The kinetics of polystyrene melt intercalation in organically modified mica-type silicates were studied using X-ray diffraction and transmission electron microscopy. By monitoring the change in the integrated intensity of the basal reflection of the silicate host, the rate of conversion from unintercalated to intercalated silicate was determined at various temperatures and for various molecular weights of polystyrene. Hybrid formation is limited by mass transport into the primary particles of the host silicate and not specifically by diffusion of the polymer chains within the silicate galleries. The activation energy of hybrid formation is similar to that previously measured for polystyrene self-diffusion in the melt, implying that the mobility of the polymer chains within the host galleries is at least comparable to that in the melt.