STYRENE-METHACRYLIC

The combination of durability and clarity and the ability to tailor molecules relatively easily to specific applications have made acryflc esters prime candidates for numerous and diverse applications. At normal temperatures the polyacrylates are soft polymers and therefore tend to find use in applications that require flexibility or extensibility. However, the ease of copolymerizing the softer acrylates with the harder methacrylates, styrene, acrylonitrile, and vinyl acetate, allows the manufacture of products that range from soft mbbers to hard nonfilm-forming polymers. 

Radical copolymerization is used in the manufacturing of random copolymers of acrylamide with vinyl monomers. Anionic copolymers are obtained by copolymerization of acrylamide with acrylic, methacrylic, maleic, fu-maric, styrenesulfonic, 2-acrylamide-2-methylpro-panesulfonic acids and its salts, etc., as well as by hydrolysis and sulfomethylation of polyacrylamide Cationic copolymers are obtained by copolymerization of acrylamide with jV-dialkylaminoalkyl acrylates and methacrylates, l,2-dimethyl-5-vinylpyridinum sulfate, etc. or by postreactions of polyacrylamide (the Mannich reaction and Hofmann degradation). Nonionic copolymers are obtained by copolymerization of acrylamide with acrylates, methacrylates, styrene derivatives, acrylonitrile, etc. Copolymerization methods are the same as the polymerization of acrylamide. 

Methyl methacrylate-styrene-butadiene-acrylonitrile copolymer >10 8.4 1.4 87 4,700 480 0,020 0,025 C11... 

Suriyachi, P., Kiatkamjomwong, S., and Prasassarkich, P. Natural Rubber-g-Glycidyl Methacrylate/Styrene as a CompatibiUzer in Natural Rubber/PMMA Blends, Rubber Chem. Technol. 77(5), 914—930, November/December 2004. 

Figure 9 shows the result of injecting 10 gA of the total low molecular weight fraction from GPC 1 (Column Code A2) into GPC 2 (Column Code Bl). With this column code, GPC 2 is performing as a High Performance Liquid Chromatograph (HPLC). Separation is based upon solubility (i.e. composition differences) rather than upon molecular size. Methyl methacrylate monomer was used as a reference and added to the solution injected into GPC 1. Concentrations of n-butyl methacrylate, styrene and conversion are readily calculated from the peak areas and initial concentrations. 

Lignite can be grafted with synthetic comonomers to obtain lignite fluid loss additives [873]. Comonomers can be AMPS, N,N-dimethylacrylamide, acrylamide, vinylpyrrolidone, vinylacetate, acrylonitrile, dimethylaminoethyl methacrylate, styrene sulfonate, vinyl sulfonate, dimethylaminoethyl methacrylate methyl chloride quaternary, and acrylic acid and its salts. 

Some characteristics of free-radical terpolymerization of tri-butylstannyl methacrylate, styrene and maleic anhydride governed by the pentacoordination state of the tin atom are reported in Refs. 95),96). It is shown that a coordination-bound monomer has a considerable effect on chain initiation and propagation. Copolymerization mainly involves the participation of complex-bound monomers. 

Radiation Induced Reactions. Graft polymers have been prepared from poly(vinyl alcohol) by the irradiation of the polymer-monomer system and some other methods. The grafted side chains reported include acrylamide, acrylic acid, acrylonitrile, ethyl acrylate, ethylene, ethyl methacrylate, methyl methacrylate, styrene, vinyl acetate, vinyl chloride, vinyl pyridine and vinyl pyrrolidone (13). Poly(vinyl alcohols) with grafted methyl methacrylate and sometimes methyl acrylate have been studied as membranes for hemodialysis (14). Graft polymers consisting of 50% poly(vinyl alcohol), 25% poly(vinyl acetate) and 25% grafted ethylene oxide units can be used to prepare capsule cases for drugs which do not require any additional plasticizers (15). 

List C contains peroxidisable monomers, where the presence of peroxide may initiate exothermic polymerisation of the bulk of material. Precautions and procedures for storage and use of monomers with or without the presence of inhibitors are discussed in detail. Examples cited are acrylic acid, acrylonitrile, butadiene, 2-chlorobutadiene, chlorotrifluoroethylene, methyl methacrylate, styrene, tetraflu-oroethylene, vinyl acetate, vinylacetylene, vinyl chloride, vinylidene chloride and vinylpyridine [1]. 

Okano, T., Katayama, M., and Shinohara, 1. The influence of hydrophobic and hydrophilic domains on water wettability of 2-hydrooxyethyl methacrylate/styrene copolymers, J. Appl. Polmer Sci, 1978, 22, 361-ill. 

Either addition sequence works if the two monomers are in the same family (e.g., methyl acrylate and butyl acrylate or methyl methacrylate and butyl methacrylate or styrene and 4-acetoxystyrene), because the equilibrium constants (for activation) for both types of chain ends have about the same value. The situation is usually quite different for pairs of monomers from different families. Chain ends from monomers with large equilibium constants can initiate the polymerization of monomers with lower equilibrium constants thus, cross-propagation is efficient. Methacrylate works well as the first monomer to form methacrylate-acrylate and methacrylate-styrene blocks. 

Penultimate effects have been observed for many comonomer pairs. Among these are the radical copolymerizations of styrene-fumaronitrile, styrene-diethyl fumarate, ethyl methacrylate-styrene, methyl methacrylate l-vinylpyridine, methyl acrylate-1,3-butadiene, methyl methacrylate-methyl acrylate, styrene-dimethyl itaconate, hexafluoroisobutylene-vinyl acetate, 2,4-dicyano-l-butene-isoprene, and other comonomer pairs [Barb, 1953 Brown and Fujimori, 1987 Buback et al., 2001 Burke et al., 1994a,b, 1995 Cowie et al., 1990 Davis et al., 1990 Fordyce and Ham, 1951 Fukuda et al., 2002 Guyot and Guillot, 1967 Hecht and Ojha, 1969 Hill et al., 1982, 1985 Ma et al., 2001 Motoc et al., 1978 Natansohn et al., 1978 Prementine and Tirrell, 1987 Rounsefell and Pittman, 1979 Van Der Meer et al., 1979 Wu et al., 1990 Yee et al., 2001 Zetterlund et al., 2002]. Although ionic copolymerizations have not been as extensively studied, penultimate effects have been found in some cases. Thus in the anionic polymerization of styrene t-vinylpyri-dine, 4-vinylpyridine adds faster to chains ending in 4-vinylpyridine if the penultimate unit is styrene [Lee et al., 1963]. 

Although this method yields a mixture of homopolymer and graft copolymer, and probably also ungrafted backbone polymer, some of the systems have commercial utility. These are high-impact polystyrene (HIPS) [styrene polymerized in the presence of poly(l,3-buta-diene)], ABS and MBS [styrene-acrylonitrile and methyl methacrylate-styrene, respectively, copolymerized in the presence of either poly(l,3-butadiene) or SBR] (Sec. 6-8a). 

Preparation of a t-Butyl Methacrylate/Styrene/f-Butyl Methacrylate Acrylic Acid/Styrene/Acrylic Acid) Triblock Copolymer... 

Figure 2 Property distributions in a linear copolymer composition distribution, molecular weight distribution and sequence length distribution of poly styrene-co-n-butyl methacrylate). (Styrene units are represented by "A and n-butyl methacrylate units by B".)...

Figure 17 (69) shows the mechanical behavior of different synthetic elastomers. They were found to be generally less efficient than natural rubber in promoting polymerization because of reduced stress during mastication due to greater softening by monomer addition. Nitrile rubber crumbed with methyl methacrylate, styrene and acrylonitrile. 

Ceresa synthetized also block copolymers of poly(methyl methacrylate) with acrylonitrile and styrene and of polyethylene with methyl methacrylate, styrene using this method (104). 

Fig. 8. R/Platelet in individual platelets adhering to polymer surfaces. HSB data were statistically confirmed to be different from PSt (P < 0.5), HSR (P < 0.5) and PHEMA (P < 0.5) after 40 s R/Platelet (an index of cytoplasmic free calcium concentration) is the ratio of fluorescence emission intensitie of a Ca2 + indicator dye (Fura 2) loaded in platelets when they are excited at 340 nm and 380 nm. (Reproduced from J Biomed Mater Res [Ref 84 Prevention of changes in platelet cytoplasmic free calcium levels by interaction with 2-hydroxyethyl methacrylate/styrene block copolymer surfaces] through the courtesy of John Wiley Sons, Inc.)...

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