SYNTHESIS OF POLY(STYRENE-GRAFT-ETHYLENE OXIDE) BY ETHOXYLATION OF AMIDE GROUP CONTAINING STYRENE COPOLYMERS

Graft copolymers containing poly (ethylene oxide) side chains on a pol ystyrene backbone have been synthesized. Styrene copolymers synthesize d by free radical mechanism and containing between 5 and 15 mol % acry lamide or methacrylamide were used as backbones. The amide groups in t he copolymers were ionized by using potassium tert-butoxide or potassi um naphthalene, and grafting was achieved by utilizing the amide anion s as initiator sites for the polymerization of ethylene oxide in 2-eth oxyethyl ether at 65-degrees-C. The graft copolymers were characterize d with respect to molecular weight and composition using elemental ana lysis, NMR, gel permeation chromatography, IR, and viscosity measureme nts. The size of the side chains were between 600 and 2000 g/mol. GPC results from a hydrolyzed graft copolymer sample suggest a narrow size distribution for the poly(ethylene oxide) grafts. Solution properties of the graft copolymers were investigated in different toluene/methan ol mixtures. The intrinsic viscosities of the graft copolymers were fo und to depend primarily on the poly(ethylene oxide) content rather tha n the graft density or the poly(ethylene oxide) chain length.