Polymerization of lactides and Lactones, 8 - Study on the ring-opening polymerization of 3-phenyl-epsilon-caprolactone and 5-phenyl-epsilon-caprolactone

摘要

Ring-opening polymerization of 3-phenyl-epsilon -caprolactone (3-ph-CL) and 5-phenyl-epsilon -caprolactone (5-ph-CL) by tin(II) salt, Al((OPr)-Pr-1)(3) and CpNa has been studied; 3-ph-CL cannot be initiated by Al((OPr)-Pr-1)(3). Polymerization of 5-ph-CL initiated with Al((OPr)-Pr-1)(3) in toluene at 15 degreesC yielded a polymer of a predictable molecular weight and a narrow molecular weight distribution. 3-ph-CL and 5-ph-CL can be polymerized by initiating with tin(II) salt, and CpNa. In CpNa-based polymerization, high molecular weight P(3-ph-CL) and P(5-ph-CL) were obtained. DSC studies indicate that P(5-ph-CL) is an amorphous material exhibiting a rubber state at room temperature. Compared with PCL, the glass transition temperature of P(3-ph-CL) and P(5-ph-CL) is higher (-60 degreesC), in contrast to the melting temperature, which is higher for PCL. These new monomers give a route to novel aliphatic polyesters. References: 23