Abstract:
Conventional thermal and microwave curings were used to cure fly ash/epoxy composites and the
mechanical and morphological properties of the composites were evaluated with respect to the
effects of fly ash content and silane coupling agent content The conventional thermal curing was
performed at 70oC for 80 min and microwave curing was carried out at 240 watt for 18 min for
achieving the optimum percentage cures of the composites, determined using a Differential
Scanning Calorimeter (DSC). The results suggested that the tensile, flexural and impact strengths,
and elongation at break decreased with idcreasing fly ash content while the effect became opposite'
for the tensile and flexural moduli, and hardness. It was found that the overall mechanical properties
of the composite could be obtained through use ofN-2(aminoethyl)-3-aminopropyltrimethoxysilane
(KBM603) coupling agent. The silane concentrations of 0.5wf% were recommended for the
optimum mechanical properties of the fly ash/epoxy composites. Beyond this recommended
content, the mechanical properties greatly reduced, except for the flexural modulus. 80 phr of fly
ash were recommended in this work for high modulus composites. The comparative results
indicated that the composites by the microwave cure used shorter cure time and had higher ultimate
strengths and elongation at break than those by the conventional thermal cure, while the composites
with higher tensile and flexural moduli, and greater hardness could be obtained if the conventional
thermal cure was used.