In this study, a low molecular weight epoxy resin diglycidyl ether of bisphenol A (DGEBA) is cured isothermally with an aliphatic and aromatic amine hardeners separately. (1) Triethylenetetramine (TETA), (2) diamino diphenylmethane (DDM). The samples were prepared for different hardener/resin ratios, (under stoichiometry, stoichiometry and above stoichimetry). The mechanical Properties impact strength, tensile strength, hardness, flexural strength, compression strength and bending strength of an epoxy system has been investigated in this work. For DGEBA/TETA system the tests were done on four hardener/resin ratios (10, 13, 15 and 20) phr and for DGEBA/DDM system the hardener/resin ratios were four also; (24, 27, 30 and 34) phr. The results showed
that the above stoichiometry ratio formulation (15 phr for DGEBA/TETA system and 30 phr for DGEBA/DDM system) gave the best mechanical properties, while the DGEBA/DDM system showed better mechanical properties than the DGEBA/TETA system.