BLOCK COPOLYMERIZATION OF ETHYLENE-OXIDE AND STYRENE BY SEQUENTIAL INITIATION OF AN ANION AND A PHOTOINDUCED CHARGE-TRANSFER COMPLEX

A block copolymer composed of crystalline polyethylene oxide (PEG) and noncrystalline polystyrene (PS) was prepared by the combination of anion and photoinduced charge transfer polymerization (CTP) using p-aminophenol as the parent compound. The whole copolymerization was divided into two stages. In the first stage, the amino group of p-aminophenol was protected by benzaldehyde first and then reacted with metallic potassium. The phenoxy anion formed initiated polymerization of EO. In the second stage, the PEO prepolymer with the Schiff base end group was deprotected by acidolysis with acetic acid. Then the recovered amino group and added benzophenone (BP) constituted a charge transfer complex (CTC) under UV irradiation to initiate the polymerization of styrene. The block copolymer of EO and St (PEO-b-PS) and the intermediates were characterized in detail by elemental analysis, GPC, UV, DSC, IR, and NMR.