PDF(Pubmed)
Abstract：
High-molecular-weight poly(L-lactide)-b-poly(ethylene glycol)-b-poly(L-lactide) (PLLA-PEG-PLLA) is a flexible and biodegradable bioplastic that has promising potential in flexible food packaging but it has no antibacterial ability. Thus, in this work, the effect of zinc oxide nanoparticles (nano-ZnOs) which have antimicrobial activity on various properties of PLLA-PEG-PLLA was determined. The addition of nano-ZnOs enhanced the crystallization, tensile, UV-barrier, and antibacterial properties of PLLA-PEG-PLLA. However, the crystallization and tensile properties of nanocomposite films decreased again as the nano-ZnO increased beyond 2 wt%. The nano-ZnO was well distributed in the PLLA-PEG-PLLA matrix when the nano-ZnO content did not exceed 2 wt% and exhibited some nano-ZnO agglomerates when the nano-ZnO content was higher than 2 wt%. The thermal stability and moisture uptake of the PLLA-PEG-PLLA matrix decreased and the film\'s opacity increased as the nano-ZnO content increased. The PLLA-PEG-PLLA/ZnO nanocomposite films showed good antibacterial activity against bacteria such as Escherichia coli and Staphylococcus aureus. It can be concluded that nano-ZnOs can be used as a multi-functional filler of the flexible PLLA-PEG-PLLA. As a result, the addition of nano-ZnOs as a nucleating, reinforcing, UV-screening, and antibacterial agent in the flexible PLLA-PEG-PLLA matrix may provide protection for both the food and the packaging during transportation and storage.
摘要：
高分子量聚（L-丙交酯）-b-聚（乙二醇）-b-聚（L-丙交酯）（PLLA-PEG-PLLA）是一种柔性且可生物降解的生物塑料，在柔性食品包装中具有广阔的潜力，但没有抗菌能力。因此，在这项工作中，测定了具有抗菌活性的氧化锌纳米颗粒(纳米ZnOs)对PLLA-PEG-PLLA各种性能的影响。纳米ZnOs的加入增强了结晶，拉伸,紫外线屏障，和抗菌性能的PLLA-PEG-PLLA。然而,随着纳米ZnO含量超过2wt％，纳米复合薄膜的结晶和拉伸性能再次下降。当纳米ZnO含量不超过2wt％时，纳米ZnO在PLLA-PEG-PLLA基质中分布良好，当纳米ZnO含量高于2wt％时，表现出一些纳米ZnO团聚体。随着纳米ZnO含量的增加，PLLA-PEG-PLLA基质的热稳定性和吸湿性降低，薄膜的不透明性增加。PLLA-PEG-PLLA/ZnO纳米复合薄膜对大肠杆菌和金黄色葡萄球菌等细菌表现出良好的抗菌活性。可以得出结论，纳米ZnOs可以用作柔性PLLA-PEG-PLLA的多功能填料。因此,添加纳米ZnOs作为成核剂，加强，紫外线屏蔽，柔性PLLA-PEG-PLLA基质中的抗菌剂可以在运输和储存期间为食品和包装提供保护。
