Curing Kinetics, Thermal and Mechanical Properties of Epoxy Layered Silicate Nanocomposite Toughened With Modified Natural Rubber

摘要

The glass transition temperature, T-g, curing kinetics, mechanical properties and morphology of the diglycidyl ether of bisphenol A (DGEBA) toughened with liquid epoxidised natural rubber (LENR) and Cloisite 30B as filler were studied. Poly(etheramine) was used as the curing agent at different ratios. Mechanical stirring was used for the mixing process and the samples were cured at room temperature. Generally, it was found that epoxy toughened with modified natural rubber showed higher values of T-g compared to the unmodified epoxy system. Compared to other epoxy-LENR samples, five grams of LENR per 100g of epoxy resin produced a higher result for the tensile Young's modulus. The addition of clay nanoparticles (Cloisite 30B) with a high amine ratio increased the Tg and mechanical properties of the system. The activation energy, Ea of the curing reaction was obtained using the Kissinger and Flynn-Wall-Ozawa method. The ternary system containing 2g of Cloisite 30B in 5g of LENR per 100g of epoxy resin (R5C2 system) showed the lowest E-a value. This system reached maximum curing in the shortest time. It was observed that a higher amount of rubber content in the material gave larger size rubber particles and hence, led to lower mechanical properties. SEM images of fractured samples showed that adhesion of rubber with epoxy seemed to be poor when using higher rubber content while the use of lower amine ratio material might result in unreacted areas that imparted poor mechanical properties.