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In polymer chemistry, polymerization (American English), or polymerisation (British English), is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks. [1] [2] [3] There are many forms of polymerization [4] and different systems exist to categorize them. IUPAC definition for ...
In the simplest example oxygen can be used as it exists naturally in its triplet state (i.e. it is a diradical). This is referred to as air inhibition and is a diffusion-controlled reaction with rates typically in the order of 10 7 –10 9 mol −1 s −1 , [ 3 ] the resulting peroxy radicals (ROO•) are less reactive towards polymerisation.
Autoacceleration of the overall rate of a free-radical polymerization system has been noted in many bulk polymerization systems. The polymerization of methyl methacrylate, for example, deviates strongly from classical mechanism behavior around 20% conversion; in this region the conversion and molecular mass of the polymer produced increases rapidly.
Step-growth polymerization can be divided into polycondensation, in which low-molar-mass by-product is formed in every reaction step, and polyaddition. Example of chain polymerization: Radical polymerization of styrene, R. is initiating radical, P. is another polymer chain radical terminating the formed chain by radical recombination.
In polymer chemistry, emulsion polymerization is a type of radical polymerization that usually starts with an emulsion incorporating water, monomers, and surfactants.The most common type of emulsion polymerization is an oil-in-water emulsion, in which droplets of monomer (the oil) are emulsified (with surfactants) in a continuous phase of water.
Polymerization of ethylene oxide is an exothermic process. Overheating or contaminating ethylene oxide with catalysts, such as alkalis or metal oxides, can lead to runaway polymerization, which can end in an explosion after a few hours. Polyethylene oxide, or high-molecular-weight polyethylene glycol, is synthesized by suspension polymerization.
An obvious example of the need to resist ESC in everyday life is the automotive industry, in which a number of different polymers are subjected to a number of fluids. Some of the chemicals involved in these interactions include petrol, brake fluid and windscreen cleaning solution. [ 6 ]
Synthetic polymers are ubiquitous in commercial materials and products in everyday use, such as plastics, and rubbers, and are major components of composite materials. Polymer chemistry can also be included in the broader fields of polymer science or even nanotechnology , both of which can be described as encompassing polymer physics and ...