PREPARATION AND CHARACTERIZATION OF PA-BASED COMPOSITES

Abstract

New transparent organIc-InorganIc hybrid materials were synthesized by introducing alumina and titania networks In ploy(trimethylhexamethylene terephthalamide) matrix USIng sol-gel process. Various proportions of titanium-IVbutoxide and aluminium-tri-sec-butoxide were mixed in polyamide using anhydrous dimethylformamide as solvent. After complete mixing the metal alkoxides were hydrolyzed and condensed in-situ, using diethylamine as catalyst. Transparent films containing various proportions of alumina and titania were obtained by solvent elution technique. Optical, mechanical and dynamic mechanical thermal measurements were carried out on these hybrid films. An increase in tensile modulus was observed for hybrid films containing alumina upto 5-wt. % while this value increased in case of titania hybrids upto 10-wt. %. However, the percent elongation at rupture was found to increase first then decreased for alumina system on further addition of ceramic contents while titania system showed decreasing trend. Dynamic mechanical thermal analysis performed on the samples indicates an increase in the glass transition temperature. The pure polyamide sample gave glass transition temperature at 101°C and 140°C for the fi lm having I5-wt.% of alumina in the matrix. In case of titania system, the 10-wt.% titania sample exhibited glass transition temperature value at 155°C. The storage modulus was also found to increase with increase in inorganic contents in the matrix. The decrease in the storage modulus of the hybrids with increase in temperature was observed to be much smaller as compared to that of pure polymer.