Abstract The present manuscript focuses on the effect of pH on the thermomechanical and water uptake properties of plasma protein-based bioplastics. Therefore, pH was modified through addition of either an acid or a base and subsequent freeze drying. Flours obtained were then blended with a plasticizer (glycerol) in a 1/1 ratio, and next injection-moulded to produce diverse bioplastics. A different behaviour of the eventual bioplastics depending on the pH was observed. Thus, the poorest mechanical properties and the maximum water uptake capacity were displayed by the sample prepared at the most acidic conditions (pH 3). On the other hand, the lowest water uptake was found at the isoelectric point (IEP: 5), being related to the hindering of electrostatic interactions due to the absence of net charges. The microstructure observed after swelling and freeze-drying helped to explain the greater mechanical properties displayed by the sample at pH 8 compared to pH 3.

中文翻译：

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pH值对猪血浆基超吸水材料性能的影响

摘要 本手稿重点研究 pH 值对基于血浆蛋白的生物塑料的热机械和吸水性能的影响。因此，通过添加酸或碱以及随后的冷冻干燥来改变 pH。然后将获得的面粉与增塑剂（甘油）以 1/1 的比例混合，然后注射成型以生产各种生物塑料。观察到最终生物塑料的不同行为取决于 pH 值。因此，在最酸性条件 (pH 3) 下制备的样品显示出最差的机械性能和最大的吸水能力。另一方面，在等电点（IEP：5）处发现最低吸水量，这与由于没有净电荷而阻碍静电相互作用有关。