Influence of biomass on the curing of novolac-composites
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Karagiannis, K
(EN)
Simitzis, J
(EN)
Zoumpoulakis, L
(EN)
Novolac resin (N) was cured with hexamethylenetetramine (hexa) without or with biomass (B). The agricultural/industrial by-product of olive stones was used as biomass. The curing was followed by DSC and i.r.-spectroscopy and the kinetic of curing was performed based on DSC scans. For the cured composites having high amounts of hexa (28.6%), the characteristic peaks of hexa were present, whereas for the material having low amounts of hexa (10%) these peaks disappeared. The composites containing high proportions of novolac (N = 70%) exhibit the same values of the enthalpy changes Delta H and Delta H-m, the latter calculated from the law of mixtures, whereas the composites with high proportion of biomass (B = 30%) show different values of Delta H and Delta H-m. The kinetic parameters of activation energy E and frequency factor k(o) of the total curing reaction of novolac with hexa are almost the same for high amounts of hexa (20%, 28.6%) but are slightly increased with decreased amounts of hexa (10%, 5%). The incorporation of biomass in the mass of novolac-hexa leads to an increase of E and k(o). Generally, the curing reaction for all materials is a first order reaction. Copyright (C) 1996 Elsevier Science Ltd
(EN)
