Polymer ethyl cellulose

McjC = CHCOCH3. Colourless liquid b.p. 129"C, with a strong peppermint-like odour. Prepared by distilling diacetone alcohol in the presence of a trace of iodine. Converted to phorone by heating in propanone with dehydrating agents such as sulphuric acid. It is a solvent For cellulose acetate and ethyl-cellulose and other polymers. 

By use of a modification of the well-known Williamson synthesis it is possible to prepare a number of cellulose ethers. Of these materials ethyl cellulose has found a small limited applieation as a moulding material and somewhat greater use for surfaee eoatings. The now obsolete benzyl cellulose was used prior to World War II as a moulding material whilst methyl eellulose, hyroxyethyl eellulose and sodium earboxymethyl eellulose are useful water-soluble polymers. 

Ethyl ether and ethyl alcohol which are formed as by-products are removed by distillation and the ethyl cellulose is precipitated by hot water. The polymer is then carefully washed to remove sodium hydroxide and sodium chloride and dried. 

Figure 13 Schematic diagram of the dependence of <7 on pressure. (F) Denotes folded-chain nucleus, (B) denotes bundle-like nucleus and (B ) denotes addition of ethyl cellulose liquid crystal polymer. (From Refs. 104, 110, 111, and 117.)...

Cellulosic They are tough, transparent, hard or flexible natural polymers made from plant cellulose feedstock. With exposure to light, heat, weather and aging, they tend to dry out, deform, embrittle and lose gloss. Molding applications include tool handles, control knobs, eyeglass frames. Extrusion uses include blister packaging, toys, holiday decorations, etc. Cellulosic types, each with their specialty properties, include cellulose acetates (CAs), cellulose acetate butyrates (CABs), cellulose nitrates (CNs), cellulose propionate (CAPs), and ethyl celluloses (EC). 

O Rosen, L Picullel. Interactions between covalently crosslinked ethyl(hydroxy-ethyl)cellulose and SDS. Polym Gels Networks 5 185-200, 1997. 

Another approach for ion-sensing (here copper and zinc) is based on the water-soluble ligand zincon and the ion pair with quaternary ammonium halides shown in Figure 17 which can be homogeneously dissolved in polymers such as plasticized poly(vinyl acetate), ethyl cellulose, and polyurethane. 

Chlorinated ethanes and ethylenes comprise ethyl chloride, ethylene dichloride (1,2 dichloroethane), vinyl chloride, trichloroethylene (TCE), perchloroethylene (RCE), and several CFCs. Some of the major uses of these compounds are as degreasing agents, dry-cleaning solvents, building blocks for manufacturing of polymers (e.g., RVC, ethyl cellulose), and raw material for the production of tetraethyl lead and CECs. We discuss ethylene dichloride, trichloroethylene, and perchloroethylene as examples of this group. 

LMC is used in underwater concrete for both new construction and repair. The important requirements to obtain antiwashout capability, such as segregation resistance, flowability, self-leveling characteristics and lower bleeding are provided by the addition of viscosity-enhancing polymeric admixtures at polymer-cement ratios of 0.2-2.0%. These admixtures are water-soluble polymers, and classified under two groups, viz., cellulose types such as methyl cellulose and hydroxy ethyl cellulose and polyacrylamide types such as polyacrylamide and polyacrylamide-sodium acrylate [101]. 

Eq. (5) in conjunction with Eqs. (8) and (9) have, so far, provided adequate representation of experimental isotherms6 32, which are characterized by an initial con vex-upward portion but tend to become linear at high pressures. Values of K, K2 and s0 have been deduced by appropriate curve-fitting procedures for a wide variety of polymer-gas systems. Among the polymers involved in recent studies of this kind, one may cite polyethylene terephthalate (PET) l2 I4), polycarbonate (PC) 19 22,27), a polyimide l6,17), polymethyl and polyethyl methacrylates (PMMA and PEMA)l8), polyacrylonitrile (PAN)15), a copolyester 26), a polysulphone 23), polyphenylene oxide (PPO)25), polystyrene (PS) 27 28), polyvinyl acetate 29) and chloride 32) (PVAc and PVC), ethyl cellulose 24) (EC) and cellulose acetate (CA) 30,3I>. A considerable number of gases have been used as penetrants, notably He, Ar, N2, C02, S02 and light hydrocarbons. 

Mock, R. A., and W. N. Vanderkooi Kinetics of mutual radiation grafting of styrene onto ethyl cellulose film. J. Polymer Sci. 56, 69 (1962). 

Saxena, V., and Stem, S.A., Concentration-Dependent Transport of Gases and Vapors in Glassy Polymers II. Organic Vapors in Ethyl Cellulose, J. Memb. Sci., 12, 65-85 (1982). 

Allyl-diglycol-carbonate polymer Diallyl phthalate (DAP) polymer Cellulosics Cellulose acetate resin Cellulose-acetate-propionate resin Cellulose-acetate-butyrate resin Cellulose nitrate resin Ethyl cellulose resin Rayon... 

Many PSPs are composed of probe dyes, such as polycyclic aromatic hydrocarbons (e.g., pyrene) and coordination compounds (e.g., platinum por-phryins and ruthenium(II) polypyridyl complexes) immobilized in various gas permeable polymer films such as silicon polymer, organic glassy polymers (e.g., poly(methylmethacrylate), polystyrene), fluorinated polymers, or cellulose derivatives such as ethyl cellulose [9,10]. As probe molecules interact with polymer matrices directly, the properties of PSPs strongly depend on the properties of polymer matrices. The oxygen permeability of polymer matrix is an especially important factor for highly sensitive PSP. 

Finally, PSPs based on the OEP metal complexes in various cellulose derivative polymers also have been introduced. Cellulose derivative polymers such as ethyl cellulose, cellulose acetate etc., as shown in Fig. 9, also provide a mechanical strength to thin film. The oxygen permeability, diffusion constant, and solubility for oxygen for typical cellulose derivative polymers are listed in Table 1. Cellulose derivative polymer films with plasticizer tributyl phosphate (TBP) have large oxygen permeability. Cellulose acetate with TBP... 

Figure 2.21 Changes in the diffusion coefficient of dichloroethane in ethyl cellulose as a function of the volume fraction of dichloroethane dissolved in the polymer matrix. Data of Artsis et al. [29]...

A plot of the temperatures required for clouding versus surfactant concentration typically exhibits a minimum in the case of nonionic surfactants (or a maximum in the case of zwitterionics) in its coexistence curve, with the temperature and surfactant concentration at which the minimum (or maximum) occurs being referred to as the critical temperature and concentration, respectively. This type of behavior is also exhibited by other nonionic surfactants, that is, nonionic polymers, // - a I k y I s u I Any lalcoh o I s, hydroxymethyl or ethyl celluloses, dimethylalkylphosphine oxides, or, most commonly, alkyl (or aryl) polyoxyethylene ethers. Likewise, certain zwitterionic surfactant solutions can also exhibit critical behavior in which an upper rather than a lower consolute boundary is present. Previously, metal ions (in the form of metal chelate complexes) were extracted and enriched from aqueous media using such a cloud point extraction approach with nonionic surfactants. Extraction efficiencies in excess of 98% for such metal ion extraction techniques were achieved with enrichment factors in the range of 45-200. In addition to metal ion enrichments, this type of micellar cloud point extraction approach has been reported to be useful for the separation of hydrophobic from hydrophilic proteins, both originally present in an aqueous solution, and also for the preconcentration of the former type of proteins. 

Before discussing theoretical approaches let us review some experimental results on the influence of flow on the phase behavior of polymer solutions and blends. Pioneering work on shear-induced phase changes in polymer solutions was carried out by Silberberg and Kuhn [108] on a polymer mixture of polystyrene (PS) and ethyl cellulose dissolved in benzene a system which displays UCST behavior. They observed shear-dependent depressions of the critical point of as much as 13 K under steady-state shear at rates up to 270 s Similar results on shear-induced homogenization were reported on a 50/50 blend solution of PS and poly(butadiene) (PB) with dioctyl phthalate (DOP) as a solvent under steady-state Couette flow [109, 110], A semi-dilute solution of the mixture containing 3 wt% of total polymer was prepared. The quiescent... 

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