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The biggest quantity of stabilizers is used for polyvinyl chloride (PVC), as the production and processing of this type of plastic would not be possible without stabilizing chemicals. [1] Common polymer degradation processes include oxidation , UV-damage , thermal degradation , ozonolysis , combinations thereof such as photo-oxidation , as well ...
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]
While extremely useful as a food packaging agent, the major disadvantage of polyvinylidene chloride is that it will undergo thermally induced dehydrochlorination at temperatures very near to processing temperatures.
In a fire, PVC can form hydrogen chloride fumes; the chlorine serves to scavenge free radicals, making PVC-coated wires fire retardant. While hydrogen chloride fumes can also pose a health hazard in their own right, it dissolves in moisture and breaks down onto surfaces, particularly in areas where the air is cool enough to breathe, so would ...
Vinyl polymers are subject of several structural variations, which greatly expands the range of polymers and their applications. With the exception of polyethylene, vinyl polymers can arise from head-to-tail linking of monomers, head-to-head combined with tail-to-tail, or a mixture of those two patterns. Additionally the substituted carbon center in such polymers is stereogenic (a "chiral center")
It is an important industrial chemical chiefly used to produce the polymer polyvinyl chloride (PVC). Vinyl chloride is a colourless flammable gas that has a sweet odor and is carcinogenic . Vinyl chloride monomer is among the top twenty largest petrochemicals ( petroleum -derived chemicals) in world production. [ 2 ]
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Natural proteins as well as some common plastics such as nylon and PETE are formed in this way. Condensation polymers are formed by polycondensation, when the polymer is formed by condensation reactions between species of all degrees of polymerization , or by condensative chain polymerization , when the polymer is formed by sequential addition ...