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The proper selection of adhesive composition components during the bonding process is a fundamental
issue. As the requirements for constructions using assembly joints are increasing, the basic
adhesives are often subject to extensive modifications. The most common way to modify structural
adhesives is to physically modify them, which involves inserting fillers into the adhesive. The aim of the
research was to determine the impact of physical modification of epoxy adhesive compositions. Epoxy
compositions made on the basis of solvent-free Epidian 5 epoxy resin and three types of curing agents:
TFF Mannich-type principle, Z-1 amine hardener and PAC polyamide hardener were tested. The compositions
were modified using three fillers of natural origin: NanoBent ZR2 montmorillonite, CaCO3calcium carbonate and CWZ-22 active carbon. Each filler was added in the amount of 5 wt. % of
the composition. For comparison purposes samples made of unmodified composition were also tested.
Adhesive samples in cured state were tested. The influence of modification on selected mechanical
properties of the composition - tensile, compressive and bending strength was verified. The analysis of
the obtained results showed that the addition of a filler to the matrix of the adhesive composition does
not always improve the analyzed properties. The highest tensile strength was obtained for Epidian 5
epoxy resin composition, TFF curing agent and CaCO3 calcium carbonate. The distribution of results
was similar in case of compression strength analysis. When considering the bending strength, the tests
were carried out in a three-point bending test. In case of all the compositions, the modification resulted
in deterioration of the results obtained, however, among the modified ones, the composition of Epidian
5 epoxy resin, TFF curing agent and CaCO3 calcium carbonate also obtained the highest bending
strength. In order to precisely analyze the obtained results, a statistical analysis of the results was carried
out using ANOVA statistics. Additionally, the cracking surface of epoxy compositions was analyzed
using a scanning electron microscope in order to assess the distribution of fillers in the structure of
cured adhesive.
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