Abstract Tuned one-step melt spinning of poly (lactic acid) (PLA)/poly (butylene terephthalate) (PBT) blends containing 1–10 wt% of PBT, was carried out successfully to induce in situ nanofibrils of PBT with average diameter of 23–51.4 nm. Scanning electron microscopy (SEM) images showed the morphology of PBT nanofibrils (NFs) in the PLA matrix and it was found that the aspect ratio of PBT NFs was more than 400. The crystal morphology of the PLA melt spun fibers in the presence and absence of PBT NFs was analyzed using polarized optical microscopy. Dramatic changes in the crystal morphology of PLA were observed in the presence of PBT NFs. Scattered spherulites in the PLA fibers changed to very small crystals oriented in the PBT NFs direction in the PLA/PBT fibers. Non-isothermal crystallization studies of PLA in the in situ nanofibrillar composites (NFCs) prepared by compression molding demonstrated a significant improvement of crystallinity (27.5%) as well as crystallization rate. Enhanced crystallization rate provided comparative conditions to study the crystal forms of PLA and their relative populations nucleated during the cold and melt crystallizations. Moreover, the crystallization behavior of PLA/PBT blend with droplet-matrix morphology was compared with that of the NFC sample at the same PBT content to emphasize the tremendous effect of the morphological tailoring of blends.

中文翻译：

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原位纳米原纤维聚（乳酸）/聚（对苯二甲酸丁二醇酯）复合材料的开发：非等温结晶和晶体形态

摘要 聚乳酸 (PLA)/聚对苯二甲酸丁二醇酯 (PBT) 共混物的一步熔融纺丝成功地诱导了 PBT 的原位纳米原纤维，平均直径为23–51.4 纳米。扫描电子显微镜 (SEM) 图像显示了 PLA 基体中 PBT 纳米原纤维 (NFs) 的形态，发现 PBT NFs 的纵横比大于 400。 PLA 熔纺纤维在存在和不存在下的晶体形态使用偏振光学显微镜分析 PBT NF。在 PBT NF 存在下观察到 PLA 晶体形态的显着变化。PLA 纤维中分散的球晶变成了非常小的晶体，在 PLA/PBT 纤维中沿 PBT NFs 方向取向。通过压缩成型制备的原位纳米纤维复合材料 (NFCs) 中 PLA 的非等温结晶研究表明，结晶度 (27.5%) 和结晶速率显着提高。提高的结晶速率为研究 PLA 的晶型及其在冷和熔融结晶过程中成核的相对种群提供了比较条件。此外，将具有液滴基质形态的 PLA/PBT 共混物的结晶行为与具有相同 PBT 含量的 NFC 样品的结晶行为进行比较，以强调共混物形态调整的巨大影响。提高的结晶速率为研究 PLA 的晶型及其在冷和熔融结晶过程中成核的相对种群提供了比较条件。此外，将具有液滴基质形态的 PLA/PBT 共混物的结晶行为与具有相同 PBT 含量的 NFC 样品的结晶行为进行比较，以强调共混物形态调整的巨大影响。提高的结晶速率为研究 PLA 的晶型及其在冷和熔融结晶过程中成核的相对种群提供了比较条件。此外，将具有液滴基质形态的 PLA/PBT 共混物的结晶行为与具有相同 PBT 含量的 NFC 样品的结晶行为进行比较，以强调共混物形态调整的巨大影响。