Acrylonitrile heterogeneous copolymerization

The heterogeneous copolymerization of styrene and acrylonitrile in various diluents as reported by Riess and Desvalois (22). Although the copolymer composition in these studies was not strongly influenced by the diluent choice, the preferential adsorption of acrylonitrile monomer onto the polymer particles shifted the azeotropic copolymerization point from the 38 mole % acrylonitrile observed in solution to 55 mole % acrylonitrile. 

Heterogeneous combustion, 7 449-454 Heterogeneous copolymerization of acrylonitrile, 11 203—204 with VDC, 25 698-699 Heterogeneous enzyme systems, 10 255-256 Heterogeneous gas-solid catalytic reactions, 21 340-341 Heterogeneous Ideal Adsorbed Solution Theory (HIAST), gas separation under, 1 628, 629... 

Cheetham PL, Tabner BJ. A spin-trap study of the aqueous heterogeneous copolymerization of acrylonitrile and vinyl acetate. Eur Polym J 1993 29 451 54. 

Copolymerization. See also Copolymers of acrylonitrile, 11 202-204 anionic, 7 624-626 catalytic, 7 627-632 cationic, 7 626-627 chloroprene-sulfur, 19 833-834 of cyclic olefins, 16 112-113 with depropagation, 7 617-619 free-radical, 7 611-624 heterogeneous, 11 203-204 homogenous, 11 202-203 with metallocene catalysts, 16 111... 

The solvent can affect the copolymerization behavior, however, inasmuch as it can change the monomer concentration at the reaction site. The local concentrations are inserted into the copolymerization equation as the monomer concentrations. In many cases, these local concentrations are identical to the overall concentration. Deviations may be anticipated when a monomer associates or, as is quite general in heterogeneous polymerization, exhibits a solubility different from that of the second monomer. For example, the reactivity ratios in the copolymerization of acrylonitrile with methylacrylate (50°C) differ considerably according to the polymerization technique used (Table 22-8). 

Free-radical-initiated copolymerization of MA with acrylonitrile has been investigated under both bulk " and solution conditions. In solution, the copolymerizations were studied under both heterogeneous (benzene. 

The polymer particles with heterogeneous structure (e.g., core-shell, rusberry-like...) can be form by the classical batch emulsion copolymerization of unsaturated monomers with different reactivities and hydrophobicities. For example, the emulsion copolymerization of butyl acrylate and vinyl acetate gave polymer particles with a butyl acrylate-iich core and a vinyl acetate - rich shell [67]. The similar stmcture of polymer particles were reported in the emulsion copolymerization of acrylonitrile with hydrophobic unsaturated monomers such as bulyl aciylate [68]. 

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