Effects of physicochemical treatments of illite on the thermo-mechanical properties and thermal stability of illite/epoxy composites

In this study, the effects of physicochemical treatments of illite on thermo-mechanical properties and thermal stability of the hybrid illite/epoxy composites were investigated. Illite was chemically modified with octadecylamine (ODA), to become more organophilic and also physically modified by wet ball-milling process, so that the illite dispersion in the epoxy matrix and interfacial adhesion between illite and epoxy resin could be improved. Then, as-received illite and physically and/or chemically modified illites were mixed with epoxy separately to produce hybrid illite/epoxy composites and their thermo-mechanical properties and thermal stability were investigated. Chemical modification was confirmed with FTIR and the aforementioned properties of illite/epoxy composites were characterized with SEM, DMA, and TGA. IR results show that ODA modification of illite was successful and thermo-mechanical properties were enhanced with illite introduction to the epoxy resin, especially when physically and chemically modified illite was added, showing about 100% increase in storage and loss modulus, compared to the pure epoxy. However, thermal stability was not enhanced by forming the illite/epoxy composites, because the composites prepared in this study were intercalated and flocculated illite/epoxy microcomposites.