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首页> 外文期刊>Journal of Macromolecular Science. Pure and Applied Chemistry >POLYMERS OF CARBONIC ACID. 15. POLYMERIZATION OF CYCLOTRIMETHYLENE CARBONATE WITH TiCl_4 OR SbCl_5 AS INITIATOR
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POLYMERS OF CARBONIC ACID. 15. POLYMERIZATION OF CYCLOTRIMETHYLENE CARBONATE WITH TiCl_4 OR SbCl_5 AS INITIATOR

机译：碳酸聚合物。 15.以TiCl_4或SbCl_5为引发剂的环碳酸亚乙烯酯的聚合

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摘要

Bulk polymerization of cyclotrimethylene carbonate (TMC) was conducted with either TiCl_4 or SbCl_5 as initiator. Reaction time, temperature, and monomer/initiator (M/I) ratio were varied. High yields ( > 90%) were obtained with both initiators, but the weight-average molecular weights (M_w) never exceeded 75,000. In contrast to SbCl_5, TiCl_4 does not cause decarboxylation at temperatures below 150℃ so that polycarbonates free of ether groups were formed. However, both initiators yield polycarbonates with more CH_2Cl than CH_2OH endgroups. In contrast to the sluggish TiCl_4, SbCl_5 is reactive enough to initiate the polymerization of TMC in CHCl_3 at 25℃. Both TiCl_4 and SbCl_5 form complexes with the monomer via the carbonyl group. In the case of TiCl_4, a solid 1:2 complex was isolated and characterized by IR- and ~(13)C-NMR CP/MAS spectroscopy. Furthermore, a crystalline 1:2 complex was synthesized with neopentanediol carbonate (NPC). In the case of SbCl_5, no well-defined complex was obtained with TMC but a crystalline 1:1 complex was obtained with NPC. These NPC complexes proved to be useful as initiators of bulk polymerizations of TMC.
机译：用TiCl_4或SbCl_5作为引发剂进行碳酸环三亚甲基酯（TMC）的本体聚合。反应时间，温度和单体/引发剂（M / I）之比是变化的。两种引发剂均能获得高收率（> 90％），但重均分子量（M_w）从未超过75,000。与SbCl_5相比，TiCl_4在低于150℃的温度下不会引起脱羧，因此形成了不含醚基的聚碳酸酯。然而，两种引发剂均产生具有比CH_2OH端基更多的CH_2Cl的聚碳酸酯。与缓慢的TiCl_4相比，SbCl_5具有足够的反应活性，可以在25℃下于CHCl_3中引发TMC的聚合反应。 TiCl_4和SbCl_5都通过羰基与单体形成配合物。在TiCl 4的情况下，分离出固体1：2络合物并通过IR-和〜（13）C-NMR CP / MAS光谱进行表征。此外，用碳酸新戊二醇酯（NPC）合成了1：2晶体配合物。在SbCl_5的情况下，用TMC不能得到明确的络合物，而用NPC可以得到1：1的晶体。这些NPC络合物被证明可用作TMC本体聚合的引发剂。

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