麦秸/聚氯乙烯复合材料新疆户外老化性能

为探讨新疆强紫外线与干热环境对木塑复合材料抗老化性能的影响，添加不同种类抗老剂(UV-531、1010和168)，采用挤出成型制备麦秸/聚氯乙烯(PVC)复合材料，进行90天新疆户外老化。测试和分析麦秸/PVC复合材料老化前后表面官能团和颜色变化、表面形貌和力学性能，计算羰基指数、木质素指数和表面粗糙度。结果表明:老化后表面麦秸纤维与PVC发生分解，出现褪色现象，粗糙度升高，力学性能下降。抗老剂均能提高麦秸/PVC复合材料的抗老化性能。其中，添加抗老剂UV-531的麦秸/PVC复合材料效果最优，与对照组相比，其羰基指数提高了19.27%，木质素指数降低了4.44%，色差ΔE降低了11.12%，表面粗糙度S_a降低了33.38%，弯曲强度和拉伸强度分别提高了5.87%和6.44%，表面更平整，麦秸裸露少。该研究结果可为提高木塑复合材料抗老化效力提供试验数据和理论参考，有利于延长木塑复合材料在新疆干热环境下的使用寿命。 

Outdoor exposure aging performance of wheat straw/polyvinyl chloride composites in Xinjiang

In order to investigate the effect of strong ultraviolet and dry heat environment on the aging resistance of wood-plastic composites in Xinjiang, the anti-aging agent(UV-531, 1010 and 168) was used to prepare wheat straw/polyvinyl chloride(PVC) composites by extrusion molding. The wheat straw/PVC composites were subject to outdoor exposure aging in Xinjiang for 90 days. The changes of surface functional groups, color changes, surface morphology and mechanical properties of the wheat straw/PVC composites before and after aging were tested and analyzed, and the carbonyl index, lignin index and surface roughness were calculated. The results show that three anti-aging agents can improve the aging resistance of wheat straw/PVC composites. After aging for 90 days, the functional groups on wheat straw/PVC composites surface change significantly indicating the decomposition of the wheat straw/PVC composites surface. Compared with the control group, the carbonyl index of the wheat straw/PVC composites added with UV-531 increases by 19.27%, the lignin index decreases by 4.44%, the color difference ΔE decreases by 11.12%, and the surface roughness S_a decreases by 33.38%, the flexural strength and tensile strength are increased by 5.87% and 6.44%, the surface is smoother, and the wheat straws are less exposed. The results will provide experimental data and theoretical reference for improving the anti-aging effect of wood-plastic composites, which is beneficial to prolong the service life of wood-plastic composites under dry heat conditions in Xinjiang.