College of Food Science and Engineering, Shandong Agricultural University, Engineering and Technology Center for Grain Processing of Shandong Province, Taian, P.R. China.
J Sci Food Agric. 2023 Aug 15;103(10):4966-4974. doi: 10.1002/jsfa.12569. Epub 2023 Apr 7.
Poor mechanical and water barrier properties of starch-based films severely restrict their applications as packaging materials. In this study, glycerol was combined with various small molecular esters (SMEs) with different molecular structures to plasticize high-content starch/poly(butylene adipate-co-terephthalate) (80/20, w/w) films (SPFs) prepared by extrusion blowing. The effects of co-plasticization on the physicochemical properties and film-forming mechanism of SPFs were investigated.
The addition of glycerides to SPFs reduced intermolecular interaction, increased molecular chain mobility, and decreased glass transition, melting temperatures, and crystallinity. Mechanical and water barrier properties of SPFs were improved significantly with the co-plasticization of glycerol and SMEs. The incorporation of triacetate glyceride increased tensile strength of SPFs by 54% and the water contact angle by up to 95°. The SPF with diacetate glyceride exhibited the minimum water vapor permeability, which decreased by 39%.
The levels of hydrophilic/hydrophobic groups in SMEs and their molecular weights were essential for the plasticizing effects. Glycerides tended to infiltrate into starch for effective plasticization compared with citrates. The combination of glycerol and glycerides had better plasticizing effects on starch. © 2023 Society of Chemical Industry.
基于淀粉的薄膜机械性能和防潮性能差，严重限制了其作为包装材料的应用。在这项研究中，甘油与不同分子结构的各种小分子酯（SMEs）结合，用于增塑挤出吹塑制备的高含量淀粉/聚（己二酸丁二醇酯-co-对苯二甲酸）（80/20，w/w）薄膜（SPF）。共增塑对 SPF 的物理化学性质和成膜机制的影响进行了研究。
甘油酯的添加降低了分子间相互作用，增加了分子链的流动性，降低了玻璃化转变温度、熔融温度和结晶度。甘油和 SMEs 的共增塑显著改善了 SPF 的机械和防潮性能。三醋酸甘油酯的加入使 SPF 的拉伸强度提高了 54%，水接触角提高了 95%。二醋酸甘油酯的 SPF 表现出最低的水蒸气透过率，降低了 39%。
SMEs 中的亲水/疏水基团水平及其分子量对增塑效果至关重要。与柠檬酸盐相比，甘油酯更倾向于渗透到淀粉中进行有效增塑。甘油和甘油酯的组合对淀粉具有更好的增塑效果。© 2023 化学工业协会。
