GRAFTING ON POLYBUTADIENE WITH MACRO OR MACROMONOMER INITIATORS CONTAINING POLY(ETHYLENE GLYCOL) UNITS


HAZER B.

MACROMOLECULAR CHEMISTRY AND PHYSICS, vol.196, no.6, pp.1945-1952, 1995 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 196 Issue: 6
  • Publication Date: 1995
  • Doi Number: 10.1002/macp.1995.021960614
  • Title of Journal : MACROMOLECULAR CHEMISTRY AND PHYSICS
  • Page Numbers: pp.1945-1952

Abstract

Crosslinked poly(ethylene glycol)-block-polybutadiene block copolymers were obtained by coupling reaction of polybutadiene (PBd) with macromonomer azo initiators (macroinimers) or polyazoesters (PAE) in moderate yield (22-75%). NMR and FT-IR spectroscopy measurements were used to characterize and determine the poly(ethylene glycol) (PEG) contents (20-66%). The latter depends on the initial concentration of the azo compounds. Broad melting peaks appear in the DSC curves in a temperature range from about 65-130 degrees C. The crosslinked polymers containing PEG-1500 units showed sharp melting transitions and the second heating cycle showed that recrystallization rates are very high. Swelling ratios of the polymer networks were determined in water (1,22-2,96) and in CHCl3 (7,81 -20,84). The morphology of the cold fractured area of the crosslinked polymers was analyzed by scanning electron microscopy (SEM).