RING-OPENING POLYMERIZAION OF 2,2-DIMETHYLTRIMETHYLENE CARBONATE INITIATED BY IN SITU GENERATED, TETRAHYDROSALEN STABLIZED YTTRIUM BOROHYDRIDE COMPLEX AND RANDOM COPOLYMERIZATION WITH ε-CAPROLACTONE

• Published in: Chinese journal of polymer science 2011, Vol.29 (3), p.390-396
• Main Author: Jing Huang Jian-fang Yu Han-jian Yu Wei-lin Sun Zhi-quan Shen
• Format: Article
• Language: English
• Subjects: 二甲基碳酸酯; 共聚物; 原位生成; 硼氢化; 碳酸盐; 聚己内酯; 钇稳定; 随机结构
• ISSN: 0256-7679; 1439-6203
• DOI: 10.1007/s10118-011-1044-8

The poly（2,2-dimethyltrimethylene carbonate） （PDTC） with one hydroxyl and one formate terminal functions was synthesized by in situ generated, tetrahydrosalen stabilized yttrium borohydride complex. The influences of monomer/initiator molar ratio, temperature and reaction time on polymerization of DTC were investigated. Under the condition： [DTC]/[I] = 500, 55℃, toluene： 0.5 mL, DTC： 0.6 g, PDTC with Mn = 15600 and PDI = 2.15 was obtained. Through 1H-NMR and 13C-NMR analyses, the structure of PDTC was characterized and a coordination-insertion mechanism was proposed. In addition, the random copolymerization of DTC and caprolactone （CL） initiated by rare-earth borohydride compound was studied. The microstructure of PDTC-co-PCL includes four diads： DTC-CL, CL-CL, DTC-DTC and CL- DTC, which were determined by the specific signals in lH-NMR spectra. Based on the typical signals of the formate （δ = 8.08） and hydroxyl （δ= 3.34） end groups of PDTC-co-PCL, a mechanism involving DTC monomer inserts before CL during the initiation process was presumed. Furthermore, the thermal properties of amorphous copolymer were characterized by differential scanning calorimetry （DSC）. The results support the random structure of PDTC-co-PCL.