Title: The effect of the moisture state of samples on the change in the elastic-strength parameters of epoxy polymers during natural climatic ageing

Authors: D.R. Nizin; T.A. Nizina; V.P. Selyaev; N.S. Kanaeva

Addresses: Department of Building Structures, Ogarev Mordovia State University, 68 Bolshevistskaya Street, Saransk, The Republic of Mordovia, 430005, Russia ' Department of Building Structures, Ogarev Mordovia State University, 68 Bolshevistskaya Street, Saransk, The Republic of Mordovia, 430005, Russia ' Department of Building Structures, Ogarev Mordovia State University, 68 Bolshevistskaya Street, Saransk, The Republic of Mordovia, 430005, Russia; Russian Academy of Architecture and Building Science, Research Institute of Building Physics, Moscow, Locomotive passage, 21, 127238, Russia ' Department of Building Structures, Ogarev Mordovia State University, 68 Bolshevistskaya Street, Saransk, The Republic of Mordovia, 430005, Russia

Abstract: The paper provides the results of studying the effect of the moisture state of epoxy polymers on the change in their elastic-strength parameters during natural ageing in a temperate continental climate. The object of the study was a polymer material based on Etal-247 modified epoxy resin and Etal-45M hardener. Based on the results of the studies, we determined the similarity of the curves of the change in the tensile strength of the samples under tension in the limiting equilibrium-moisture states (dried and moisturesaturated). Depending on the duration of natural climatic ageing, the range of variation in the tensile strength of samples in extreme moisture conditions is from 16 to 34% of the tensile strength in the dried state. The synergistic effect between irreversible structural changes in the polymer matrix under the effect of environmental factors and adsorbed moisture has been identified and quantified, which is expressed both in the expansion and contraction of the reversible moisture range effect. It has been established that for the late stages of natural climatic ageing of epoxy polymer samples based on Etal-247 epoxy resin and Etal-45M hardener, the point of maximum elongation under tension does not coincide with the point corresponding to the dried state.

Keywords: epoxy polymers; moisture content; tensile strength; elongation; reversible changes; irreversible changes; synergistic changes.

DOI: 10.1504/IJNT.2024.136510

International Journal of Nanotechnology, 2024 Vol.21 No.1/2, pp.59 - 68

Published online: 05 Feb 2024 *

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