Plant Fiber Materials Research Center, State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640, China.
Guangdong Provincial Key Laboratory of Plant Resources Biorefinery, Guangzhou 510006, China.
Molecules. 2023 Jun 9;28(12):4667. doi: 10.3390/molecules28124667.
Polylactide (PLA) has become a popular alternative for petroleum-based plastics to reduce environmental pollution. The broader application of PLA is hampered by its brittle nature and incompatibility with the reinforcement phase. The aim of our work was to improve the ductility and compatibility of PLA composite film and investigate the mechanism by which nanocellulose enhances PLA polymer. Here, we present a robust PLA/nanocellulose hybrid film. Two different allomorphic cellulose nanocrystals (CNC-I and CNC-III) and their acetylated products (ACNC-I and ACNC-III) were used to realize better compatibility and mechanical performance in a hydrophobic PLA matrix. The tensile stress of the composite films with 3% ACNC-I and ACNC-III increased by 41.55% and 27.22% compared to pure PLA film, respectively. Compared to the CNC-I or CNC-III enhanced PLA composite films, the tensile stress of the films increased by 45.05% with 1% ACNC-I and 56.15% with 1% ACNC-III. In addition, PLA composite films with ACNCs showed better ductility and compatibility because the composite fracture gradually transitioned to a ductile fracture during the stretching process. As a result, ACNC-I and ACNC-III were found to be excellent reinforcing agents for the enhancement of the properties of polylactide composite film, and the replacement some petrochemical plastics with PLA composites would be very promising in actual life.
聚乳酸（PLA）已成为减少环境污染的石油基塑料的热门替代品。但其脆性和与增强相的不兼容性限制了 PLA 的更广泛应用。我们的工作旨在提高 PLA 复合膜的延展性和相容性，并研究纳米纤维素增强 PLA 聚合物的机制。在这里，我们提出了一种坚固的 PLA/纳米纤维素混合膜。使用两种不同形态的纤维素纳米晶体（CNC-I 和 CNC-III）及其乙酰化产物（ACNC-I 和 ACNC-III），以实现疏水性 PLA 基质中更好的相容性和机械性能。与纯 PLA 薄膜相比，复合薄膜中添加 3% ACNC-I 和 ACNC-III 时，拉伸应力分别提高了 41.55%和 27.22%。与 CNC-I 或 CNC-III 增强的 PLA 复合薄膜相比，添加 1% ACNC-I 和 56.15% ACNC-III 时，薄膜的拉伸应力分别提高了 45.05%和 56.15%。此外，添加 ACNC 的 PLA 复合薄膜具有更好的延展性和相容性，因为在拉伸过程中复合断裂逐渐转变为韧性断裂。因此，ACNC-I 和 ACNC-III 被发现是增强聚乳酸复合薄膜性能的优秀增强剂，用 PLA 复合材料替代一些石化塑料在实际生活中具有广阔的前景。
