Abstract In this paper, a lactic acid (LA) aqueous solution and a mixed acid (MA) aqueous solution, composed of lactic acid and hydrochloric acid (HCl), were used as plasticizers to plasticize thermoplastic chitosan. The plasticizing behavior of chit-osan under melt processing with different concentrations of the LA and MA solutions and different ratios of HCl and LA were studied. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) indicated that the acidity and concentration of the ac-id solution had direct impacts on the chitosan structure. The thermal melting effect o-f chitosan was improved with increasing lactic acid concentration in the LA solutio-n and HCl concentration in MA solution. The sheet light transmission, hydrophobicit-y, thermal stability and mechanical properties of thermoplastic chitosan could be adj-usted by changing the ratios of hydrochloric acid and lactic acid in the MA solutio-n. This work expanded the theoretical knowledge of acid solution modified thermopla-stic chitosan.

中文翻译：

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乳酸及混酸水溶液对热塑性壳聚糖制备、结构和性能的影响

摘要 本文以乳酸（LA）水溶液和由乳酸和盐酸（HCl）组成的混合酸（MA）水溶液作为增塑剂对热塑性壳聚糖进行增塑。研究了壳聚糖在不同浓度的 LA 和 MA 溶液以及不同的 HCl 和 LA 比例下熔融加工的塑化行为。扫描电子显微镜 (SEM) 和 X 射线衍射 (XRD) 表明酸溶液的酸度和浓度对壳聚糖结构有直接影响。随着LA溶液中乳酸浓度和MA溶液中HCl浓度的增加，壳聚糖的热熔作用得到改善。薄片透光率、疏水性、热塑性壳聚糖的热稳定性和机械性能可以通过改变MA溶液中盐酸和乳酸的比例来调节。这项工作扩展了酸溶液改性热塑性壳聚糖的理论知识。