摘要:
以麦秸秆粉为填充材料(质量分数50%),以聚丙烯(PP)膜为基体材料,采用混炼模压成型制备麦秸秆/PP木塑复合材料,对其进行紫外线加速老化实验,对比研究不同填充材料的木塑复合材料老化前后的力学性能和颜色变化,用FTIR分析探讨了复合材料老化机制,用SEM观察其表面微观形貌。结果表明,紫外线加速老化会导致麦秸秆/PP复合材料力学性能降低,当老化时间小于960 h时,麦秸秆/PP木塑复合材料弯曲强度、拉伸强度下降幅度较小,老化时间大于960 h时,力学性能下降幅度较大,材料褪色明显; 老化1200 h其弯曲强度、拉伸强度、冲击强度分别下降67.2%、47.89%、32.41%; 麦秸秆纤维中羟基加速了PP的紫外光降解,最终材料表面出现明显裂纹,部分纤维剥落并伴随有PP粉化现象。
Abstract:
Wheat straw/polypropylene(PP) wood-plastic composites (WPC) filled with 50% wheat straw powder were prepared by mixing compression molding. WPC were accelerated ageing by ultra violet (UV) radiation. The mechanical properties and color change of the original and ageing PP wood-plastic composites filled with different plant fiber were investigated. UV weathering mechanism was analyzed by FTIR. The tensile sections of the composites were observed by SEM. The results show that the mechanical performance decreases substantially caused by the UV accelerated ageing. When the aging time is less than 960 h, bending strength and tensile strength decrease slightly. Then the mechanical performance decreases rapidly and WPC fade obviously. Bending strength, tensile strength and impact strength decrease respectively 67.2%, 47.89%, 32.41% when ageing time is 1200 h. The hydroxyl in the wheat straw fiber evidently accelerates the degradation of PP. Finally the partial fiber drops out from the face of material with cracks while PP occurs pulverization phenomena.
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