Long-Term Chemical Resistance of Ecological Epoxy Polymer Composites

Abstract

Resin concretes belong to a small group of building materials which, besides high strength parameters, also have a very good chemical resistance. This is confirmed by the studies carried out by various research institutions around the world. However, there is little data on the behaviour of composite resin exposed to corrosive solutions for an extended period of time. This article presents the results of the research on weight changes in samples of epoxy mortar modified with poly(ethylene terephthalate) glycolysates, immersed for 5 years in four different aggressive media i.e. 10% aqueous solutions of sulphuric and nitric acids, sodium hydroxide, and sodium chloride. The actual average weight changes obtained were compared with the data calculated on the basis of the regression functions fitted to the data recorded after 3.5 years of exposure. This allowed verification of the model selection correctness and evaluation of the effectiveness of the fitted regression curve. In the case of aqueous sodium hydroxide and sodium chloride solutions, it can be assumed that the logarithmic model describes weight changes well. It was observed that the weight of the samples exposed to NaCl solutions and NaOH stabilizes over prolonged monitoring time and reaches a plateau. However, the weight changes in mortar samples immersed for 5 years in aqueous solution of sulphuric and nitric acids quite significantly differ from the data calculated on the basis of the trend line fitted to the results of the tests carried out after 3.5 years of exposure. It seems that the better solution in this case is the selection of an exponential model. In addition, placing the logarithmic trendlines for all corrosive media together on a chart allows to note which of the solutions is the most aggressive. It was found that after 5 years of immersion in aqueous solutions of acids, mortar samples became brittle, and the observation of their fractures confirmed the weakness of the connection on the resin/aggregate phase boundary. Changes in the appearance of the samples were also noted, namely the surface of samples submerged in a solution of nitric acid strongly yellowed, and those treated with sulphuric acid were tarnished.

Analysis of properties of epoxy compositions that operate in contact with water and oil products

“…In particular, such compositions can protect structures of transport service stations and other structures affected by mixtures of water with oil products, surfactants, etc. We should note that filled epoxy composites show good results in long-term tests for chemical resistance [15], however, authors of paper [12] note a significant deterioration in mechanical characteristics of polymeric solutions under the influence of oil products. It is almost impossible to conduct long-term tests of materials in inhomogeneous media (mixtures of water and oil products).…”

The use of discriminant analysis methods for diagnosis of the causes of differences in the properties of resin mortar containing various fillers

“…Based on the available literature data [12] and our own findings on resin mortars [13][14][15], a fixed ratio of resin to aggregate of 0.22 was established.…”

Assessment of the Mechanical Parameters of Resin Composites with the Addition of Various Types of Fibres

“…Resin concretes are characterized by very high compressive strength (over 100 MPa) and bending strength, as well as very good chemical resistance. Their characteristic feature is also the short time needed to achieve operational efficiency and their good adhesion to various building materials [4,9]. Their high strength-to-weight ratio, good damping properties and ability to form complex shapes make them ideal for prefabrication [10,11].…”