聚酰胺6/短切碳纤维复合材料制备及力学性能

Preparation and Mechanical Properties of Polyamide 6/Short Carbon Fiber Composites

为了提高聚酰胺(PA6)树脂的力学性能,以短切碳纤维(CF)为增强相,采用双螺杆挤出机和注塑机制备PA6/CF复合样条,研究不同CF含量对复合样条结构和力学性能的影响。结果表明:CF经浓硝酸和硅烷偶联剂处理后表面引入活性官能团;CF的添加使得PA6产生新的α晶型特征峰,当CF质量分数低于10%时,随着CF含量的增加,α晶型特征峰越来越明显;随着CF含量的增加,复合样条的熔融温度、结晶温度和结晶度均增加;CF质量分数低于10%时,CF在PA6基体中均匀分散,裸露的CF表面黏附有PA6树脂,当CF质量分数高于10%时,CF出现聚集现象;复合材料的储能模量逐渐增大,tanδ先减小后增大;当CF质量分数为10%时,拉伸强度和拉伸弹性模量达到最大,分别为213.05 MPa和3.15 GPa,与纯PA6样条相比,分别提高了108.4%和183.8%。

Chopped carbon fiber(CF) was used as the reinforcement phase in order to improve the mechanical properties of polyamide 6(PA6) resin,and PA6/CF composite splines were prepared by twin-screw extruder and injection molding machine.The effect of different CF contents on the structure and mechanical properties of composite splines were investigated.The results show that the surface of CF is treated with concentrated nitric acid and silane coupling agent in order to introduce active functional groups.A new characteristic peak of α crystal form is produced with the addition of CF.When CF content is lower than 10%,the characteristic peaks of α crystal form is more and more obvious with the increase of CF content,the melting temperature,crystallization temperature and crystallinity degree of the composite splines increase with the increase of CF content.When the CF mass fraction is lower than 10%,CF is uniformly dispersed in the PA6 matrix,and PA6 resin is adhered to the surface of exposed CF.When the CF content is higher than 10%,CF aggregates,the storage modulus of the composite increases gradually and the tanδ decreases firstly and then increases.When the mass fraction of CF is 10%,the tensile strength and Young’s moduli reach the maximum at 213.05MPa and 3.15 GPa,respectively,which are 108.4% and 183.8% higher than that of pure PA6 splines respectively.