Silicon-containing poly(amide-imide)s: preparation, characterization, and properties

Reactions of 3-aminophenol with dichlorodiphenylsilane in the presence of triethylamine resulted in the preparation of a diamine named as bis(m-aminophenoxy)diphenylsilane. Reaction of the diamine with two moles of trimellitic anhydride led to the preparation of a diacid with preformed imide structures. Silicon-containing poly(amide-imide)s were then prepared by polycondensation reactions of the diacid with different diamines in the presence of triphenyl phosphite. All the products and polymers were characterized and the physical properties of the polymers including solubility, solution viscosity, thermal stability, thermal behavior, flameretardency, crystallinity, and morphology were studied. The polymers showed high thermal stability and flameretardency, as well as enhanced solubility in polar solvents. The glass transition temperature of the polymers was about 187-196 degrees C, the temperature for 10% gravimetric loss was in the range of 375-400 degrees C, and also the weight of the polymer remaining at 700 degrees C was about 39-44%. They were flame-retardant, soluble in dipolar aprotic solvents, and showed some crystalline structures.