Ring-opening polymerization of ϵ-caprolactone initiated by rare earth complex catalysts

✍ Scribed by Xianmo Deng; Zhixue Zhu; Chengdong Xiong; Lianlai Zhang

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 149 KB
• Volume: 64
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19970516)64:7<1295::aid-app8>3.0.co;2-e

✦ Synopsis

The polymerization of caprolactone ( 1-CL) was initiated by yttrium triisopropoxide {Y(OP i r ) 3 }, bimetallic isopropoxide of yttrium and aluminum {Y[Al(OP i s ) 4 ] 3 }, yttrium and tin(II) {Y[Sn(OP i r ) 3 ] 3 }, and tin(II) and yttrium {Sn[Y(OP i r ) 4 ] 2 }, respectively. The polymerization was carried out through coordinative insertion of a monomer into the free metal-oxygen bond. The molecular weight and yield of poly(1-caprolactone) (PCL) were affected drastically by the mol % of the initiator to the monomer (C 0 /M 0 ). The results showed that Y(OP i r ) 3 and Sn[Y(OP i r ) 4 ] 2 were more effective than were {Y[Al(OP i r ) 4 ] 3 } and {Y[Sn(OP i r ) 3 ] 3 } for the polymerization of 1-CL. When polymerization was conducted at 5ЊC using Y(OP i r ) 3 as the initiator or at 10ЊC using Sn[Y(OP i r ) 4 ] 4 as the initiator, polymers with a molecular weight of 45.9 1 10 3 or 54.0 1 10 3 and high yield resulted in 30 or 5 min, respectively. The polymer was characterized by FTIR, H-NMR, and GPC.