THERMAL DEGRADATION OF EPOXY FOAMS REINFORCED WITH RICE HUSK ASH

D. GARCÍA; R. BALART; J. LÓPEZ; P.M. STEFANI; A. JIMENEZ

Lyon-Francia

Congreso; MODEST 2004; 2004

Féderétian de Polyméristes Lyonnais

Epoxy foams have been recently developed due to their high thermal and chemical stability. But one of their main drawbacks is their high price when used in industrial processing at high amounts. The addition of waste products, such as rice husk ash, could contribute to the reduction of costs and to improve their mechanical properties. The aim of this work is the characterization of the thermal behaviour of such systems. Two different rice husk ashes were used to modify epoxy foams, black ash obtained from pyrolysis of rice husk in argon atmosphere and white ash obtained by combustion in air of the samples. TGA tests were carried out in nitrogen and oxygen atmospheres in order to obtain the main thermal parameters of blends (mainly degradation temperatures and kinetic parameters) at different degradation conditions. Some differences in the thermal behaviour with the change atmosphere were observed. A certain influence of thermooxidative conditions will contribute to an acceleration of the thermal degradation of such blends. Kinetic parameters were calculated by using the isoconversional Friedman method, which can be applied in an easiest way, as well as give more homogeneous results in apparent activation energies. The main conclusion of this study indicates that it is possible to modified the epoxy foam with waste products, leading to a reduction in costs as well as a better mechanical behaviour without significant losses in thermal stability.