汉麻纤维表面改性对其增强聚丙烯复合材料性能及挥发性有机化合物释放影响

通过非织造-热压工艺制备了汉麻纤维增强聚丙烯（HF/PP）复合材料。采用热重-质谱联用仪（TG-MS）研究了HF/PP复合材料的挥发性有机化合物（Volatile organic compounds，VOC）释放来源及汉麻经聚乙烯醇（PVA）改性和尿素改性对HF/PP复合材料VOC释放的影响，同时研究了两种改性方法对HF/PP复合材料热学性能和力学性能的影响。结果表明：HF/PP复合材料中的VOC主要来源于汉麻纤维，改性后的HF/PP复合材料力学性能相比未处理的均有不同程度的提升，尿素改性后，HF/PP复合材料的拉伸强度和弯曲强度达到最大值，较未处理时分别提升了19.32%和15.04%。PVA改性后，HF/PP复合材料的拉伸模量、弯曲模量和剪切强度达到最大值，相比未改性时分别提升了17.72%、15.94%和24.72%。改性后HF/PP复合材料热稳定性能和VOC释放相较未处理时均得到了优化：PVA改性后HF/PP复合材料热稳定性最优，三个阶段总活化能较未处理时提高了121.99%，达到了392.56 kJ·mol^-1，并且HF/PP复合材料热稳定性与界面性能密切相关；尿素及PVA改性后HF/PP复合材料的总VOC（TVOC）释放量相较未处理时均降低。

Effect of hemp fiber modification on the properties and volatile organic compounds emission of its reinforced polypropylene composites

Hemp fiber/polypropylene(HF/PP) composites were prepared via non-woven and compressing technology. The volatile organic compounds(VOC) emission source of HF/PP composites was studied and TG-mass spectrometry (TG-MS) was used to study the effect of PVA and urea modification on the VOC emission of HF/PP composites. At the same time the effect of the above methods on the mechanical and thermal properties of HF/PP composites were also investigated. The results reveal that the VOC emission of HF/PP composites mainly comes from hemp fiber. Compared with the untreated composite, the mechanical properties of the modified HF/PP composites are improved. The tensile strength and flexural strength of the composite reach the maximum value after urea modification which increase by 19.32% and 15.04% compared with untreated. The tensile modulus, flexural modulus and impact strength of the HF/PP composite reach the maximum value after PVA modification which increase by 17.72%, 15.94% and 24.72% compared with untreated. The thermal stability and VOC emission of the modified HF/PP composites are optimized after modification. The HF/PP composite attains the optimal thermal stability after PVA modification, and the total activation energy increases by 121.99% compared with untreated, and reaches to 392.56 kJ·mol^-1. The thermal stability of HF/PP composites is closely related to its interfacial properties. The total VOC cumulative emission of the modified HF/PP composites decreases compared with untreated, and the urea modified composite exhibits the best effect.