剑麻/聚丙烯复合材料的冲击性能及其预测

Prediction on impact strength of sisal fiber/polypropylene composites

采用注塑工艺制备剑麻纤维增强聚丙烯复合材料,研究纤维含量、长度及其分布、不同基体树脂和相容剂类型等对复合材料冲击性能的影响。分析单纤维强度的分散性,采用修正的Weibull分布模型估算临界纤维强度,并对复合材料的冲击强度进行预测。结果表明:剑麻/聚丙烯的冲击强度随纤维含量增加而升高,树脂基体的性质对冲击强度具有显著的作用;界面层为刚性层的相容剂MAPP对冲击强度具有负作用,而界面层为柔性层的相容剂PP g GMA对冲击强度具有提高作用;同等含量下,使用PP g GMA后复合材料的冲击强度比使用MAPP提高21.7%。通过KH550硅烷溶液处理后的纤维与PP g GMA反应,在界面处引入更加柔性的界面层,使冲击强度比引入MAPP提高50.7%。将纤维取向因子引入冲击强度模型后,预测值与实测值符合较好。

The sisal fiber（SF） reinforced polypropylene composites were manufactured by injection molding.The effects of fiber content,fiber length distribution,matrix types and compatibilizer types on the impact strength of the composites were studied.The distribution of individual fiber tensile strength was analyzed.The tensile strength of fibers at the critical fiber length was estimated by the modified Weibull distribution model.The impact strength of the composites was predicted.The results show that the impact strength increases with the fiber content.The matrix types have important influence on the impact strength.Owing to forming a rigid interfacial layer between the matrix and fiber,the MAPP compatibilizer has a negative influence on the impact strength,while the PP-g-GMA compatibilizer has a positive influence on the impact strength owing to forming a soft interfacial layer.The impact strength of the composite with PP-g-GMA is 21.7% higher than with MAPP at the same compatibilizer content.When the softer interfacial layer is introduced through the reactions of the natural fiber treated by KH550 silane with PP-g-GMA compatibilizer,the impact strength is 50.7% higher than that with MAPP.The predicted and the experimental values are reasonably well approximated considering the fiber orientation factor to the impact strength model.