used to produce high-quality products.
According to data from Sculpteo and other sources, the most utilized 3D printing techniques among 1,000 surveyed companies are SLS (33%), DFM (36%), and SLS (25%) Additionally, the number of inventions related to 3D printing saw a significant increase from 2012 to 2017, with 7,141 inventions recorded in 2017—double that of 2016 and triple that of 2015 This surge underscores the growing interest and research potential in 3D printing technology during this period.
At the Institute for Tropical Technology, Hoang Tran Dung conducted a research project from 2019 to 2020, focusing on the development of 3D printers and 3D printing inks for applications in the electrical-electronic industry The project yielded a functional 3D printer system and a specialized 3D printing ink, with the findings published in several VAST journal articles Notably, the research team successfully fabricated a 3D printer utilizing PLA filament and synthesized an ink containing carbon nanotubes and ferromagnetic oxide, which was subsequently used to create electrical supercapacitors via the 3D printing system.
Nghiên cứu này tập trung vào việc chế tạo và phân tích đặc trưng tính chất của vật liệu nanocompozit poly(methyl methacrylat) zirconia (PMMA-ZrO2) lai ghép hữu cơ, với mục tiêu ứng dụng trong in 3D dạng rắn Các kết quả cho thấy PMMA-ZrO2 có tính chất cơ lý tốt, phù hợp cho các ứng dụng công nghiệp và y tế, đặc biệt trong lĩnh vực sản xuất vật liệu in 3D Nghiên cứu cũng chỉ ra rằng sự kết hợp giữa PMMA và zirconia mang lại độ bền và độ ổn định cao cho sản phẩm cuối cùng.
P.X Lan et al [63] Hanoi University of Science and Technology fabricated the frame material from poly(propylene fumarate)/diethylene fumarate (PPF/DEF) with the orientation of application in bone tissue engineering This material was modified by immersion in simulated body fluid (SBF) solution to coat a layer of apatite The post-denaturation material was implanted with MC3T3-E1 osteogenic cells Study results showed that the fabrication of PPF/DEF skeleton by stereolithography and SBF modification was suitable for bone tissue culture
D.X Phuong at Nha Trang University and Park H.-S (Korea Ulsan University) had made smart metal molds for plastic processing using 3D printing techniques SLS [64] Ha Thuy Tran Thi, Nguyen Dac Hai, and colleagues at Hanoi University of Industry studied, designed, and manufactured a 2-axis tilt-angle condenser sensor using a 3D printer of Stratasys company (USA) With this technology, the sensor had high quality, uniformity, low cost, and met some requirements of conventional sensors Author Tran Ngoc Hien (University of Transport) had found the optimal operating mode for a type of 3D printing device using commercial PLA and ABS plastic filaments [65] Based on an overview of the research status on 3D printing technology and 3D printing materials in Vietnam, it can be seen that Vietnamese scientists and technologists have been interested in this field Most of studies only concentrated at an overview level, introduced the research status on 3D printing in the world, some of studies made some investigations with the commercial polymer filaments, manufacture of 3D printers, preparation of 3D printing ink for capacitors The amounts of studies performed by Vietnamese authors related to the fabrication of new 3D printing materials from polymers is limited Nevertheless, there are several inventions related to 3D printing technology registered in the Intellectual property office of Vietnam [66]
PMMA is a widely recognized polymer in the biomedical field, particularly valued for its biocompatibility, making it a key component of bone and acrylic cement Despite its advantages, PMMA faces limitations such as low thermal stability and brittleness To enhance these properties, researchers are exploring the combination of PMMA with inorganic nanoparticles to create polymer nanocomposites, which have shown promising results in improving performance.
The study focuses on the synthesis and characterization of poly(methyl methacrylate) zirconia (PMMA-ZrO2) nanocomposites for 3D printing applications High inorganic content in these materials often leads to agglomeration of organic particles, negatively impacting their mechanical properties To enhance compatibility and dispersity within the polymer matrix, researchers have modified zirconia using organic compounds, particularly trialkoxysilane moieties These modifications allow for the formation of covalent bonds with acrylic monomers during polymer synthesis, resulting in improved hybrid materials For instance, Jiaxue Yang et al demonstrated that nanozirconia fillers treated with 3-aminopropyltriethoxysilane (APTES) or (3-mercaptopropyl)trimethoxysilane (MPTS) significantly enhanced the mechanical properties of Bis-GMA-based resin composites Similarly, Dan Li et al utilized vinyltrimethoxysilane (VTMS) to modify zirconia, successfully grafting vinyl acetate (VAc) onto the ZrO2 surface, as confirmed by FTIR and TGA analyses.
Research on inorganic-organic hybrid materials, particularly PMMA grafted ZrO2 nanoparticles, has indicated that these hybrids can improve the properties of PMMA However, there is a scarcity of manufacturing publications focused on modified zirconia to enhance its interaction with polymer matrices My research, titled “Fabrication and Characterization of,” aims to address this gap in the literature.
PMMA/ZrO 2 hybrid nanocomposites towards the application in 3D printing filament materials”
Nghiên cứu này tập trung vào việc chế tạo và phân tích các đặc trưng của vật liệu nanocompozit poly(methyl methacrylate) zirconia (PMMA-ZrO2) lai ghép hữu cơ, với ứng dụng chính trong in 3D dạng rắn Vật liệu này hứa hẹn mang lại những cải tiến đáng kể về tính chất cơ lý và khả năng ứng dụng trong công nghệ in 3D, mở ra hướng đi mới cho các sản phẩm có độ bền và tính thẩm mỹ cao.
EXPERIMENTAL
Materials
Zirconia nano particles (ZrO2, 99.9%) in white color with density (d = 5.68 g/cm 3 ), particle size of 20 - 80 nm was provided by Aladdins Chemical Corporation (Shanghai, China) Methyl methacrylate (MMA, 99%, contains ~
The chemicals used in this study included 30 ppm MeHQ, α,α'-azobis(isobutyronitrile) (AIBN, 98%), and 3-(trimethoxysilyl) propyl methacrylate (MPTS, 98%), all sourced from Sigma-Aldrich (USA) Methyl methacrylate (MMA) was purified by passing it through a column of basic alumina to remove the MeHQ inhibitor Additionally, reagent-grade solvents such as acetone (99.7%), ammonia (28%), methanol (99.7%), ethanol (99.7%), and 1,4-Dioxane (99.5%) were obtained from Guangzhou Chemical Company, Ltd (Guangzhou, China) The poly(methyl methacrylate) (PMMA), known as ACRYPET-VH001, was supplied by Mitsubishi (Tokyo, Japan) and has a melt flow index of 5.7 (at a load of 3.8 kg and 230 °C) along with a density of 1.19 g/cm³.
Sample preparation
Into a 500 mL round bottom flask, 100 g of nano zirconia was mixed with
200 mL methanol and 20 mL dioxane, the mixture was continuously stirred for
To achieve a pH of 8.5 ± 0.2, 2 mL of 28% ammonia solution was added and stirred for 30 minutes In a 20 mL vial, a mixture of 10 g of MPTS was prepared by dissolving it in a methanol and water solution at a weight ratio of 6:2:1 The MPTS solution was then slowly injected into the bottom flask using a syringe-needle over a period of 2 minutes The mixture was continuously stirred at room temperature (23 - 27 °C) for 24 hours to facilitate the grafting reaction between MPTS and ZrO2 nanoparticles To remove residual MPTS, the mixture underwent three washing cycles with methanol/dioxane and centrifugation at 6000 rpm, followed by drying in a vacuum oven at 40 °C until a constant weight was achieved The final product, modified ZrO2 nanoparticles (mZrO2), was obtained by grinding the solid using an agate pestle mortar.
Nghiên cứu chế tạo và đặc trưng tính chất của vật liệu nanocompozit poly(methyl methacrylat) zirconia (PMMA-ZrO2) là một chủ đề quan trọng, đặc biệt trong ứng dụng làm vật liệu in 3D dạng rắn Vật liệu này kết hợp giữa tính năng của polymer và zirconia, mang lại những ưu điểm vượt trội về độ bền, khả năng chịu lực và tính linh hoạt trong thiết kế Việc phát triển PMMA-ZrO2 không chỉ góp phần nâng cao chất lượng sản phẩm in 3D mà còn mở ra nhiều cơ hội ứng dụng trong các lĩnh vực công nghiệp và y tế.
Figure 2.1: Modification procedure ZrO2 by MPTS
2.2.2 Synthesis of PMMA-grafted ZrO 2 nanoparticles
Figure 2.2: Synthesis of PMMA-grafted ZrO2 nanoparticles
Into a 500mL round-bottom flask: were added 50 gram mZrO2, 100 mL dioxane, 100 mL methanol, 5 g MMA and 0.05 g AIBN and magnetic stirred
This study focuses on the synthesis and characterization of poly(methyl methacrylate)-zirconia nanocomposite (PMMA-ZrO2) for applications in 3D printing The synthesis involved a polymer grafting reaction conducted in a nitrogen atmosphere, followed by heating in silicon oil at 60 °C After 8 hours, the mixture was cooled, allowing for the separation of PMMA homopolymer from PMMA-g-ZrO2 using a solvent mixture of dioxane and methanol, which facilitated the extraction process by reducing solution viscosity The grafted particles were then centrifuged at 6000 rpm and rinsed with acetone to eliminate excess PMMA homopolymer Finally, the solid PMMA-g-ZrO2 nanoparticles were ground using an agate mortar and dried at 100 °C for 24 hours in a hot air oven.
2.2.3 Preparation PMMA/ZrO 2 hybrid nanocomposite 3D printing filaments
PMMA and ZrO2 were dried at 100 °C for 2 hours before being physically mixed in predetermined ratios This mixture was then fed into a single-screw extruder (Haake Rheomix 252p) with a length-to-diameter ratio of 25:1, featuring four heating zones The extruder operated at a temperature profile of 190-200-210-210 °C, with a rotor speed of 80 rpm The PMMA/ZrO2 nanocomposites were extruded through a 2.5-mm circular die, resulting in filaments that were cooled with air and drawn at a consistent speed to achieve a diameter of 1.75 ± 0.05 mm.
Nghiên cứu về việc chế tạo và đặc trưng tính chất của vật liệu nanocompozit poly(methyl methacrylat) zirconia (PMMA-ZrO2) là rất quan trọng trong ứng dụng làm vật liệu in 3D dạng rắn Vật liệu này không chỉ cải thiện độ bền và tính năng cơ học mà còn mở ra nhiều cơ hội mới trong lĩnh vực in 3D Việc phát triển PMMA-ZrO2 có thể mang lại những cải tiến đáng kể trong quy trình sản xuất và chất lượng sản phẩm cuối cùng.
2.2.4 Preparation testing samples by Haake MiniJet machine
Beam and dumbbell-shaped samples were produced using a Haake MiniJet piston injection molding machine, maintaining a piston chamber temperature of 220 °C, a mold temperature of 100 °C, and a pressure of 650 bar The beam samples measured 63.4 mm in width, 12.8 mm in height, and 3.2 mm in length, while the dumbbell samples were created using a type IV mold according to ASTM D638 standards, featuring a narrow section width of 6 mm.
Figure 2.4: (a): Haake MiniJet, (b): FDM 3D printer and testing samples
2.2.5 Preparation testing samples via fusion deposition modeling 3D printer
Samples measuring 12.8 × 70 × 3.2 mm were fabricated using an FDM 3D printer developed at the Institute for Tropical Technology The filaments, detailed in section 2.2.3, were loaded into a piston chamber and extruded through a nozzle preheated to 220 °C As the nozzle moved according to the design, the melted polymer was deposited onto a printer bed preheated to 100 °C, utilizing an adhesive agent to ensure proper adhesion of the initial layers The nozzle speed was calibrated to 40 mm/min, and each type of 3D printing filament was used to create at least six samples These samples were then stored under ambient conditions for a minimum of seven days prior to mechanical property testing.
Nghiên cứu chế tạo và đặc trưng tính chất của vật liệu nanocompozit poly(methyl methacrylat) zirconia (PMMA-ZrO2) là một lĩnh vực quan trọng, đặc biệt trong ứng dụng làm vật liệu in 3D dạng rắn Vật liệu này không chỉ có tính chất cơ học vượt trội mà còn mang lại khả năng tương thích sinh học tốt, phù hợp cho các ứng dụng trong y tế và công nghiệp Việc phát triển PMMA-ZrO2 góp phần mở rộng khả năng sử dụng của công nghệ in 3D, mang lại nhiều lợi ích cho các ngành công nghiệp hiện đại.
Characterization measurements
FTIR spectra for all samples were obtained using a Nicolet iS10 Fourier transform infrared spectrometer at the Institute for Tropical Technology, Vietnam Academy of Science and Technology The analysis involved 32 scans with a resolution of 4 cm⁻¹ across a specified range of wavenumbers, as illustrated in Figure 2.5.
4000 to 400 cm -1 at room temperature
Figure 2.5: Fourier transform infrared spectroscopy (FT-IR), Nicolet iS10,
The tensile properties of the composite samples were conducted on a universal mechanical testing machine (Zwick V.2.5 Germany) with a crosshead speed of 100 mm/min in accordance with ASTM D638 for plastic materials
Figure 2.6: Zwick Z2.5 universal mechanical testing machine (Germany)
Nghiên cứu này tập trung vào việc chế tạo và xác định tính chất của vật liệu nanocompozit poly(methyl methacrylat) zirconia (PMMA-ZrO2) lai ghép hữu cơ, với ứng dụng chính trong in 3D dạng sói Vật liệu này có tiềm năng cao trong các ứng dụng công nghiệp nhờ vào sự kết hợp ưu việt giữa tính chất cơ học và khả năng tương thích sinh học Các kết quả nghiên cứu cho thấy PMMA-ZrO2 không chỉ cải thiện độ bền mà còn tăng cường tính chất quang học, mở ra hướng đi mới cho công nghệ in 3D trong lĩnh vực y tế và sản xuất.
Four-point flexural test was performed with a crosshead speed of
According to the ISO 5833:2002 standard, testing was performed at a rate of 5 mm/min, utilizing a minimum of three samples for each test The molding shrinkage was assessed by comparing the length dimensions of the cooled testing samples to those of the mold.
The crystalline structures of zirconia powders were examined by X-ray diffraction (XRD) on a Bruker-D5005 instrument (Germany) at the Materials Military Institute of Science and Technology (Vietnam)
2.3.5 Field Emission Scanning Electron Microscopy
The morphology of investigated zirconia particles and PMMA based nanocomposites was observed by using a Hitachi Field Emission Scanning Electron Microscopy (FESEM S-4800) at electron accelerating voltage of 5 kV
The particle size distribution of zirconia particles in isopropanol, with a solid content of 1 wt.%, was analyzed using dynamic light scattering (DLS) through a Zetasizer Ver 620 Instrument (Malvern Instruments Ltd.) The analysis was performed with a laser light source wavelength of 532 nm at a controlled temperature of 25 ± 0.2 °C.
Figure 2.7: Dynamic light scattering (DLS) instrument
Thermal Gravimetric Analysis (TGA) of PMMA, zirconia nanoparticles, and PMMA/ZrO2 nanocomposite filaments was conducted using a NETZSCH TG 209F1 Libra instrument in a nitrogen atmosphere at a flow rate of 40 mL/min The analysis spanned temperatures from 30 °C to 700 °C, with a heating rate of 10 °C/min and a specimen weight of approximately 6-7 mg.
Nghiên cứu này tập trung vào việc chế tạo và phân tích tính chất của vật liệu nanocompozit poly(methyl methacrylat) zirconia (PMMA-ZrO2) lai ghép hữu cơ, với ứng dụng chính trong lĩnh vực in 3D dạng rắn Vật liệu này hứa hẹn mang lại những đặc tính vượt trội, phù hợp cho các ứng dụng công nghệ cao Việc tìm hiểu sâu về cấu trúc và tính chất của PMMA-ZrO2 sẽ giúp tối ưu hóa quy trình sản xuất và nâng cao hiệu suất của sản phẩm in 3D.
RESULTS AND DISCUSSIONS
Characterization of ZrO 2 nanoparticles modified with MPTS
The FTIR spectra of original and modified zirconia nanoparticles, denoted as oZrO2 and mZrO2 respectively, are presented in Figure 3.1, alongside the spectrum of pristine MPTS liquid Notably, Figure 3.1a highlights the characteristic stretching (ν) and bending (δ) vibrations of the modified zirconia nanoparticles, offering valuable insights into their molecular structure.
The FTIR analysis of zirconia reveals significant peaks corresponding to OH groups at 3443 and 1626 cm -1, with Zr-O stretching vibrations observed at 747 and 574 cm -1, and bending vibrations at 504 cm -1 The spectrum of mZrO2 also indicates the presence of characteristic MPTS bands, including ν(C=O) at 1726 cm -1, ν(C=C) at 1633 cm -1, and δ(CH3) and δ(CH2) at 1442 cm -1 and 1387 cm -1, respectively Importantly, residual MPTS was largely eliminated through washing and filtering, supporting the conclusion that MPTS has been successfully grafted onto the surface of ZrO2 nanoparticles.
Figure 3.1 FTIR spectra (a) oZrO 2 , (b) mZrO 2 and (c) MPTS
Nghiên cứu này tập trung vào việc chế tạo và xác định các đặc trưng tính chất của vật liệu nanocompozit poly(methyl methacrylat) zirconia (PMMA-ZrO2) lai ghép hữu cơ, với ứng dụng chính trong in 3D dạng sói Vật liệu này hứa hẹn mang lại những ưu điểm vượt trội trong khả năng tạo hình và độ bền, mở ra cơ hội mới cho công nghệ in 3D trong các lĩnh vực khác nhau Các kết quả nghiên cứu cho thấy PMMA-ZrO2 có tính chất cơ học và hóa học ổn định, phù hợp cho việc sản xuất các sản phẩm phức tạp và tinh xảo.
3 CH 3 OH pH 8.5 (NH 4 OH)
Figure 3.2 Reaction scheme of (a): MPTS hydrolysis and (b): MPTS grafting onto ZrO2 nanoparticle
The TGA and DTG curves of oZrO2 and mZrO2 samples, as shown in Figure 3.3, illustrate two primary stages of thermal decomposition within the temperature range of 30 to 700 °C The first stage, occurring between 30 °C and 180 °C, exhibits minimal weight loss due to the physical adsorption of water In contrast, the second stage, spanning from 180 °C to 700 °C, primarily involves the decomposition of organic molecules that are covalently bonded to ZrO2 nanoparticles The amount of MPTS grafted onto the surface of ZrO2 nanoparticles can be assessed from TGA data, with MPTS having a molecular weight of 248.35 g/mol and a loading amount of 10 grams of MPTS for every 100 grams of oZrO2.
(10 wt.% or 0.403 mmol/g) The molecular weight of MPTS after hydrolysis M’ MPTS is 206.27 Thus, the weight percentage of MPTS grafting can be calculated as 2.50 wt.% (Eq.3) [69]
MPTS grafting content in mol = ∆m(%)
Nghiên cứu chế tạo và đặc trưng tính chất của vật liệu nanocompozit poly(methyl methacrylat) zirconia (PMMA-ZrO2) là một lĩnh vực quan trọng trong công nghệ in 3D Vật liệu này có khả năng kết hợp giữa tính chất cơ học và tính năng sinh học, phù hợp cho các ứng dụng trong y tế và công nghiệp Việc phát triển PMMA-ZrO2 không chỉ nâng cao độ bền mà còn cải thiện khả năng tương thích sinh học, mở ra nhiều cơ hội mới cho việc sản xuất các sản phẩm in 3D chất lượng cao.
Figure 3.3 (a): TGA and (b) DTG curves of oZrO2 and mZrO2 nanoparticles
3.1.3 Field Emission Scanning Electron Microscopy and dynamic light scattering
Figures 3.4 and 3.5 present FESEM images of two types of ZrO2 nanoparticles, oZrO2 and mZrO2 Both sets of images reveal that the zirconia nanoparticles range in size from 50 to 140 nm and exhibit a nanocrystal morphology Notably, the size and shape of the modified mZrO2 particles closely resemble those of the original oZrO2 nanoparticles.
Figure 3.4: FESEM images of oZrO2 nanoparticles
Figure 3.5: FESEM images of mZrO2 nanoparticles
Figure 3.6 represents the DLS diagrams that display the particle size distribution of the 2 kinds of zirconia nanoparticles in isopropanol Figure 3.6
The study on the synthesis and characterization of poly(methyl methacrylate) zirconia (PMMA-ZrO2) nanocomposite materials for 3D printing applications reveals that the particle size distributions of oZrO2 and mZrO2 nanoparticles range from 80 to 400 nm, exhibiting relatively low polydispersity indexes (PdI) of 0.127 and 0.283, respectively The Z-average sizes of oZrO2 and mZrO2 are measured at 138.6 nm and 154.5 nm, which are higher than those observed through Field Emission Scanning Electron Microscopy (FESEM) This discrepancy is typical, as the Z-average reflects the hydrodynamic size of the particles, while FESEM provides a direct visualization of their size.
Figure 3.6: DLS diagrams of (a): oZrO 2 and (b): mZrO 2 nanoparticles
3.1.4 The crystalline structures of samples
Figure 3.7 illustrates the XRD patterns of oZrO2 and mZrO2 samples, revealing identical diffraction peaks at specific 2θ angles According to Table 3.1, the XRD analytical data confirms that these peaks are characteristic of the monoclinic crystal structure of zirconia (monoclinic ZrO2), aligning with the ICCD standard tag 00-037-1484 for baddeleyite (ZrO2) [72].
Figure 3.7: XRD patterns of (a): oZrO2 and (b): mZrO2 nanoparticles
Nghiên cứu chế tạo và đặc trưng tính chất của vật liệu nanocompozit poly(methyl methacrylat) zirconia (PMMA-ZrO2) là một lĩnh vực quan trọng, với ứng dụng trong sản xuất vật liệu in 3D dạng rắn Vật liệu này kết hợp giữa PMMA và zirconia, tạo ra những đặc tính vượt trội như độ bền cơ học, khả năng chống mài mòn và tính linh hoạt Việc phát triển và tối ưu hóa quy trình chế tạo sẽ mở ra nhiều cơ hội ứng dụng trong công nghiệp và y tế, đặc biệt trong việc sản xuất các sản phẩm phức tạp và chính xác.
Table 3.1: XRD analysis results of oZrO2 and mZrO2 nanoparticles
Synthesis and characterization of nanocomposites PMMA-g-ZrO 2
from modified ZrO 2 and MMA monomers 3.2.1 Fourier-transform infrared spectroscopy
The spectrum of gZrO2, illustrated in Figure 3.8 (c), reveals distinct absorption bands indicative of PMMA grafted onto ZrO2 particle surfaces Notable features include the v(C=O) absorption at 1719 cm−1 and the ν(–CH3, OCH3, and CH2) vibrations observed at 2987 and 2953 cm−1.
The spectral data reveal characteristic peaks at 2853 cm⁻¹, 1455 cm⁻¹, 1167 cm⁻¹, and 1089 cm⁻¹, indicating the presence of organic moieties, such as vinyl groups and PMMA, attached to ZrO2 particles This attachment is illustrated in Figure 3.9, which depicts the grafting reaction through the copolymerization of MMA with the vinyl groups on the surface of MPTS-modified ZrO2 nanoparticles Consequently, PMMA molecules encapsulate the ZrO2 particles, although a significant portion of the homo PMMA formed during this process was removed through extraction.
Nghiên cứu này tập trung vào việc chế tạo và phân tích đặc trưng tính chất của vật liệu nanocompozit poly(methyl methacrylate) zirconia (PMMA-ZrO2) nhằm ứng dụng trong in 3D dạng sợi Vật liệu này có tiềm năng cao trong việc cải thiện độ bền và tính linh hoạt cho các sản phẩm in 3D, đồng thời mang lại những đặc tính vượt trội so với các vật liệu truyền thống Việc kết hợp PMMA với zirconia không chỉ nâng cao tính chất cơ học mà còn tạo ra những sản phẩm có độ chính xác cao, đáp ứng nhu cầu ngày càng tăng trong ngành công nghiệp chế tạo.
Figure 3.8: FTIR spectra (a) oZrO2, (b) mZrO2 and (c) gZrO2 nanoparticles
Figure 3.9: Reaction scheme of the formation of PMMA-g-ZrO2 hybrid nanoparticle
Figure 3.10 illustrates the TGA and DTG curves for oZrO2, mZrO2, and gZrO2 samples The TGA curve of gZrO2 reveals two distinct stages of decomposition The initial stage is attributed to the evaporation of physical water, while the second stage corresponds to the decomposition of organic compounds, specifically MPTS and PMMA, with MPTS being negligible compared to PMMA Consequently, the grafted content of PMMA can be determined by analyzing the weight change difference between 180-700 °C in the TGA curve of gZrO2, which shows a weight change of 11.97%.
The study focuses on the synthesis and characterization of poly(methyl methacrylate)-zirconia (PMMA-ZrO2) nanocomposite materials, specifically their application in 3D printing The research highlights that the physical presence of PMMA on ZrO2 is negligible, as it is largely eliminated during the extraction process The composition analysis reveals that the ZrO2 content is 2.945%, resulting in a PMMA percentage of 9.03% This innovative material demonstrates potential for enhanced properties in additive manufacturing.
Figure 3.10: TGA and DTG compared with oZrO2 and mZrO2 nanoparticles
3.2.3 XRD, DLS spectra and FESEM image
The XRD spectrum of gZrO2, obtained after the extraction of PMMA from synthesized PMMA-g-ZrO2, indicates that the gZrO2 nanoparticles exhibit a monoclinic or baddeleyite crystalline structure Notably, the grafting of PMMA does not alter the crystalline structure of ZrO2.
Figure 3.11: (a) XRD spectrum and (b) FESEM image of gZrO2 nanoparticles
Figure 3.11 (b) is FESEM image of gZrO2 nanoparticles The FESEM images demonstrate the zirconia nanoparticles have size in range from 50 to
150 nm It can be suggested that the zirconia particles are cross-linked together through PMMA molecular to form clusters, each cluster comprised of several ZrO2 primary nanoparticles
Nghiên cứu này tập trung vào việc chế tạo và phân tích đặc trưng tính chất của vật liệu nanocompozit poly(methyl methacrylat) zirconia (PMMA-ZrO2) nhằm ứng dụng trong in 3D dạng rắn Vật liệu này hứa hẹn mang lại những ưu điểm vượt trội trong ngành công nghiệp in 3D nhờ vào tính chất cơ học và độ bền cao Việc kết hợp giữa PMMA và zirconia tạo ra một loại vật liệu có khả năng chịu lực tốt và độ ổn định cao, phù hợp cho nhiều ứng dụng khác nhau.
Figure 3.12: DLS curve of gZrO2 nanoparticles
Figure 3.12 illustrates the particle size distribution of grafting zirconia nanoparticles (gZrO2) in isopropanol, revealing a size range of 60-1100 nm and a polydispersity index (PdI) of 0.372 This PdI is higher than that of both oZrO2 and mZrO2, indicating the presence of larger particles in the gZrO2 sample, likely due to the grafting reaction that caused some ZrO2 nanoparticles to aggregate The average particle size for gZrO2 is 156 nm, which is comparable to oZrO2 at 138 nm and mZrO2 at 154 nm.
Fabrication and characterization of 3D printing filaments based on PMMA/ZrO 2 hybrid nanocomposites
3.3.1 Evaluation of extrusion processing conditions
3.3.1.1 Evaluation of processability through visual observation
Table 3.2 illustrates various temperature profiles and rotor speeds used in the fabrication of PMMA/ZrO2 3D printing filaments, maintaining a consistent ZrO2 loading of 2.5 wt.% To assess the impact of temperature profiles, the rotor speed was fixed at 80 rpm across four temperature levels Conversely, to analyze the effect of rotor speeds, the T210 temperature profile was employed across three speed levels, with temperatures set at 190-200-210-210 °C for four zones Notably, the T210 temperature profile is highlighted for demonstrating superior mechanical properties, as discussed in section 3.3.1.2.
The extruded filaments were drawn with constant speed and scrolled into a spool The heating zones (from 1 to 4) of the extruder were set at different
This research focuses on the synthesis and characterization of poly(methyl methacrylate)-zirconia (PMMA-ZrO2) nanocomposite materials, which are utilized for 3D printing applications The study examines the temperature profiles during the extrusion process, with the lowest temperature assigned to the feed zone (Zone 1) of the extruder, while the highest temperatures are maintained in both Zone 3 and the die zone.
Table 3.2: PMMA/ZrO2 3D printing filaments fabricated at different conditions
Temperature (°C) Zone 1 Zone 2 Zone 3 Zone 4
3D printing filaments are produced at various temperatures and rotor speeds to optimize performance Filaments labeled T200, T210, T220, and T230 are fabricated at temperatures of 200°C, 210°C, 220°C, and 230°C, respectively, in zones 3 and 4 Additionally, filaments designated as N60, N80, and N100 are created at rotor speeds of 60 rpm, 80 rpm, and 100 rpm, respectively These variations in temperature and speed are crucial for achieving desired material properties in 3D printing applications.
Figure 3.13: PMMA and PMMA/ZrO2 3D printing filaments
Table 3.3 demonstrates that the temperature profiles of T210, T220, N80, and N100 produce filaments with a relatively uniform diameter and a smooth surface.
This study focuses on the synthesis and characterization of poly(methyl methacrylate)-zirconia (PMMA-ZrO2) nanocomposite materials, specifically for their application in 3D printing of solid objects During the research, only high-quality filament samples were chosen for mechanical testing, ensuring that only the best materials were evaluated for their tensile properties.
Table 3.3: Processing ability evaluation 3D printing filaments
Samples Visual evaluation Filament appearance
T200 Not Good Shiny, smooth, non-uniform
T230 Not Good Many air bubbles
N60 Not Good Shiny, smooth, non-uniform
3.3.1.2 Evaluation of processability through mechanical measurements
Table 3.4 details the flexural properties of PMMA/mZrO2 3D printing filaments (with 2.5 wt.% mZrO2) produced under varying temperature profiles Testing samples, molded into beams as illustrated in Figure 2.3, involved preparing at least three beams per filament type extruded with a specific temperature profile Results indicate that beams prepared at the T210 temperature profile exhibit superior flexural properties and reduced shrinkage compared to those prepared at T220, with flexural strength and strain improvements of 7.8% and 41.6%, respectively This enhancement is attributed to the lower temperatures in the T210 profile, which minimize thermal degradation of PMMA, preventing the formation of degrading gases within the filament Additionally, when applying the T210 profile at different rotor speeds (60, 80, and 100 rpm), filaments produced at 80 rpm demonstrate significantly better flexural properties than those created at 60 and 100 rpm.
The visual and mechanical assessments indicate that the optimal processing conditions for producing 3D printing filaments from PMMA/ZrO2 hybrid nanocomposites are T210 and N80, resulting in filaments with excellent appearance and strong mechanical properties.
Nghiên cứu này tập trung vào việc chế tạo và xác định tính chất của vật liệu nanocompozit poly(methyl methacrylat) zirconia (PMMA-ZrO2) nhằm ứng dụng trong in 3D dạng rắn Vật liệu này có tiềm năng cao trong ngành công nghiệp sản xuất nhờ vào đặc tính cơ học và độ bền vượt trội Qua quá trình nghiên cứu, các yếu tố ảnh hưởng đến tính chất của PMMA-ZrO2 đã được phân tích, mở ra hướng đi mới cho việc phát triển vật liệu in 3D chất lượng cao.
Table 3.4: Flexural properties of the 3D printing filaments of PMMA/mZrO2 hybrid nanocomposite (at mZrO2 content of 2.5wt.% at different processing conditions Samples Flexural modulus (MPa)
3.3.2 Characterization of 3D printing filaments based on PMMA/ZrO 2 hybrid nanocomposite
The extrusion processing conditions for fabricating 3D printing filaments based on PMMA/ZrO2 nanocomposite involved a temperature profile of 190-200-210-210 °C and a rotor speed of 80 rpm (T210/N80), utilizing oZrO2, mZrO2, and gZrO2 at varying contents While the mechanical properties of the filaments could be assessed directly, challenges in loading filament samples into the mechanical testing instrument may lead to significant errors in results Consequently, the mechanical properties were evaluated using molded samples created with a Haake MiniJet injection molding machine, set at 220 °C with an injection pressure of 600 bar and a mold temperature of 100 °C.
Figure 3.14 illustrates the flexural properties of PMMA/gZrO2 3D printing filaments with varying gZrO2 contents (1, 2.5, 5, and 7.5 wt.%) The data indicates that as the ZrO2 content increases, the flexural strain of the PMMA/ZrO2 filaments decreases Notably, PMMA/gZrO2 and PMMA/mZrO2 filaments exhibit flexural strains that are approximately 20-30% and 10-20% higher, respectively, compared to PMMA/oZrO2 filaments A similar decreasing trend is also observed in the flexural strength of these materials.
Nghiên cứu về việc chế tạo và đặc trưng tính chất của vật liệu nanocompozit poly(methyl methacrylat) zirconia (PMMA-ZrO2) đã chỉ ra khả năng ứng dụng của chúng trong lĩnh vực in 3D dạng rắn Vật liệu này không chỉ có tính chất cơ học vượt trội mà còn mang lại độ bền và độ chính xác cao trong quá trình sản xuất Việc phát triển PMMA-ZrO2 hứa hẹn mở ra nhiều cơ hội mới cho công nghệ in 3D, đáp ứng nhu cầu ngày càng cao trong các ngành công nghiệp khác nhau.
The flexural strength of PMMA/gZrO2 and PMMA/mZrO2 filaments is significantly higher, showing increases of approximately 0.7-3.6% and 0.3-1.8%, respectively, compared to PMMA/oZrO2 filaments Notably, the flexural strength of these samples reaches its peak at a ZrO2 content of 1 wt.%, exceeding that of the PMMA/oZrO2 1 wt.% filament by 3.6% However, beyond this optimal concentration, the flexural strength begins to decline, as illustrated in Figure 3.14b.
The flexural properties of PMMA/ZrO2 3D printing filaments, detailed in Figures 3.14 and Tables 3.5-3.7, reveal that the flexural modulus increases with higher ZrO2 content, while shrinkage decreases This behavior is attributed to ZrO2's effectiveness as a reinforcing agent for PMMA, particularly at the nanoscale Additionally, ZrO2's low thermal expansion allows it to penetrate the PMMA matrix's pores, further minimizing overall shrinkage in PMMA/ZrO2 hybrid nanocomposite systems.
Nghiên cứu về chế tạo và đặc trưng tính chất của vật liệu nanocompozit poly(methyl methacrylat) zirconia (PMMA-ZrO2) lai ghép hữu cơ có ứng dụng trong in 3D dạng rắn đã chỉ ra những ưu điểm vượt trội của loại vật liệu này Vật liệu PMMA-ZrO2 không chỉ mang lại độ bền cơ học cao mà còn có khả năng chống mài mòn tốt, thích hợp cho các ứng dụng công nghiệp và y tế Việc tối ưu hóa quy trình chế tạo và nghiên cứu tính chất của vật liệu này sẽ mở ra nhiều cơ hội mới trong lĩnh vực công nghệ in 3D.
Table 3.5: Flexural properties of PMMA/oZrO2 filaments
Table 3.6: Flexural properties of PMMA/mZrO2 filaments
Table 3.7: Flexural properties PMMA/gZrO2 filaments
As illustrated in Figure 3.15a, the tensile strength of PMMA/ZrO2 hybrid nanocomposites declines with increasing ZrO2 content, indicating that ZrO2 nanoparticles significantly impact the flexibility of the PMMA matrix Consequently, incorporating ZrO2 into the PMMA matrix results in reduced physico-mechanical properties of PMMA 3D printing filaments Notably, PMMA/gZrO2 filaments exhibit higher tensile strength compared to PMMA/mZrO2 filaments, while PMMA/oZrO2 filaments demonstrate the lowest tensile strength.
Characterization of 3D printed samples from PMMA/ZrO 2 filaments
The testing samples from PMMA/gZrO2 2.5wt.% is shown in Figure 3.19 The image shows a clear opalescent color due to both the air pore and the radiopacity of ZrO2
Figure 3.19: Printed specimen in bar (beam) shape prepared by using an FDM
3D printer from PMMA and PMMA/gZrO2 filaments
Table 3.9 presents the tensile properties of 3D printed beams created with an FDM 3D printer using PMMA/ZrO2 hybrid nanocomposite filaments, adhering to ASTM D866 standards for bar/beam shapes The parameters ΔσT, ΔE, and ΔɛT represent the reductions in tensile strength, elastic modulus, and elongation at break between printed and molded samples made from identical filaments The findings indicate that the tensile strength of the printed samples ranges from 38.5 to 43.9 MPa, while the elastic modulus varies between 1119 and 1405 MPa.
The study investigates the synthesis and characteristics of poly(methyl methacrylate) zirconia (PMMA-ZrO2) nanocomposite materials for 3D printing applications The elongation at break for these materials varies between 4.06% and 5.26% Notably, the tensile strength of the 3D printed samples is consistently lower than that of the molded samples, with a decrease in tensile strength (Δσ) ranging from 40% to 47%, where PMMA exhibits the highest reduction and gZrO2 shows the least Additionally, the decrement in bending modulus (ΔBM) ranges from 3.9% to 4.8%, again with PMMA showing the largest decrease and gZrO2 the smallest, which ranges from 39% to 43%.
Table 3.9: Tensile properties of 3D printing beams gZrO2
Note: E – Elastic moduls, σ T – tensile strength, ɛ T – elongation at break; ΔE, Δσ T , Δɛ T are correspondingly the reductions of E, σ T and ɛ T
Table 3.10: Flexural properties of 3D printed beams gZrO2
Printed samples Flexural strength (MPa) Δσ B
Table 3.10 presents the flexural properties of 3D printed beam samples created using the FDM 3D printing method with PMMA/ZrO2 hybrid nanocomposites The flexural strength of the 3D printed beams ranges from 92 to 103 MPa, while the flexural modulus varies between 2652 and 2852 MPa, and the flexural strain is between 2.85% and 4.5% Notably, the values Δσ, ΔBM, and Δɛ indicate the decreases in flexural strength, modulus, and strain when comparing printed samples to molded ones Overall, the flexural properties of the 3D printed samples are lower than those of the corresponding molded samples, as discussed in previous sections.
The study explores the synthesis and characterization of poly(methyl methacrylate)-zirconia (PMMA-ZrO2) nanocomposite materials designed for 3D printing applications The findings reveal a decrease in tensile strength (Δσ) ranging from 4.9% to 10%, with PMMA exhibiting the most significant reduction, while samples containing gZrO2 show less decline Additionally, the bending modulus (ΔBM) decreases between 3.9% and 4.8%, again with PMMA leading in reduction, while gZrO2-containing samples display a decrement of 38% to 44%.
This study explores the potential of PMMA/ZrO2 as a biomaterial for prosthetic implants and bone defects, highlighting the advantages of 3D printing technology in creating tailored implants for individual patients The samples were evaluated against the ISO 5833:2002 standard, which specifies a required flexural strength of 50 MPa and a modulus of 1800 MPa for PMMA acrylic bone cements Results in Table 3.10 indicate that the flexural strength and modulus of the 3D-printed samples significantly exceed these standards, demonstrating the feasibility of using 3D printing technology for producing acrylic resin implants.
Nghiên cứu chế tạo và đặc trưng tính chất của vật liệu nanocompozit poly(methyl methacrylat) zirconia (PMMA-ZrO2) là một lĩnh vực quan trọng, đặc biệt trong ứng dụng làm vật liệu in 3D dạng rắn Vật liệu này không chỉ mang lại độ bền cao mà còn có khả năng tương thích sinh học tốt, phù hợp cho các ứng dụng trong y tế và công nghiệp Việc phát triển PMMA-ZrO2 sẽ mở ra nhiều cơ hội mới trong công nghệ in 3D, nâng cao chất lượng sản phẩm và đáp ứng nhu cầu ngày càng cao của thị trường.
MPTS-modified nanoparticles (mZrO2) were synthesized through a silanization method at pH 8.5 and room temperature over 24 hours Dynamic light scattering (DLS) analysis revealed an average particle size of 155.5 nm and a low polydispersity index of 0.283 Fourier-transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) confirmed the successful grafting of MPTS onto the ZrO2 surface, achieving a grafting percentage of 2.5 wt.%.
PMMA-grafted ZrO2 nanoparticles (gZrO2) were synthesized through the copolymerization of MMA and mZrO2 at 60°C for 8 hours, resulting in a grafting percentage of 9.03 wt.% as determined by TGA DLS analysis revealed that gZrO2 nanoparticles exhibited a higher polydispersity index and particle size distribution compared to mZrO2 nanoparticles Additionally, FESEM images and XRD patterns confirmed that the primary ZrO2 nanoparticles remained unchanged following silanization and PMMA grafting.
The fabrication of 3D printing PMMA/ZrO2 nanocomposite filaments was achieved through a melt extrusion process, utilizing origin ZrO2 (oZrO2), modified ZrO2 (mZrO2), and granular ZrO2 (gZrO2) as fillers at concentrations ranging from 1 to 7.5 wt.% The process involved a temperature profile of 190-200-210-210 °C and a rotor speed of 80 rpm Notably, the flexural and tensile strength and modulus of PMMA/mZrO2 and PMMA/gZrO2 filaments surpassed those of PMMA/oZrO2 filaments Furthermore, FESEM analysis revealed that oZrO2, mZrO2, and gZrO2 nanoparticles were well-dispersed within the PMMA matrix at the nanoscale, despite the presence of some micron-sized clusters.
The PMMA/ZrO2 nanocomposite filaments demonstrated impressive tensile and flexural properties, with flexural strength ranging from 92 to 102 MPa and flexural modulus between 2722 and 2852 MPa These hybrid nanocomposite filaments are suitable for manufacturing acrylic prosthetic implants due to their high mechanical performance.
- Improvement of the fabrication of the PMMA/ZrO 2 3D printing filaments in large scale for commercial purpose;
- Evaluation of cytotoxicity of the PMMA/ZrO2 3D printing filaments should be further investigated
Nghiên cứu chế tạo và đặc trưng tính chất của vật liệu nanocompozit poly(methyl methacrylat) zirconia (PMMA-ZrO2) lai ghép hữu cơ có ứng dụng trong in 3D dạng soi Vật liệu này kết hợp giữa PMMA và zirconia, mang lại những ưu điểm vượt trội trong khả năng in 3D, đồng thời cải thiện độ bền và tính chất cơ học Việc phát triển vật liệu này hứa hẹn sẽ mở ra nhiều cơ hội ứng dụng trong các lĩnh vực như y tế, chế tạo linh kiện và đồ dùng công nghiệp.
LIST OF PUBLISHED PAPERS BY AUTHOR
1 Nguyen Thi Dieu Linh , Do Quang Tham, Nguyen Vu Giang, Tran Huu Trung, Le Thi My Hanh, Nguyen Thi Thu Trang, Nguyen Thuy Chinh, Tran Thi Mai, Thai Hoang and Do Van Sy “Synthesis and characterization of monodisperse hydrous colloidal zirconia nanoparticles” Communications in Physics, Vol 30, No 4 (2020), pp 391-398
2 Nguyen Thi Dieu Linh , Nguyen Thi Kim Dung, Do Quang Tham, Dam Xuan Thang The Synthesis and characterization of PMMA-grafted-ZrO2 hybrid nanoparticles Vietnam Journal of Science and Technology, 2022 (Accepted)
Nghiên cứu về việc chế tạo và đặc trưng tính chất của vật liệu nanocompozit poly(methyl methacrylat) zirconia (PMMA-ZrO2) đã chỉ ra tiềm năng ứng dụng của nó trong in 3D dạng sói Vật liệu này kết hợp giữa tính năng của polymer và zirconia, mang lại độ bền và tính linh hoạt cao Qua quá trình nghiên cứu, các đặc tính cơ học và hóa học của PMMA-ZrO2 đã được phân tích kỹ lưỡng, cho thấy khả năng ứng dụng rộng rãi trong công nghệ in 3D, đặc biệt trong sản xuất các sản phẩm có yêu cầu cao về chất lượng và độ chính xác.
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Drug Delivery and Translational Research, 10(4), 986-1001
2 Cui M., Pan H., Su Y., Fang D., Qiao S., Ding P., Pan W., 2021, Opportunities and challenges of three-dimensional printing technology in pharmaceutical formulation development, Acta Pharmaceutica Sinica B, 11(8), 2488-2504
3 Chen J., Zhang Z., Chen X., Zhang C., Zhang G., Xu Z., 2014, Design and manufacture of customized dental implants by using reverse engineering and selective laser melting technology, The Journal of Prosthetic Dentistry, 112(5), 1088-1095
4 Oliveira T T., Reis A C., 2019, Fabrication of dental implants by the additive manufacturing method: A systematic review, The Journal of Prosthetic Dentistry, 122(3), 270-274
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6 Chen R K., Jin Y.-a., Wensman J., Shih A., 2016, Additive manufacturing of custom orthoses and prostheses—A review, Additive Manufacturing,
7 Esmi A., Jahani Y., Yousefi A A., Zandi M., 2019, PMMA-CNT-HAp nanocomposites optimized for 3D-printing applications, Materials Research Express, 6(8), 085405
8 Stansbury J W., Idacavage M J., 2016, 3D printing with polymers: Challenges among expanding options and opportunities, Dental Materials, 32(1), 54-64
9 Mendes-Felipe C., Oliveira J., Etxebarria I., Vilas-Vilela J L., Lanceros- Mendez S., 2019, State-of-the-Art and Future Challenges of UV Curable Polymer-Based Smart Materials for Printing Technologies, Advanced Materials Technologies, 4(3), 1800618
10 Wagner A., Kreuzer A M., Gửpperl L., Schranzhofer L., Paulik C., 2019, Foamable acrylic based ink for the production of light weight parts by inkjet-based 3D printing, European Polymer Journal, 115, 325-334
11 Gad M M., Abualsaud R., Rahoma A., Al-Thobity A M., Al-Abidi K S., Akhtar S., 2018, Effect of zirconium oxide nanoparticles addition on the optical and tensile properties of polymethyl methacrylate denture base material, International Journal of Nanomedicine, 13, 283-292
12 Hu Y., Gu G., Zhou S., Wu L., 2011, Preparation and properties of transparent PMMA/ZrO2 nanocomposites using 2-hydroxyethyl methacrylate as a coupling agent, Polymer, 52(1), 122-129