黄麻纤维织物增强乙烯酯复合材料的制备与力学性能

织物增强聚合物(TRP)因其具有优异的机械性能而被广泛应用于汽车、建筑等领域。传统TRP材料通常以玻璃纤维、碳纤维作为增强体,由于成本高及不可降解等问题限制了发展和应用。本研究采用可生物降解的天然黄麻纤维为增强体,以乙烯酯为基体树脂,采用模压工艺制备双层黄麻织物增强乙烯酯树脂复合材料。考察经纱和纬纱的取向对复合材料密度、孔隙率及力学性能的影响。通过调整黄麻织物的纱线角度(0°,30°,45°,60°和90°),研究经纬纱角度对复合材料性能的影响,采用的模压成型工艺是80℃、7 MPa条件下压制2.5 h。为了考察模压温度的影响,将纱线角度为60°的试样在40℃的低温条件下(其余条件不变)压制成型。结果表明:与纯乙烯酯相比,黄麻纤维具有一定的增强作用,复合材料的弯曲强度和冲击强度分别提高24.77%和39.83%,拉伸性能降低30.52%。扫描电子显微镜结果显示,复合材料力学强度的提高与纱线间的孔隙分布有关。在研究范围内,经纬纱定向对复合材料的冲击强度影响比较显著。低温(40℃)条件下,制备的定向角为60°时的黄麻纤维增强乙烯基酯复合材料的各项力学性能达到最佳。

Preparation and mechanical properties of vinyl ester composites reinforced with jute woven fabric

Textile reinforced polymers(TRP)are rapid developed due to their inestimable performances such as light weight and high mechanical properties.TRP has been used as an important raw material in automotive vehicles,buildings,and electronic devices.To be engineering products,it is desirable to have high-class mechanical properties.Thus,glass fibers and carbon fibers are used in the conventional TRP-reinforced composites,however,their high costs and nonbiodegradability limited the development and application of the composites.The objective of this work was to fabricate vinyl ester composites using naturally renewable and biodegradable jute woven fabrics as reinforcing material via mold pressing to increase the composite mechanical performances.The effects of yarn orientation on the density,void content,and mechanical properties of the composites were investigated.In order to study the effects of warp and weft yarn angle on the mechanical behaviors of the composites,one of the bilayers of the woven jute fabrics was arranged at five different angles,i.e.90°,60°,45°,30°and 0°,respectively.The mold pressing condition of the composites was set with a pressure of 7 MPa at 80℃ for 150 min.In order to examine the effect of pressing temperature on the composite,another composite of 30°was prepared at lower temperature condition with a pressure of 7 MPa at 40℃ for 150 min.The results showed that,compared with the control,the jute woven fabrics can enhance the mechanical properties of the composites.The flexural strength increased by about 24.77%and the impact strength also increased by up to 39.83%compared with the control.This was obtained due to the space created by the yarn width.The gap between the two warp yarns and the weft yarns of the fabrics was also contributed to the improved properties.The orientation of the fabric(warp and weft yarns)demonstrated its capacity to influence the impact strength of the composites significantly.It was found that the density and the void content of the composite had significant impact on the mechanical properties of the composite.The voids created by the warp and weft yarns could be a great indicator of the density of the composite and an important place for the resin to be stacked.Within the research scope,the condition of warp yarn angle at 60°and pressing temperature at 40℃was the most suitable condition to fabricate woven jute fabric reinforced vinyl ester composites.