Handbook of Plastics Technologies Part 10 potx

PLASTICS ADDITIVES 5.47 and quinacridones produce reds; disazos, isoindolines, and isoindolinones produce reds to yellows; anilines produce orange; monoazos produce orange to yellows; anthraquinones, diarylides, and nickel azos produce yellows; and phthalocyanines produce greens to blues. Overall, there is a trend to give up inorganics of suspected toxicity and replace them by organics, but the organics must be chosen carefully to retain the heat and light stability re- quired in processing and using plastics. 5.8.4 Criteria in Choosing Colorants A typical checklist includes dispersability, rheology, plate-out, thermal stability, appear- ance, light fastness, weathering, migration, and toxicity in both processing and use, partic- ularly in leaching from solid waste. 5.8.5 Market Analysis In worldwide tonnage, titanium dioxide is about 8 billion pounds. In plastics, inorganic white pigments were 72 percent of the total market, inorganic colored pigments 8 percent, FIGURE 5.10 CIE chromaticity diagram. Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2006 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. PLASTICS ADDITIVES 5.48 CHAPTER 5 carbon black 13 percent, organic pigments 5 percent, and dyes 2 percent. But recent trends have probably favored the replacement of inorganic by organic colorants. Prices for inorganic colorants are mostly $1 to $3 per pound, and $3 to $30 for organic colorants. 5.8.6 Compounding Techniques 5.8.6.1 Powdered Color Pigments. The primary particles are individual crystals. These are firmly bonded into tight clumps called aggregates. These are further bonded into loose clumps called agglomerates. It takes skill and energy to disperse these into molten plas- tics, and this is best done by experts. The average compounder/processor may waste much time looking for the optimum technique. 5.8.6.2 Colored Compound. Processors can buy the plastic compound already precol- ored. This is commonly done with specialty plastics. It is expensive and leaves the proces- sor with inventory problems. FIGURE 5.11 Organic colorants. Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2006 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. PLASTICS ADDITIVES PLASTICS ADDITIVES 5.49 5.8.6.3 Color Concentrate (Masterbatch). Expert compounders disperse colorants at 20 to 60 percent concentration in a carrier polymer, using high shear to break down ag- glomerates and produce uniform dispersion of maximum coloring efficiency. This color concentrate is used by processors, simply blending it with virgin (natural color) resin (“let- down with natural”). Typical ratios of concentrate/natural are 1/20 to 1/100. This tech- nique is low in cost, does not create inventory problems, and is most commonly used with commodity resins. 5.8.6.4 Liquid Color. The colorant is predispersed in a liquid carrier, hopefully compat- ible with the resin. It is metered into the base of the hopper or the beginning of the screw in extrusion or injection molding and blends uniformly with the resin by the time it reaches the exit from the screw. Although originally billed as a universal technique, it has rather found applications in certain processes where it is the optimum technique. 5.8.6.5 Color Infusion. This immerses the finished plastic product in a hot aqueous dis- persion of colorant + dispersant. In several minutes, the color diffuses into the plastic product, giving it permanent coloration. The length of time determines the depth of the color. 5.8.7 Special Colorants Fluorescent colors are used to produce brighter reds and yellows. Phosphorescent colors are used to produce brighter yellows-greens-blues. Pearlescent colors combine internal and external reflections; they are made by techniques such as coating titanium dioxide on mica. Metallic flakes are added to colorants to give them a metallic sheen. Aluminum flakes give a silvery sheen and also improve UV stability and impermeability. Bronze flakes can be formulated into a range of colors from green to red to gold. 5.8.8 Fluorescent Whiteners Most polymers tend to form conjugated unsaturation during aging, absorbing blue light from the visible spectrum and therefore turning somewhat yellow. One way to mask this is to add fluorescent whiteners. These are primarily bis-benzoxazoles, triazines and triazoles of phenyl coumarins, and bis-styryl biphenyls (Fig. 5.12). They absorb invisible UV light, dispose of part of the en- FIGURE 5.12 Fluorescent whiteners. Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2006 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. PLASTICS ADDITIVES 5.50 CHAPTER 5 ergy, and re-emit the rest as visible light at the blue-violet end of the visible spectrum. This neutralizes the yellowness in the polymer, and emits a brilliant white. They are frequently used in polyolefins, polystyrene, ABS, PVC, polycarbonate, and polyurethanes. Concen- trations are typically 0.01 to 0.1 percent. 5.8.9 Reference Texts The major texts in the field are T. C. Patton’s Pigment Handbook (John Wiley & Sons, now out of print) and F. W. Billmeyer’s Textbook of Color Science (Wiley-Interscience). 5.9 ANTISTATS When two materials are in contact with each other, electrons migrate across the interface. When they are separated, some electrons may be caught on the wrong side, producing a static charge. Conventional structural materials are conductive enough to bleed off the charge to ground. Organic polymers are nonconductors, and may hold the charge for a long time. The charge on plastics may develop during separation from the mold or roll, from fric- tion during manufacture or use, or simply from evaporation of water from the surface. This sometimes causes problems in processing, particularly in handling thin films and fibers. It causes a much greater range of problems in the use of the product: collection of dust; un- sightly packaging; cling and discomfort of clothing and upholstery; shock; occasional dust explosions; oxygen hazard in hospitals; “noise” in sound recordings and photography and magnetic tapes and discs, computer chips, military electronics; and electromagnetic inter- ference (EMI) of electronic equipment in general. These are arranged more or less in order of increasing need for static dissipation. They are generally classified in terms of electrical resistance. For example, over 10 12 Ω-cm is nonconductive insulation, 10 10–12 is antistatic, 10 6–10 is statically dissipative, 10 2–6 is slightly conductive, 10 1 is EMI shielding, 10 0 to –3 is semiconductive, and 10 –3 to –5 is me- tallic conductivity. Various techniques are used to minimize these problems. In manufacturing, it is possi- ble to ionize the air and thus neutralize static charges. In textile manufacturing, it is com- mon to humidify the air to make fiber surfaces more conductive. Organic additives can make plastics fairly conductive to dissipate a static charge. In more extreme cases, high loading with carbon black makes rubber and plasticized PVC fairly conductive. And load- ing with carbon fibers and metallic fillers (particularly aluminum flakes and fibers) makes plastics conductive for EMI shielding. 5.9.1 Mechanisms of Antistatic Action When organic antistats are used to reduce static charge on plastics, several theories are of- fered to explain their action. Most commonly, it is assumed that the additive is polar enough to exude to the surface of the plastic, where it absorbs moisture from the air, per- mitting ionic impurities to conduct current electrolytically. The most effective antistats ac- tually contain ionic groups that are free to migrate and conduct. Some theorists believe that simple passage of water vapor over the surface of the plastic may be enough to carry away the static charge. From a different point of view, static charge is created by friction; the antistat acts as a surface lubricant, reducing friction and therefore reducing the buildup of a static charge. Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2006 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. PLASTICS ADDITIVES PLASTICS ADDITIVES 5.51 5.9.2 Commercial Antistats Quaternary ammonium soaps, R 4 N + X – , have the most powerful antistatic action. Unfor- tunately, they tend to decompose in high-temperature processing, so they are sometimes post-applied as a 1 to 2 percent solution. They also encounter objections from the FDA. Ethoxylated amines, RNH(CH 2 CH 2 O) n H, approach quaternary ammonium soaps, both in effectiveness and in problems. Ethoxylated esters, RCO 2 (CH 2 CH 2 ) n OH, are the most widely used class. By balancing the organic acid portion (R) against the polyoxyethylene portion, it is possible to control polarity and therefore semicompatibility and rate of migration to the surface of the plastic, thus making it self-renewable over the lifetime of the product. They adsorb water to the surface, making it conductive and lubricating it to reduce friction. They are usually non- toxic and stable enough for melt processing. Ethoxylated alcohols, RO(CH 2 CH 2 O) n H, are also used. Glycerol mono- and di-esters perform fairly similarly to ethoxylated esters and are used for this reason. Being derived from natural products, they are easily acceptable to FDA. Organic phosphate esters are also reported in similar use. More recently, alkali sulfonates have been reported in PS and PVC. 5.9.3 Use in Commercial Plastics LDPE typically uses 0.05 to 1.0 percent, HDPE 0.2 to 0.3, PP 0.5, and PS 2 to 4 percent. Rigid PVC uses 1 to 2 percent, and plasticized PVC 2 to 5 percent. 5.9.4 Test Methods 5.9.4.1 Dust Attraction. Dust attraction is the oldest and crudest method. The techni- cian rubs the plastic sample against his clothing, and then lowers it toward a dish of dust, and notes the height at which the dust jumps up to the charged plastic. A more sophisti- cated test uses a sooty flame to deposit soot on the plastic, and then measures the amount of soot collected. 5.9.4.2 Surface Conductivity. Determining the surface conductivity of the plastic sam- ple is a popular, simple measurement that is often assumed to correlate with antistatic be- havior. Practical proof would be more reassuring. 5.9.4.3 Electrostatic Decay. A high static charge is applied to the sample electrically. Then the rate of decay is measured instrumentally. In all these methods, relative humidity is the most treacherous variable that must be considered. This can produce a 10 4 range in electrical resistivity over the normal range of ambient humidity. 5.9.5 Market Analysis Ethoxylated fatty amines are 48 percent of the market, aliphatic sulfonates 25 percent, fatty acid esters 16 percent, quaternary ammonium compounds 2 percent, others 9 percent. For use in individual plastic materials, styrenics used 39 percent of the market, LDPE/ LLDPE 20 percent, HDPE 13 percent, PVC 12 percent, PP 11 percent, and others 5 per- cent. Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2006 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. PLASTICS ADDITIVES 5.52 CHAPTER 5 5.10 ORGANIC PEROXIDES The O:O bond in peroxides is quite unstable. RO:OR → RO . + . OR While they are difficult to make, ship, store, and handle, the radicals they produce are very useful in vinyl free-radical polymerization, cure of unsaturated polyesters, cross-linking of thermoplastics, grafting, and compatibilization of polymer blends. Stability/reactivity is generally measured by the temperature at which the half-life of the peroxide is 10 hr, called “the ten-hour half-life temperature.” It is controlled by choice of the R groups and accelerated by raising the temperature, radiation, catalysis by cobalt soaps, amines, or redox reaction with reducing agents. 5.10.1 Major Classes of Peroxides Major classes of peroxides are shown in Fig. 5.13. 5.10.1.1 Acyl Peroxides • Benzoyl peroxide is the longest-established and most widely used. With 10-hr half-life at 71°C, it is used to polymerize styrene and other vinyl polymers, for medium-temper- ature cure of unsaturated polyesters, and for a variety of grafting and compatibilization reactions. • Lauroyl peroxide (61°C) is used for somewhat higher reactivity. Its aliphatic structure also gives lighter color in polymers than can be obtained with the aromatic benzoyl per- oxide. • Decanoyl peroxide is used to a lesser extent. 5.10.1.2 Ketone Peroxides. MEK peroxide is used for room-temperature cure of unsat- urated polyesters. Typical concentrations are 0.5 to 2.0 percent. It may be catalyzed by 0.05 to 0.3 percent of cobalt naphthenate and also further catalyzed by amines. 5.10.1.3 Peroxy Esters. These cover a wide range of reactivities and uses. • t-butyl peroxy pivalate is a typical low-temperature peroxide. • t-butyl peroctoate (70°C) is a typical medium-temperature peroxide. • t-butyl perbenzoate (101°C) is a typical high-temperature peroxide, useful in polymer- izing styrene and in cure of BMC and SMC unsaturated polyesters. 5.10.1.4 Dialkyl Peroxides. These are typically high-temperature materials. • Dicumyl peroxide (dicup or DCP) (104°C) is useful in cross-linking LDPE, EVA, EPR, and EPDM. • Di-t-butyl peroxide (125°C) is useful for the high-temperature finish of styrene poly- merization to reduce residual styrene monomer content and thus improve modulus, HDT, taste, and odor. 5.10.1.5 Hydroperoxides. Hydroperoxides such as cumene hydroperoxide are used pri- marily for low-temperature emulsion polymerization of butadiene to make “cold rubber.” Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2006 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. PLASTICS ADDITIVES PLASTICS ADDITIVES 5.53 They are catalyzed by redox systems consisting of reducing sugars, iron soaps, and phos- phates. 5.10.1.6 Peracetic Acid (CH 3 CO 3 H). This is used mainly in epoxidizing olefins such as soybean oil for vinyl stabilizers and in synthesis of aliphatic epoxy resins. 5.10.1.7 Peroxyketals. These are particularly popular for cure of BMC and SMC unsat- urated polyesters. 5.10.1.8 Peroxydicarbonates. These are the least stable class, often too unstable for shipment, in which case they must be synthesized where they are going to be used. They have become the leading initiator for vinyl chloride polymerization. FIGURE 5.13 Peroxides. Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2006 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. PLASTICS ADDITIVES 5.54 CHAPTER 5 5.10.1.9 2,5-Dimethyl-2,5-di-t-Butyl Peroxy Hexyne-3. This, having a 10-hr half-life temperature 135°C, was developed specifically for the higher temperature processing re- quired in the cross-linking of HDPE. 5.10.2 Safety Precautions • Peroxides are often sold and handled in dilute form to reduce the danger of explosive re- action. • Heat should be avoided in shipping, storing, and handling. Some must be kept refriger- ated. • Friction should be avoided, both in packaging (no tight-fitting or screwed lids) and in handling and processing. • Organic impurities should not be allowed to contaminate peroxides, as the attack on them would be exothermic and kick off the entire batch. • Peroxides and catalysts/promoters should never be mixed together in the pure state. The batch of polymer should be divided in half. Then, the peroxide is added to one half and the catalysts/promoters to the other half. In this diluted form, the two halves can then be mixed to start the reaction. 5.10.3 U.S. Market Analysis Table 5.33 provides an analysis of peroxides used in plastics in the United States. 5.11 POLYMER BLENDS Polymer properties may be improved by adding a second polymer. This is not a general rule, but a number of polymer blends have offered so much improvement that 40 percent of commercial plastics are now based on polymer blends. 5.11.1 Miscibility If the two polymers are completely miscible down to the molecular and even segmental level, they form a single homogeneous phase, and properties are generally proportional to TABLE 5.33 Peroxides Used in Plastics Type Amount, millions of pounds MEK peroxide 11 Benzoyl peroxide 10 Peroxy esters 9 Dialkyl peroxides 5 Others 5 Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2006 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. PLASTICS ADDITIVES PLASTICS ADDITIVES 5.55 the ratio of the two polymers in the blend. Miscibility depends on equal polarity or mutual attraction such as hydrogen bonding or cocrystallization. This is not very common, but there are several important examples of such completely miscible blends. It gives the com- pounder simple straightforward control over balance of properties. 5.11.2 Practical Compatibility Most polymer pairs are too dissimilar for complete miscibility. They reject each other and separate into two or more phases. Generally, the major polymer forms a continuous matrix phase and retains most of its original properties. The minor polymer separates into dis- persed “domains” and may affect certain specific properties. When the domains are ex- tremely fine, sensitive properties may detect the phase separation, but many practical properties may resemble homogeneous single-phase blends. When the domains are larger in size, they will have distinct effects on certain specific properties; when these effects are beneficial, the blend is described as theoretically immiscible but practically compatible. When the domains are too coarse, most properties will suffer, and the blend is described as incompatible. 5.11.3 Interface/Interphase In multiphase polyblends, a critical factor is the interface between the phases. If the two polymers reject each other and separate into phases, they are likely to reject each other at the interface as well. Such a weak interface will fail under stress, and most properties will suffer. Thus, most polymer blends are practically incompatible. Yet, most successful com- mercial polyblends are multiphase systems. This means that there must be a mechanism to strengthen the interface. In some cases, the two polymers have some partial miscibility, so the interface is not a sharp separation of one polymer from the other but, rather, a modulating solution of the two polymers in each other, offering a gradual interphase rather than a sharp interface. Such an interphase can modulate properties gradually from one phase to the other and thus reduce the stress. 5.11.4 Compatibilizers In most cases, it is necessary to add a compatibilizing agent to strengthen the interface. In basic research, the preferred compatibilizing agent is a diblock copolymer, with one block soluble in one phase and the other block soluble in the other phase. The block copolymer tends to locate at the interface. This creates primary covalent bonds across the interface and thus strengthens it. In commercial practice, the compatibilizing agent is usually a graft copolymer, with a backbone soluble in one phase and side-chains soluble in the other phase; this is not as theoretically satisfying, but it is usually easier and more economical to make and appears to work perfectly well in practice. In some cases, the graft copolymer is made separately and then added to the polyblend during compounding; in other cases, it may be formed directly during compounding by reactive processing. 5.11.5 Effect of Polyblend Ratio on Polyblend Properties When two polymers are blended in ratios from 100/0 to 0/100, and the effect on properties is measured, we may observe one of four types of behavior (Fig. 5.14). Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2006 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. PLASTICS ADDITIVES 5.56 CHAPTER 5 5.11.5.1 Type I. If the two polymers are completely miscible down to the molecular level and form a single homogeneous phase, properties are generally proportional to the ratio of the two polymers in the blend. Even if the two polymers are immiscible and form fine phase separation, many property tests are relatively insensitive to fine-phase separa- tion and may still show such “homogeneous behavior.” Practically, this is useful to com- pounders who want the ability to produce a spectrum of balance of properties at low cost. 5.11.5.2 Type II. When two polymers are immiscible and form two separate phases, the major polymer will form the continuous matrix phase and retain most of its original prop- erties, while the minor polymer will form finely dispersed domains and contribute certain specific properties. Thus, high A/B ratios will have properties similar to poly-A, and high B/A ratios will have properties similar to poly-B. Obviously, at fairly equal ratios of A and B, there will be a phase inversion with a rapid change of properties from one plateau to the other. This explains the two leading uses of polymer blends. (1) When rigid plastics suffer from brittleness, dispersion of fine rubbery domains in the rigid matrix can add great im- pact strength with little sacrifice of rigidity. (2) Rubber molecules must be tied together to give them strength, creep resistance, and insolubility; while this is usually done by ther- moset vulcanization, it can also be done by dispersion of fine rigid thermoplastic domains, either glassy or crystalline, to form thermoplastic elastomers. 5.11.5.3 Type III. When two polymers are immiscible and separate into two phases, there may be so little attraction between them that the interface between the phases is ex- tremely weak and will fail under stress. This is most often seen in ultimate tensile strength and ultimate elongation. In most products, this would be labeled “incompatibility.” How- ever, there are occasional examples where such behavior is actually beneficial. For exam- ple, adding an immiscible polymer may decrease melt viscosity and thus improve melt processing. Or it may decrease breaking strength, producing a package that is easier to open and therefore more customer friendly. Thus, it is safer to label Type III behavior “U- shaped” or “trough-shaped,” rather than simply incompatible. 5.11.5.4 Type IV. Once in a while, the polymer blend may exhibit properties greater than either of the individual polymers, a major synergistic improvement in practical utility. The leading example of this phenomenon is the use of finely dispersed rubbery domains to increase the impact strength of a brittle glassy matrix polymer. Commodity examples are FIGURE 5.14 Properties vs. polymer/polymer ratio in a polyblend. Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2006 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. PLASTICS ADDITIVES [...]... Terms of Use as given at the website Source: Handbook of Plastics Technologies CHAPTER 6 NANOMANUFACTURING WITH POLYMERS Daniel Schmidt, Joey Mead, Carol Barry Department of Plastics Engineering University of Massachusetts Lowell, Massachusetts Julie Chen Department of Mechanical Engineering University of Massachusetts Lowell, Massachusetts 6.1 INTRODUCTION Nanotechnology offers the promise of unique... Doshi et al .100 ,111 used PEO of MW of 145 × 103 g/mol, surface tension of 61 dynes/cm, conductivity of 400 µS/cm, and solution viscosity of 400 to 800 centipoise for their process optimization studies Deitzel et al.116 and Bunyan133 also studied the effect of polymer feed rate, applied voltage, and the properties of the solution (surface tension, viscosity, concentration) on the morphology of the PEO... dry spinning, is closest to the focus of this section— electrospinning of nanofibers The use of spinnerets becomes impractical as the desired fiber diameter approaches the nanoscale because of the high pressures needed at much smaller hole diameters and the effect of dimensions approaching the radius of gyration of individual molecular chains One particular method of submicron diameter fiber formation... Modifiers Handbook, Van Nostrand Reinhold, 1992 2 J T Lutz and R F Grossman, Polymer Modifiers and Additives, Dekker, 2000 3 Hans Zweifel, Plastics Additives Handbook, Hanser, 2001 5.14 SPECIALIZED REFERENCES 1 H S Katz and J V Milewski, Handbook of Fillers for Plastics, Van Nostrand Reinhold, 1987 2 J W Lyons, The Chemistry and Uses of Fire Retardants, Wiley-Interscience 1970 3 J V Milewski and H S Katz, Handbook. .. it is obtained, the achievement of a nanostructure with significant silicate dispersion has been the goal of the majority of polymer/layered silicate nanocomposite research As a result, a number of thermodynamic descriptions of such systems have been attempted.26–28 As with any additive, however, the presence of unbound compatibilizing agents will impact the properties of the blend as a whole, potentially... products offer an advantage because of their lighter weight, flexibility, and biological compatibility In addition, polymers also provide the benefit of ease of fabrication using high-rate and continuous processing As a result, it is anticipated that polymeric materials will play a more important role in the future of the nanotechnology revolution One of the critical issues in advancing the field of nanotechnology... on the tip, a large amount of fibers would be attached on the tip A rotating wheel at one end of the belt was designed to collect the fibers from the tip of the electrodes A high voltage of 56 kV was used for this process The method and the apparatus had some limitations in regard to the collection of the fibers The fibers would adhere to the moving belt, drum, and other parts of the apparatus, thereby... structures of amorphous silica.17 General characteristics of most of these materials include layer thicknesses of ~1 nm and lateral dimensions ranging from ~25 nm to ~5 µm, and cation-exchange capacities between 0.65 and 1.50 meq/g Naturally occurring silicates are known to contain quartz and other particulate impurities, which, because of their size (submicron to micron diameter) and lack of interactions,... treatment, and the use of special surfactants In addition to these methods, which often involve harsh conditions that may degrade the properties of the carbon nanotubes, techniques of specific interest due to milder conditions and the potential for application in polymer nanocomposites include vapor-phase amination to give good solvent compatibility3 and the use of highly charged nanoparticles to allow... reserved Any use is subject to the Terms of Use as given at the website PLASTICS ADDITIVES 5.58 CHAPTER 5 termediate modulus plateau is proportional to the ratio of the two polymers in the blend, and the useful temperature range extends from the glass transition of the rubber to the glass transition or melting point of the rigid polymer This explains the successful use of immiscible, compatible polymer blends . For example, over 10 12 Ω-cm is nonconductive insulation, 10 10–12 is antistatic, 10 6 10 is statically dissipative, 10 2–6 is slightly conductive, 10 1 is EMI shielding, 10 0 to –3 is semiconductive,. Handbook of Fillers for Plastics, Van Nostrand Reinhold, 1987. 2. J. W. Lyons, The Chemistry and Uses of Fire Retardants, Wiley-Interscience 1970. 3. J. V. Milewski and H. S. Katz, Handbook of. Terms of Use as given at the website. PLASTICS ADDITIVES 6.1 CHAPTER 6 NANOMANUFACTURING WITH POLYMERS Daniel Schmidt, Joey Mead, Carol Barry Department of Plastics Engineering University of Massachusetts Lowell,