ALPHA-METHYL STYRENE COPOLYMER

R.C. Leiberich, R. Dohm, H.C. Waldmann, and H. Alberts, Preparation of alpha-san copolymers from alpha-methyl styrene and acrylonitrile, DE Patent 19618832, assigned to Bayer AG, November 13,1997. 

Abbreviations for the polymeric units in Table 2.10 (C H )- - phenyl ring, a-MS - alpha-methyl styrene, AN, acrylonitrile, BMA - butylmethacrylate, CHMA - cyclohexylmethacrylate. Cl - caprolactone, C(VC) - unit of chlorinated PVC, DNS - 2,4-dini-trostyrene-co-styrene, DTC -2,2-dimethyltrimethylenecarbonate, HFPC - hexafluoro bisphenol-A polycarbonate, MA - maleic anhydride, MMA - methylmethacrylate, PAr - unit of polyarylate, Phenoxy - unit of polyhydroxy ether of bisphenol-A, PPE - unit of poly(2,6-dimethyl-1,4-phenylene ether), S - styrene, TMPAr - unit of tetramethyl bisphenol-A polyarylate, TMPC - unit of tetramethyl bisphenol-A polycarbonate, VAc - vinyl acetate, VC - vinyl chloride, VCVAc90 - VC-co-VAc copolymer with 90 wt% VC, VME - vinylmethylether. 

Acrylate styrene acrylonitrile Acrylate modified styrene acrylonitrile Acrylic acid ester rubber Acrylonitrile butadiene rubber or nitrile butadiene rubber Acrylonitrile butadiene styrene Acrylonitrile styrene/chlorinated polyethylene Acrylonitrile methyl methacrylate Acrylonitrile styrene/EPR rubber or, acrylonitrile ethylene propylene styrene Alpha methyl styrene Atactic polypropylene Butadiene rubber or, cis-1,4-polybutadiene rubber or, polybutadiene rubber Butadiene styrene block copolymer Butyl rubber Bulk molding compound Casein formaldehyde Cellulose acetate Cellulose acetate butyrate Cellulose acetate propionate Cellulose nitrate Chlorinated polyethylene Chlorinated polyvinyl chloride Chloro-polyethylene or, chlorinated polyethylene. 

Raman spectroscopy has been used in structural studies of a wide range of homopolymers and copolymers [109-122] including crystalline PE [123], polyaniline [124], polystyrene-co-p-(hexafluoro-2 hydroxyisopropyl)-alpha methyl styrene/polypropylene carbonate blends [125], PE [126], PP [126], polylactide [127], polyacrylonitrile [128], Nylon-6 - polyvinyl alcohol blends [129], poly(4-vinyl pyridine cupric salt complexes [130] and regenerated cellulose [131]. 

Despite these difficulties, the depolarization of monomer fluorescence of copolymers of styrene 32 179, 1-vinylnaphthalene 32,179 183,18S,> and 2-vinylnaphthalene i79) has been studied in low-temperature solvent glasses. The same experiments were performed on PS 32,186) and PIVN 32, i86). Monomer fluorescence depolarization from room-temperature films of styrene i87) and 1-vinylnaphthalene 187) copolymers, and from blends of P(1 VN-co-MMA) with PMMA 179), has also been recorded. Finally, exci-mer fluorescence depolarization from room-temperature films of PS 188,189) and P(alpha-methyl S) 189) has been studied. 

The high sensitivity provided by supersonic beam spectrometry permitted the detection of minor species, thus styrene monomer is produced from poly alpha methylstyrene by cleavage of a methyl group and by proton rearrangement. Because the ablation is carried out at high temperatures it is possible to obtain results on thermally stable polymers such as poly-p-methyl styrene. The technique was applied to polystyrene foam, styrene-butadiene copolymers and acrylonitrile-butadiene-styrene terpolymers. 

These polymers, which are commercially available, are not thermally stable and decompose to produce the monomer when heated. Copolymers of alpha methylstyrene with methyl methacrylate or styrene are transparent plastics with heat deflection temperatures greater than that of PS. 

The composition and microstracture of polymers in a latex system were studied by pyrolysis gas chromatography. The composition and microstructure of a polymer in the emulsion phase were identified by direct pyrolysis of the latex system, followed by comparing the trimer peak pattern with appropriate microstructure standards. The polymer in the aqueous phase was pre-pyrolysis derivatised with tetrabutylammonium hydroxide to convert the acid to its butyl ester. Similar procedures were then used to explore the composition and microstructure of the polymer in the aqueous phase. Polymers analysed included SCX-2660 (probably a styrene-methyl methacrylate-butyl acrylate terpolymer), styrene-butyl acrylate copolymer and styrene-alpha-methylstyrene-butyl acrylate terpolymer. 17 refs. 

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