Polymerization of lactones, 17. Synthesis of ethylene glycol‐L‐lactide block copolymers

The anionic polymerization of L ‐lactide in the presence of the sodium poly(ethylene glycol)ate in tetrahydrofuran at 25°C yields “tailored” ABA triblock copolymers having the expected compositions and molecular weights. During the polymerization, a slight racemization of L‐lactide was observed. The water absorption experiments indicate that the introduction of the poly(ethylene glycol) block into the L‐lactide polymer chain markedly increases its hydrophilicity. It was revealed that the morphology and mechanical properties of block copolymers depend strongly on their composition and thermal treatment.