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采用模压工艺制备不饱和聚酯树脂/大麻纤维复合材料,研究紫外线光老化试验对此种复合材料及氨水处理复合材料力学性能的影响,利用红外光谱(FTIR)技术研究老化前后复合材料结构的变化。研究结果表明,氨水处理大麻纤维可以改善复合材料的拉伸性能以及拉伸模量。未处理及氨水处理的复合材料,在试验一个周期后,两种复合材料的拉伸强度较老化前分别提高了10.8%和19.1%,未处理的复合材料的弯曲强度在两个试验周期时达到最大值。氨水处理的复合材料,在试验的第一周期时,拉伸模量下降最快,进一步老化之后,下降幅度明显减缓。氨水处理的复合材料的拉伸模量在第三个试验周期结束时,弯曲模量和冲击强度比未老化前分别上升6.3%和25.3%。FTIR显示,老化后,两种复合材料的吸收峰强度减弱,但氨水处理的复合材料吸收峰强度比未处理的强。
The unsaturated polyester resin / hemp fiber composites were prepared by compression molding. The effects of UV-Aging on the mechanical properties of the composites and ammonia-treated composites were studied. The changes of the composites before and after aging were studied by using infrared spectroscopy (FTIR) . The results show that ammonia treatment of hemp fibers can improve the tensile properties and tensile modulus of composites. The tensile strength of the untreated and ammonia-treated composites increased by 10.8% and 19.1%, respectively, after one cycle of test. The flexural strength of the untreated composites reached at two test cycles Maximum Ammonia-treated composites showed the fastest decrease in tensile modulus at the first cycle of the test, and a significant decrease after a further aging. Tensile Modulus of Ammonia-Treated Composites At the end of the third test period, flexural modulus and impact strength increased by 6.3% and 25.3%, respectively, before un-aged. FTIR showed that after aging, the absorption peak intensities of the two composites decreased, but the ammonia-treated composites had stronger absorption peak intensity than the untreated ones.