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U. Szeluga, L. Kurzeja, H. Galina

Modification of epoxy-novolak compositions with reactive rubbers and coal as a filler

Polimery 2006, No 11-12, 809


Summary

The effects of types and amounts of the additives: butadiene-acrylonitrile rubbers, with carboxyl or epoxy groups as chain ends (CTBN and ETBN, respectively), on mechanical properties and morphology of epoxy composition consisting of low molecular weight epoxy resin, type Bisphenol A diglycidyl ether („Epikote 827”), phenol-formaldehyde novolak (NZ) and up to 16 wt. % of coal showing medium metamorphism degree as a filler, were investigated. Mechanical properties were evaluated using static (Table 1) and dynamic methods (DMTA, Fig. 1-6). Optical microscopy and transmission electron microscopy (TEM) methods were used to study the morphology of the products. DMTA analyses results showed the effects of CTBN and ETBN on storage modulus (E') in the whole range of measurement temperature (from room temperature up to 250°C). The effect of rubber addition on glass transition temperature (Tg, evaluated as maximum tg δ) of tested cured compositions is marginal. It was found that the addition of only coal filler deteriorated mechanical strength and impact strength of the composition while introduction of a system: coal filler/rubber did not cause that adverse effect. It was also found that morphology and phase separation influenced the mechanical properties significantly (Fig. 7-10). The optimal concentration of CTBN or ETBN rubber introduced to the composition containing - or not - the coal filler is 6 wt. %. This amount of a rubber does not lower Tg of the composition yet.


Key words: epoxy resins, modification, reactive rubbers, coal filler, phase separation, mechanical properties, morphologygy


e-mail: ula@karboch.gliwice.pl


U. Szeluga, L. Kurzeja, H. Galina

Modification of epoxy-novolak compositions with reactive rubbers and coal as a filler