改性小麦秸秆粉/聚丙烯复合材料的性能研究

Properties of Modified Wheat Straw Powder/Polypropylene Composites

研究了碱处理(AT)、苯甲酸(BA)或/和硬脂酸(SA)改性对小麦秸秆粉(WSP)/聚丙烯(PP)复合材料(WSP/PP-CM)力学性能、热稳定性能、流变性能、润湿性能和吸水性能的影响。结果表明:碱处理可提高WSP/PP-CM的拉伸强度(TS)、弯曲强度(FS)、冲击强度(IS)、起始热分解温度(Ti)和接触角(θ),而使平衡扭矩(BT)和吸水率(WU)减小,因为AT使得WSP表面活性增加、疏水性增强。在AT基础上再进行BA或者SA改性,WSP/PP-CM的TS、FS、IS及Ti继续提高,BT进一步降低;在AT基础上再进行BA/SA复合改性,WSP/PP-CM的TS、FS、IS及Ti大幅提高了41.21%、32.02%、38.68%和35.7℃,BT进一步下降至9.7N·m。AT后再进行BA或/和SA改性,复合材料的疏水性虽然优于未改性WSP/PP-CM,但效果均不及单纯的AT。

Effects of alkalli treatment(AT), modification by benzoic acid(BA) or/and stearic acid(SA) on mechanical properties, thermal stability, rheological properties, wettability and water uptake of wheat straw powder(WSP) reinforced polypropylene(PP) composites(WSP/PP-CM) were studied. Results show that, when WSP was alkalli treated, the tensile trength(TS), flexural strength(FS), impact strength(IS), initial decomposition temperature(Ti) of WSP/PP-CM and the contact angle(θ) between WSP/PP-CM and distilled water can be increased, respectively, while the balance torque(BT) and water uptake(WU) decreases. These may be due to the increased surface activity and enhanced hydrophobicity of the WSPthe by AT. After alkalli treatment, if the WSP was modified by BA or SA again, TS, FS, IS and Ti of WSP/PP-CM can be increased while BT decreased. After alkalli treatment, if the WSP was modified by BA and SA together again, TS, FS, IS and Ti of WSP/PP-CM can be increased by 41.21%, 32.02%, 38.68% and 35.7℃ while BT decreased to 9.7 N·m. The hydrophobicity of the composites was better than that of the unmodified WSP/PP-CM, although the effect was less than that of AT alone.