MICROPHASE SEPARATION OF GRADIENT COPOLYMER AQUEOUS SOLUTIONS

摘要

Gradient copolymers (abbreviated by Grad) have recently prepared by Aoshima et al. by living cationic polymerization. A Grad has a gradient composition variation along the polymer chain. Microphase separation in a Grad solution is expected to be very different from that of a block copolymer solution which has a stepwise composition variation along the chain. Lefebvre et al. predicted that a gradient in composition along the chain makes phase separation more difficult than for a block copolymer. It is of interest to compare the strength of microphase separation between Block and Grad systems. We carried out small-angle neutron scattering investigations on semi-dilute aqueous solutions of Grad and block copolymers (Block) comprising pEOVE and pMOVE, p(EOVE-grad-MOVE)_(600) (Grad) and pEOVE_(300)-block-pMOVE_(300) (Block). Here, pEOVE and pMOVE denote poly(2-ethoxyethyl vinyl ether) and poly(2-methoxyethyl vinyl ether), respectively and the numbers indicate the degrees of polymerization.