Abstract This paper delves into the role plasticisers play in the formulation and processing of bioplastics and nanobiocomposites, trying to understand their effect on nanoclays dispersion and, consequently, on mechanical and gas barrier properties of protein-based nanobiocomposites. Egg white protein/montmorillonite clay nanobiocomposites were obtained by thermomechanical processing plasticised with varying molar concentration of different components (water, glycerol, polyethylene glycol). The extent of dispersion of the filler was evaluated by X-ray diffraction and transmission electron microscopy. Tensile tests and solid-state rheological measurements were conducted to evaluate glass transition temperature and thermomechanical behaviour of plasticised protein-clay nanobiocomposites, whereas gas permeability tests were used to study their gas barrier properties. The results showed that the samples plasticised by a blend of 1:1 glycerol/water presented the most exfoliated structures, resulting in an improvement in gas barrier and mechanical properties. Morphological analyses combined with tensile and permeability tests have shown a lesser effect of polyethylene glycol of 300 molecular weight (PEG 300) on the exfoliation extent into such nanobiocomposites. Moreover, the larger size of PEG 300 does not allow the formation of a structure as compact as in the case of water and glycerol, as a consequence of an apparent phase separation, leaving more spaces that facilitate the diffusion of gases through the material.

中文翻译：

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增塑剂对蛋白基纳米生物复合材料形态、力学性能和渗透性的影响

摘要 本文深入研究了增塑剂在生物塑料和纳米生物复合材料的配制和加工中的作用，试图了解它们对纳米粘土分散的影响，进而对基于蛋白质的纳米生物复合材料的机械和气体阻隔性能的影响。蛋清蛋白/蒙脱石粘土纳米复合材料是通过热机械加工获得的，用不同摩尔浓度的不同组分（水、甘油、聚乙二醇）塑化。通过 X 射线衍射和透射电子显微镜评估填料的分散程度。进行了拉伸测试和固态流变测量，以评估增塑蛋白质粘土纳米生物复合材料的玻璃化转变温度和热机械行为，而气体渗透性测试用于研究它们的气体阻隔性能。结果表明，由 1:1 甘油/水的混合物增塑的样品呈现出最多的剥离结构，从而提高了气体阻隔性和机械性能。结合拉伸和渗透性测试的形态学分析表明，300 分子量的聚乙二醇 (PEG 300) 对这种纳米生物复合材料的剥离程度影响较小。此外，较大尺寸的 PEG 300 不允许形成像水和甘油一样紧凑的结构，这是明显相分离的结果，留下更多空间促进气体通过材料扩散。1 甘油/水呈现出最易剥落的结构，从而提高了气体阻隔性和机械性能。结合拉伸和渗透性测试的形态学分析表明，300 分子量的聚乙二醇 (PEG 300) 对这种纳米生物复合材料的剥离程度影响较小。此外，较大尺寸的 PEG 300 不允许形成像水和甘油一样紧凑的结构，这是明显相分离的结果，留下更多空间促进气体通过材料扩散。1 甘油/水呈现出最易剥落的结构，从而提高了气体阻隔性和机械性能。结合拉伸和渗透性测试的形态学分析表明，300 分子量的聚乙二醇 (PEG 300) 对这种纳米生物复合材料的剥离程度影响较小。此外，较大尺寸的 PEG 300 不允许形成像水和甘油一样紧凑的结构，这是明显相分离的结果，留下更多空间促进气体通过材料扩散。结合拉伸和渗透性测试的形态学分析表明，300 分子量的聚乙二醇 (PEG 300) 对这种纳米生物复合材料的剥离程度影响较小。此外，较大尺寸的 PEG 300 不允许形成像水和甘油一样紧凑的结构，这是明显相分离的结果，留下更多空间促进气体通过材料扩散。结合拉伸和渗透性测试的形态学分析表明，300 分子量的聚乙二醇 (PEG 300) 对这种纳米生物复合材料的剥离程度影响较小。此外，较大尺寸的 PEG 300 不允许形成像水和甘油一样紧凑的结构，这是明显相分离的结果，留下更多空间促进气体通过材料扩散。