| abstract |
A novel vinyl-ether-based ABA triblock copolymer comprising a polyvinyl ether and hydroxystyrene units; and a process by which the ABA type copolymer can be easily produced via a series of steps. The novel ABA triblock copolymer is made up of segments (A) comprising hydroxystyrene repeating units (a) and a segment (B) comprising vinyl ether repeating units (b), each segment (A) being bonded to the segment (B) through a single bond. This triblock copolymer can be produced via a series of simple steps, i.e., by polymerizing a vinyl ether monomer such as ethyl vinyl ether by living cationic polymerization in the presence of a bifunctional initiator and a Lewis acid, subsequently adding a hydroxystyrene monomer such as p-hydroxystyrene, and polymerizing the hydroxystyrene monomer by living cationic polymerization. |