Preparation and properties of poly(amide-imide) containing acetylene unitsin the main chain

Poly(amide-imide) containing internal acetylene units in the backbone was p repared from trimellitic anhydride chloride and bis(3-aminophenyl)acetylene in N-methyl-2-pyrrolidone at room temperature, followed by thermal imidiza tion. Differential scanning calorimetry measurements of the poly(amide imid e) showed an exotherm due to the crosslinking reaction of the internal acet ylene units. With higher heat treatment, the exotherm shifted to higher tem peratures and the amount of the exotherm decreased. The exotherm finally di sappeared after 400 degreesC treatment. Viscoelastic measurements revealed that the crosslinked polymer had a higher glass transition temperature and maintained a storage modulus up to higher temperatures. The thermogravimetr ic analyses profile showed that the crosslinking of internal acetylene unit s gave a thermally stable structure.