玻璃纤维改性热塑性聚酰亚胺复合材料弯曲性能(Ⅱ)——高温力学性能

Bending strength of TPI-GF composites(Ⅱ)——mechanical properties at high temperature

采用热模压成型工艺制备玻璃纤维增强热塑性聚酰亚胺复合材料(TPI-GF),通过对试样在常温和高温下弯曲性能测试和分析,研究了TPI-GF在高温条件下的弯曲强度和模量的变化规律.实验表明:在225℃以下时其弯曲强度和模量的保留率都在60%以上,仍具有较高的承载能力.GF的加入可以增加材料的玻璃化温度(Tg),并显著提高材料在高温环境下的弯曲性能,而大尺寸填料的作用更加明显.利用Tr-n模型对几种复合材料高温弯曲性能进行的预测结果与实验结果基本相符,证明此模型对于聚酰亚胺及其复合材料是可行的.因为填料与基体较差的结合力,在常温下并没有体现填料的增强效果.

Glass fiber reinforced polyimide composites （TPI-GF） were prepared by thermo-molding process. By testing and analyzing their bending strength under normal and high temperatures, the bending strength and changing law of the holding ratio of strength and modulus of the high performance thermoplastic composites under high temperatures were studied. The experiments showed that the retention of bending strength and bending modulus were above 60% below 225℃, which had super high loading capacity. Furthermore, glass transition temperature （Tg） was improved as the increasement of filler content, and improved the bending strength of composite at high tempera-ture, the effect of big-sized filler was more notable. The experimental results of bending strength of the composite at elevated temperatures were found basically identical with the predicated value using the model of “Tr-n”. For the weak interaction between filler and matrix, the bending strength was fallen in some extent at normal temperature.