Photosensitive polyamide/layered silicate nanocomposites (PAN) were prepared via a solution polymerisation process from polyamide 3 containing chalcone moieties and organo-MMT in a solution of N,N-dimethylacetamide. Incorporation of small amounts of an organoclay can reduce the coefficient of thermal expansion (CTE) of photosensitive polymer formulations (photoresists). The organoclay was examined for its dispersion behaviour in the polyamide matrix. Polyamide chains were synthesised from 4,4'-diaminochalcone 2 and terephthaloyl chloride (TPC) in dimethylacetamide. These amide chains were selectively end-capped with carbonyl chloride end groups to interact chemically with modified montmorillonite clay. The resulting composite films containing 5-15 wt.% of organoclay were characterized by SEM, XRD, TGA, DSC and water absorption measurements. The distribution of organoclay and nanostructure in the composites was investigated by XRD and SEM analyses. The photosensitive properties of the polyamide 6 in the DMF solution were studied by UV spectrophotometry. The nanocomposites exhibited increases in their glass transition temperatures relative to pristine polyamide, implying interfacial interactions between the two phases. The percentage water absorptions of the polymers were found to be much reduced upon the addition of modified layered silicates indicating decreased permeability. 20 Refs.
