Abstract It is challenging to fabricate a starch derivative with a plasticizing effect and good dispersion in a poly(lactic acid) matrix to achieve desirable performance. In this study, self-suspended starch fluids composed of modified granules as the core and polyethylene glycol-substituted tertiary amines as the shell were first fabricated via a combined carboxymethylation and acylation reaction. The as-prepared starch fluids exhibited liquid-like behavior and had semiconductor electric conductivity (4.91 × 10−5 S/cm) at room temperature without a solvent. The modulus of starch fluids was clearly reduced under the heating process and exhibited its initial flow properties upon cooling, displaying thermo-reversible behavior. The resultant fluids were then incorporated into a poly(lactic acid) matrix to produce fully biodegradable composites with desirable performance. At a loading level of 10 wt%, starch fluids exhibited simultaneous enhancements in elongation at break (increase of 164.7%) and thermal conductivity (increase of 119%) of PLA composites compared to pure PLA, attributable to the good dispersion and heat-transfer properties of starch fluids. In addition, PLA composites with 10 wt% loading of starch fluids demonstrated excellent antistatic performance (3.08 × 10−4 S/cm), suggesting that polar groups of the PLA structure and PEG groups of starch fluids contributed synergistically to the electrical conductivities of composites. These results indicate that starch fluids are promising antistatic agents and plasticizers for potential applications in biodegradable materials.

中文翻译：

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自悬浮淀粉流体同时优化聚乳酸复合材料的韧性、导电性和导热性

摘要 在聚乳酸基体中制备具有增塑效果和良好分散性的淀粉衍生物以达到理想的性能具有挑战性。本研究首先通过羧甲基化和酰化反应合成了以改性颗粒为核、聚乙二醇取代叔胺为壳的自悬浮淀粉流体。制备的淀粉流体在室温下无溶剂时表现出类似液体的行为，并具有半导体电导率 (4.91 × 10-5 S/cm)。淀粉流体的模量在加热过程中明显降低，并在冷却时表现出其初始流动特性，表现出热可逆行为。然后将所得流体掺入聚（乳酸）基质中，以生产具有理想性能的完全可生物降解的复合材料。在 10 wt% 的负载水平下，与纯 PLA 相比，淀粉流体在断裂伸长率（增加 164.7%）和热导率（增加 119%）方面表现出同时增强，这归因于良好的分散性和传热性淀粉流体的性质。此外，淀粉液负载量为 10 wt% 的 PLA 复合材料表现出优异的抗静电性能（3.08 × 10−4 S/cm），表明 PLA 结构的极性基团和淀粉液的 PEG 基团对复合材料的导电性有协同作用.