Cyclopolymerization of dimethyl dipropargylmalonate in supercritical carbon dioxide to give a highly regular polyene containing predominantly five-membered rings.

Poly(dimethyl dipropargylmalonate) synthesized in scCO2 contained more than 95% five-membered rings, i.e., highly regular polyene was produced, which shows carbon dioxide as a reaction medium plays a significant role in determining a highly selective polymer structure.

Ring-opening polymerization of L-lactide and preparation of its microsphere in supercritical fluids.

The ring-opening polymerization of L-lactide initiated by stannous octoate was carried out in supercritical chlorodifluoromethane (scR22) at various reaction conditions (time and temperature) and reactant concentrations (initiator, monomer, and solvent). The monomer conversion increased to ca. 70% on increasing the reaction time to 1 h.