Preparation and properties of disilane‐containing photodegradable aromatic polyamides from bis(p‐aminophenyl)tetramethyldisilane and aromatic diacid chlorides

Abstract 1,2‐Bis(p‐aminophenyl)tetramethyldisilane was synthesized from 1,2‐dichlorotetramethyldisilane and 4‐[N,N‐bis(trimethylsilyl)amino]phenyllithium. The diamine was reacted with various aromatic diacid chlorides giving disilane‐containing aromatic polyamides (aramids), whose inherent viscosities were between 0.27 and 0.70 dL/g, depending on the diacid chlorides used. The aramids had glass transition temperatures between 194 and 255°C. No weight loss was observed below 350°C. Some of the polymers were found to be semicrystalline based on their x‐ray diffractograms. The aramid films showed a strong ultraviolet (UV) absorption at 287 nm, which decreased during irradiation with UV light, suggesting that cleavage of the silicon‐silicon bond in the aramid backbone occurs. A decrease in the inherent viscosity and molecular weight of the soluble aramid derived from phenylindanedicarbonyl chloride was also observed by irradiation with UV light.