Studies on thermal, mechanical and morphological properties of organoclay filled azomethine modified epoxy nanocomposites

Abstract

Inter cross-linked networks of organoclay-filled, azomethine-modified epoxy nanocomposites have been developed. Two types of azomethine epoxies (AE1 and AE2) incorporated into diglycidyl ether of bisphenol A (DGEBA) epoxy resin with varying percentages (5, 10 and 15%) were cured with diamine diphenyl methane (DDM). The azomethine epoxies were synthesized and characterized by Fourier transform infrared and 1H-NMR spectroscopy. The incorporation of azomethine epoxies into DGEBA epoxy resin improved both thermal and mechanical properties to an appreciable extent. The introduction of organoclay into DGEBA epoxy resin exhibited almost similar characteristics to that of the azomethine-modified DGEBA epoxy resin. Both azomethine epoxy and organoclay have been incorporated into DGEBA epoxy resin in order to improve the thermal and mechanical properties in comparing other modified epoxies. The glass transition temperature and thermal degradation temperature of azomethine-modified epoxies, organoclay-filled epoxy and organoclay-filled azomethine-modified DGEBA epoxies were determined by using differential scanning calorimeter and thermogravimetric analysis. The mechanical properties, namely the tensile strength, flexural strength and impact strength of the resultant nanocomposites were studied as per ASTM standards. X-ray diffraction studies of the cured nanocomposites indicate that the organophillic montmorillonite clay was exfoliated into the cured product. The homogeneous morphology of azomethine-modified DGEBA epoxy and organoclay-filled azomethine-modified epoxy were ascertained by scanning electron microscopy.