不饱和聚酯树脂／大麻纤维复合材料紫外老化性能的研究

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.

UV AGEING OF UNSATURATED POLYESTER RESIN/HEMP FIBER COMPOSITES

Unsaturated polyester resin/hemp fiber composites are formed by compression molding process,UV ageing test is carried out for both untreated and ammonia treated composites,the ageing cycles on the mechanical properties of the composites are studied,and FTIR technology is applied to characterize the structures of the comp- soites.The results show that,treating hemp fiber with ammonia can improve the tensile strengths and tensile modulli of the composites.The composites,either treated or untreated,get the greatest tensile strengths after one testing cy- cle,10.8% and 19.1% increased from those of the unaged composites respectively;the flexural strengths,tensile modulli and flexural modulli of the untreated composites become the greatest ones when 2 periodically aged.As for the ammonia treated composites,their tensile moduli and flexural strengths decrease dramatically during the first ag- ing period,then continue to decrease but much more slowly.On the contrary,their flexural modulli and impact strengths are increased by 6.3% and 25.3% respectively from those of the unaged composites after 3 aging cycles. FTIR spectra shows that,the ammonia treated composites have stronger peaks than the untreated ones though the ab- sorbence peaks of both the two composites become weaker after UV aging.