MICROWAVE ASSISTED LACTIDE-GLYCOLIDE HOMO AND COPOLYMERIZATION INITIATED BY MAGNESIUM LACTATE

Autor: Matheus Alves Coelho, Marcos L. Dias
Jazyk: English<br />Spanish; Castilian<br />Portuguese
Rok vydání: 2024
Předmět:
Zdroj: Química Nova, Vol 47, Iss 8 (2024)
Druh dokumentu: article
ISSN: 1678-7064
0100-4042
DOI: 10.21577/0100-4042.20240037
Popis: In this work, microwave-assisted ring opening polymerization (ROP) of lactide (LA) and glycolide (GA) initiated by magnesium lactate was investigated. The influence of microwave power, temperature, and reaction time on homopolymers and copolymer’s structure and thermal properties is discussed. Polymerization of L-lactide (LLA) initiated by the magnesium compound resulted in yields up to 78% and poly(L-lactic acid) (PLLA) with average molar mass of up to 30,600 g mol−1. Homopolymerization of glycolide generate poly(glycolic acid) (PGA) in yields up to 90% and in L-lactide/glycolide copolymerizations yields between 34-82%. PLLA prepared with the initiator presented microstructure with significant amount of stereo errors as the result of a racemization process during polymerization as well as low glass transition temperature (Tg) and melting temperature (Tm), while the PGAs presented high Tg, due to high crystallinity, and Tm in accordance with the literature. LLA and GA copolymerization result in poly(lactic acid-co-glycolic acid) (PLGA) with composition close to polymerization feed composition.
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