GRAFT-COPOLYMERS BY FREE-RADICAL COUPLING REACTIONS .1. POLYSTYRENE-POLYBUTADIENE GRAFT-COPOLYMERS


HAZER B.

JOURNAL OF MACROMOLECULAR SCIENCE-PURE AND APPLIED CHEMISTRY, pp.81-90, 1995 (Journal Indexed in SCI) identifier

  • Publication Type: Article / Article
  • Volume:
  • Publication Date: 1995
  • Doi Number: 10.1080/10601329508020317
  • Title of Journal : JOURNAL OF MACROMOLECULAR SCIENCE-PURE AND APPLIED CHEMISTRY
  • Page Numbers: pp.81-90

Abstract

Polybutadiene-polystyrene graft copolymers were prepared by free radical coupling method at 80 degrees C. Oligo(adipoyl-5-peroxy-2,5-dimethyl n-hexyl peroxide) or oligo dodecandioyl peroxide were used in the polymerization of styrene at 60 or 80 degrees C to prepare active polystyrene samples having undecomposed peroxy groups in the main chain. Homogeneous mixtures of active polystyrene and polybutadiene gave graft copolymers at 80 degrees C under vacuum. Polystyrene-g-polybutadiene copolymers were separated from corresponding homopolymers by fractional precipitation. UV,IR,NMR and GPC techniques were used for analysis of pure graft copolymers formed in the yield range between 12% and 92%. DSC curves of graft copolymers exhibited a wide endotherm transition between 40 and 80 degrees C while the corresponding homopolymers showed only glass transitions.