建筑用聚丙烯基木塑复合材料耐水性能研究

Study on Water Resistance of Polypropylene Based Wood-Plastic Composites Used in Building

制备了聚丙烯(PP)基木塑复合材料(WPC),研究了马来酸酐(MAH)、木粉用量以及木粉粒径对WPC性能的影响,并考察了浸泡及擦干放置后WPC的性能变化和恢复情况。结果表明:随着增容剂MAH用量的增加,WPC的拉伸强度和冲击强度均先增大后减小,吸水率则呈下降趋势;当浸水1天后,WPC浸水试样的拉伸强度下降,冲击强度则有所提升,并且随着MAH用量的增加,材料拉伸强度的下降趋于显著,冲击强度的提升幅度则逐渐减小;当MAH用量超过8份后,干燥后的WPC浸水试样(擦干放置1天),力学性能基本恢复。随着木粉用量的增加,WPC的拉伸强度先增大后减小,冲击强度不断减小,而吸水率则有所增大,其中当木粉含量超过10份时,干燥后的WPC浸水试样,其拉伸强度仅能得到部分恢复。另外随着木粉粒径的减小,WPC的吸水率明显增大,冲击强度有所提高;而木粉粒径对干燥后WPC浸水试样的拉伸强度恢复情况影响不大,其中当木粉粒度为60目时,试样的冲击强度比浸水前有所提升。

Polypropylene（PP） based wood-plastic composites（WPC） were prepared, then the influences of maleic anhydride（MAH） content, wood flour content and particle size on water resistance of the WPC were studied, and the performance changes before and after immersing in water and property restoration of the WPC were also investigated. The result show that with the increasing of MAH, the tensile strength and impact strength of WPC increase at first and then decrease, and water absorption decreases. After immersing in water for 1 day, the tensile strength of WPC decreases but the impact strength increases, and with the increasing of MAH, the reducing extent of tensile strength increases, but the improvement extent of impact strength gradually decreases. When the MAH content exceeds 8 phr, the impact strength of dried WPC samples（dried for 1 day） can be recovered basically. With the increasing of wood flour, the tensile strength of WPC increases at first and then decreases, the impact strength decreases, and water absorption increases. When the wood flour content exceeds 10 phr, the impact strength of dried WPC samples can only recover partially. With the decreasing of wood flour particle size, the water absorption of WPC increases obviously and impact strength improves slightly, and the particle size of wood flour has little influence on the recovery of tensile strength of the dried WPC samples. The impact strength of dried WPC samples is higher than that of unsoaked WPC, when the particle size of wood flour is 60 meshes.