Functionalization of Methylenated Polycaprolactone by Thiol-ene Reaction for Application to Bio Medical Materials

Polycaprolactone (PCL) is one of the typical aliphatic polyesters, which attract much attention as biodegradable material for environmental or medical applications. The general functionalization of PCL, through copolymerization with functional CL monomer, is sometimes complicated. Recently, we have reported successful direct methylenation of PCL using catalytic dimethyltitanocene. In this study, thiol-ene reactions using thioglycolic acid, aminoethanethiol hydrochloride or mercaptoethanol were carried out for further functionalization of methylenated PCLs. Interestingly, although thermal properties of methylenated PCL changed, functionalized PCL with carboxyl or amino groups showed higher melting points and larger enthalpy changes. These results suggested that interaction between those functional groups would, promote crystallization of the polymers. Such functionalized materials would be applicable as bioconjugates or scaffolds in regenerative medicine.Polycaprolactone (PCL) is one of the typical aliphatic polyesters, which attract much attention as biodegradable material for environmental or medical applications. The general functionalization of PCL, through copolymerization with functional CL monomer, is sometimes complicated. Recently, we have reported successful direct methylenation of PCL using catalytic dimethyltitanocene. In this study, thiol-ene reactions using thioglycolic acid, aminoethanethiol hydrochloride or mercaptoethanol were carried out for further functionalization of methylenated PCLs. Interestingly, although thermal properties of methylenated PCL changed, functionalized PCL with carboxyl or amino groups showed higher melting points and larger enthalpy changes. These results suggested that interaction between those functional groups would, promote crystallization of the polymers. Such functionalized materials would be applicable as bioconjugates or scaffolds in regenerative medicine.