Search Results for epoxy thermoset

Plasma spray deposition of epoxies under normal conditions produces coatings with low wear resistance. The research shows that the difficulty in achieving satisfactory properties is a result of the rapid heat flow from the coating to the substrate, which suppresses the crosslinking reaction. The results indicate that the use of substrate preheating or ceramic undercoats enhances the wear resistance by promoting the curing reaction during spraying.

Experimental studies of the subsonic combustion process have been conducted in order to determine the quality and economics of polyester, epoxy, urethane, and hybrid polyester-epoxy coatings. Thermally sprayed polymer coatings are of interest to several industries for anti-corrosion applications, including the infrastructural, chemical, automotive, and aircraft industries. Classical experiments were conducted, from which a substantial range of thermal processing conditions and their effect on the resultant coating were obtained. The coatings were characterized and evaluated by a number of techniques, including Knoop microhardness tests, optical metallography, image analysis, and bond strength. Characterization of the coatings yielded thickness, bond strength, hardness, and porosity.

Statistical design-of-experiment studies of the thermal spraying of polymer powders are presented. Studies of the subsonic combustion (i.e., Flame) process were conducted in order to determine the quality and economics of polyester and urethane coatings. Thermally sprayed polymer coatings are of interest to several industries for anticorrosion applications, including the chemical, automotive, and aircraft industries. In this study, the coating design has been optimized for a site-specific application using Taguchi-type fractional-factorial experiments. Optimized coating designs are presented for the two powder systems. A substantial range of thermal processing conditions and their effect on the resultant polymer coatings is presented. The coatings were characterized by optical metallography, hardness testing, tensile testing, and compositional analysis. Characterization of the coatings yielded the thickness, bond strength, Knoop microhardness, roughness, deposition efficiency, and porosity. Confirmation testing was accomplished to verify the coating designs.

The polyethylene terephtalate (PET) is a polymer with a high melting (265°C) and glass transition (67°C) temperatures, insensitive to moisture and common solvents. Also it has an wide range of mechanical properties attainable by variations of molecular weight, orientation and crystallinity. Due to these characteristics allied with the glass-like transparency, light weight and unbreakable character, PET is used to form high performance bottles for carbonated soft drinks, wines, beers and food packing. The world annual consumption of PET for these purposes is increasing, with impressive prospects for the future. This characteristic leads to other situation. The consumption of energy and natural resources together with the environmental problems caused by disposable plastics, make the engineering and materials scientists try to find for different ways to recycled plastics. The characteristics of PET mentioned above seen to be very proper to use as a material for coating.

In thermal spraying of metal-polymer coatings, the processes of polymers oxidation and destruction can have special features, as the temperature of heating of the filler particles can significantly exceed the temperature of destruction of the polymer binder. Hence, the need to study the features of the process of formation of thermal sprayed coatings from filled polymers and their physico-chemical, mechanical and service properties. This paper describes the influence of a filler composition and conditions of flame spraying on a structure and mechanical properties of composite polymer coatings. It is observed that addition of 5-10 vol. % of Fe-Ni-B alloy powder to low-pressure polyethylene polymer matrices, improves the wear resistance of thermal sprayed coatings 1.2-1.3 times under the conditions of gas-abrasive wear, compared to purely polymer coating, owing to the combination of the higher hardness of the coating with the high damping properties of the polymer matrix.