hrvatski

Priprava i karakterizacija fenolformaldehidnih smola modificiranih dodatkom epoksida i p-krezola

An introductory investigation of potentially flexible phenolic resins is described in this paper. Modified resole resins were synthesised: epoxy additive diglycidylether of butandiol (DGEBD) was used to introduce flexible crosslinking moieties and p-cresole was added to reduce the crosslinking density. Curing behaviour of the resins as well as thermal properties of cured samples were studied by the differential scanning calorimetry method (DSC). Enthalpies of endothermic low-temperature curing reactions in the temperature range of 120 to 165 °C were determined. A transition phenomenon is observed in the samples cured at 180 °C, that may be attributed to the wide (120&middot ; &middot ; &middot ; 170 °C) low-intensity glass transition. The temperature range of the transition is lower in comparison to unmodified resins (>150 °C). This may indicate a certain degree of the flexibilisation.

fenol-formaldehidne smole; epoksid; p-krezol; fleksibilnost; diferencijalna pretražna kalorimetrija

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