Comerford James W, Byrne Fergal P, Weinberger Simone, Farmer Thomas J, Guebitz Georg M, Gardossi Lucia, Pellis Alessandro
Green Chemistry Centre of Excellence, Department of Chemistry, University of York, Heslington, York YO10 5DD, UK.
Department of Agrobiotechnology IFA-Tulln, Institute of Environmental Biotechnology, University of Natural Resources and Life Sciences, Konrad Lorenz Strasse 20, 3430 Tulln an der Donau, Austria.
Materials (Basel). 2020 Jan 13;13(2):368. doi: 10.3390/ma13020368.
The enzymatic synthesis of polyesters in solventless systems is an environmentally friendly and sustainable method for synthetizing bio-derived materials. Despite the greenness of the technique, in most cases only short oligoesters are obtained, with limited practical applications or requiring further chemical processing for their elongation. In this work, we present a catalyst-free thermal upgrade of enzymatically synthesized oligoesters. Different aliphatic and aromatic oligoesters were synthesized using immobilized lipase B (iCaLB) as the catalyst (70 °C, 24 h) yielding poly(1,4-butylene adipate) (PBA, M = 2200), poly(1,4-butylene isophthalate) (PBI, M = 1000), poly(1,4-butylene 2,5-furandicarboxylate) (PBF, M = 600), and poly(1,4-butylene 2,4-pyridinedicarboxylate) (PBP, M = 1000). These polyesters were successfully thermally treated to obtain an increase in M of 8.5, 2.6, 3.3, and 2.7 folds, respectively. This investigation focused on the most successful upgrade, poly(1,4-butylene adipate), then discussed the possible effect of di-ester monomers as compared to di-acids in the thermally driven polycondensation. The herein-described two-step synthesis method represents a practical and cost-effective way to synthesize higher-molecular-weight polymers without the use of toxic metal catalysts such as titanium(IV) -butoxide, tin(II) 2-ethylhexanoate, and in particular, antimony(IV) oxide. At the same time, the method allows for the extension of the number of reuses of the biocatalyst by preventing its exposure to extreme denaturating conditions.
在无溶剂体系中酶促合成聚酯是一种合成生物基材料的环境友好且可持续的方法。尽管该技术具有绿色环保的特点，但在大多数情况下，只能得到短链低聚酯，其实际应用有限，或者需要进一步化学处理以延长其链长。在本工作中，我们展示了一种对酶促合成的低聚酯进行无催化剂热升级的方法。使用固定化脂肪酶B（iCaLB）作为催化剂（70℃，24小时）合成了不同的脂肪族和芳香族低聚酯，得到了聚（1,4 - 丁二醇己二酸酯）（PBA，M = 2200）、聚（1,4 - 丁二醇间苯二甲酸酯）（PBI，M = 1000）、聚（1,4 - 丁二醇2,5 - 呋喃二甲酸酯）（PBF，M = 600）和聚（1,4 - 丁二醇2,4 - 吡啶二甲酸酯）（PBP，M = 1000）。这些聚酯成功地进行了热处理，其分子量分别提高了8.5倍、2.6倍、3.3倍和2.7倍。本研究聚焦于最成功的升级产物聚（1,4 - 丁二醇己二酸酯），然后讨论了在热驱动缩聚反应中与二元酸相比二元酯单体可能产生的影响。本文所述的两步合成方法是一种实用且经济高效的合成高分子量聚合物的方法，无需使用有毒金属催化剂，如四丁氧基钛、二（2 - 乙基己基）锡和特别是氧化锑（IV）。同时，该方法通过防止生物催化剂暴露于极端变性条件，使得生物催化剂的重复使用次数得以增加。
