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Commercial phenyl ether polymers belong to two chemical classes: polyphenyl ethers (PPEs) and polyphenylene oxides (PPOs). The phenoxy groups in the former class of polymers do not contain any substituents whereas those in the latter class contain 2 to 4 alkyl groups on the phenyl ring.
Poly(p-phenylene oxide) (PPO), poly(p-phenylene ether) (PPE), poly(oxy-2,6-dimethyl-1,4-phenylene), often referred to simply as polyphenylene oxide, is a high-temperature thermoplastic with the general formula (C 8 H 8 O) n. It is rarely used in its pure form due to difficulties in processing.
The NORYL family of modified resins consists of amorphous blends of polyphenylene oxides (PPO) or polyphenylene ether (PPE) resins with polystyrene.They combine the inherent benefits of PPE resin (affordable high heat resistance, good electrical insulation properties, excellent hydrolytic stability and the ability to use non-halogen fire retardant packages), with excellent dimensional ...
Phenol is readily alkylated at the ortho positions using alkenes in the presence of a Lewis acid such as aluminium phenoxide: [citation needed] CH 2 =CR 2 + C 6 H 5 OH → R 2 CHCH 2-2-C 6 H 4 OH. More than 100,000 tons of tert-butyl phenols are produced annually (year: 2000) in this way, using isobutylene (CH 2 =CMe 2) as the alkylating agent.
Good solvents are likely to be diethyl ether and hexane. (However, PE only dissolves at temperatures well above 100 °C.) (However, PE only dissolves at temperatures well above 100 °C.) Poly(styrene) has a solubility parameter of 9.1 cal 1/2 cm −3/2 , and thus ethyl acetate is likely to be a good solvent.
Ether groups allow a free rotation of the polymer chains. This leads to a significantly reduced melting point and also improves the mechanical properties by an increased impact strength . [ 7 ] The alkyl groups in bisphenol A act also as a flexible element.
Polyphenylene sulfide is a useful high temperature plastic. Coenzyme M, CH 3 SCH 2 CH 2 SO − 3, is the precursor to methane (i.e. natural gas) via the process of methanogenesis. Selected thioethers, from left: dimethylsulfide, coenzyme-M, the amino acid methionine, the vitamin biotin, and the engineering plastic polyphenylene sulfide.
Sugar alcohols can be, and often are, produced from renewable resources.Particular feedstocks are starch, cellulose and hemicellulose; the main conversion technologies use H 2 as the reagent: hydrogenolysis, i.e. the cleavage of C−O single bonds, converting polymers to smaller molecules, and hydrogenation of C=O double bonds, converting sugars to sugar alcohols.