Epoxidized natural rubber (ENR) was first precured with 3-aminopropylt
riethoxysilane (APS) by the normal compression molding technique. The
resultant sheet was further subjected to moisture cure, via hydrolysis
and condensation reactions, by soaking it in water. The moisture-cure
d sample, when prepared under appropriate reaction conditions, demonst
rated partial strain-induced crystallization behavior and moderate ten
sile strength, as opposed to typical peroxide-cured and sulfur-cured v
ulcanizates. The suitability of the ENR-APS precured sample for in-sit
u silica reinforcement by the sol-gel process, using tetraethyl orthos
ilicate (TEOS) as the silica precursor, was also demonstrated. Silica
content as high as 36% by weight could be incorporated into the rubber
, and TEOS-to-silica conversion of over 60% was observed Comparative a
nalysis with a typical peroxide-cured sample that was subjected to the
same sol-gel process indicates that the silica in the final ENR-APS s
ol-gel vulcanizate is chemically bound to the rubber network.