Vinylbenzyl-Type Polyamide Macromer Synthesized from Bicyclic Oxalactam. Preparation and Characterization of Graft Copolymer Composed of Polystyrene as a Stock and Hydrophilic Polyamide as Branches

Abstract

Vinylbenzyl-type polyamide macromers (1) of various average molecular weights (Mn; 3900, 5400, and 8400) were prepared by the anionic ring-opening polymerization of a bicyclic oxalactam, 8-oxa-6-azabicyclo[3.2.1]octan-7-one (abbreviated as BOL, 2) followed by a reaction with p-vinylbenzylamine. The relative reactivity of the macromer (M1) in the radical copolymerization with styrene (M2) was found to be lower than that of p-methylstyrene from the estimation of the reciprocal monomer reactivity ratio (1/r2). The resulting graft copolymer composed of a polystyrene stock and polyamide branches was characterized by structural analysis, solubility test, and determination of moisture sorption. Two kinds of transparent binary blend films, which were i) the graft copolymer and homopolystyrene and ii) the graft copolymer and polyBOL, were cast on a glass plate from the corresponding chloroform and chloroform-methanol (9:1) solutions, respectively. In the case of the former film comprising mainly polystyrene, the hydrophilic polyamide segment of the graft copolymer as a really minor component was found to be located on the glass-side surface from the contact angle measurement and the attenuated total reflection-infrared spectroscopy.