聚丙烯基木塑复合材料的吸水性能及其影响

用挤出成型法制备了聚丙烯(PP)基木塑复合材料(WPC),研究了浸水时间、相容剂(马来酸酐接枝聚丙烯)、硅烷偶联剂等对WPC吸水率的影响,并研究了WPC吸水后对弯曲强度、吸水膨胀率和氧化诱导时间(OIT)的影响。结果表明,随着WPC浸水时间增加,初期WPC的吸水率增加较快,浸水约30 d以后,WPC的吸水率达到饱和而不再增加;加入硅烷偶联剂和相容剂都可以降低WPC的吸水率,但加入硅烷偶联剂只能降低WPC的初期吸水率,而加入相容剂既可降低WPC的初期吸水率,也可以降低其饱和吸水率;随着吸水率增加,WPC的弯曲强度降低,当WPC吸水饱和后,WPC的弯曲强度也趋于稳定;加入硅烷偶联剂和相容剂都能提高WPC的强度,但相容剂提高强度的幅度大于硅烷偶联剂;随着浸水时间增加,WPC的OIT逐渐减小。

Water Absorption and Effect of PP/WPC

Polypropylene(PP)/wood flour composites(WPC)were prepared by extrusion.The influence of immersion time,the compatibilizer(maleated polypropylene)and silane coupling agent on water absorption of WPC was studied.The effect of the water absorption on flexural strength,expansion of water absorption and the oxidation induction time(OIT)was also studied.The results showed that with increasing immersion time,the water absorption of WPC increased rapidly within the first 30 days and stopped increasing thereafter.Both the silane coupling agent and the compatibilizer reduced the water absorption of WPC,however,the silane coupling agent only reduced the initial absorption percentage,while the compatibilizer reduced the initial absorption percentage,as well as the saturated absorption percentage.The flexural strength of WPC reduced rapidly with increasing the absorption percentage and then tended to become stable after the WPC saturated with water.Both the silane coupling agent and the compatibilizer could improve the strength of WPC,while the compatibilizer can achieve the improvement to a greater extent.The OIT of WPC decreased with increasing the immersion time.