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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.
Polyols may be classified according to their chemistry. [5] Some of these chemistries are polyether, polyester, [6] polycarbonate [7] [8] and also acrylic polyols. [9] [10] Polyether polyols may be further subdivided and classified as polyethylene oxide or polyethylene glycol (PEG), polypropylene glycol (PPG) and Polytetrahydrofuran or PTMEG.
Ethylene oxide in presence of water can hydrolyze to ethylene glycol and form polyethylene oxide, which then eventually is oxidized by air and leads to hotspots that can trigger explosive decomposition. Fires caused by ethylene oxide are extinguished with conventional media including foam, carbon dioxide, or water.
In this application, ethoxylation is known as "PEGylation" (polyethylene oxide is synonymous with polyethylene glycol, abbreviated as PEG). Carbon chain length is 8-18 while the ethoxylated chain is usually 3 to 12 ethylene oxides long in home products.
For example ethylene oxide polymerizes to give polyethylene glycol, also known as polyethylene oxide. The reaction of an alcohol or a phenol with ethylene oxide, ethoxylation, is widely used to produce surfactants: [28] ROH + n C 2 H 4 O → R(OC 2 H 4) n OH. With anhydrides, epoxides give polyesters. [29]
IUPAC Polymer Nomenclature are standardized naming conventions for polymers set by the International Union of Pure and Applied Chemistry (IUPAC) and described in their publication "Compendium of Polymer Terminology and Nomenclature", which is also known as the "Purple Book".
Ionic polymerization generates many polymers used in daily life, such as butyl rubber, polyisobutylene, polyphenylene, polyoxymethylene, polysiloxane, polyethylene oxide, high density polyethylene, isotactic polypropylene, butadiene rubber, etc. Living anionic polymerization was developed in the 1950s.
Organic peroxides are widely used to initiate polymerization of olefins, e.g. the formation of polyethylene. A key step is homolysis: ROOR ⇌ 2 RO. The tendency to homolyze is also exploited to modify polymers by grafting or visbreaking, or cross-link polymers to create a thermoset.