通过Yamazaki聚合方法,将对苯二胺(PPD)、4-(4-三氟甲基苯基)-2,6-二(4-胺基苯基)吡啶(TMPBAPP)和双(4-羧基苯基)苯基氧化膦进行共缩聚反应,合成了一类高相对分子质量含氧化膦和吡啶结构的新型氟化共聚酰胺,并以FTIR、DSC、WAXD等方法对其结构和性能进行了表征.结果表明:共聚物的玻璃化转变温度为252~290℃,对数比浓黏度为0.78 ~ 0.98 dL/g.在氮气气氛中,5%的热失重温度为435 ~500℃,800℃时的残炭率为30%~ 58%,均为无定形结构;聚合物易溶于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,其拉伸强度为78~86 MPa,拉伸膜量为2.2 ~2.6 GPa,断裂伸长率为9%~13%.同时,该聚合物具有良好的透光率(截断波长为340~376 nm),体积电阻、表面电阻和介电常数分别为8.45×10^15 ~ 8.78×10^15Ω·cm、9.52×10^14 ~9.82×10^14Ω和3.46 ~ 3.60(100 Hz),呈现了良好的电绝缘性能.
A new class of fluorinated aromatic copolyamides containing phosphine oxide and pyridine moieties was prepared from p-phenylenediamine ( PPD ), 4- ( 4-trifluoromethylphenyl ) -2,6-bis ( 4-aminophenyl ) pyridine ( TMP- BAPP) and bis(4-carboxyphenyl)phenylphosphine oxide using Yamazaki method via direct polycondensation. The structure and properties of the resulting polymers were studied by FTIR, DSC and WAXD techniques, etc. These ob- tained polyamides with amorphous structures had high molecular weight with the inherent viscosity of 0. 78 ~ 0.98 dL · g- 1 ,glass transition temperature of 252 - 290 ℃ and 5 % mass loss temperature of 435 - 500℃ and char yield of 30% ~ 58% at 800 ℃ under Nz. The polymers could dissolve easily in NMP, DMF and m-cresol. Transparent, flexible, and tough film of the polymer cast from DMAc solution exhibited tensile strength in the range of 78 ~ 86 MPa, elongation at break in the range of 9%- I3 % , tensile modulus in the range of 2.2 -2.6 GPa. The new polyamides had high transparency with an ultraviolet-visible absorption cut-off wavelength of 340 -376 nm, and their electrical properties such as the volume resistivity of 8.45 ×10^15 ~ 8.78×10^15Ω·cm, surface resistivity of 9.52 ×10^14 ~9.82×10^14Ω and dielectric constant of 3.46 ~ 3.60( 100 Hz) indicated their excelllent electrical re- sistance property.