Polylactide (PLA) exhibits various types of crystal modifications depending on the preparation conditions, including the components. To solve the open question, a reliable calculation method for crystallinity, crystal forms, and composition in neat PLA and PLA composites was developed on the basis of temperature-dependent synchrotron wide-angle X-ray diffraction results. The relative composition of amorphous, α-form, and α’-form phases of PLA and its composites filled with halloysite nanotubes during heating was successfully obtained. It was found that only 47–56% of α’-form crystals transform into α-form crystals during a 2 °C/min heating process for PLA with a molecular weight of 54,300 g/mol. The loading of halloysite nanotubes decreases the cold crystallization and starting transition (α’ crystals transform into α-form crystals) temperatures of PLA. The crystallinity and the main diffraction peak intensity as a function of temperature were also analyzed. These results suggest that the α’-to-α form transition is a solid-solid phase transition. Polylactide (PLA) exhibits various types of crystal modifications depending on the preparation conditions, including the components. To solve the open question, a reliable calculation method for crystallinity, crystal forms and composition in neat PLA and PLA composites was developed on the basis of temperature-dependent synchrotron wide-angle X-ray diffraction results. The relative composition of amorphous, α-form, and α’-form phases of PLA and its composites filled with halloysite nanotubes during heating was successfully obtained.

中文翻译：

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X射线衍射研究聚丙交酯及其复合材料的晶体多晶型

聚乳酸 (PLA) 根据制备条件（包括组分）表现出​​各种类型的晶体变体。为了解决这个悬而未决的问题，基于温度相关的同步加速器广角 X 射线衍射结果，开发了一种可靠的计算纯 PLA 和 PLA 复合材料中结晶度、晶型和组成的方法。成功获得了PLA及其填充埃洛石纳米管的复合材料在加热过程中的非晶相、α相和α'相的相对组成。结果表明，对于分子量为 54,300 g/mol 的 PLA，在 2 °C/min 的加热过程中，只有 47-56% 的 α' 型晶体转化为 α 型晶体。埃洛石纳米管的负载降低了 PLA 的冷结晶和起始转变（α' 晶体转变为 α 型晶体）温度。还分析了作为温度函数的结晶度和主衍射峰强度。这些结果表明 α' 到 α 形式的转变是一种固-固相转变。聚乳酸 (PLA) 根据制备条件（包括组分）表现出​​各种类型的晶体变体。为了解决这个悬而未决的问题，基于温度相关的同步加速器广角 X 射线衍射结果，开发了一种可靠的计算纯 PLA 和 PLA 复合材料中结晶度、晶型和组成的方法。无定形、α-形式的相对组成，