Polyethylene/polymethylene oxide

Polymers with Tg/Tm ratios below 0.5 are highly symmetrical and have short repeating units consisting of one or two main-chain atoms each, carrying substituents consisting of only a single atom (polymethylene, polyethylene, polytetrafluoroethylene, polymethylene oxide). They are markedly crystalline. 

The most well-known member of this class is the polyether, polyethylene oxide, whose complexes with lithium perchlorate have been used commercially in lithium batteries.60-62 The good solvating power of polyethylene oxide is attributed to an optimal spacing of the electron-donating ether oxygens along a flexible backbone that allows multiple contacts between the polymer backbone and cations. When this distance is decreased, as in polymethylene oxide, chain flexibility is greatly reduced when it is increased, as in 1,3-polypropylene oxide, the distance between... 

Polyethylene oxide (PEO) is an uncharged polymer that has a high solubility in water, especially when compared to its analogues polymethylene oxide (PMO) and pol)T)ropylene oxide (PPO) which are essentially insoluble in water. PEO solutions... 

Chemically Modified Waxes. Hydrocarbon waxes of the microcrystaHine, polyethylene, and polymethylene classes are chemically modified to meet specific market needs. In the vast majority of cases, the first step is air oxidation of the wax with or without catalysts (11). The product has an acid number usuaHy no higher than 30 and a saponification number usuaHy no lower than 25. An alternative step is the reaction of the wax with a polycarboxyHc acid, eg, maleic, at high temperature (12). Through its carboxyl groups, the oxidised wax can be further modified in such reactions as saponification or esterification. Oxidised wax is easily emulsified in water through the use of surfactants or simple soaps, and is widely used in many coating and poHsh appHcations. 

The donor-acceptor distance may not be unique, especially when the donor and acceptor are linked by a flexible chain (e.g. end-labeled oligomers of polymethylene or polyethylene oxide, oligopeptides, oligonucleotides, polymer chains). 

This chromatographic method has been used to examine the polyethylene oxide-co-polymethylene (PM) block system (79). The solvent is chosen so that the PEO is at its critical condition, ie, there is no separation with respect to the molecular mass of the PEO, but there is separation with respect to PM. MALDI-tof-ms was nsed as a detector on this system. Each separate PM peak was continuously transferred onto a MALDI target. The fractionation was made into separate PM peaks. Within each PM peak there is a MMD of PEO. This allowed the authors to estimate both the MMD and MOD for the whole polsrmer. 

Polymer electrolytes are used in lithium ion rechargeable batteries. Pure polymer electrolyte systems include polyethylene oxide (PEO), polymethylene-polyethylene oxide (MPEG), or polyphosphazenes. Chlorinated PVC blended with a terpoly-mer comprising vinylidene chloride/acrylonitrile/methyl methacrylate can make a good polymer electrolyte. Rechargeable lithium ion cells use solid polymer electrolytes. Plasticized polymer electrolytes are safer than liquid electrolytes because of a reduced amount of volatiles and flammables. The polymer membrane can condnct lithinm ions. The polymer membrane acts as both the separator and electrolyte [7],... 

Poly(vinyl alcohol) Polyacrolein Poly(acrylic acid) Poly(vinyl alkyl ethers) Poly(vinyl methyl ketone) Polymethylene Chlorinated polyethylene Chlorosulfonated polyethylene Polyacrylonitrile Sulfonated polystyrene Poly(ethylene oxide) Poly(ethylene terephthalate)... 

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