Formation of porous matrices from lactide and ε-caprolactone copolymers in supercritical carbon dioxide medium

A series of lactide and ε-caprolactone copolymers containing 4–24 mol % of ε-caprolactone with 20- to 30-kDa molecular weights are synthesized. Based on them, porous materials are produced by foaming in supercritical carbon dioxide. The pore size was shown to decrease with increasing ε-caprolactone content in copolymer, while the porosity of the entire sample was not altered. The resulting pore size also decreases if 7 wt % polyethylene glycol is added to the initial monomer mixture. The Young’s modulus of the porous samples decreases with increasing ε-caprolactone content and when polyethylene glycol is added.