A sustainable process to 100% bio-based nylons integrated chemical and biological conversion of lignocellulose
Ruijia Hu, Ming Li, Tao Shen, Xin Wang, Zhuohua Sun, Xinning Bao, Kequan Chen, Kai Guo, Lei Ji, Hanjie Ying, Pingkai Ouyang, Chenjie Zhu
Abstract
Considerable progress has been made in recent years to the development of sustainable polymers from bio-based feedstocks. In this study, 100% bio-based nylons were prepared via an integrated chemical and biological process from lignocellulose. These novel nylons were obtained by the melt polymerization of 3-propyladipic acid derived from lignin and 1,5-pentenediamine/1,4-butanediamine derived from carbohydrate sugar. Central to the concept is a three-step noble metal free catalytic chemical funnelling sequence (Raney Ni mediated reductive catalytic fractionation - reductive funnelling - oxidative funnelling), which allowed for obtaining a single component 3-propyladipic acid from lignin with high efficiency. The structural and thermodynamic properties of the obtained nylons have been systematically investigated, and thus obtained transparent bio-based nylons exhibited higher Mw (>32,000) and excellent thermal stability (Td5% > 265 °C). Considering their moderate Tg and good melt strength, these transparent bio-based nylons could serve as promising functional additives or temperature-responsive materials.