Mechanical Properties of Epoxy Compounds Based on Bisphenol a Aged in Aqueous Environments

Abstract

(1) Background: The aim of the work is to determine the influence of selected aqueous environments of various types of liquids on the strength of adhesive compositions prepared from epoxy resin based on bisphenol A combined with two different curing agents: tritethylenetetramine and polyaminoamide C. (2) Methods: The cured epoxy adhesive compounds samples were seasoned in four aqueous environments of the liquid: rainwater, demineralized water, tap water, and a sweetened drink. Three variants of the aging time in the above-mentioned operating environments were adopted: one month, two months, and three months. After the specified maturing time, samples of epoxy adhesive compositions were subjected to the strength tests on the Zwick/Roell 150 testing machine, which is in accordance with ISO 604 standard, determining the compressive strength. (3) Results: On the basis of the obtained strength test results and their analysis, it was noticed, inter alia, that the strength of the epoxy compounds decreases with the aging time in all used aqueous environments. Moreover, in the case of both types of the epoxy compounds, the highest strength was achieved after aging in demineralized water.

The Comparison of the Influence of Bisphenol A (BPA) and Its Analogue Bisphenol S (BPS) on the Enteric Nervous System of the Distal Colon in Mice

“…Bisphenol A (BPA), chemical name 4,4′-(propane-2,2-diyl) diphenol, is an organic substance synthetized for the first time in the late 19th century. It is characterized by high stability and mechanical stability [ 1 , 2 ]. Due to these properties BPA is commonly used in various branches of industry, mainly as a plasticizer in the production of plastics [ 3 ].…”

“…Till now the presence of BPA was found in the surface water, soil, air and food of animal and plant origin around the world [ 3 , 4 , 6 , 7 ]. BPA may also penetrate to the human and animal organisms and have negative effects on the health status [ 2 , 3 , 4 ]. Due to its similarity to estrogen, BPA binds to estrogen receptors localized in many internal organs and shows multidirectional adverse effects [ 2 , 3 , 4 ].…”

Adhesive Joint Degradation Due to Hardener-to-Epoxy Ratio Inaccuracy under Varying Curing and Thermal Operating Conditions

“…Further research in the topic is planned to analyse the influence of other parameters on the strength of adhesive joints, including: the method of surface preparation, the use of admixtures of materials that modify the properties of the adhesive, the degradation of joints due to aggressive environmental conditions and variable cyclic fluctuations in the temperature of the working environment of the joint [ 82 , 83 , 84 , 85 ]. To this end, statistical tools will be used to support mathematical modelling, and it is also planned to apply an analytical approach and use finite element numerical analysis software [ 86 , 87 , 88 , 89 , 90 ].…”

Application of an Artificial Neural Network in the Modelling of Heat Curing Effects on the Strength of Adhesive Joints at Elevated Temperature with Imprecise Adhesive Mix Ratios

“…If there is too little of a hardener per unit of resin, incomplete polymerisation may occur, whereas too much of the hardener may result in brittleness and fragility of the cured compound, leading to corrosion of the metallic interfaces [12][13][14]. Other characteristics of adhesives, such as resistance to heat or rigidity, may also change with deviations from the specified resin-to-hardener ratios or when admixtures are used [15][16][17][18][19][20]. This is due to the different degree of crosslinking, i.e., the case of an incomplete or different mode of curing the polymeric adhesive material when there is a shortage of hardener; on the other hand, when there is an excess, a certain amount of unreacted hardener remains in the adhesive.…”