Polyethers - Polyethylene Glycol, Polyphenyl Ether, Polyoxymethylene Plastic, Peek, Paraformaldehyde, Polypropylene Glycol, Polydioxanone (Paperback)

Purchase includes free access to book updates online and a free trial membership in the publisher's book club where you can select from more than a million books without charge. Chapters: Polyethylene Glycol, Polyphenyl Ether, Polyoxymethylene Plastic, Peek, Paraformaldehyde, Polypropylene Glycol, Polydioxanone, Nonoxynols, Poly(tetramethylene Ether) Glycol, Peg 400, Techron. Excerpt: Chemical structure of a nonylphenol ethoxylates. Nonoxynols or nonylphenol ethoxylates are mixtures of nonionic surfactants used as detergents, emulsifiers, wetting agents, defoaming agents, etc. nonoxynol-9, the compound with approximately 9 repeating ethoxy groups, is a spermatocide, formulated primarily as a component of vaginal foams and creams. Production These compounds are produced by ethoxylation of alkylphenols . The precursor nonylphenol is derived from phenol and a mixture of nonenes . Toxicity concerns Concerns about the environmental impact of these compounds has increased since the 1990's. These surfactants have a mild to medium estrogenic function. Consequently, this class of detergents has been effectively banned for commercial "down-the-drain" applications in Europe, and these compounds are not found in laundry detergents in the USA. References (URLs online) A hyperlinked version of this chapter is at PEEK item Density: 1320 kg/m item Young's modulus ( E ): 3.6 G Pa item Tensile strength ( t): 90-100 M Pa item Elongation @ break: 50 % item notch test: 55 k J /m item Glass temperature: 143 C item melting point: 343 C item Thermal Conductivity: 0.25 W/m.K item Water absorption, 24 hours (ASTM D 570): - 0.1 % item source: Polyether ether ketone (PEEK) is a colourless organic polymer thermoplastic used in engineering applications. Synthesis PEEK polymers are obtained by step-growth polymerization by the dialkylation of bisphenolate salts. Typical is the reaction of 4,4'-difluorobenzophenone with the disodium salt of hydroquinone, which is generated in sit...