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Polycarbonate. Polycarbonates (PC) are a group of thermoplastic polymers containing carbonate groups in their chemical structures. Polycarbonates used in engineering are strong, tough materials, and some grades are optically transparent. They are easily worked, molded, and thermoformed. Because of these properties, polycarbonates find many ...
In polymer chemistry photo-oxidation (sometimes: oxidative photodegradation) is the degradation of a polymer surface due to the combined action of light and oxygen. [1] It is the most significant factor in the weathering of plastics. [2] Photo-oxidation causes the polymer chains to break (chain scission), resulting in the material becoming ...
Concrete is used to create hard surfaces which contribute to surface runoff that may cause soil erosion, water pollution and flooding. Conversely, concrete is one of the most powerful tools for proper flood control, by means of damming, diversion, and deflection of flood waters, mud flows, and the like.
Properties of concrete. Concrete has relatively high compressive strength (resistance to breaking when squeezed), but significantly lower tensile strength (resistance to breaking when pulled apart). The compressive strength is typically controlled with the ratio of water to cement when forming the concrete, and tensile strength is increased by ...
Concrete is mostly damaged by the corrosion of reinforcement bars due to the carbonatation of hardened cement paste or chloride attack under wet conditions. Chemical damage is caused by the formation of expansive products produced by chemical reactions (from carbonatation, chlorides, sulfates and distillate water), by aggressive chemical ...
Polymer degradation is the reduction in the physical properties of a polymer, such as strength, caused by changes in its chemical composition.Polymers and particularly plastics are subject to degradation at all stages of their product life cycle, including during their initial processing, use, disposal into the environment and recycling. [1]
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A UV coating (or more generally a radiation cured coating) is a surface treatment which either is cured by ultraviolet radiation, or which protects the underlying material from such radiation's harmful effects. [1] They have come to the fore because they are considered environmentally friendly and do not use solvents or produce volatile organic ...