Poly(l,l-lactide) Microspheres by Ring-Opening Polymerization

摘要: Poly(l,l-lactide) microspheres were synthesized directly during the ring-opening precipitation polymerizations of l,l-lactide. The carried out in heptane−1,4-dioxane (4:1 v/v) mixed solvent presence various poly(dodecyl acrylate)-g-poly(e-caprolactone) copolymers (poly(DA−CL)) used as surface active agents. Copolymers with different molecular weights, average number poly(e-caprolactone) grafts per macromolecule, and weights these used. number-average diameters (Dn) from 2.46 to 4.07 μm polydispersity parameters (Dv/Dn, where Dv denotes volume-average diameter) 1.08 1.45 obtained. dependence Dn Dv/Dn on structure concentration poly(DA−CL) was investigated. narrow diameter (Dv/Dn = 1.08) obtained when poly(DA−CL), containing an 1.3 (with Mn 4700 g/mol) copolymer m...