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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.
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]
Polyvinyl alcohol (PVOH, PVA, or PVAl) is a water-soluble synthetic polymer. It has the idealized formula [CH 2 CH(OH)] n. It is used in papermaking, textile warp sizing, as a thickener and emulsion stabilizer in polyvinyl acetate (PVAc) adhesive formulations, in a variety of coatings, and 3D printing. It is colourless (white) and odorless.
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 ...
Alpha-olefins such as 1-hexene may be used as co-monomers to give an alkyl branched polymer (see chemical structure below), although 1-decene is most commonly used for lubricant base stocks. [8] 1-hexene, an example of an alpha-olefin. Many poly-alpha-olefins have flexible alkyl branching groups on every other carbon of their polymer backbone ...
Acrylates (IUPAC: prop-2-enoates) are the salts, esters, and conjugate bases of acrylic acid. The acrylate ion is the anion CH 2 =CHCO − 2. Often, acrylate refers to esters of acrylic acid, the most common member being methyl acrylate. These acrylates contain vinyl groups.
A monomer is dispersed or emulsified in a solution of surfactant and water, forming relatively large droplets in water. Excess surfactant creates micelles in the water. Small amounts of monomer diffuse through the water to the micelle. A water-soluble initiator is introduced into the water phase where it reacts with monomer in the micelles.
For example, in polyethylene terephthalate (PET or "polyester"), the repeat unit is -CO-C 6 H 4-CO-O-CH 2-CH 2-O-. The polymer is formed by the condensation reaction of the two monomers terephthalic acid (HOOC-C 6 H 4-COOH) and ethylene glycol (HO-CH 2-CH 2-OH), or their chemical derivatives. The condensation involves loss of water, as an H is ...