Di Bisceglie Federico, Quartinello Felice, Vielnascher Robert, Guebitz Georg M, Pellis Alessandro
Department of Agrobiotechnology, University of Natural Resources and Life Sciences Vienna, 3430 Tulln an der Donau, Austria.
Austrian Centre of Industrial Biotechnology, 3430 Tulln an der Donau, Austria.
Polymers (Basel). 2022 Jan 20;14(3):411. doi: 10.3390/polym14030411.
Polyurethanes (PU) are one of the most-used classes of synthetic polymers in Europe, having a considerable impact on the plastic waste management in the European Union. Therefore, they represent a major challenge for the recycling industry, which requires environmentally friendly strategies to be able to re-utilize their monomers without applying hazardous and polluting substances in the process. In this work, enzymatic hydrolysis of a polyurethane-polyester (PU-PE) copolymer using cutinase (HiC) has been investigated in order to achieve decomposition at milder conditions and avoiding harsh chemicals. PU-PE films have been incubated with the enzyme at 50 °C for 168 h, and hydrolysis has been followed throughout the incubation. HiC effectively hydrolysed the polymer, reducing the number average molecular weight (M) and the weight average molecular weight (M) by 84% and 42%, respectively, as shown by gel permeation chromatography (GPC), while scanning electron microscopy showed cracks at the surface of the PU-PE films as a result of enzymatic surface erosion. Furthermore, Fourier Transform Infrared (FTIR) analysis showed a reduction in the peaks at 1725 cm, 1164 cm and 1139 cm, indicating that the enzyme preferentially hydrolysed ester bonds, as also supported by the nuclear magnetic resonance spectroscopy (NMR) results. Liquid chromatography time-of-flight/mass spectrometry (LC-MS-Tof) analysis revealed the presence in the incubation supernatant of all of the monomeric constituents of the polymer, thus suggesting that the enzyme was able to hydrolyse both the ester and the urethane bonds of the polymer.
聚氨酯（PU）是欧洲使用最广泛的合成聚合物类别之一，对欧盟的塑料废物管理产生了相当大的影响。因此，它们对回收行业构成了重大挑战，回收行业需要采用环保策略，以便在不使用危险和污染性物质的情况下重新利用其单体。在这项工作中，研究了使用角质酶（HiC）对聚氨酯 - 聚酯（PU - PE）共聚物进行酶促水解，以在较温和的条件下实现分解并避免使用苛刻的化学物质。将PU - PE薄膜与该酶在50°C下孵育168小时，并在整个孵育过程中跟踪水解情况。如凝胶渗透色谱（GPC）所示，HiC有效地水解了聚合物，使数均分子量（M）和重均分子量（M）分别降低了84%和42%，而扫描电子显微镜显示PU - PE薄膜表面由于酶促表面侵蚀而出现裂缝。此外，傅里叶变换红外（FTIR）分析表明，在1725 cm、1164 cm和1139 cm处的峰减少，表明该酶优先水解酯键，核磁共振光谱（NMR）结果也支持这一点。液相色谱飞行时间/质谱（LC - MS - Tof）分析表明，在孵育上清液中存在聚合物的所有单体成分，因此表明该酶能够水解聚合物的酯键和脲键。
