Enhanced biodegradable copolymers: Synthesis and characterization of high molecular weight poly(L‐lactide‐r‐ε‐caprolactone)

• Published in: Polymer engineering and science Vol. 65; no. 3; pp. 1242 - 1254
• Main Authors: Dongyang, Liu, Qi, Xia, Wuyou, Ye, Shinuo, Zhang, Wenjie, Yu, Zhengzhe, Zhou, Zhongyong, Fan
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.03.2025; Society of Plastics Engineers, Inc; Blackwell Publishing Ltd
• Subjects: Biocompatibility; biodegradable; Biomedical materials; Chemical composition; Chemical synthesis; Copolymerization; Copolymers; Data analysis; Glass transition temperature; High vacuum; L‐lcatide; Mechanical properties; Melt temperature; Molecular weight; NMR; Nuclear magnetic resonance; random copolymerization; Ring opening polymerization; sequence structure; Tensile strength; ε‐Caprolactone
• ISSN: 0032-3888; 1548-2634
• DOI: 10.1002/pen.27072

Semi‐crystalline poly(L‐lactide‐r‐ε‐caprolactone) (P(LLA‐r‐ε‐CL)) as an important biodegradable material applied in biomedical devices has attracted much attention from researchers. A series of high molecular weight P(LLA‐r‐ε‐CL) semi‐crystalline copolymers attached with various monomer molar ratio of L‐lactide (LLA) and ε‐caprolactone (ε‐CL) with M¯w up to 2.9 × 105 g/mol were synthesized first time by ring‐opening copolymerization under high vacuum condition. The chemical composition, chain sequence microstructure and their relationship of P(LLA‐r‐ε‐CL) were characterized by 1H NMR and 13C NMR. Spectra results shown that as the ε‐CL content increased from 3 mol% to 15 mol%, the average LLA sequence length decreased from 80.4 to 19.6 units. With decrease of LLA sequence length, the glass transition temperature (Tg), melting temperature(Tm) and the crystallinity (χc) of copolymers had a reduction. Meantime, it resulted in a high degradation rate of samples in enzyme‐catalyzed condition. With loss of rigid crystal and plasticization from soft ε‐CL segment, P(LLA‐r‐ε‐CL) had an improved toughness as the elongation at break reaching 195.5%, while still had a considerable tensile strength of 49.2 MPa. Further data analysis exhibited an exponential relationship between LLA sequence length and mechanical performance. Additionally, biocompatibility assessments through CCK‐8 and Live/Dead cell assays confirmed the good cytocompatibility of the enhanced biomedical materials. Semi‐crystalline P(LLA‐r‐ε‐CL) with high toughness.