In this study, polylactic acid (PLA) films with different nano‐ZnO concentration (0, 1, 3, 5, 7, 9, and 15%wt) were obtained by casting method. Overall migration values and specific migration values were studied in different food simulants (10% [v/v] ethanol and isooctane). The results demonstrated that overall migration of the composite films and specific migration of Zn²⁺ was higher in 10% (v/v) ethanol solution than in isooctane solution. The release of Zn²⁺ was affected by the percentage of nano‐ZnO in the composite films and food simulants. The migration of Zn in this study was mainly caused by polymer softening and degradation leading to the dissolution of Zn. Scanning electron microscope analysis indicated that with the migration of Zn²⁺, the structure of the composite films changed greatly. Differential scanning calorimeter analysis indicated that the thermal stability was decreased and the glass transition temperature and crystallization temperature were reduced.

中文翻译：

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Zn迁移过程中纳米ZnO /聚乳酸复合薄膜的热性能和微观结构的变化

在这项研究中，通过流延方法获得了具有不同纳米ZnO浓度（0、1、3、5、7、9和15％wt）的聚乳酸（PLA）膜。在不同的食物模拟物（10％[ v / v]乙醇和异辛烷）中研究了总迁移值和特定迁移值。结果表明，在10％（v / v）乙醇溶液中，复合膜的整体迁移和Zn ^2+的比迁移均高于异辛烷溶液。Zn ²⁺的释放受复合膜和食品模拟物中纳米ZnO百分比的影响。锌的迁移主要是由于聚合物的软化和降解导致锌的溶解。扫描电子显微镜分析表明，随着Zn ²⁺的迁移，复合膜的结构发生了很大变化。差示扫描量热仪分析表明，热稳定性降低，玻璃化转变温度和结晶温度降低。