通过Yamazaki聚合方法,将4-(4-三氟甲基苯基)-2,6-二(4-胺基苯基)吡啶(TMPBAPP)分别和9,9-二[4-(4-羧基苯氧基)苯基]呫吨(BCPX)和1,1-二[4-(4-羧基苯氧基)苯基]环己烷(BCPC)进行缩聚反应,合成了2种高相对分子质量的Cardo型氟化聚吡啶酰胺,并以FTIR、DSC、WAXD等方法对其结构和性能进行了表征.结果表明:2种聚合物的玻璃化转变温度分别为252℃和290℃,对数比浓黏度分别为0.78 d L·g^-1和0.98 d L·g^-1.在氮气气氛中,5%的热失重温度分别为435℃和500℃,800℃时的残炭率分别为55%和58%,均为无定形结构;2种聚合物均易溶于N-甲基吡咯烷酮、N,N-二甲基乙酰胺、间甲酚等有机溶剂中,并可浇注得到韧性好而透明的薄膜,其拉伸强度分别为78 MPa和86 MPa,拉伸膜量分别为2.2 GPa和2.6 GPa,断裂伸长率分别为9%和13%.同时,合成的聚合物具有良好的透光率(截断波长分别为340 nm和376 nm),体积电阻、表面电阻和介电常数分别为8.45-8.78×10^15Ω·cm、9.52-9.82×10^14Ω和3.46-3.60(100 Hz),呈现了良好的电绝缘性能.
Two new fluorinated aromatic cardo poly( pyridine amide) s were prepared from 4-( 4-trifluoromethylphenyl)-2,6-bis( 4-aminophenyl) pyridine( TMPBAPP) with 9,9-bis [4-( 4-carboxyphenoxy) phenyl]xanthene( BCPX) and 1,1-bis[4-( 4-carboxyphenoxy) phenyl]cycolhexane( BCPC) using Yamazaki method via direct polycondensation,respectively. The structure and properties of the resulting polymers were studied by FTIR,DSC and WAXD techniques,etc. These obtained polyamides with amorphous structures had high molecular weight with the inherent viscosity of 0. 78 - 0. 98 d L·g^-1,glass t ransition temperature of 252 - 290 ℃ and 5% mass loss temperature of 435 - 500 ℃ and char yield of 30% - 58% at 800 ℃ under N2. The polymers were readily soluble in polar solvents such as NMP,DMF and m-cresol. Transparent,flexible,and tough film of the polymer cast from DMAc solution exhibited tensile strength of 78 - 86 MPa,elongation at break of 9% - 13%,tensile modulus of 2. 2 - 2. 6 GPa.The new polyamides exhibited high transparency with an ultraviolet-visible absorption cut-off wavelength in the range of 340 - 376 nm,and their electrical properties such as the volume resistivity of 8. 45 - 8. 78 × 10^15Ω· cm,surface resistivity of 9. 52 - 9. 82 × 10^14Ω and dielectric constant of 3. 46 - 3. 60( 100 Hz) indicated their excelllent electrical resistance property.