Styrene-co-acrylonitrile

FIGURE 38.10 Transmission electron micrograph of styrene-co-acrylonitrile/acrylonitrile butadiene mbber/ waste NBR (SAN/NBR/w-NBRybased thermoplastic elastomer (TPE). (Reprinted from Anandhan, S., De, P.P., Bhowmick, A.K., Bandy opadhyay, S., and De, S.K., J. Appl Polym. Sci., 90, 2348, 2003. With permission from Wiley InterScience.)... 

We can readily copolymerize styrene with a variety of comonomers. Commercially, the two most important random styrene copolymers are styrene co-acrylonitrile and styrene cobutadiene, the general chemical structures of which are shown in Fig, 21.3. 

We commonly copolymerize styrene to produce random and block copolymers. The most common random copolymers are styrene-co-acrylonitrile and styrene-co-butadiene, which is a synthetic rubber. Block copolymerization yields tough or rubbery products. 

Why, in the production of styrene-co-acrylonitrile, do we introduce a 62 38 ratio of styrene to acrylonitrile in the reaction vessel ... 

Attractive interactions are also the reason for the self-assembly of PS-fo-PB-fo-PMMA at the interface of poly(styrene-co-acrylonitrile), SAN, and poly(2,6-dimethylphenylene ether), PPE. In this blend, PS and PPE are miscible on one side and PMMA and SAN are miscible on the other one, with negative / parameters. This blend, in which the rubbery domain is located at the interface between SAN/PMMA and PPE/PS, was originally prepared by coprecipitation of all components from a common solution [195]. From a processing point of view, in this system the difficulty was to get the dispersion of PPE in SAN via melt mixing of SAN, PPE and the triblock terpolymer. 

Priddy, D.B. Thermal Discoloration Chemistry of Styrene-co-Acrylonitrile. Vol. 121, pp. 123-154. 

Similarly to homopolymers, source-based nomenclature has been applied to copolymers [4]. The principal problem is to define the kind of arrangement in which various types of monomeric units are related to each other. Seven types of separate arrangements have been defined, which are shown in Table 1, where A, B and C represent the names of monomers. The monomer names are linked either through an italicized qualifier or connective (infix), such as -CO- , to form the name of the copolymer, as in poly(styrene-co-acrylonitrile). The order of citation of the monomers is arbitrary. 

E4 polystyrene-Z)/ocA -[l,4-polybutadiene-grq/Z -poly(styrene-co-acrylonitrile)] (copolymer from styrene and acrylonitrile grafted to a 1,4-polybutadiene-polystyrene two-block copolymer at unspecified sites of some of the but-2-ene-... 

Fostacryl Poly(styrene-co-acrylonitrile) Foster Grant... 

Alternating, statistical, and random copolymers are named by following the prefix poly with the names of the two repeating units. The specific type of copolymer is noted by inserting -alt-, -stat-, or -ran- in between the names of the two repeating units with -co- used when the type of copolymer is not specified, for example, poly(styrene-ofi-acrylonitrile), poly(styrene-i fat-acrylonitrile), poly(styrene-ran-acrylonitrile), and poly(styrene-co-acrylonitrile) [Wilks,... 

Plastomers. The production of resins (polyfvinyl chloride], polystyrene, and poly [styrene-co-acrylonitrile]) with relatively high toughness has been one of the most important aims of industry. This can be achieved by modifying a rigid chain with small amounts of elastomers. The best results have been obtained by the use of block and graft copolymers. 

R. Schafer, J. Zimmermann, J. Kressler, and R. Miilhaupt, Morphology and phase behaviour of poly(methyl methacrylate)/poly(styrene-co-acrylonitrile) blends monitored by fti.r. microscopy, Polymer, 38(15) 3745-3752, July 1997. 

Figure 9.7-1 Experimental cloud-point curve of the polymer blend Poly(methyl methacrylate)/Poly(styrene-co-acrylonitrile (28%AN)) as a function of pressure.

Beginning in the late forties, copolymers were fractionated by adsorption chromatography poly (butadiene-co-styrene)32 34), poly(butadiene-co-acrylonitrile)32), polystyrene- -vinyl acetate)35), poly(styrene-h-ethylene oxide)36) and poly(styrene-co-acrylonitrile) 37). HPLC adsorption chromatography was first applied to copolymer analysis by Teramachi et al. in 1979 38>. 

Poly(styrene-co-acrylonitrile) samples (SAN) have been fractionated through methanol-acetone or methanol-dichloromethane mixtures of stepwise-altered composition 108) through methanol/dichloromethane, n-hexane/dichloromethane, or methanol/acetone gradients109), cyclohexane/methyl ethyl ketone gradients 110), or (toluene — 1-propanol 50 50)/dimethyl formamide gradients111. Mixtures of ethylene cyanohydrin — ethylene carbonate 112) or cyclohexane — methyl ethyl ketone 113 have also been used for the separation of SAN copolymers. Both the latter systems as well as the n-hexane/dichloromethane gradient109) had the efficacy of fractionating SAN copolymers by composition. 

The influence of pore size on the elution of SAN samples was small. Short columns yielded better separation than longer ones. This is similar to a recent observation in protein RPC 73), vide supra. Figure 29 shows that a 55 mm column was superior to a 150 mm one in separating a mixture of five poly(styrene-co-acrylonitrile) samples. (Note that the leading pseudopeak was also diminished.)... 

Fig. 31. Chromatographic cross-fractionation of 0.87 mg poly(styrene-co-acrylonitrile). The sample was a mixture of 59.3 % copolymer with 16.1% AN and 40.7 % of another copolymer with 30 % AN. The latter produced the band at 15-20 min elution time, the former the band at about 9 min. SEC slices of 0.5 ml each as indicated in the upper right part of the figure. They were used without any additional treatment for the second separation. The molar mass data indicated refer to the shaded SEC slices1391.

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