Methylstyrene, alpha copolymers

Deng et al. (2007) compatibilized PA-66 blends with PP through addition of alpha-methylstyrene-GMA copolymer. Evidence was presented that the copolymer acts to functionalize PP in situ with GMA groups. PA-6 blends with PP or PE were also prepared using this method. 

Isocyanates can be added to solvent-borne CR adhesive solutions as a two-part adhesive system. This two-part adhesive system is less effective with rubber substrates containing high styrene resin and for butadiene-styrene block (thermoplastic rubber) copolymers. To improve the specific adhesion to those materials, addition of a poly-alpha-methylstyrene resin to solvent-borne CR adhesives is quite effective [76]. An alternative technique is to graft a methacrylate monomer into the polychloroprene [2]. 

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. 

There is some reason to expect that conversion of the anhydride to a half-ester might reduce the sensitivity of the copolymers. Hiraoka (10) determined the relative sensitivities of PMMA, PMA (polymethacrylic acid) and PMA AN (polymethacrylic anhydride) by measuring the gaseous products (CO, C02, and H2) given off when these polymers were exposed to electron beam radiation of 2.5 keV at 297 °K. He found that the G values (number of chemical events produced per 100 eV of absorbed radiation) for the removal of side groups are 2.0, 7.4 and 16 for PMMA, PMA and PMA AN, respectively. Anderson (11) found a similar relative order of sensitivity. For copolymers of methylmethacryate with 25% dimethylitaconate, 25% monomethyl itaconate or 25% itaconic acid (or anhydride) the G(s) values were 1, 2, 3, respectively. For the copolymer of alpha-methylstyrene and monomethyl maleate, on the other hand, we find an increase in sensitivity by a factor of 2.5 over the corresponding anhydride as described below. 

Gaur, U. and Wunderlich, B. Study of microphase separation in block copolymers of styrene and alpha-methylstyrene in the glass transition region using quantitative thermal analysis. Macromolecules 13, 1618 (1980)... 

In this case the only possible addition reactions are those of maleic anhydride to alpha-methylstyrene (or to its ring sulstituted derivative) and vice versa. The five further possible addition reactions have negligible rates. In the copolymer chains maleic anhydride alternates with one or the other alpha-methylst3nr ie. The ratio between the molar concentrations of the two alpha-methylstyrenes is given by d[Mj... 

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. 

Goh, Paul, and Barlow [10] found that an alpha-methylstyrene-acrylonitrile (AMS-AN) copolymer at 50 mole fraction AN formed miscible polymer blends with poly(methyl methacrylate) (PMMA) and with poly(ethyl methacrylate) (PEMA). AMS-AN copolymer did not form miscible blends with polyacrylates or polyvinyl acetate. The miscible blends were found to exhibit lower critical solution temperature (LCST) behavior. 

It can be seen that the replacement of styrene with AMS in SAN copolymers decreases the compositional window of miscibility. The phase separation temperatures are lowered. Homopolymer blends of polystyrene and TMPC have been found miscible with each other. Blends of poly(alpha-methylstyrene) and TMPC have been found to be immiscible. 

In this paper we describe the preparation and the properties of the title triblock with a low vinyl-1,2 (or 3,4 in the case of polyisoprene) polydiene center block. Two different solvent systems were used as the media of polymerization. In the first system, the polydiene center block was prepared in cyclohexane. Alpha-methylstyrene (AMS) and a polar solvent tetrahydrofuran (THF) were then added. This was followed by a slow and continuous styrene addition to complete the end block preparation. In the second system, AMS itself was used as the solvent with no other solvent added. The second solvent system enabled us to use several different polymerization schemes. The center block could be prepared first to form a tapered or untapered triblock. The end block copolymer also could be prepared first and then the diblock and then coupled to form a tri- or a radial block polymer. Instead of coupling, more styrene could be added to complete the triblock. All these different routes of preparation were used in this work. 

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. 

Attempts to produce a copolymer by heating alpha-methylstyrene and tert-butyl perbenzoate with an alkyd were unsuccessful. However, a graft copolymer was obtained with a 5050 mixture of alpha-methylstyrene, styrene, and tert-butyl perbenzoate heated with the medium-oil alkyd resin. 

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