Polymerization of lactides and lactones, 9 - Synthesis and characterization on novel random copolyesters containing 5-phenyl-epsilon-caprolactone units

Full Paper: 3-Ph-CL and 5-Ph-CL can copolymerize with LA or CL initiated by Sn(Oct)(2) in bulk at 150 degreesC. The copolymerization of 3-Ph-CL with L A and CL only produced oligomer. High molecular weight P(5-Ph-CL)-PLA and P (5-Ph-CL)-PCL were obtained by copolymerizing 5-Ph-CL with LA or CL. The co polymerization of 5-Ph-CL with CL, the content of P(5-Ph-CL) is in agreemen t with the feed ratio. However, in the case of 5-Ph-CL with LA, irrespectiv ely of the monomer feed ratio, the content of P(5-Ph-CL) in the copolymer i s less than that in the monomer feed. The 5-Ph-CL feed ratio has little inf luence on the molecular weight and the molecular weight distribution of P(5 -Ph-CL)-PCL and P(5-Ph-CL)-PLA, but with the increase of 5-Ph-CL feed ratio , the yield of copolymer decreases. The DSC study of P(5-Ph-CL)-PLA and P(5 -Ph-CL) PCL indicated that the content of P(5-Ph-CL) affects the properties of the copolymer. When the content of P(5-Ph-CL) reaches 50%, both copolym ers became rubber-like and non-crystalline. [GRAPHICS] Effects of the content of 5-Ph-CL on the yield or P(5-Ph-CL)-PCL and P(5-Ph -CL)-PLA. Reaction condition: 5 h at 150 degreesC.