Poly(p-phenylene methylene)-based block copolymers by mechanistic transformation

The synthesis of poly(p-phenylene methylene) (PPM)-based block copolymers such as poly(p-phenylene methylene)-b-poly(ε-caprolactone) and poly(p-phenylene methylene)-b-polytetrahydrofuran by mechanistic transformation was described. First, precursor PPM was synthesized by acid-catalyzed polymerization of tribenzylborate at 16 °C. Then, this polymer was used as macroinitiators in either ring-opening polymerization of ε-caprolactone or cationic ring-opening polymerization of tetrahydrofuran to yield respective block copolymers. The structures of the prepolymer and block copolymers were characterized by GPC and ¹H NMR investigations. The composition of block copolymers as determined by ¹H NMR and TGA analysis was found to be in very good agreement. The thermal behavior and surface morphology of the copolymers were also investigated, respectively, by differential scanning calorimetry and atomic force microscopy measurements, and the contribution of the major soft segment has been observed.