Silicone containing aqueous polymer dispersions with hybrid particle structure

Silicone-containingaqueous polymer dispersions with hybridparticle structure Janusz Kozakiewicz, Izabela Ofat, Joanna Trzaskowska PII: S0001-8686(15)00061-5 DOI: doi: 10.1016/j.cis.2015.04.002 Reference: CIS 1530 To appear in: Advances in Colloid and Interface Science Please cite this article as: Kozakiewicz Janusz, Ofat Izabela, Trzaskowska Joanna, Silicone-containing aqueous polymer dispersions with hybrid particle structure, Advances in Colloid and Interface Science (2015), doi: 10.1016/j.cis.2015.04.002 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. ACCEPTED MANUSCRIPT ACCEPTED MANUSCRIPT Silicone-containing aqueous polymer dispersions with hybrid particle structure Janusz Kozakiewicz 1 , Izabela Ofat and Joanna Trzaskowska Industrial Chemistry Research Institute, 01-793 Warsaw, Poland Abstract In this paper the synthesis, characterization and application of silicone-containing aqueous polymer dispersions (APD) with hybrid particle structure are reviewed based on available literature data. Advantages of synthesis of dispersions with hybrid particle structure over blending of individual dispersions are pointed out. Three main processes leading to silicone- containing hybrid APD are identified and described in detail : (1) emulsion polymerization of organic unsaturated monomers in aqueous dispersions of silicone polymers or copolymers, (2) emulsion copolymerization of unsaturated organic monomers with alkoxysilanes or polysiloxanes with unsaturated functionality and (3) emulsion polymerization of alkoxysilanes (in particular with unsaturated functionality) or/and cyclic siloxanes in organic polymer dispersions. The effect of various factors on the properties of such hybrid APD and films as well as on hybrid particles composition and morpholgy is presented. It is shown that core-shell morphology where silicones constitute either the core or the shell is predominant in hybrid particles. Main applications of silicone-containing hybrid APD and related hybrid particles are reviewed including (1) coatings which show specific surface properties such as enhanced water repellency or antisoiling or antigraffiti properties due to migration of silicone to the surface, and (2) impact modifiers for thermoplastics and thermosets. Other processes in which silicone-containing particles with hybrid structure can be obtained (miniemulsion polymerization, polymerization in non-aqueous media, hybridization of organic polymer and polysiloxane, emulsion polymerization of silicone monomers in silicone polymer dispersions and physical methods) are also discussed. Prospects for further developments in the area of silicone-containing hybrid APD and related hybrid particles are presented. Key words: silicones, nanoparticles, core-shell, aqueous polymer dispersions, hybrid polymers, emulsion polymerization 1 Corresponding author; e-mail: Janusz.kozakiewicz@ichp.pl ACCEPTED MANUSCRIPT ACCEPTED MANUSCRIPT Contents: 1. Introduction 2. Silicones as components of hybrid polymer materials 3. Synthesis and characterization of silicone-containing APD with hybrid particle structure 3.1. Synthesis of silicone-containing APD with hybrid particle structure through emulsion polymerization of organic unsaturated monomers in aqueous dispersions of silicone polymers or copolymers 3.1.1. Batch vs. seeded emulsion polymerization and the mode of monomers addition in a seeded process 3.1.2. Effect of the method applied to synthesis of silicone polymer 3.1.3. Effect of silicone polymer composition and structure 3.1.4. Effect of organic polymer composition and structure 3.1.5. Effect of silicone/organic polymer ratio 3.2. Synthesis of silicone-containing APD with hybrid particle structure through emulsion copolymerization of unsaturated organic monomers with alkoxysilanes or polysiloxanes with unsaturated functionality 3.2.1. Effect of copolymer composition 3.2.2. Effect of the method of conducting the polymerization process 3.2.3. Synthesis of microemulsions containing silicone-organic polymer hybrid particles 3.3. Effect of initiator and surfactant on emulsion polymerization of organic monomers carried out in the presence of silicone polymers or silicone monomers 3.3.1. Effect of initiator 3.3.2. Effect of surfactant 3.4. Synthesis of silicone-containing APD with hybrid particle structure through emulsion polymerization of alkoxysilanes (in particular with unsaturated functionality) or/and cyclic siloxanes in organic polymer dispersions 3.4.1. Possible approaches to synthesis of hybrid APD with organic polymer-silicone core- shell particles 3.4.2. Effect of the proportions of reactants and polymerization conditions 3.4.3. Comparison of synthesis of silicone-containing APD with hybrid particle structure through emulsion polymerization of alkoxysilanes or/and cyclic siloxanes in organic polymer dispersions with other approaches applied to obtain such APD 3.5. Synthesis of aqueous dispersions of polymers containing polysiloxane segments (other than copolymers referred to in Section 3.2) ACCEPTED MANUSCRIPT ACCEPTED MANUSCRIPT 3.5.1. Synthesis of aqueous dispersions of poly(siloxaneurethaneurea) ionomers 3.5.2. Effect of polysiloxane segment structure, content and length on the properties of poly(siloxaenurethaneurea) dispersions and films 3.5.3. Other methods of producing aqueous dispersions of poly(siloxaneurethane)s or poly(siloxaneurethaneurea)s 4. Other synthetic routes that may lead to silicone-containing polymer nanoparticles with hybrid structure 4.1. Miniemulsion polymerization 4.2. Emulsion polymerization in non-aqueous media 4.3. Hybridization of organic polymer and polysiloxane 4.4. Emulsion polymerization of silicone monomers in silicone polymer dispersions 4.5. Physical methods (a) Block copolymer microphase separation (b) Mixing two dispersions at a very high shear rate 5. Applications of silicone-containing APD with hybrid particle structure and of silicone-containing composite polymer nanoparticles 5.1. Coatings and related products 5.1.1. Architectural paints, impregnates for building materials and coatings for paper and for other materials 5.1.2. Coatings from poly(siloxaneurethaneurea) ionomer dispersions 5.1.3. Antigraffiti, anti-soiling and anti-icing coatings 5.1.4. Other coatings with enhanced surface hydrophobicity 5.2. Silicone-containing core-shell structured impact modifiers 5.2.1. Modification of powder coatings 5.2.2. Modification of thermoplastics and thermoset resins 5.3. Impact resistant polymer materials obtained through direct emulsion or suspension polymerization of organic unsaturated monomers in (or in the presence of) hybrid APD with silicone-containing core-shell nanoparticles 5.4. Other applications 5.4.1. Membranes from silicone-containg hybrid APD for separation of gases and liquids 5.4.2. Medical applications of silicone-containing hybrid polymer particles 6. Concluding remarks ACCEPTED MANUSCRIPT ACCEPTED MANUSCRIPT List of abbreviations: ABS – Acrylonitrile-Butadiene-Styrene copolymer ABSA – alkylbenzenesulfonic acid AFM – Atomic Force Microscopy APD – Aqueous polymer dispersion(s) ATRP - Atom Transfer Radical Polymerization BA – Butyl acrylate D 4 – Octamethylcyclotetrasiloxane D 4 V – Tetravinyltetramethylcyclotetrasiloxane (se also : ViD 4 ) DPD – Dissipative Particle Dynamics EDS – Energy-Dispersive X-ray Spectroscopy FTIR – Fourier Transform Infrared Spectroscopy GPC – Gel Permeation Chromatography MA – Methacrylic acid MMA – Methyl methacrylate MPS – Methacryloxypropyltrimethoxysilane NHMA – N-hydroxymethyl acrylamide NMR – Nuclear Magnetic Resonance PDMS - Polydimethylsiloxane PHMS – Poly(hydrogenmethylsiloxane) PPE – Poly(phenylene ether) PS – Polystyrene PTFE – Polytetrafluoroethylene PTMA – Poly(methyl methacrylate) PTMG – Poly(tetramethylene glycol) PVC – Poly(vinyl chloride) RAFT – Reversible Addition-Fragmentation Chain Transfer SAN – Styrene-Acrylonitrile copolymer SAXS – Small Angle X-ray Scattering SDBS – Sodium dodecylbenzenesulfonate SEM – Scanning Electron Microscopy ST – Styrene XPS – X-ray Photoelectron Spectroscopy TEM – Transmission Electron Microscopy ViD 4 - Tetravinyltetramethylcyclotetrasiloxane (see also : D 4 V ) VTS – Vinyltriethoxysilane 1. Introduction Aqueous polymer dispersions (APD) are among the most common commercial forms of polymers. Each year ca. 7.5-8 mln tons of polymers are produced and sold on a global market in a form of APD [1, 2]. It corresponds to ca. 15 mln tons of APD which are used in a range of applications including, inter alia, coatings, paints, adhesives, rubbers, plasters, sealants, impregnating agents, drug release systems and others. Extended review of APD applications is contained in [1]. The reasons for such widespread and still growing use of APD are not only lack of environment-related problems or easy handling and application, but also possibility of tailoring the composition and structure of dispersion particles to meet the required properties of final product. If the size of dispersion particles is lower than 100 nm, the particles can be called ―nanoparticles‖ and specific interactions between polymeric constituents of the particle are possible on a nano scale which may result in a synergistic effect leading to unexpected new features of films, coatings or powders produced from such dispersions. If the aqueous dispersions of two different polymers (e.g. acrylic polymer and polyurethane) are blended, direct interaction between both polymers will not be possible since ACCEPTED MANUSCRIPT ACCEPTED MANUSCRIPT each will be contained in a separate particle. However, if hybrid 2 dispersion with particles composed of both polymers is synthesized a synergistic effect can be observed [5]. Obviously, ―true hybrid‖ particle structure where macromolecules of both polymers are truly mixed on a nano-scale is only hypothetical, but it can be expected that better compatibility of both polymers would result in better interaction between polymer chains and would then be advantageous in terms of final properties of film or coating. As it was stated in [6] ―In particular, we can expect a better compatibility and a more regular distribution of the two phases within the film material without the occurrence of significant phase segregation‖. Advantages of hybrid APD over mixtures of APD were proved in many reports, e.g. [7-11] and the general issue of heterogeneity in waterborne systems including APD was discussed extensively in a critical review paper focused mainly on polymer coatings [12]. A number of books and review papers deal with synthesis, characterization and applications of hybrid polymer materials or APD, but only few discuss specific features of polymer dispersions of hybrid particle structure and methods of their synthesis [13-19]. Most of those publications focus on so called ―core-shell‖ dispersions where the core is made of one polymer and another polymer constitutes the shell, but several other structures of hybrid APD particles can also occur – see Fig. 1. Recently, two comprehensive literature reviews covering synthesis and characterization of core-shell nanoparticles were published [20, 21]. While all particles shown in Fig. 1 are spherical, APD containing nanoparticles with nonspherical morphologies have also been obtained [16] Fig. 1 It was emphasized by the authors of the publications dealing with APD (see e.g. [14]) that structure of hybrid polymer dispersion particles could be as important for the properties of dispersions and films as their chemical composition. Methods of assessing the particle structure of hybrid APD are described, inter alia, in [15, 22-26]. Obviously, also other features of dispersion particles like e.g. size [27] or even size distribution [12] were proved to influence the properties of films and coatings produced from APD containing such particles. Generally, hybrid particle morphology is affected mostly by both the type of relevant polymers (monomers) and the methods applied for preparation of hybrid APD, though other factors like e.g. surfactant type and concentration can also be important. Discussion of presumable mechanism of hybrid particle formation can be found iter alia in [5, 28-52]. Fundamental aspects of hybrid dispersion particle morphology development have been reviewed in [53] and recently dissipative particle dynamics (DPD) simulation has been 2 In a broader sense ―hybrid material‖ means ―a material that includes two (or more) moieties blended on a molecular scale‖ [3]. While in the relevant literature, the term ―hybrid‖ is usually applied mostly to inorganic-organic composites [3, 4], it will be used in this paper also with respect to systems of non-uniform morphology involving two or more different polymers or polymer segments, specifically those which constitute APD particles. ACCEPTED MANUSCRIPT ACCEPTED MANUSCRIPT employed to examine the formation of complex colloidal particles [54]. Specifics of the systems where one or both polymers forming the particle are crosslinked have been also subject of research interest [55-58]. Ionomeric polyurethane-acrylic [7, 51, 59, 60], polyurethane-acrylic/styrene [5] or polysiloxaneurethane and polysiloxaneurethane-acrylic [61] dispersions with hybrid particle structure can also be classified to that category. Recently, polymer films were prepared from ionically crosslinked core-shell APD and were named as ―a new class of nanostructured ionomers‖ [62]. Based on the existing literature it can be generally understood that the following criteria shall be met to obtain core-shell particle morphology via emulsion polymerization: (1) the ―core‖ polymer has to be more hydrophobic than the ―shell‖ polymer in order to avoid migration of polymer chains from the core to the particle surface which may lead to an inverted core-shell morphology [63], and (2) secondary nucleation leading to formation of separate particles has to be avoided what can be achieved through keeping the surfactant content at the lowest possible level - since that would limit micellar nucleation, and also through keeping monomer concentration in the reaction mixture and the value of RxN (R= core polymer dispersion particle radius and N = concentration of starting dispersion particles) as low as possible - since that would limit homolytic nucleation). Based on the assumption that eventually the ability of free radical to penetrate into the existing dispersion particle would be a critical factor determining the formation of specific hybrid particle morphology in a seeded emulsion polymerization process [33], a ―decision tree‖ has been designed (see Fig. 2) and applied to predict the particle structure [45] using computer software packages. Fig. 2 Other methods of obtaining hybrid polymer particles with core-shell morphology in aqueous systems have also been reported comprising miniemulsion polymerization [8, 9, 18, 64-67], heterocoagulation of small particles with larger ones [68, 69] or self-assembling of the polyelectrolyte layers on polymer latex particles [68, 70], the latter approach being named ―Layer-by-Layer (LbL) colloid templating strategy‖. Finally, new polymerization techniques based on ATRP (Atom Transfer Radical Polymerization) or RAFT (Reversible Addition- Fragmentation Chain Transfer) concepts have also been used to synthesize latex particles of hybrid morphology - see e.g. [26, 71-74]. Possibility of precise design of the aqueous system offered by ATRP or RAFT allows for synthesis of functionalized core-shell nanoparticles with controlled surface architecture. More detailed explanation of the advantages of those techniques in respect to synthesis of structured latex nanoparticles can be found in [14] and [75-77]. While all of the publications quoted above referred to nano-sized hybrid particles of different morphologies, synthesis of micron-sized core-shell particles has also been reported [78]. Apart from APD with hybrid polymer-polymer (i.e. organic polymer - organic polymer or organic polymer - silicone) particles also inorganic-organic, organic-inorganic or ACCEPTED MANUSCRIPT ACCEPTED MANUSCRIPT inorganic-inorganic hybrids produced in a form of aqueous dispersions, mainly of core-shell type, have been discussed in a number of published papers and patents, but those are out of the scope of this review. Summaries of the existing literature in that field can be found, inter alia, in [3, 4, 13, 15-19, 65, 68,79-81]. The subject of this review is synthesis, characterization and application of silicone- containing APD with hybrid particle structure. 2. Silicones as components of hybrid polymer materials Silicone-containing hybrid polymer materials have become very popular in the recent years because of very specific features the silicone component may bring to the hybrid due to very specific properties of polysiloxane (usually polydimethylsiloxane – PDMS) chain [82, 83]. High energy of Si-O bond (550 kJ/mole as compared to 340 kJ/mole for C-C or C-O bond) makes breaking of Si-O bond very difficult what results in high thermal resistance of silicones. High mobility of PDMS chain (angle in Si-O-Si is 145 o while in C-O-C it is 109.5 o ) results in very low (around -120 o C) glass transition temperature (Tg) and thus in very good elasticity of silicone polymers at low temperatures. Due to very loose packing of PDMS chains, certain gases (including water vapor) can diffuse easily through PDMS-containing films and that phenomenon is utilized in membrane technologies as well as in paints and medical applications (―breathing‖ ability). Finally, high hydrophobicity of methyl groups attached to polysiloxane chains leads to very low surface free energy of PDMS and is a driving force for migration of polysiloxane chains to the surface of silicone-containing hybrid materials which results in specific surface properties like anti-adhesive properties, water repellency or ―silicone touch‖. Therefore, it can be expected that through modification of organic polymers with silicones new polymeric materials with interesting features will be obtained. The main problem in incorporating silicone to any organic polymer system is its low compatibility with great majority of organic polymers. The value of solubility parameter is around 15 MPa 1/2 for PDMS [84] while for polystyrene (PS) and for poly(methyl methacrylate) (PMMA) it is around 23 MPa 1/2 and for poly(vinyl chloride) (PVC) it is around 19 MPa 1/2 [85]. The problem of low compatibility of silicones with other polymers can be solved effectively through synthesizing an APD with silicone-containing hybrid polymer nanoparticles. It was confirmed already in the nineties that phase separation on a nano-scale which occurred in a silicone-containing nanoparticles present in APD did not result in phase separation on a macro-scale, i.e. in a final hybrid material (e.g. coating or film) produced from such APD [86]. No review that would specifically cover silicone-containing APD with hybrid particle structure and nanoparticles (or final hybrid materials) derived from such dispersions was found in the literature, though some relevant information is contained in certain books or general review papers dealing with silicones [87], hybrid materials [3, 4], or APD [18, 88]. ACCEPTED MANUSCRIPT ACCEPTED MANUSCRIPT 3. Synthesis and characterization of silicone-containing APD with hybrid particle structure 3.1. Synthesis of silicone-containing APD with hybrid particle structure through emulsion polymerization of organic unsaturated monomers in aqueous dispersions of silicone polymers or copolymers First attempts to obtain APD with hybrid particle structure containing silicone polymer in the core were made in the early seventies either through dissolving silicone rubber in organic monomers, emulsifiying the solution in water and conducting the subsequent polymerization [89], or through polymerization of organic monomers in aqueous silicone dispersion [90]. Later, it became obvious that seeded emulsion polymerization of organic unsaturated monomers in silicone polymer aqueous dispersions would be the most effective route leading to silicone-containing APD with hybrid (usually core-shell) particle structure. Indeed, a number of papers and patents have been published so far describing such process - see them reviewed below. It is worth to note that in the early patents, e.g. [90] a product of the process of emulsion polymerization of acrylic monomers in a dispersion of silicone polymer containing vinyl groups was called ―siloxane-acrylate copolymer‖ and it is hard to believe that the ―copolymer’ was actually obtained since no evidence was given of the structure of final product. Later, such terminology was rather avoided and the patents and papers were referring to hybrid ―core-shell‖ particles. Usually starting silicone polymer dispersions were obtained in a one-step process where all silicone monomers, i.e. octamethylcyclotetrasiloxane (D 4 ) (or silanol groups – terminated PDMS) and/or alkoxysilanes, were polymerized together using either acid or base catalyst [91], but also a two-step process was described where some silicone monomers were polymerized first to form the core of the particle and then the other silicone monomers were further polymerized in the dispersion obtained in the first step [92-95], so the intermediate polysiloxane shell could be produced. Usually, the silicone monomers added in the second step contained vinyl or acrylic groups (e.g. methacryloxypropyltrimethoxy silane (MPS)) which allowed for further grafting of the shell monomers [95]. In a number of patents MPS was included for the same purpose as component of the silicone monomers used to produce the particle core. Similarly, while in the processes described in many publications - see e.g. [96] - the organic monomers were added at one step (in a batch or semicontinuous mode) to the seed silicone polymer dispersion, in some publications the monomers which were supposed to make the shell of the APD hybrid particle were added in two distinctly separated steps, so a kind of silicone core - double organic polymer shell particle morphology could be obtained [97-101]. The advantage of such method clearly explained in [101] was that in that case grafting of the second monomer on the hybrid silicone-acrylic polymer core-shell particle could be facilitated as compared to grafting on purely silicone polymer core. However, neither final structure of the particles nor the occurrence of grafting was confirmed. Applying additional step in polymerization of monomers on a silicone polymer core could be further justified if the polymer obtained by polymerization of first monomer, e.g. butyl acrylate (BA), had quite low Tg, so it could contribute to similar features of silicone and enhance the properties of the core-shell particles when applied as impact modifiers. ACCEPTED MANUSCRIPT ACCEPTED MANUSCRIPT In [102] a combination of those two approaches was described. A dispersion of silicone polymer was obtained first, next step was crosslinking the silicone core of the dispersion particle with tri- or tetrafunctional alkoxy silane, third step was grafting the unsaturated silicone monomer on the silicone core and finally the last step was producing the final shell of the dispersion particle that was composed of PS which was crosslinked due to the presence of small amount of divinylbenzene in the monomer mixture. Synthesis of a three-layer core-shell hybrid latex particles where polysilsesquioxane constituted the core was patented in 1969 [103], but only recently it was discussed extensively in a published paper [104]. The process comprised the sequential polymerization of acrylic monomers and D 4 in poly(methacryloxypropylsilsesquioxane) latex. Based on the XPS data the authors of that paper stated that the particles they obtained had PDMS outer shell. However, those hybrid particles could be rather called ―inorganic-organic polymer‖ than ―silicone-organic polymer‖ and as such would be out of the scope of this review since the chemical composition of polysilsesquioxane core was closer to silica than to silicone and, indeed, the authors of the relevant paper named their particles ―inorganic-organic‖. The same research group published two more papers on similar subject where synthesis of core-shell particles with polysilsesquioxane core and fluoro-acrylic polymer shell [105, 106] was described. Core-shell dispersions with hybrid particles containing silicones [107] and not containing silicones [108-111] in which shell was composed of fluoropolymers were also developed with an aim to create highly hydrophobic film surfaces. The results of investigations of various factors on the process of synthesis of hybrid APD with silicone-containing particles via emulsion polymerization of organic monomers in silicone polymer dispersions and on the properties of the resulting hybrid dispersions and films will be reviewed below. 3.1.1. Batch vs. seeded emulsion polymerization and the mode of monomers addition in a seeded process If the organic polymer that is formed in the process of standard seeded emulsion polymerization of organic monomers in a silicone polymer dispersion is more hydrophilic than silicone (what is usually the case), APD with core-shell particle structure is supposed to be obtained where silicone constitutes the core and the shell is made of an organic polymer. However, if the emulsion polymerization is carried out in a batch mode ( i.e. all monomers are added to the starting dispersion before polymerizations starts) swelling of starting dispersion particles with the monomers is easier and may result in different particle morphology - as it was shown for hybrid APD which did not contain silicones, e.g. [5], [29], [37]. The results of comparison of those both approaches with the process of emulsion polymerization of unsaturated organic monomers in silicone polymer dispersion were presented in [112-114]. In the study reported in [114] BA and N-hydroxymethyl acrylamide (NHMA) were polymerized in aqueous dispersion of poly(hydrogenmethylsiloxane) (PHMS) that was used instead of PDMS because the presence of hydrogen substituents in polysiloxane chain allowed for hydrosilylation reaction to proceed during the course of polymerization which led to formation of crosslinks between the core and the shell of the dispersion particle. When the [...]... obtain hybrid APD of good stability with up to 50% content of silicone in the copolymer MA 3.4 Synthesis of silicone- containing APD with hybrid particle structure through emulsion polymerization of alkoxysilanes (in particular with unsaturated functionality) or/and cyclic siloxanes in organic polymer dispersions AC CE P TE D The process of synthesis of silicone- containing APD with hybrid (core-shell) particle. .. with well documented organic polymersilicone core-shell structured particles 3.4.1 Possible approaches to synthesis of hybrid APD with organic polymer -silicone core-shell structured particles While the synthetic routes leading to silicone- containing APD with hybrid particle structure described in Sections 3.1 and 3.2 would usually lead to core-shell particles containing silicone in the core, the routes... of silicone part of the shell through hydrolysis of alkoxy groups of VTS 3.4.3 Comparison of synthesis of silicone- containing APD with hybrid particle structure through emulsion polymerization of alkoxysilanes or/and cyclic siloxanes in organic polymer dispersions with other approaches applied to obtain such APD In some of the publications the properties of hybrid APD with the same composition, but with. .. and by the fraction volumes of those two polymers : Va - fraction volume of PA polymer NU Vs - fraction volume of PSi polymer D MA According to the authors of [179] particles with organic polymer shell and silicone polymer core may only be formed if the equations (2) and (3) are fulfilled: (3) AC CE P TE (2) and particles with organic polymer core and silicone polymer shell may only be formed if the... [161] that hybrid dispersions containing 1% of that additive were drying faster and had smaller particle size In another paper the emulsion polymerization of a mixture of organic and silicone monomers in silica sol was described and it was stated that the hybrid dispersion with core-shell silicaorganic polymer /silicone particles were obtained [163] 3.2.2 Effect of the method of conducting the polymerization... PSi polymer and water SC R γaw - interfacial tension between PA polymer and water IP γsa - interfacial tension between PSi polymer and PA polymer T three extreme morphologies of particles in emulsion polymerization involving silicone monomers and their conclusion was that the particle morphology was dominated by interfacial tensions between the two polymers (PA - organic polymer) and PSi (silicone polymer) :... core-shell particles were ACCEPTED MANUSCRIPT formed in the process of seeded emulsion polymerization of organic monomers, but if that silicone dispersion was synthesized by emulsion polymerization of D4 with strong base as catalyst the new organic polymer particles were produced along with core-shell particles - see Fig 3 and Fig 4, respectively Fig 4 SC R 3.1.3 Effect of silicone polymer composition and structure. .. deposition of silicone polymer on the particle surface, but preventing formation of separate silicone- only particles The effect of those three factors on the properties of the resulting hybrid APD and the particle structure will be briefly discussed below AC CE P TE The effect of the amount of MPS grafted onto the organic polymer particles in seeded emulsion polymerization process on particle size... explained by formation of separate particles of crosslinked silicone polymer The average particle size increased smoothly with increased MPS concentration due to deposition of polymerized MPS onto organic polymer particle The increase in particle size with increased silicone comonomer (VTS) content was also observed in another study [183] and was explained by crosslinking of the copolymer proceeding through... hybrid particles with silicone polymer in the shell Then it became clear that if just those approaches were applied, the silicone polymer that would eventually be formed in the dispersion would be contained rather in separate silicone- only particles As it will be shown below, only under specific conditions the emulsion polymerization of alkoxysilanes or/and cyclic siloxanes may lead to hybrid APD with . of silicone-containing aqueous polymer dispersions (APD) with hybrid particle structure are reviewed based on available literature data. Advantages of synthesis of dispersions with hybrid particle. of hybrid polymer materials 3. Synthesis and characterization of silicone-containing APD with hybrid particle structure 3.1. Synthesis of silicone-containing APD with hybrid particle structure. lead to silicone-containing polymer nanoparticles with hybrid structure 4.1. Miniemulsion polymerization 4.2. Emulsion polymerization in non -aqueous media 4.3. Hybridization of organic polymer