基体改性对连续玻纤增强尼龙复合材料性能的影响

Effect of matrix modification on the properties of continuous glass fiber reinforced nylon composites

提升连续玻璃纤维增强尼龙6复合材料(cGF/PA6)力学性能的重要途径之一是改善玻璃纤维与尼龙之间的界面结合。本文将星形支化聚酰胺6(SPA6)应用于cGF/PA6复合材料体系,采用熔融挤出结合热压成型法制备了不同SPA6含量的cGF/PA6-SPA6复合材料。通过接触角实验测得SPA6与cGF具有更相近的极性。DSC检测结果表明PA6与SPA6共混后基体熔融温度相差不大、结晶温度和结晶度有所提高。三点弯曲法测得PA6-SPA6基体的弯曲强度相对于PA6和SPA6有所降低,但cGF/5wt%SPA6和c GF/10wt%SPA6复合材料的弯曲强度相对于cGF/PA6分别提高了4.9%和6.4%。短梁剪切试验测得cGF/5wt%SPA6和cGF/10wt%SPA6复合材料的层间剪切强度相对于cGF/PA6分别提高了16.7%和15.6%。悬臂梁摆锤冲击实验测得cGF/PA6和cGF/SPA6复合材料的冲击强度分别是PA6和SPA6的12倍和26.3倍。结合冲击断口形貌观察,可以推断在cGF/PA6复合材料中加入5wt%或10wt%的SPA6可以提高复合材料的弯曲和剪切强度,而对其冲击强度影响不大,且成本较低,具有一定的应用价值。

One of the important ways to improve the mechanical properties of continuous glass fiber reinforced nylon 6 composites(cGF/PA6)is to improve the interface interactions between glass fiber and nylon 6.In this study,star-branched polyamide 6(SPA6)was applied to cGF/PA6 composite system,and continuous glass fiber reinforced nylon composites with different contents of SPA6(cGF/PA6-SPA6)were prepared by melt extrusion combined with hot pressing.The characterization of contact angle indicates that the polarity between SPA6 and cGF is more similar.DSC results show that there is not much difference in the melting temperature among PA6,SPA6 and PA6-SPA6 composite matrix,and both the crystallization temperature and crystallinity of PA6-SPA6 are increased.The flexural strength of PA6-SPA6 matrix is lower than that of PA6 and SPA6 measured by three-point flexural tests.However,compared with cGF/PA6,the flexural strength of cGF/5wt%SPA6 and cGF/10wt%SPA6 composites increased by 4.9% and 6.4%,respectively,and the shearing strength of cGF/5wt%SPA6 and cGF/10wt%SPA6 composites increased by 16.7% and 15.6%,respectively.The impact strength of cGF/PA6 and cGF/SPA6 composites is 12 times and 26.3 times that of PA6 and SPA6,respectively.Combined with the observation of impact fracture morphology,it can be inferred that adding 5wt% or 10wt%SPA6 to cGF/PA6 composites can improve the flexural and shearing strength of the composites,while having little influence on the impact strength,and considering its cost-effectiveness,it proves to be of practical value for applications.