文摘
A new method for the synthesis of miktoarm star copolymers is proposed. To demonstrate its viability, diblock copolymers, PA-b-PSCOOH, with a carboxyl-bearing short PSCOOH block, and triblock copolymers, PB-b-PNH2-b-PB, with an amino-bearing short PNH2 block, were synthesized and characterized. Here PA and PB denote poly(tert-butyl acrylate) and poly(methyl methacrylate), respectively. The carboxyl- and amino-bearing blocks of the copolymers associated with one another due to carboxylate and ammonium ion pairing in dichloromethane. The addition of a coupling agent caused the amino and carboxyl groups to amidize and resulted in the fusion of the associating chains, thus producing miktoarm copolymers μ-(PA)1(PB)2 and μ-(PA)2(PB)2. Factors affecting the relative and total yields of μ-(PA)1(PB)2 and μ-(PA)2(PB)2 formation were investigated.