耐辐照透明聚酰亚胺的制备与性能研究

Preparation and Properties of Irradiation-resistant Transparent Polyimide

近年来,聚酰亚胺材料得益于自身优异的力学性能、良好的热稳定性能、轻质柔性、易成型加工等技术优势,在空间用太阳电池柔性盖片等领域表现出广阔的应用前景,但是其光学透明度和耐辐照性能仍有待提高.将2,2'-二(三氟甲基)二氨基联苯、1,4-双(4-氨基-2-三氟甲基苯氧基)苯和4,4'-(六氟异丙烯)二酞酸酐共聚,并掺杂离子液体1-乙基-3-甲基咪唑啉双(三氟甲基磺酰基)亚胺,制备得到了一种新型透明聚酰亚胺薄膜;进而利用电子束蒸镀技术,在聚酰亚胺薄膜表面依次蒸镀氟化镁和二氧化硅两层增透膜,获得了新型二氧化硅/氟化镁/透明聚酰亚胺(SiO_(2)/MgF_(2)/CPI)复合薄膜.通过对材料的热学、力学和光学性能的研究表明,这种新型SiO_(2)/MgF_(2)/CPI复合薄膜的初始热分解温度为394.8℃,拉伸强度达到65.81 MPa,在550 nm处透光率高达93.43%.经过能量为50 keV、注量分别为4×10^(14)、2×10^(15)、4×10^(15) e/cm^(2)的电子辐照后,SiO_(2)/MgF_(2)/CPI复合薄膜的热稳定性、透光率和力学性能均没有显著下降,表现出优异的耐辐照性能,在空间飞行器太阳电池柔性盖片等领域有良好的应用前景.

In recent years,polyimide has shown great application prospects in the fields of cover sheet for space solar cell due to its outstanding mechanical property,excellent thermal stability,light weight,easy processing and other properties.However,the transparency and irradiation-resistant properties of optically transparent polyimides need to be further improved.Herein,a new transparent polyimide film is prepared by the copolymerization of 2,2'-bis(trifluoromethyl)diaminobenzene,1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene and 4,4'-(hexafluoroisopropylidene)diphthalic anhydride and doping with fluorine-containing ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide.Magnesium fluoride and silicon dioxide antireflective films are successively coated on the surface of the polyimide film by electron beam evaporation technology,and a novel silicon dioxide/magnesium fluoride/transparent polyimide(SiO_(2)/MgF_(2)/CPI)composite film that can be used as cover sheet for solar cell is obtained.The investigation of the thermal,optical,mechanical and irradiation-resistant properties shows that the initial thermal decomposition temperature of this SiO_(2)/MgF_(2)/CPI composite film is 394.8℃,the tensile strength reaches 65.81 MPa,and the light transmittance at 550 nm is as high as 93.43%.After electron irradiation with electron energy of 50 keV and irradiation fluences of 4×10^(14),2×10^(15) and 4×10^(15) e/cm^(2),the thermal stability,light transmittance and mechanical properties of the SiO_(2)/MgF_(2)/CPI composite film have no significant decrease,showing excellent irradiation-resistant property and good application prospect in solar cell cover sheets of space vehicles.