Candida antarctica lipase b-catalyzed synthesis of poly(butylene succinate):: Shorter chain building blocks also work
Candida antarctica lipase b-catalyzed synthesis of poly(butylene succinate):: Shorter chain building blocks also work
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DOI：
10.1021/bm060574h
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发表时间：
2006-11-13
影响因子：
6.2
通讯作者：
Gross, Richard A.
中科院分区：
文献类型：
--
作者：
Azim, Himanshu;Dekhterman, Alex;Gross, Richard A.
利用脂肪酶催化合成了高分子量的聚丁二酸丁二醇酯(PBS)。丁二酸与1，4-丁二醇共聚的尝试由于反应物的相分离而失败。为了解决这一问题，以丁二酸二乙酯和1，4-丁二醇为原料制备了单相反应混合物。对这些反应进行了整体研究和溶液研究。在所评价的有机溶剂中，二苯醚是首选，其产物的相对分子质量较高。在二苯醚中反应24 h后，在60℃、70℃、80℃和90℃下聚合可得到M-n分别为2000、4000、8000和7000的PBS。进一步延长反应时间至72小时，M-n几乎或没有进一步增加。然而，延长反应时间可得到M-w/M-n极低的PBS，这是因为低分子齐聚物与链之间的扩散和反应比链间酯交换发生的频率更高。时间进程研究和80℃下聚合的目测观察表明，PBS在5-10小时内沉淀，限制了链的生长。为了保持单相反应混合物，21h后聚合温度从80℃提高到95℃，使PBS的相对分子质量增加到M-w=38 000(M-w/M-n=1.39)。这项工作为合成PBS大单体和聚合物铺平了道路，这些大单体和聚合物含有不同数量的具有化学敏感部分的单体(例如，有机硅、环氧树脂、乙烯基)。此外，本研究还确定了利用脂肪酶催化α，omega-直链脂肪族二乙酯/二醇单体合成六碳以下聚酯的可行性。
Lipase catalysis was successfully employed to synthesize high molecular weight poly(butylene succinate) (PBS). Attempts to copolymerize succinic acid with 1,4-butanediol were unsuccessful due to phase separation of the reactants. To circumvent this problem, monophasic reaction mixtures were prepared from diethyl succinate and 1,4-butanediol. The reactions were studied in bulk as well as in solution. Of the organic solvents evaluated, diphenyl ether was preferred, giving higher molecular weight products. After 24 h in diphenyl ether, polymerizations at 60, 70, 80, and 90 degrees C yielded PBS with M-n of 2000, 4000, 8000, and 7000, respectively. Further increase in reaction time to 72 h resulted in little or no further increase in M-n. However, increasing the reaction time produced PBS with extraordinarily low M-w/M-n due to the diffusion and reaction between low-molecular weight oligomers and chains that occurs at a greater frequency than interchain transesterification. Time-course studies and visual observation of polymerizations at 80 degrees C revealed PBS precipitates at 5 to 10 h, limiting the growth of chains. To maintain a monophasic reaction mixture, the polymerization temperature was increased from 80 to 95 degrees C after 21 h. The result was an increase in the PBS molecular weight to M-w = 38 000 (M-w/M-n = 1.39). This work paves the way for the synthesis of PBS macromers and polymers that contain variable quantities of monomers with chemically sensitive moieties (e.g., silicone, epoxy, vinyl). Furthermore, this study established the feasibility of using lipase catalysis to prepare polyesters from alpha,omega-linear aliphatic diethyl ester/diol monomers with less than six carbons.