Synthesis and morphology of polycaprolactone–block-polyimide–block-polycaprolactone triblock copolymers for film separation membranes

Triblock copolymers with the central polyimide block and peripheral polycaprolactone blocks were synthesized by controlled ring-opening anionic coordination polymerization of ε-caprolactone on polyimide macroinitiators with terminal hydroxy groups. The chemical structure of the products was determined by spectroscopic methods, and the molecular-mass characteristics of the triblock copolymers and their separate blocks were determined by size-exclusion chromatography. Examination of the phase morphology of strong self-supporting films formed from the copolymer solutions revealed microphase segregation on the nanometer level in the films.