Ring-opening polymerization of ∈-caprolactone was carried out smoothly and effectively with constant microwave powers of 170, 340, 510, and 680 W, respectively, with a microwave oven at a frequency of 2.45GHz. The temperature of the polymerization ranged from 80 to 210℃. Poly (∈-caprolactone) (PCL) with a weightaverage molar mass (Mw) of 124,000g/mol and yield of 90% was obtained at 680W for 30min using 0.1%(mol/mol) stannous octanoate as a catalyst. When the polymerization was catalyzed by 1% (w/w) zinc powder, the Mw of PCL was 92,300g/mol after the reaction mixture was irradiated at 680W for 270min.

Poly (∈-caprolactone) was blended with various polylactide-based polymers and processed to films by the solution casting method. Blends of 25/75, 50/50, 75/25, 90/10, and 95/5 (w/w) poly(∈-caprolactone)/poly-(L-lactide), a 95/5 (w/w) blend of poly(∈-caprolactone) with a poly (D-lactide), a 50/50 (w/w) poly (L-lactide)-poly (D-lactide) mixture, and a poly (L-lactide-co-∈-caprolactone) copolymer were considered comparatively. The various phase-separated films were allowed to degrade in the presence of Pseudomonas lipase, biodegradation being monitored by proton nuclear magnetic resonance, size exclusion chromatography, differential scanning calorimetry, X-ray diffraction, and environmental scanning electron microscopy. The formation of separated phases during solvent evaporation and their morphologies are discussed. The introduction of poly(L-lactide) dramatically decreased the degradation rate of poly(∈-caprolactone)/poly (Llactide) blends. The higher the percentage of poly(L-lactide), the slower the degradation, while the presence of cracks and increasing the lipase concentration acted in favor of the enzymatic degradation. Long-term enzymatic degradation of the various 95/5 blends was investigated over 480 h. The poly(∈-caprolactone) phase was enzymatically degraded by the lipase regardless of the blend type, the degradation rate depending on the nature of the co-components.

Acid-initiated ring-opening polymerization (ROP) of ε-caprolactone (ε-CL) was con-ducted under microwave imadiation (MI) at 2.45 GHz. At this frequency, metallic catalysts were no longer necessary, The effects of microwave power, imadiation time, ε-CL: acid molar ratio and acidity of acid on the polymerization were investigate. Both the rate of polymerization and the mollar mass of polymer obtained were enhanced in comparison with conventiona thermal method. Poly (ε-caprolactone) (PCL) with weight-average molar mass (Mw) over 12000g/mol and Mw/Mn below 1.6 was synthesized in the presence o carboxylic acids such as maleic acid (MA), succinic acid (SA) and adipic acid (AA). The polymerization was also carried out when the monoiner contained a certain amount of ibuprofen (IBU), by which, the IBU-PCL controlled release systern was prepared directly. The release of IBU from the systern was sustained from 12h to 9 days with IBU content in weight increasing from 5 to 20%. It seems that this is a prornising method to prepare drug controlled release systerns.

polymer (Mw3000g mol 1 with Mw/Mn 1.2) was obtained by the copper-catalyzed nitrogenelimination of allyl diazoacetate. Its structure was determined as poly (carballyloxycarbene) (PCACB) by 1H and 13C NMR and IR spectroscopy.