木粉表面改性对聚氯乙烯/木粉复合材料性能的影响

The Effect of Modification of Wood Flour on the Properties of Poly(Vinyl Chloride)/Wood Flour Composites

选用不同偶联剂对木粉(WF)进行表面改性。对聚氯乙烯/木粉(PVC/WF)复合材料力学性能测试结果表明,异氰酸酯偶联剂更适合对WF的表面改性。WF经异氰酸酯偶联剂处理后疏水性得到明显改善。随WF填充量增加,PVC/WF复合材料冲击强度和线性热膨胀系数下降,吸水率和维卡软化温度上升,并且异氰酸酯偶联剂处理WF填充的PVC/WF复合材料(PVC/WF-1)各种性能都较未处理WF填充的PVC/WF复合材料(PVC/WF-2)好。填充30份时,PVC/WF-1复合材料的拉伸强度比纯PVC提高约10%,吸水率小于0.6%,维卡软化温度比PVC提高2.9℃,线性热膨胀系数从PVC的8.55×10-5℃-1降低到6.01×10-5℃-1。扫描电镜观察结果证明异氰酸酯偶联剂处理WF有利于提高WF与PVC基体的界面相互作用。

Poly（vinyl chloride）/wood flour （PVCAVF） composites were prepared by melt mixing processing and the WF being used was modified by two kinds of coupling agents respectively. For the isocyanate coupling agent modified WF, the data of hydrophilic property in 1 h decreased from 84.73 mm to 4.50 mm. With the increase of WF content, the impact strength, the coefficient of thermal expansion clecreased the water absorption and the Vicat soften point of PVCAVF composites increased. Moreover, all the properties of PVC/modified WF composites are better than those of PVC/unmodified WF ones. When modified WF content is 30 phr, for PVC/WF composite,% the water absorption is lower than 0.6 %, the Vicat soften point is 2.9℃ higher than that of PVC and the coefficient of thermal expansion decreases from 8.55×10-5℃ -1 of PVC to 6.01 × 10-5^-1, all these results indicate that the PVC/WF composites with good properties can be obtained by the introduction of modified WF. SEM micrographs future demonstrate that the interfacial interaction between WF and PVC can be improved when WF is modified by isocyanate coupling agent,