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Typical monomers are those that undergo radical polymerization, are liquid or gaseous at reaction conditions, and are poorly soluble in water. Solid monomers are difficult to disperse in water. If monomer solubility is too high, particle formation may not occur and the reaction kinetics reduce to that of solution polymerization.
Polyethylene absorbs almost no water; the gas and water vapour permeability (only polar gases) is lower than for most plastics. Oxygen, carbon dioxide and flavorings, on the other hand, can pass it easily. Polyethylene burns slowly with a blue flame having a yellow tip and gives off an odour of paraffin (similar to candle flame). The material ...
Ethylene vinyl alcohol (EVOH) is a formal copolymer of ethylene and vinyl alcohol. Because the latter monomer mainly exists as its tautomer acetaldehyde , the copolymer is prepared by polymerization of ethylene and vinyl acetate to give the ethylene vinyl acetate (EVA) copolymer followed by hydrolysis.
For example, polyester chains grow by reaction of alcohol and carboxylic acid groups to form ester links with loss of water. However, there are exceptions; for example polyurethanes are step-growth polymers formed from isocyanate and alcohol bifunctional monomers) without loss of water or other volatile molecules, and are classified as addition ...
Two broad classes of monomers are susceptible to anionic polymerization. [3] Vinyl monomers have the formula CH 2 =CHR, the most important are styrene (R = C 6 H 5), butadiene (R = CH=CH 2), and isoprene (R = C(Me)=CH 2). A second major class of monomers are acrylate esters, such as acrylonitrile, methacrylate, cyanoacrylate, and acrolein.
Epoxide monomers may be cross linked with themselves, or with the addition of a co-reactant, to form epoxy; BPA is the monomer precursor for polycarbonate; Terephthalic acid is a comonomer that, with ethylene glycol, forms polyethylene terephthalate. Dimethylsilicon dichloride is a monomer that, upon hydrolysis, gives polydimethylsiloxane.
Polyacrylic acid is a weak anionic polyelectrolyte, whose degree of ionisation is dependent on solution pH. In its non-ionised form at low pHs, PAA may associate with various non-ionic polymers (such as polyethylene oxide, poly-N-vinyl pyrrolidone, polyacrylamide, and some cellulose ethers) and form hydrogen-bonded interpolymer complexes. [17]
AGE is prepared commercially by the etherification of allyl alcohol with epichlorohydrin. Hydrogen chloride, the byproduct of their condensation, is removed with a base. [5] The synthesis of allyl glycidyl ether by condensation of allyl alcohol and epichlorohydrin. AGE can also be synthesized by monoepoxidation of diallyl ether. [6] [7]