چكيده به لاتين
Abstract:
Evaluating effect of solvents (water or other chemical solvents, acid, alkali, salt, organic and inorganic) on behavior of polymers in the industry is of great importance. Depending on the chemical nature of the polymer and the polarity of the solvent and polymer, polymersand especially thermoset ones absorb water and other chemical solutions when exposed to theses solutions. As a result of long-term exposure, the polymeric binder ages and its usability and durability are affected. Because of the extensive consumption of unsaturated polyester resins and their application in concrete polymer, determination of the durability and mechanical performance of these thermosetting polymers in water, chemical environments and sewage situation is important. In this study, the durability of unsaturated polyester resins from the perspective of swelling in water, gas oil, sulfuric acid one normal and alkaline solution made of water, sodium carbonate and sodium bicarbonate is evaluated. Because of the effect of reinforcing micro-size particles and nanoparticles on polymeric matrices, polyester composites and nanocomposites were also prepared and their durability and performance were compared to those of pure resin samples. Weight and volume changes in the solutions, as well as changes in mechanical properties (tensile and flexural) were examined after three-day, one month, three months and six months of exposure to solutions. In order to compare the resin samples with polymer concretes, the changes in weight and volume of polymer concrete samples, were also evaluated. The results show that the swelling of the resin samples continues until one month and then reaches equilibrium. Furthermore, the biggest drop was seen in the mechanical properties in the third month of exposure. Alkaline solution and water had the greatest impact on long-term properties of the samples. Tensile strength of polyester specimens in water and alkali decreased 50% and 60.4% respectively. Nanocomposites showed a very poor performance and less durability compared to other samples.
Keywords: Swelling; Unsaturated polyester resin; Nanocomposite; Durability
