Todea Anamaria, Bîtcan Ioan, Aparaschivei Diana, Păușescu Iulia, Badea Valentin, Péter Francisc, Gherman Vasile Daniel, Rusu Gerlinde, Nagy Lajos, Kéki Sándor
University Politehnica Timisoara, Faculty of Industrial Chemistry and Environmental Engineering, Biocatalysis Group, C. Telbisz 6, 300001 Timisoara, Romania.
Faculty of Civil Engineering, Hydrotechnical Department, Politehnica University of Timisoara, Victoriei Sq. 2, 30006 Timisoara, Romania.
Polymers (Basel). 2019 Aug 26;11(9):1402. doi: 10.3390/polym11091402.
Following the latest developments, bio-based polyesters, obtained from renewable raw materials, mainly carbohydrates, can be competitive for the fossil-based equivalents in various industries. In particular, the furan containing monomers are valuable alternatives for the synthesis of various new biomaterials, applicable in food additive, pharmaceutical and medical field. The utilization of lipases as biocatalysts for the synthesis of such polymeric compounds can overcome the disadvantages of high temperatures and metal catalysts, used by the chemical route. In this work, the enzymatic synthesis of new copolymers of ε-caprolactone and 5-hydroxymethyl-2-furancarboxylic acid has been investigated, using commercially available immobilized lipases from B. The reactions were carried out in solvent-less systems, at temperatures up to 80 °C. The structural analysis by MALDI TOF-MS, NMR, and FT-IR spectroscopy confirmed the formation of cyclic and linear oligoesters, with maximal polymerization degree of 24 and narrow molecular weight distribution (dispersity about 1.1). The operational stability of the biocatalyst was explored during several reuses, while thermal analysis (TG and DSC) indicated a lower thermal stability and higher melting point of the new products, compared to the poly(ε-caprolactone) homopolymer. The presence of the heterocyclic structure in the polymeric chain has promoted both the lipase-catalyzed degradation and the microbial degradation. Although, poly(ε-caprolactone) is a valuable biocompatible polymer with important therapeutic applications, some drawbacks such as low hydrophilicity, low melting point, and relatively slow biodegradability impeded its extensive utilization. In this regard the newly synthesized furan-based oligoesters could represent a "green" improvement route.
随着最新进展，由可再生原料（主要是碳水化合物）制得的生物基聚酯在各个行业中可与化石基同类产品竞争。特别是，含呋喃的单体是合成各种新型生物材料的有价值替代品，适用于食品添加剂、制药和医疗领域。利用脂肪酶作为生物催化剂合成此类聚合物化合物可克服化学路线中使用的高温和金属催化剂的缺点。在这项工作中，研究了使用来自B.的市售固定化脂肪酶酶促合成ε-己内酯和5-羟甲基-2-呋喃羧酸的新型共聚物。反应在无溶剂体系中进行，温度高达80°C。通过基质辅助激光解吸电离飞行时间质谱（MALDI TOF-MS）、核磁共振（NMR）和傅里叶变换红外光谱（FT-IR）进行的结构分析证实了环状和线性低聚酯的形成，最大聚合度为24，分子量分布窄（分散度约为1.1）。在多次重复使用过程中探索了生物催化剂的操作稳定性，而热分析（TG和DSC）表明，与聚（ε-己内酯）均聚物相比，新产品的热稳定性较低且熔点较高。聚合物链中杂环结构的存在促进了脂肪酶催化的降解和微生物降解。尽管聚（ε-己内酯）是一种具有重要治疗应用的有价值的生物相容性聚合物，但一些缺点，如低亲水性、低熔点和相对较慢的生物降解性，阻碍了其广泛应用。在这方面，新合成的基于呋喃的低聚酯可能代表一条“绿色”改进路线。
