苎麻短纤维层间增韧碳纤维/环氧树脂复合材料

采用热压机层压成型工艺制备了苎麻短纤维(SRF)层间增韧碳纤维/环氧树脂(CF/EP)复合材料层压板,研究了SRF的长度、面密度及其表面偶联处理对CF/EP复合材料层间断裂韧性的影响,并进一步研究了SRF的铺入对复合材料弯曲、拉伸性能的影响。研究结果表明,层间SRF的铺入明显改善了CF/EP复合材料的I型和II型层间断裂韧性(G_(IC)和G_(IIC)),当表面偶联处理的纤维长度为6mm、面密度为12g·m~(-2)时,增韧效果最佳,GIC由497.48J·m~(-2)增加到667.54J·m~(-2),提高了34.24%;GIIC由508.52J·m~(-2)增加到862.11J·m~(-2),提高了69.54%。此外,铺入SRF对复合材料的弯曲、拉伸性能也有一定程度的提高。通过SEM观察发现,SRF的增韧机制与其层间桥联以及裂纹扩展过程中从基体中拔出与劈裂等现象有关。

Interlayer-toughening carbon fiber/epoxy composites with short ramie fiber

The interlayer-toughed carbon fiber/epoxy resin (CF/EP) composite laminates with short ramie fiber (SRF) were made through hot press laminated molding process.The interlaminar fracture toughness,the flexsural properties and tensile properties of the CF/EP composites with different SRF lengths,surface densities and surface coupling treatment were investigated.The results indicate that the insert of SRF significantly improves the CF/EP composites' mode I and mode II interlaminar fracture toughness (GIC and GIIC),and the best interlaminar fracture toughness property can be obtained when the length of SRF is 6 mm and the surface density of SRF is 12 g·m-2.GIC of the composites improves from 497.48 J·m-2 to 667.54 J·m-2,which increases by 34.24%,and GIIC of the composites improves from 508.52 J·m-2 to 862.11 J·m-2,which increases by 69.54%.In addition,the flexural pro-perties and tensile properties of the composites are also slighted improved with SRF.Through the observation of scanning electron microscope (SEM),it can be obtained that the toughening mechanism is related to SRF' bridging and pulling out and splitting in the process of crack propagation.