A novel rare earth coordination catalyst for polymerization of biodegradable aliphatic lactones and lactides

✍ Scribed by Zhang, Jie; Gan, Zhihua; Zhong, Zhiyuan; Jing, Xiabin

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 316 KB
• Volume: 45
• Category: Article
• ISSN: 0959-8103
• DOI: 10.1002/(sici)1097-0126(199801)45:1<60::aid-pi891>3.0.co;2-w

✦ Synopsis

A novel rare earth coordination system composed of lanthanide tri-Ñuoroacetates (Ln \ Y, Yb, Nd, Tm, Ho, La, Pr) and tri-Ln(CF 3 COO) 3 isobutylaluminium Al(i-Bu) was used as catalyst for the polymerization of 3 e-caprolactone (CL), D,L-lactide (DLLA) and their copolymerization. The inÑuence of temperature, time and catalyst concentration on polymerization yields and molecular weights of the polyesters have been studied. It was shown that the ring-opening polymerization of cyclic esters catalysed by Ln(CF 3 COO) 3 /Al(ihas some living character and the molecular weight of the polyester could Bu) 3 be controlled by adjusting the molar ratio of monomer to catalyst. The DLLA/CL copolymer was synthesized by sequential addition of monomers and the structure of the copolyester was characterized by GPC, NMR and DSC. 1998 SCI. ( Polym. Int. 45, 60È66 (1998)