Improvement of the adhesion properties of silicone rubber by the incorporation of silane-modified montmorillonite

A silicone rubber precursor was amended by the incorporation of γ‐aminopropyl triethoxysilane (APS) into siloxane to prepare an elastomeric thermal insulator adhering to the isocyanate‐group‐containing liner sheets, which are actually used to envelop rocket propellants. This improved adhesion may protect the liners of the rocket motor cases efficiently against the hot combustion gas. Clay was modified by cationic exchange with an amine compound, and the resulting clay was further treated with APS and N‐(2‐aminoethyl)‐3‐aminopropyl trimethoxysilane to introduce amine groups onto the surface of the clay to further improve the adhesion of the silicone rubber to the liner. The neat and modified clays were compounded with the APS‐amended silicone rubber [room‐temperature vulcanizate (RTV)]. The effects of the clay modification on the adhesion properties were explored. The peel strength between the liner and the room‐temperature silicone rubber (RTV) based on siloxane was 0, whereas the peel strength increased to 3.7 N/cm when the silicone rubber was amended with APS. The peel strength between APS–RTV and the liner was lower than 3.7 N/cm when clay was added, whereas the peel strength became higher than 5.7 N/cm so that APS–RTV could not withstand the peeling force and was torn off before the delamination when the amine silane modified clay was added instead of clay. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013