The Thermal Properties and Degradability of Chiral Polyester-Imides Based on Several l/d-Amino Acids.

Chen Qi,Wenke Yang,Jinshui Yao,Fuyan He

doi:10.3390/polym12092053

Chen Qi, Wenke Yang + Show 2 more

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https://doi.org/10.3390/polym12092053

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Abstract

Eight kinds of chiral diacid monomers were prepared with amino acids with different side groups or configurations. Polyester-imides (PEIs) were synthesized from these diacid monomers and diphenol monomers through polycondensation reaction, and the performances and properties were compared with the chiral polyamide-imides (PAIs) previously synthesized by our work group. Their thermal properties were analyzed by thermo gravimetric analysis (TGA) and dynamic thermomechanical analysis (DMA), and it was found that the glass transition temperature (Tg) of PEI was mainly affected by the volume of side groups. Their degradability was studied through buffer degradation experiments, and the changes in their water contact angle, molecular weight, structure and appearance during the degradation process were characterized by contact angle tester, gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). With degradation, the hydrophilicity of PEI was improved, and when amino acids with larger side groups or D configuration were introduced into the backbone of PEI, the degradability decreased.

Highlights

In recent years, polymer materials have been widely used in various fields of our production and life, and have become an indispensable part of our lives
The structures of diacid monomers and PEIs were determined by Fourier transform infrared spectroscopy (FTIR) and 1 H NMR
The specific absorption peaks at 1776 and 1724 cm−1 correspond to the asymmetric stretching vibration and symmetric stretching vibration of carbonyl (C=O) on the imide ring, while the stretching vibration of C=O on the ester bond appears at 1660 cm−1

Summary

Introduction

Polymer materials have been widely used in various fields of our production and life, and have become an indispensable part of our lives. The shortcomings of polymer materials, which are difficult to degrade and can cause pollution, have caused great harm to the ecological environment [1,2,3,4,5,6,7,8]. Polyester is the most concerned material in the field of degradation, such as polylactide (PLA), while its brittleness and poor heat resistance limit its development [15,16]. Polyester-imides (PEIs) obtained by incorporating imide bond and ester bond into the polymer concurrently can overcome their shortcomings, and the introduction of amino acids improves its biocompatibility [17,18,19]

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