Controlled polymerization of ϵ‐caprolactone ‐from macromolecules to microspheres

Pseudoanionic polymerization of ϵ‐caprolactone (CL), initiated with dialkylaluminum alkoxides, was used for the tailored synthesis of poly(CL) with M̄n ≤ 100 000 and M̄w /M̄n < 1. 20. Macromolecules with functional groups at one or at both ends were obtained in this way. Controlled polymerization of CL allowed to prepare poly(dodecyl acrylate)‐g‐poly(ϵ‐caprolactone) (poly(DAC)‐g‐poly(CL)) with well defined poly(CL) grafts. These copolymers were used as the surface active agents for the direct synthesis of poly(CL) microspheres. The number average diameter (D̄n ) of poly(CL) microspheres varied from 0.628 μm to 0.94 μm and the diameter polydispersity (D̄v /D̄n ) varied from 1.038 to 1.26, depending on the composition of poly(DAC)‐g‐poly(CL). Human serum albumin (HSA) and human gamma globulins (γ G) were attached to the poly(CL) microspheres. The maximal surface concentrations of HSA and γ G adsorbed onto the microspheres were equal to 9·10−4 g/m2 and 2.0·10−3 g/m2 respectively.