ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Emulsion copolymerization of acrylonitrile and butyl acrylate. 3. Effect of the radical scavenger on the kinetics and polymerization behavior

I. Capek and J. Bartoň

Polymer Institute, Centre for Chemical Research, Slovak Academy of Sciences, CS-842 36 Bratislava

Abstract: A study of the emulsion copolymerization of acrylonitrile and butyl acrylate under batch conditions in the presence of p-benzoquinone is presented. Statistical copolymers are synthesized by the emulsion polymerization conduc­ ted to both low and high conversion using the anionic emulsifier. It has been found that the copolymer formed at low conversion is enriched with acrylonitrile structural units both in the presence and in the absence of p-benzoquinone. Addition of a small amount of a radical scavenger significant­ ly decreases the rate of polymerization and slightly decreases the size of polymer particles in the range of low surfactant concentration. It is assumed that the initiation of the emulsion copolymerization is a two-step process. It starts in the aqueous phase by the primary radicals derived from the water-soluble initiator which add water-soluble monomer. These reactions lead to the formation of water-soluble or insoluble macroradi- cals which cause at low conversion the drift in copolymer composition. The second step occurs in micelles by radicals absorbed on the surface of micelles. It is expected that the polymer particles generated by homogeneous nucleation contribute to both the polymerization rate and copolymer composition.

Full paper in Portable Document Format: 401a45.pdf

Chemical Papers 40 (1) 45–60 (1986)