Research progress on improving thermal stability of polylactic acid based on stannous inactivation and chain end-group modification

doi:10.11949/0438-1157.20240020

Abstract

Abstract:

Polylactic acid (PLA) is the most commercially available synthetic biodegradable material at present, with good mechanical properties and excellent biocompatibility. Stannous catalysts have been widely used in the industrial production of PLA because of their high catalytic activity, low price and low racemization reaction. Although the usage of stannous catalysts is tiny, the trace residue of the catalyst still promotes the thermal degradation of PLA products, and then greatly affects the performance and service life of the products. Therefore, this paper initially reviewed the mechanism of promoting thermal degradation of PLA by stannous catalysts, and then summarized the research progress on improving the thermal stability of PLA in detail from three aspects, such as stannous ion chelation, oxidation of stannous ion and chain end-group modification. It is expected that this review can provide a guideline for extending the service life of PLA products and expanding the application range of PLA products.

Key words: polylactic acid, catalyst, deactivation, oxidation, chelation, end-group modification, heat resistance

摘要：

聚乳酸(PLA)是当前人工合成的生物可降解材料中商业化程度最高的一类，具有良好的力学性能和优异的生物相容性。由于亚锡类催化剂具有催化活性高、价格低且不易发生消旋反应等优点，被广泛应用于PLA的工业化生产。虽然亚锡类催化剂的用量较少，但催化剂的微量残留仍会促进PLA制品的热降解，极大地影响制品的性能和使用寿命。首先综述了亚锡类催化剂促进PLA热降解的机制，而后从亚锡离子的螯合、亚锡离子的氧化和链端基改性3个方面出发，详细总结了提高PLA热稳定性的研究进展，以期为扩大PLA产品的应用范围和延长PLA产品的使用寿命提供指导。

关键词: 聚乳酸, 催化剂, 失活, 氧化, 螯合, 端基改性, 耐热性能

CLC Number:

TQ 322.4

Zhiming CHEN, Zefeng WANG, Gaoqi MA, Liangbo WANG, Chengtao YU, Pengju PAN. Research progress on improving thermal stability of polylactic acid based on stannous inactivation and chain end-group modification[J]. CIESC Journal, 2024, 75(3): 760-767.

陈志明, 王泽凤, 马高琪, 王良波, 余承涛, 潘鹏举. 基于亚锡灭活及链端改性提高聚乳酸热稳定性的研究进展[J]. 化工学报, 2024, 75(3): 760-767.

Figures/Tables 5

Fig. 1 Possible mechanisms of Sn-catalyzed PLA thermal decomposition[32]

Fig. 2 Chelating agents for Sn2+ chelation

Fig. 3 Peroxides effective for oxidizing Sn2+

Fig. 4 Reaction mechanism of polycarbodiimide and PLA chain end

Fig. 5 Possible mechanism of phosphite in PLA chain extension[64]

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