A paradigm for the efficient synthesis of bio-based polycarbonate with deep eutectic solvents as catalysts by inhibiting the degradation of molecular chains. Issue 11 (19th May 2021)

• Record Type: Journal Article
• Authors: Wang, Weiwei; Yang, Zifeng; Zhang, Yaqin; He, Hongyan; Fang, Wenjuan; Zhang, Zhencai; Xu, Fei
• Is Part Of: Green chemistry. Volume 23:Issue 11(2021)
• Page Start: 4134
• Page End: 4143
• Publication Date: 2021-05-19
• Subjects: Environmental chemistry -- Industrial applications -- Periodicals; Environmental management -- Periodicals; 660
• DOI: 10.1039/d1gc01150b
• Languages: English
• ISSNs: 1463-9262

Abstract

Abstract : A catalytic system composed of deep eutectic solvents (DESs) with adjustable pH was developed for the efficient synthesis of poly(isosorbide) carbonate with high molecular weight by inhibiting the depolymerization of macromolecular chains. Abstract : In this study, an efficient catalytic system composed of deep eutectic solvents (DESs) was developed by adjusting the basicity of hydrogen bond donors (HBDs) to synthesize poly(isosorbide) carbonate (PIC) with high weight average molecular weight ( M w ). It was demonstrated that the M w of PIC prepared by using nearly neutral [EminOH]Cl–2EG was the highest. The results of the transesterification kinetics with different catalysts supported that the transesterification rate was significantly promoted as the basicity of DESs increased but their strong alkalinity inhibited the M w of PIC. Therefore, the degradation of PIC was investigated to reveal the mechanism of the influence of basicity on the molecular weight of PIC. The strong alkalinity of DESs would cause the depolymerization of the macromolecular chains and ultimately limit the molecular weight of the product, proving the experimental fact that a near-neutral catalyst was more conducive to the M w of PIC. Finally, a reasonable mechanism of synergistic catalysis was proposed based on 1 H NMR spectroscopy, Fourier transform infrared spectroscopy (FT-IR) and experimental results. The metal-free, low-cost, high catalytic activity DES catalyst involved here is a practical candidate for advanced bio-based polycarbonate.