文献类型：期刊文献

英文题名：The catalytic mechanism and limiting factor of polyamide hydrolysis for chemical recycling: the classic hydrolysis of polyamide 4

作者：Wang, Mingda[1,2,3];Qiu, Yongjun[1,2,3];Chen, Tao[2,3,4];Zhao, Liming[1,2,3]

机构：[1]East China Univ Sci & Technol, Sch Biotechnol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China;[2]Natl Light Ind Council, Key Lab Biobased Mat Engn China, Shanghai 200237, Peoples R China;[3]Shanghai Collaborat Innovat Ctr Biomfg Technol SCI, Shanghai 200237, Peoples R China;[4]East China Univ Sci & Technol, Sch Mat Sci & Engn, Shanghai Key Lab Adv Polymer Mat, Shanghai 200237, Peoples R China

年份：2023

卷号：30

期号：5

外文期刊名：JOURNAL OF POLYMER RESEARCH

收录：;EI(收录号：20231914080698);WOS:【SCI-EXPANDED(收录号:WOS:000983232800002)】；

基金：This work was supported by the Research and Development of Technical Standards for Bio-based Material Polybutyrolactam Project (21DZ2205900), the National Key R & D Program of China (2022YFC2104500), the 111 Project (B18022), the Fundamental Research Funds for the Central Universities (22221818014), and the Open Project Funding of the State Key Laboratory of Bioreactor Engineering, ECUST (ZDXM2019), and Shanghai Sailing Program (20YF1409900).

语种：英文

外文关键词：Polyamide 4; Chemical recycling; Chemistry hydrolysis; Molecular dynamics simulation

摘要：A series of chemical recycling methods have been developed for polyamides (PAs) for green and sustainable technologies of plastic waste. However, the study of the essential mechanism of advanced thermo-chemical recycling of PAs is still lacking. To select efficient and green catalysts, a thorough understanding of the limiting factors of PAs hydrolysis reactions is necessary. Herein, to discuss the limiting factors of hydrolysis and the catalytic mechanism of common catalysts, polyamide 4 (PA4), a green and sustainable advanced polyamide, was studied. Firstly, the hydrolysis products and the degradation mechanism of PA4 were investigated. The only product is butyrolactam. Hydrolysis is characterized by both a depolymerization mechanism and a random chain scission mechanism. Secondly, the kinetic process of hydrolysis was investigated from the perspectives of molecular weight and solid product mass ( E alpha( M-v) = 15.87kJ/mol, E alpha(R-sr,1) = 44.87kJ/mol, Ea(R-sr,2) = 89.71kJ/mol). Finally, the existence of phase separation near the polymer chains was verified both experimentally and by molecular dynamics simulations. Furthermore, the extremely high correlation (r = 0.95, p < 0.05) between the molecular diffusion rate and the hydrolysis rate under certain reaction conditions explained the catalytic mechanism of common catalysts. Compared with the proton concentration in the system, the mass transfer efficiency in polymer chain cages is a more essential restricting factor. This mechanism is available to all PAs and provides a theoretical support for the selection of green catalysts for polyamide hydrolysis, which will greatly promote the application of chemical recycling technology.