Improving the water resistance of epoxy–anhydride matrices by the incorporation of bentonite

Abstract

Epoxy-anhydride based polymers are commonly used as a matrix in pipeline systemsexposed to water during their in-service life. Water absorption at moderatetemperatures and/or at long exposure times could lead to irreversible hydrolysisreaction decreasing considerably the polymer overall performance. A strategy toenhance the barrier properties of epoxy resins is to add nano-fillers to traditional matrices. In this work, we added bentonite and chemically modified bentonite to this purpose. Water absorption of the resulting materials at three different temperatures (22°C, 80 °C and 93 °C) was studied and simultaneously, the evolution during the immersion tests of glass transition temperature and flexural modulus was recorded.Long-term gravimetric results showed that composites with chemically modified bentonite produce a delay on the hydrolysis of epoxy-anhydride matrix, which is a relevant result, due to the tough application and uses of the system, from the technological point of view.