The thermoplastic polyimide(PI) foam was prepared with one-step method by adding high-temperature foaming agent into PI powder.The effects of several key controlling factors,such as mold sealing,foaming temperature and the amount of foam agent on structure and mechanical properties of PI foam were discussed.The results show that mold scaling and the amount of foam agent have great effects on the properties of PI foam.The optimal preparation conditions are as follows:resin powder is pretreated at 60℃ for 2 h,foaming agent mass fraction is 2％,molding temperature is 280℃,pressure is 10 MPa,foaming time is 30 min.At these conditions,the prepared thermoplastic PI foam sample has the density of 0.463 g/cm3 and has good mechanical properties,such as compression strength 10.86 MPa,impact strength 6.2 kJ/m2,bending strength 12.8 MPa.%通过在热塑性聚酰亚胺(PI)粉末中添加高温发泡剂一步发泡制得PI泡沫材料,探讨了一步法制备PI泡沫过程中的模具密闭性、发泡温度、发泡剂用量等几个关键因素对材料结构及力学性能的影响.结果表明,一步发泡法制备PI泡沫材料过程中模具密闭性、发泡剂用量对泡沫性能有很大影响.经优化的制备条件为:树脂粉在烘箱中60℃预处理2h,发泡剂质量分数为2％,成型温度为280℃,成型压力为10 MPa,发泡时间为30 min.在优化的实验条件下制备的热塑性PI泡沫材料样品的密度为0.463 g/cm3时,压缩强度为10.86 MPa,冲击强度为6.2 kJ/m2,弯曲强度为12.8 MPa.
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