改性纳米纤维素对聚乳酸热降解动力学行为影响研究

The effect of modified cellulose nanowhisker on thermal degradation kinetics of poly(lactic acid)

采用硅烷偶联剂(KH-570)对纳米纤维素进行表面硅烷化改性,通过溶液浇筑法制备了硅烷化纳米纤维素/聚乳酸复合膜材料。通过傅里叶红外光谱仪(FT-IR)、透射电镜(TEM)和热重分析(TGA)分析了硅烷化纳米纤维素的化学结构、微观形貌、聚乳酸基体中的分散情况和不同升温速率下聚乳酸复合材料的热降解行为机制。结果表明,硅烷化改性成功发生在纳米纤维素的表面,且在聚乳酸基体中分散性好。通过CR和IKR模型分析得出改性前后纳米纤维素对聚乳酸材料表现出不同的热降解机制。

The silane agent (KH-570,MPS) was adopted to modify the surface of cellulose nanowhisker (CNW) and the solution casting method was used to prepare the M-CNW/PLA composite.The chemical structure,micromorphology,dispersion in PLA matrix and thermal degradation behavior of PLA composites under different heating rate were detected by FT-IR,SEM,and TGA,respectively.The results indicated that the M-CNW was successfully synthesized and the micromorphology of CNW was kept.M-CNW showed a good dispersion state in PLA matrix and improvement in the brittle rupture pattern of PLA.Through the analysis results of CR and IKR models,PLA showed the different thermal degradation mechanism with modified or unmodified CNW.