热氧老化和水浸渍对木粉/HDPE和稻壳粉/HDPE两种复合材料性能的影响

木粉和稻壳粉是制备木塑复合材料(WPC)常用原料。WPC在使用过程中经常受到热和水分的影响,笔者对比研究了稻壳粉/HDPE和木粉/HDPE两种复合材料经历热氧老化和长时间水浸渍后性能的变化规律。结果表明:木粉/高密度聚乙烯(HDPE)复合材料的弯曲强度和弹性模量都大于稻壳粉/HDPE的;随着热氧老化或水浸渍处理时间的延长,复合材的挠曲性能下降,其中木粉/HDPE复合材的弹性模量下降最为迅速;复合材料表面明度值随着热处理时间的延长而减小,说明颜色变暗,稻壳粉与木粉填充的复合材之间差别不大。通过光学显微镜观察发现,HDPE与稻壳粉或木粉之间都有缝隙存在,为水分和氧气的进出提供了通道。

Property Comparison of Wood Flour/HDPE and Rice HulI/HDPE Composites after Thermal-oxidation and Water Soaking Treatment

Wood flour and rice hull are commonly used to manufacture wood-plastic composites(WPCs) which frequently experiencing thermal-oxidation and water soaking in external use.The authors of this paper compared the properties of rice hull/HDPE and wood flour/HDPE composites after thermal-oxidation and water soaking treatment.The results showed that the flexural strength and MOE of wood flour/HDPE composite were larger than those of rice hull/HDPE composite;the flexural strength of two composites decreased during thermal-oxidation or water soaking,and the MOE of wood flour /HDPE composite decreased most;and the composites darkened during thermal-oxidation treatment,and there was no significant difference between wood flour and rice hull filled HDPE composite.Seen from microscope, there were checks between HDPE matrix and wood flour or rice hull flour,which provided tunnels for water and oxygen penetration.