表面改性CNF对PBS/PLA共混物的湿热老化行为的影响

以硅烷偶联剂KH550对纳米纤维素(CNF)进行表面改性，利用双螺杆挤出机熔融共混制备一系列聚丁二酸丁二醇脂(PBS)/CNF母粒改性聚乳酸(PLA)复合材料，并在湿热老化试验箱中进行老化试验。通过扫描电子显微镜、广角X射线衍射仪、差示扫描量热仪、偏光显微镜等对复合材料的结晶和力学性能进行测试。结果表明,CNF可作为异相成核剂改善PLA的结晶行为，使PLA的结晶度提高；改性后，PBS/CNF复合母粒与PLA基体之间的相容性有较大改善；老化36 h后，PLA/PBS/CNF-KH550复合材料结晶进一步完善，其结晶度、拉伸强度和断裂伸长率较老化前分别提高了28.15 %、5.54 %和8.23 %。

Effects of Surface-Modified Nanocellulose on Hygrothermal Aging Behavior of PLA/PBS Blends

Nanocellulose (CNF)was surface-modified by a silane coupling agent, KH550, and then a poly(butylene succinate)(PBS)/modified CNF masterbatch was prepared by melt blending with a twin-screw extruder. A series of poly(lactic acid)(PLA)/PBS/CNF blends were prepared by melt compounding with the obtained masterbatch, and their hygrothermal aging performance was characterized in a damp heat aging test chamber. The crystallization and mechanical properties of the blends were investigated by SEM, WAXD, DSC, polarizing microscope and universal testing machine. The results indicated that CNF could act as a nucleating agent to improve the crystallinity of PLA. The compatibility between the PLA matrix and PBS/CNF masterbatch was improved greatly due to the surface modification. The blends achieved an increase in degree of crystallinity by 28.15 %, in tensile strength by 5.54 % and in elongation at break by 8.23 % after aging for 36 h.