Chain Propagation/Step Propagation Polymerization. 1. The Polymerization of Ethylene Oxide with an Acetal-Masked Initiator.

摘要

Structure control in copolymer synthesis is a continuing challenge for the polymer chemist, a situation that certainly holds true in the synthesis of segmented copolymers by conventional step polymerization techniques. Rarely does one attain a narrow molecular weight distribution for both segments within such copolymers, though this very goal is actively sought by at least two other research groups today. In this research we are attempting the synthesis of highly regular segmented copolymers, i.e., those with narrow molecular weight distributions within each segment, by combining chain and step propagation procedures into one synthetic scheme. The thrust of this synthetic strategy focuses on synthesizing a highly regular telechelomer (a high molecular weight monomer) by anionic polymerization that in turn is converted into a copolymer of high molecular weight by step polymerization techniques. Figure 1 depicts the approach as it applies to segmented copolymers. Keywords: Synthesis chemistry; Polymer synthesis; Reprints. (kt)