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This plastic bucket has been used as an open-air flowerpot for some years. Photodegradation has made it brittle, causing part of it to break off when the bucket was moved. 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]
CPVC sprinkler pipe inside a firestop mock-up. Chlorinated polyvinyl chloride (CPVC) is a thermoplastic produced by chlorination of polyvinyl chloride (PVC) resin. CPVC is significantly more flexible than PVC, and can also withstand higher temperatures. Uses include hot and cold water delivery pipes and industrial liquid handling.
This type of cracking typically involves brittle cracking, with little or no ductile drawing of the material from its adjacent failure surfaces. [1] Environmental stress cracking may account for around 15-30% of all plastic component failures in service. [ 2 ]
This increase in elemental chlorine content contributes to CPVC's increased expression of chlorine-based characteristics, such as chemical durability, resistance to acids, bases, and salts; susceptibility to ammonia-based compounds, aromatics, esters, ketones; [9] chemical stability; heat energy transfer resistance. CPVC is commonly used in ...
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]
In January 2012, a major US West Coast healthcare provider, Kaiser Permanente, announced that it will no longer buy intravenous (IV) medical equipment made with PVC and DEHP-type plasticizers. [ 76 ] In 1998, the U.S. Consumer Product Safety Commission (CPSC) arrived at a voluntary agreement with manufacturers to remove phthalates from PVC ...
Items made from aluminum and its alloys must be carefully designed to minimize or evenly distribute flexure, which can lead to work hardening and, in turn, stress cracking, possibly causing catastrophic failure. For this reason modern aluminum aircraft will have an imposed working lifetime (dependent upon the type of loads encountered), after ...
Deformation mechanisms are commonly characterized as brittle, ductile, and brittle-ductile. The driving mechanism responsible is an interplay between internal (e.g. composition, grain size and lattice-preferred orientation) and external (e.g. temperature and fluid pressure) factors.