BLOCK COPOLYMERIZATION OF ETHYLENE-OXIDE AND ACRYLONITRILE AND THE INFLUENCE OF BLOCK LENGTH OF POLYACRYLONITRILE ON THE THERMAL-BEHAVIOR AND MORPHOLOGY OF BLOCK-COPOLYMER

A bifunctional initiator with the characteristics of anionic and charg e transfer polymerization using p-aminophenol as parent compound is us eful for synthesis of block copolymers. A block copolymer of ethylene oxide and acrylonitrile (PEO-b-PAN) is prepared by this method. In the first step, p-aminophenol potassium with protected amine group initia ted polymerization of ethylene oxide (EO) to yield polyethylene oxide (PEG) with Schiffs base end groups. The charge transfer complexes (CTC ) consisted of the PEO prepolymers with aniline group, which is formed by acidolysis of Schiffs base, and benzophenone (BP) initiated the po lymerization of acrylonitrile under UV irradiation. Successful blockin g has been confirmed by a strong change in the molecular weight of the prepolymer PEO and the block copolymer as well as IR, DSC, and NMR. T he block copolymerization are strongly dependent on the polarity of th e solvents. The effect of length of PAN block on glass transition temp erature of PAN and the crystallinity of PEO block were discussed. (C) 1996 John Wiley & Sons, Inc.