木粉含量对木粉-淀粉/聚乳酸复合材料性能的影响

Effects of wood flour contents on performance of wood flour-starch/poly(lactic acid)composites

以杨木粉、玉米淀粉和聚乳酸(PLA)为原料,甘油为相容剂,利用熔融挤出法制备了木粉-淀粉/PLA复合材料。研究了木粉含量对复合材料界面相容性、热性能、力学性能、流变性能以及吸水率的影响。结果表明:随着木粉含量的增加,PLA与木粉之间的界面相容性下降,木粉-淀粉/PLA复合材料的热稳定性下降,储能模量、损耗模量和复数黏度逐渐增加;随着木粉含量的增加,木粉-淀粉/PLA复合材料的拉伸强度和弯曲强度呈现先增大后减小的趋势,当木粉含量为18wt%时,复合材料的拉伸强度和弯曲强度均达到最大值,最大值分别为40.65 MPa和60.91 MPa;随木粉含量的增加,复合材料的断裂伸长率由9.64%减小到5.97%,而吸水率由5.38%增大到13.43%。

The wood flour-starch/poly(lactic acid)(PLA)composites were prepared by melt extrusion method with poplar wood flour,corn starch and PLA as raw material,glycerol as compatibilizer.The effect of wood flour contents on interfacial compatibility,thermal properties,mechanical properties,rheological properties and water absorption rate of composites were studied.The results show that with the increasing of wood flour contents,the interfacial compatibility between PLA and wood flour decreases,the thermal stability of wood flour-starch/PLA composites reduces,storage modulus,loss modulus and complex viscosity gradually increase.With the increasing of wood flour contents,the tensile strength and bending strength of wood flour-starch/PLA composites first increase then decrease,and reach the best values at 40.65 MPa and 60.91 MPa with 18wt% wood flour content.With the increasing of wood flour contents,the elongation at break of composites reduces gradually from 9.64% to 5.97%,and the water absorption rate increases observably from 5.38%to 13.43%.