Effect of trifluoromethyl-containing diamine monomers on properties of polyimide films
Six kinds of trifluoromethyl-containing transparent polyimide(PI)films with different proportions of diamine monomers were prepared through ternary copolymerization of two trifluoromethyl-containing diamine monomers including 2,2'-bis(trifluoromethyl)-4,4'-diamino biphenyl(TFMB),2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane(HFBAPP)with 4,4'-biphenyl ether dianhydride(ODPA).The effects of the two diamine monomers,TFMB and HFBAPP,on the structure,thermal performances,mechanical and optical properties of the PI films were studied.The results show that the thermal imidization of PI films is completely finished and the fluorinated groups are introduced.The PI films have good thermal performanc-es,the glass transition temperature of the films is 230.5-245.2℃,the 5%heat loss temperature is 480.9-503.7℃,and the 10%heat loss temperature is 517.3-534.0℃,When the molar ratio of TFMB and HFBAPP is 8∶2,the film has the best thermal perfor-mances.The addition of TFMB can improve the tensile strength of the films.When the molar ratio of TFMB and HFBAPP is 6∶4,the film's tensile strength is the highest,up to 95.26 MPa,but the elongation at break is only 4.40%.All PI films have good optical properties,the maximum transmittance in the UV-visible range is above 86.47%,and when the molar ratio of TFMB and HFBAPP is 5∶5,the optical properties of the films are the best,and the transmittance at 450 nm is 87.28%,and the maximum transmittance in the UV-visible range is 91.34%.The above results show that introducing TFMB into HFBAPP in moderation is beneficial to improve the properties of PI films.
万方数据
维普
