A Novel Functional Compatibilization Strategy for Poly(lactic acid) and Poly(butylene adipate-co-butylene terephthalate) Blends to Achieve a Stable Co-continuous Structure and Excellent Antibacterial Performance

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2024-02, Vol.482, p.149169, Article 149169
• Main Authors: Sun, Lei, Long, Yang, Peng, Tingyan, Xie, Xiaowen, Meng, Xianglei, Chew, Khian-Hooi, Zhang, Zhijun, Dai, Zhifeng, Pan, Qiangbiao, Xiong, Yubing
• Format: Article
• Language: English
• Subjects: Co-continuous structure; Compatibility; Imidazolium ionic liquid; Poly(butylene adipate-co-butylene terephthalate); Poly(lactic acid)
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2024.149169

A novel functional compatibilization strategy for poly(lactic acid) (PLA)/poly(butylene adipate-co-butylene terephthalate) (PBAT) was developed by combining reactive maleic anhydride segments with imidazolium cations. The results revealed that the PSM-R compatibilizer with the longest alkyl chains was more efficient for compatibilization, which was ascribed to the formation of a stable co-continuous structure in the matrix. Moreover, the PLA/PBAT blends exhibited excellent antibacterial properties against both gram-positive and gram-negative bacteria. [Display omitted] •A novel functional compatibilization strategy for PLA/PBAT blend was developed.•PSM-R with longer alkyl chain compatibilized the PLA/PBAT blends more efficiently.•A stable co-continuous structure was produced in PLA/PBAT blends using PSM-R.•PLA/PBAT blends exhibited excellent antibacterial performance. Blends of poly(lactic acid) (PLA) and poly(butylene adipate-co-butylene terephthalate) (PBAT) are currently the most widely studied biodegradable blends and have great potential to replace conventional polyolefin and polyester materials. However, PLA/PBAT blends still face the challenges of poor compatibility and antibacterial performance in the practice applications. In this study, antibacterial functional PLA/PBAT blends were fabricated using an alternative copolymer (PSM-D) composed of reactive maleic anhydride segments and imidazolium cations. The results revealed that PSM-D, with long alkyl chains, improved the compatibility, antibacterial properties, and mechanical properties of the PLA/PBAT blends. Under the optimized conditions, the elongation at break of PLA/PBAT blends was increased by 750%. Detailed analysis demonstrated that these outstanding improvements could be ascribed to the formation of a stable co-continuous structure in the PLA/PBAT matrix. Furthermore, the PLA/PBAT blends exhibited excellent antibacterial properties against both gram-positive Staphylococcus aureus and gram-negative Escherichia coli, which was attributed to the presence of imidazolium cations with long alkyl chains. This study provides a new “two-in-one” platform for fabricating functional compatibilization strategies for biodegradable polymer blends and is expected to have broad implications and practical relevance for packaging and medical devices.