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Glass and carbon fibre reinforced epoxy composites were fabricated for N,N,N',N'-tetraglycidyl-4,4-diaminodiphenyl methane (TGDDM) and its formulated systems with tri-and di-functional reactive epoxy diluents using 30% diaminodiphenyl sulphone (DDS) as a curing agent. The epoxy laminates were evaluated for their physical, chemical and mechanical properties [at room (26°C) and high (lOO°C) temperatures]. A marginal increase (<20%) in the mechanical properties of CFRP was found compared with GFRP laminates. Incorporation of epoxy diluents altered the mechanical properties of the composites significantly. The incorporation of triglycidyl4aminophenol diluent to TGDDM systems resulted in an improvement in mechanical properties of about 2-6%.

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Chlorine-and methyl-substituted aromatic diamines based on diaminodiphenylmethane were epoxidized and characterized. The effect of different substituents on epoxidation was studied. The cure studies of the two new tetrafunctional resins in comparison with unsubstituted resin N,N,NЈ,NЈ-tetraglycidyl-4,4Ј-diaminodiphenylmethane (TGDDM) was carried out by DSC with 3,3Ј-dichloro-4,4Јdiaminodiphenylmethane (o-DCDDM; 30% w/w) as a common curing agent. The mechanical properties such as flexural, Izod impact, heat distortion temperature (HDT), of such cured neat resins were also studied. The results of the cure studies indicate that the substitution of the ␣-hydrogen of the resin by chlorine or methyl group decreases the reactivity of the resin leading to an increase in the shelf life. This study also indicates that the functionality of the resin plays a pivotal role in the reactivity and thus the shelf life of an epoxy resin system. The results of the mechanical properties of the neat resin casts obtained by subjecting to a common cure schedule when compared with the unsubstituted resin showed a decrease in impact strength, which is obvious because of the presence of a bulky pendant group but the impact strength was higher than that of the TGOS30 resin system. Results of flexural strength of the different substituted neat resin casts did not show much of a deviation from that of the unsubstituted resin system. The HDT results indicate no significant difference in the values of the unsubstituted resin vis-a-vis with substituted resin systems.