Synthesis and characterization of polypropylene‐based block copolymers possessing polar segments via controlled radical polymerization

Abstract

AbstractA new method to prepare the polypropylene (PP) macroinitiator for controlled radical polymerization was described. Bromination of terminally‐unsaturated PP was carried out by using N‐bromosuccinimide and 2,2′‐azobis(isobutyronitrile) to give a brominated PP (PP‐Br), that has allylic bromide moieties at or near the chain ends. Thus, the obtained PP‐Br was successfully used as a macroinitiator for radical polymerization of styrene, methyl methacrylate, and n‐butyl acrylate using a copper catalyst system. From 1H NMR analysis, it was confirmed that the chain extension polymerization was certainly initiated from allylic bromide moieties with high efficiency, leading to the PP‐based block copolymers linking the polar segment. From differential scanning calorimetry, it was observed that peak melting temperature of block copolymers was higher than that of PP‐Br and the obtained PP‐PS block copolymers with different compositions of each segment demonstrated the unique morphological features due to the microphase separation between both segments. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 812–823, 2009