Preparation and properties of new photosensitive polyimides from bis(4‐aminophenyl)tetramethyldisilane and various aromatic tetracarboxylic dianhydrides

Abstract

AbstractNew photosensitive polymides containing photosensitive disilane unit were synthesised from 1,2‐bis(4‐aminophenyl)tetramethyldisilane and various aromatic tetracarboxylic dianhydrides by the usual two‐step procedure that includes ring‐opening polyaddition to yield the precursor polyamic acids, followed by cyclodehydration giving the respective polyimides. The polymaic acids had inherent viscosities between 0.63 and 0.85 dL/g depending on the tetracarboxylic dianhydride used. Excepting the polyimide obtained from pyromellitic dianhydride, all other polyimides were soluble in N‐methyl‐2‐pyrrolidone, m‐cresol, and pyridine. While the polyimide containing diphenyl sulfone unit was amorphous, the other polyimides were semi‐crystalline polymers based on their x‐ray diffractograms. The polyimides had glass transition temperatures between 235 and 304°C. They were thermally stable up to 380°C in both air and nitrogen atmospheres. All the polyamic acids showed a drastic decrease in the inherent viscosity upon UV light irradiation, implying the inherent photosensitivity of the polymers containing the disilane moiety.