Fully biodegradable chain-extended poly(butylene adipate-co-terephthalate) (CPBAT)/acetylated cellulose nanocrystals (ACNCs) nanocomposites were prepared by the melt compounding process. The dispersibility of CNCs in deionized water was improved through the surface acetylation, which was observed by atomic force microscope and transmission electron microscope. The chain extender was added to the PBAT matrix to improve the melt strength and viscoelasticity of PBAT. The ACNC nanoparticles which served as bionano-reinforcing fillers were introduced into CPBAT to further improve the crystallization behaviors and rheological properties of CPBAT/ACNCs nanocomposites. Finally, the CPBAT/ACNCs nanocomposite foams were prepared via batch supercritical CO₂ foaming process. The cell structure and morphology of various CPBAT/ACNCs foams were investigated by scanning electron microscope. It was found that the introduction of ACNC nanoparticles led to a reduction of cell size, an increase in cell density and in the uniform cell distribution owing to the heterogeneous cell nucleation effect of ACNCs. Meanwhile, the volume expansion ratio (VER) of CPBAT foams reached to 9.21 times, the highest VER reported for PBAT foam in the current literature. Also, the thermal conductive properties of nanocomposites and foams also were studied by a laser thermal conductivity analyzer.

中文翻译：

---

乙酰化纤维素纳米晶对扩链聚（己二酸丁二醇酯-共对苯二甲酸酯）固态发泡行为的影响

通过熔融复合工艺制备了完全可生物降解的扩链聚（己二酸丁二醇酯-共聚对苯二甲酸酯）（CPBAT）/乙酰化纤维素纳米晶体（ACNCs）纳米复合材料。通过原子力显微镜和透射电子显微镜观察，CNCs通过表面乙酰化提高了去离子水中的分散性。在PBAT基体中加入扩链剂以提高PBAT的熔体强度和粘弹性。将作为生物纳米增强填料的 ACNC 纳米粒子引入 CPBAT，以进一步改善 CPBAT/ACNCs 纳米复合材料的结晶行为和流变性能。最后，通过批量超临界 CO ₂制备了 CPBAT/ACNCs 纳米复合泡沫发泡工艺。通过扫描电子显微镜研究了各种 CPBAT/ACNCs 泡沫的泡孔结构和形貌。结果发现，由于 ACNC 的异质细胞成核效应，ACNC 纳米粒子的引入导致细胞尺寸减小、细胞密度增加和细胞分布均匀。同时，CPBAT 泡沫的体积膨胀比 (VER) 达到 9.21 倍，是目前文献中 PBAT 泡沫报道的最高 VER。此外，还通过激光热导分析仪研究了纳米复合材料和泡沫的导热性能。