INFLUENCE OF ACID-BASE PROPERTIES OF OXIDE FILLERS ON THE FREE SURFACE ENERGY OF EPOXY-POLYMER MATERIALS
Journal Title: Збірник наукових праць Українського державного університету залізничного транспорту - Year 2018, Vol 178, Issue 12
Abstract
The Van Oss-Chaudari-Hood (VOCH) method were used to determine the free surface energy (FSE) components of epoxy polymer composite materials, steel and glass. The research was carried out on the basis of experimental determination of boundary angle of wetting of solid surfaces with test liquids. Test liquids were used: distilled water, formamide and α-bromonaphthalene. It is established that the FSE values calculated using the computer program of calculations "Least Square Wetting Analyzer" correlate satisfactorily with the data of other authors. As materials for research, selected filled polymeric compositions based on epoxy resin of the brand ED-20 and aliphatic amine curing agent of diethylenetriamine DETA brand. The compositions solidified in the air (293-298 K) for at least 72 hours, at a temperature of 373 K - 4 hours. Oxide fillers were air-dry disperse materials based on oxides of different chemical nature of Fe2O3, TiO2, CaO. For fillers, studies were performed using scanning electron microscopy and X-ray diffraction analysis. To determine the spectrum pKa and the number of active centers on the surface of the fillers, the method of adsorption Gamet color indicators from aqueous solutions was used. It is established that the nature of the surface of the fillers is directly proportional to the acid-base properties of oxides. It is shown that with the growth of the total number of active centers of oxide fillers, the value of the constituents of the FSE (total γs, dispersion γd and acid-base γab) of composites grows in direct proportion. The presence of acid-base active centers on the surface of oxide fillers affects the values of all constituents of FSE filled composites. It was found that the ambiguous effect of the surface properties of oxide fillers on acidic γa and basic γb components of the FSE of composites is related to interphase acid-base interactions. The determined regularities will allow predicting the change of surface energy characteristics of epoxy polymer composite materials and their properties when modified with oxide fillers of different chemical nature.
Authors and Affiliations
Yuliya Danchenko, Tatiana Obigenko, Maria Kachomanova, Mykhailo Teslenko
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