Cyclo-depolymerization of olefin-containing polymers to give macrocyclic oligomers by metathesis and the entropically-driven ROMP of the olefin-containing macrocyclic esters
Cyclo-depolymerization of olefin-containing polymers to give macrocyclic oligomers by metathesis and the entropically-driven ROMP of the olefin-containing macrocyclic esters
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DOI：
10.1016/j.polymer.2007.09.014
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发表时间：
2007-11-02
期刊：
影响因子：
4.6
通讯作者：
Ben-Haida, Abderrazak
中科院分区：
文献类型：
--
作者：
Kamau, Stephen D.;Hodge, Philip;Ben-Haida, Abderrazak
A range of olefin-containing polyesters were prepared by acyclic diene metathesis (ADMET) and were then subjected to cyclo-depolymerization (CDP). CDP involves metathesis of the 1,2-disubstituted olefinic linkages and gives a homologous family of strainless macrocyclic oligomers (MCOs). When Grubbs' "first generation" catalyst was used at 23 C the CDPs were sluggish and required reaction times of several days, but with the "second generation" Grubbs' catalyst at 40 C CDPs were complete in only 2-4 h. Macrocyclic olefin-containing lactones were also prepared by ring-closing metathesis. Under appropriate reaction conditions (i.e. neat cyclics or very concentrated solutions of cyclics) the strainless macrocycles successfully underwent ring-opening metathesis polymerizations (ROMPS). Unlike most ROMPS reported in the literature, which are usually enthalpically-driven, these ROMPS are entropically-driven (ED-ROMPs). The results obtained clearly demonstrate that 21-, 24-. 27-. 28-. 38-. 45-, 52-, 63-, 64-, 68- and 84-membered macrocycles polymerized successfully. Two of the ED-ROMPS were carried out in films. These ROMPS appeared to proceed in part in the solid phase, i.e. were examples of solid state polymerization. (c) 2007 Published by Elsevier Ltd.
