Nanoclay reinforcement of liquid silicone rubber

Siloxane modified montmorillonite clay was prepared from sodium montmorillonite and quaternary ammonium-containing siloxane surfactant. X-ray diffraction and Fourier transform infrared analyses indicated that the polysiloxane oligomer chains were successfully grafted onto the surface of the montmorillonite clay platelets. The siloxane modified montmorillonite clay and commercial organo-modified montmorillonite and bentonite clays were incorporated into a rapid-cure liquid silicone rubber (LSR) matrix. The morphologies of the LSR/nanoclay composites were analyzed by SEM and TEM, and partial exfoliation of the silicate nanolayers of the clay platelets was observed. Up to a 20% reduction in water vapor permeability was achieved as well as a 24% improvement in tear strength and a 40% improvement in the compression set.