偶联改性对木粉/PLA复合材料性能的影响

Influence of Coupling Modification on the Properties of Wood Flour/PLA Composites

采用高速粉碎机对木粉进行机械活化,在此同时加入铝酸酯偶联剂对木粉进行表面改性,通过熔融挤出法制备木粉/PLA复合材料。以材料的力学性能为评价指标,研究了不同处理方法和铝酸酯用量对复合材料的改性效果,并利用红外光谱(FTIR)、X射线衍射(XRD)、热重分析(TGA)和扫描电镜(SEM)分别对改性木粉及复合材料进行了分析。结果表明:机械活化对复合材料的力学性能影响较小,但破坏了木纤维结晶结构,从而提高了偶联反应活性,强化了铝酸酯的偶联效果;且当铝酸酯用量为1.0%时,力学性能最好。TGA、SEM进一步分析表明,铝酸酯用量为0.5%时,材料相容性最好。

Wood flour （WF） was mechanically activated by a high speed disintegrator, and the aluminate coupling agent was added at the same time. Modified WF and polylactic acid （PLA） were mixed adequately, and then WF/PLA composites were prepared by melt extrusion. The effects of different treatment methods and dosages of aluminate ester on the mechanical properties of the composites were investigated. In addition, FTIR, XRD, TGA and SEM were used to characterize the modified WF and composites. The results showed that mechanical activation could destroy the crystal structure and improve the coupling reactivity of cellulose. The mechanical activation had little effect on the mechanical properties, but obviously strengthened the coupling effect, while the WF/PLA composites activated by 1.0% aluminum ester exhibited the maximum improvement. Both TGA and SEM results showed that the addition of aluminate ester can improve the compatibility of compositels two-phase, with an optimized dosage of 0.5 %.