Mechanical and Thermal Stability of Epoxy – TEOS Hybrids Materi-als using Sol-Gel Method

Abstract

Sol-gel method is the simplest method and has to preparation of nano particles, nano fibers, and nano flaks. The preparation of hybrid epoxy thermosets enables their improvement in characteristics such as mechanical properties (bending,and hardness), thermal properties. The effect of water absorption on bending and hardness test for tetraethylorthosilicate (TEOS) and epoxy hybrid have been investigated. TEOS with (0%,2%,4%,6%and 8%) volume percentage mixed with epoxy to prepared sheets of hybrid, these sheets cut as samples for ASTM water absorption, bending and hardness tests.The results show that, adding TEOS to epoxy will increase absorbance of water. bending test shows that there are increase in values of bending stress with increasing TEOS but after immersion in water all the values for bending stress will reduce. Hardnessvalues at least for the samples immersion in water from dry samples, occur the diffusion of molecules water in the polymer and hybrids leads to space molecular chains for each other and decrease the hardness values. Thermal stability of hybrids increase with increasing TEOS ratio, the glass and decomposition temperature were shift compare with epoxy pure.