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UHMWPE is polyethylene with a molecular weight numbering in the millions, usually between 3.5 and 7.5 million amu. [25] The high molecular weight makes it a very tough material, but results in less efficient packing of the chains into the crystal structure as evidenced by densities of less than high-density polyethylene (for example, 0.930–0. ...
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, 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 ...
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 .
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.
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 ...
Ethylene gas (H 2 C=CH 2) is the monomer for polyethylene. Other modified ethylene derivatives include: tetrafluoroethylene (F 2 C=CF 2) which leads to Teflon; vinyl chloride (H 2 C=CHCl) which leads to PVC; styrene (C 6 H 5 CH=CH 2) which leads to polystyrene; Epoxide monomers may be cross linked with themselves, or with the addition of a co ...
Polymer nomenclature usually applies to idealized representations meaning minor structural irregularities are ignored. A polymer can be named in one of two ways. Source-based nomenclature can be used when the monomer can be identified. Alternatively, more explicit structure-based nomenclature can be used when the polymer structure is proven.