Particulate-reinforced thermoplastic composites are designed to improve the properties and to lower the overall cost of engineering polymers. In general, the performance of filled polymers is decided on the basis of the interface attraction of filler and polymers. Therefore, a coupling agent, tetra isopropyl titanate (TYZOR TPT), was used to facilitate the link between filler and matrix (the latter consisting of nylon-6). Mica of different particle sizes (37 and 75 mu m) was used. Filler (75 mu m mica) was added to the matrix at a 30 wt% concentration. TPT at various concentrations was used to determine the optimal concentration (1 wt%), and henceforth to treat both particle sizes of mica. The tensile strength, Young's modulus, and heat distortion temperature were significantly improved with the incorporation of TPT (11 wt%). Morphological studies revealed strong interfacial interactions between the filler and the matrix on incorporating TPT.