高回复力低密度新型航天高温形状记忆材料

New astronautic high temperature shape memory material with high recovery stress and low density

针对当前高温形状记忆合金材料加工难度大、密度较高,而高温形状记忆聚合物材料回复应力小、难以满足实际应用需求的问题,制备了一种高回复力、低密度的新型高温形状记忆聚酰亚胺复合材料。该材料通过在形状记忆聚酰亚胺基体中引入双向碳纤维布作为增强相而制得,其玻璃转化温度为303℃,回复应力达130 MPa、密度为0.98×10^3 kg/m^3。其回复应力媲美一些高温形状记忆合金,远高于其他形状记忆聚合物材料,但密度则不足合金的1/6。研究结果表明,该材料在形状回复过程中,能够掀翻为其自身重量170倍的金属板,在高温连接套管、自动开尾栓、弹性变形翼等领域有重要的应用前景。

Recovery stress is crucial for the shape memory materials during function and the low recovery stress of shape memory polymer(SMP)limits their practical applications greatly,whereas the shape memory alloy(SMA)with high recovery stress needs complex and difficult processing technology.Herein,the shape memory polyimide with high recovery stress(SMPI-HRS)is easily prepared by reinforcing SMPI with carbon fiber cloth,and it possesses recovery stress of 130 MPa,glass transition temperature of 303℃and low density of 0.98×10^3 kg/m^3.Its recovery stress is comparable to those of some high temperature shape memory alloys(HTSMA)and far higher than those of other SMPs,meantime its density is less than one sixth of that of HTSMA.The SMPI-HRS can overturn metal sheet about 170 times heavier than its own weight during shape recovery,and it has great potentials in a broad range of applications such as high tem-perature adapter sleeve,automatic tail bolt and elastic wings.