Ministry of Education Engineering Research Center of Starch & Protein Processing, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, College of Light Industry and Food Sciences, South China University of Technology, Guangzhou 510640, China; College of Chemistry and Environmental Engineering, Dongguan University of Technology, Dong Guan, 523808, China.
Ministry of Education Engineering Research Center of Starch & Protein Processing, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, College of Light Industry and Food Sciences, South China University of Technology, Guangzhou 510640, China.
Carbohydr Polym. 2014 Apr 15;104:1-7. doi: 10.1016/j.carbpol.2013.12.087. Epub 2014 Jan 8.
This work studied the structural changes and the migration of triacetin plasticizer in starch acetate films in the presence of distilled water as food simulant. Fourier-transform infrared spectroscopy result showed that the macromolecular interaction was enhanced to form compact aggregation of amorphous chains. The characterization of aggregation structures via wide and small angle X-ray scattering techniques indicated that the orderly microregion was compressed and the crystallites inside were "squeezed" to form interference and further aggregation. The compact aggregation structures restricted the mobility of macromolecules, triacetin and water molecules. The overall kinetic and the diffusion model analysis manifested that Fick's second law was the predominant mechanism for the short-term migration of triacetin. The increasing relaxation within film matrix caused the subsequent migration to deviate from Fick's law. The safe and reasonable application of the starch-based materials with restrained plasticizer migration could be accomplished by controlling the molecular interaction and aggregation structures.
本工作研究了在作为食品模拟物的蒸馏水存在下，醋酸淀粉薄膜中三醋酸甘油酯增塑剂的结构变化和迁移。傅里叶变换红外光谱结果表明，通过高分子间相互作用形成了无定形链的紧密聚集。广角和小角 X 射线散射技术对聚集结构的表征表明，有序微区被压缩，内部晶区被“挤压”形成干涉并进一步聚集。紧密的聚集结构限制了高分子、三醋酸甘油酯和水分子的迁移能力。整体动力学和扩散模型分析表明，菲克第二定律是三醋酸甘油酯短期迁移的主要机制。薄膜基质内不断增加的弛豫导致随后的迁移偏离菲克定律。通过控制分子相互作用和聚集结构，可以实现对具有受限制增塑剂迁移的淀粉基材料的安全合理应用。
