Ring-opening dispersion polymerization of _L-lactide initiated by _L-arginine in supercritical carbon dioxide

摘要

The ring-opening dispersion polymerizations of _L-lactide (_L-IA) were carried out with ScCO_2 as the green solvent, _L-arginine (_L-Arg) as an initiator and PCL-PDMS-PCL triblock copolymer as the stabilizer. The poly (_L-lactide) (PLIA) products were obtained with a good disperse powders (9-22 urn), a higher number-average molecular weight (11700 g/mol), a better molecular weight distribution (PDI) (1.31) and a lower reaction temperature (150 °C). The synthesis mechanisms and synthesis procedures of the polymerization reaction were presented. The optimum reaction conditions were obtained under the pressure of 12 MPa and the reaction time of 48 h. The kinetic process of the reaction was discussed and the results showed that the reaction was controllable polymerization and a first order kinetic reaction.