Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Cellulose carboxymethylcellulose

Highly oxidizable oils such as fish oils can be protected by a process known as microencapsulation, which coats the oil with a matrix of protein (gelatin, casein), carbohydrates (starch, cellulose, carboxymethylcellulose or cellulose derivatives) and lecithin. Microencapsulation provides protection against oxidation and imparts oxidative stability. The use of carboxymethylcellulose and cyclodextrins as coatings is claimed to provide better protection of oils by improved oxygen barrier properties. For special applications as nutritional supplements, fish oils enriched in n-3 PUFA are microencapsulated, in the presence of antioxidants, into a powder that is relatively stable at ambient temperatures. However, encapsulated fish oils can impart undesirable fishy taste when incorporated into food emulsions. More research and development is needed to evaluate potential applications and benefits of active packaging to increase the shelf life of fish oils and other highly oxidizable oils in foods. [Pg.206]

D. Microencapsulation. Microencapsulation is also an effective release mechanism where small central pockets of active agents are formed within a polymeric outer coating or skin. The effect depends on the relative polarities of the core and skin as well as the relative amounts of the two. Polymers used as encapsulated skins include gelatin gum arabic, starch, sugar, ethyl cellulose, carboxymethylcellulose, and paraffin. Examples of successful systems include but are not limited to those shown in Table 4. [Pg.28]

Carboxymethylcellulose Sodium. Carboxymethyl ether of cellulose sodium salt (Citmcel) (8) is a white granular substance soluble in water depending on the degree of substitution. It is equally soluble in cold and hot water and may be prepared by treating alkaU cellulose with sodium chloroacetate. [Pg.200]

Carboxymethylcelluloses (CMC). CarboxymethylceUulose [9004 2-6] (CMC) is the carboxymethyl ether of cellulose. To prepare CMC, cellulose is steeped in sodium hydroxide solution, and the so-called alkaU cellulose is treated under controlled conditions with sodium monochloroacetate to form the sodium salt of CarboxymethylceUulose and sodium chloride. Therefore, the CMC of commerce is actuaUy sodium CarboxymethylceUulose... [Pg.489]

Abras precatorius. Purified by successive chromatography on DEAE-Sephadex A-50, carboxymethylcellulose, and DEAE-cellulose. [Wei et al. J Biol Chem 249 3061 1974.]... [Pg.505]

Beaded acrylamide resins (28) are generally produced by w/o inverse-suspension polymerization. This involves the dispersion of an aqueous solution of the monomer and an initiator (e.g., ammonium peroxodisulfates) with a droplet stabilizer such as carboxymethylcellulose or cellulose acetate butyrate in an immiscible liquid (the oil phase), such as 1,2-dichloroethane, toluene, or a liquid paraffin. A polymerization catalyst, usually tetramethylethylenediamine, may also be added to the monomer mixture. The polymerization of beaded acrylamide resin is carried out at relatively low temperatures (20-50°C), and the polymerization is complete within a relatively short period (1-5 hr). The polymerization of most acrylamides proceeds at a substantially faster rate than that of styrene in o/w suspension polymerization. The problem with droplet coagulation during the synthesis of beaded polyacrylamide by w/o suspension polymerization is usually less critical than that with a styrene-based resin. [Pg.9]

AVT Barg BD BDHR BF BOF BOOM BOP BS W BSI BTA Btu/lb BW BWR BX CA CANDUR CDI CFH CFR CHA CHF CHZ Cl CIP CMC CMC CMC COC All-Volatile treatment bar (pressure), gravity blowdown blowdown and heat recovery system blast furnace basic oxygen furnace boiler build, own, operate, maintain balance of plant basic sediment and water British Standards Institution benzotriazole British thermal unit(s) per pound boiler water boiling water reactor base-exchange water softener cellulose acetate Canadian deuterium reactor continuous deionization critical heat flux Code of Federal Regulations cyclohexylamine critical heat-flux carbohydrazide cast iron boiler clean-in-place carboxymethylcellulose (sodium) carboxy-methylcellulose critical miscelle concentration cycle of concentration... [Pg.982]

Methylcellulose and carboxymethylcellulose are forms of the familiar polysaccharide cellulose that have been treated to make them more soluble in water. Cellulose is a long chain made of the sugar glucose. The long chains mix with water to create a thick syrup or gel. [Pg.138]

Carboxymethylcellulose, polyethylene glycol Combination of a cellulose ether with clay Amide-modified carboxyl-containing polysaccharide Sodium aluminate and magnesium oxide Thermally stable hydroxyethylcellulose 30% ammonium or sodium thiosulfate and 20% hydroxyethylcellulose (HEC) Acrylic acid copolymer and oxyalkylene with hydrophobic group Copolymers acrylamide-acrylate and vinyl sulfonate-vinylamide Cationic polygalactomannans and anionic xanthan gum Copolymer from vinyl urethanes and acrylic acid or alkyl acrylates 2-Nitroalkyl ether-modified starch Polymer of glucuronic acid... [Pg.12]

Polymeric carbohydrates are usually encountered as distributions, so high resolution is rarely important. Of all biological macromolecules, carbohydrates are particularly amenable to analysis by GPC because hydrophobic interactions are typically weak. A section below is devoted to the analyses of carboxymethylcellulose and xanthan. Other examples of polysaccharides of interest are hyaluronic acid,62 polymers of (l-glucose,121125 heparin,126127 cellulose and chitin,128 and Mucorales extracellular polysaccharides.129... [Pg.334]

Aqualon Company, Aqualon Cellulose Gum. Sodium Carboxymethylcellulose. Physical and Chemical Properties, Wilmington, DE, Rev. 1-88. [Pg.374]

Although untreated starches do not swell sufficiently, certain modified forms, such as sodium starch glycolate, do swell in cold water and are better as disintegrants. Various cellulose derivatives, including methylcellulose and carboxymethylcellulose, have been used in this role, but with limited success due to the marked increase in viscosity they produce around the dispersing tablet mass. [Pg.304]

Carboxymethylcellulose, an excellent film-former, is a highly effective size on cellulosic substrates but has poor adhesion to synthetic fibres. It is easily desorbed, hot water generally being sufficient, although surfactant and alkali are usually added to increase the efficiency of... [Pg.105]

The poor adhesion of carboxymethylcellulose to synthetic fibres means that where such fibres are present, it can only be effective in combination with a synthetic size polymer (Table 10.6). This needs to be taken into account when considering suitable desizing procedures. If this cellulose derivative is to be used in conjunction with an electrolyte-sensitive acrylic acid copolymer, it is advisable to choose a salt-free carboxymethylcellulose. [Pg.106]

Early soil-release agents, applied particularly to resin-finished cellulosic goods, were water-soluble polymers, many being related to thickeners (section 10.8) such as starch, hydroxypropyl starch, sodium carboxymethylcellulose, methylcellulose, hydroxyethyl-cellulose, alginates, poly(vinyl alcohol) and poly(vinylpyrrolidone). These functioned essentially as temporary barriers and preferential reservoirs for soil, which was thus easily removed along with the finish in subsequent washing, when they then helped to minimise... [Pg.266]

Water-soluble Carboxymethylcellulose (Cellulose Glycolic Acid). 293... [Pg.297]

Unmodified and anionically modified starches, soluble cellulose derivatives such as carboxymethylcellulose, polyvinyl alcohol, latex and other polymers are also used in some specialised applications. Starch, however, because of its cost, is by far the most common dry strength additive, about twenty times more being used than, for example, polyacrylamide. [Pg.118]

An interesting feature of current commercial products is that the polymer vehicles available for formulation have been limited to nonionic and anionic materials. The delivery vehicles available included off-the-shelf polymers such as carboxymethylcellulose, soluble starch, hydroxyethyl-cellulose, polyvinyl alcohol, poly(acrylic acid), and polyvinylpyrrolidone, or mixtures thereof. The choice of available polymeric delivery system primarily depends on component compatibility, aesthetics, and efficacy. However, by reliance upon available (off-the-shelf) systems, limitations on bioadhesion, drug bioavailability, contraceptive efficacy, and end-use characteristics has been limited. [Pg.217]

Some of the exchanged resins were coated with cellulose acetate butyrate or cellulose acetate phthalate. The results showed relaxation rate enhancement in 25% water suspensions containing 2% carboxymethylcellulose (CMC) as a surfactant. The relaxivities, however, were rather low. It should be noted, however, that the measurements were made at high field, 300 MHz, where the relaxivity enhancements are always smaller. [Pg.281]

Sodium carboxymethylcellulose is formed by the reaction of sodium chloroacetate with basic cellulose solutions. The sodium form of carboxymethylcellulose is known as CMC or as a food grade product as cellulose gum. It is soluble in both hot and cold water. [Pg.271]


See other pages where Cellulose carboxymethylcellulose is mentioned: [Pg.88]    [Pg.410]    [Pg.239]    [Pg.7168]    [Pg.208]    [Pg.240]    [Pg.436]    [Pg.192]    [Pg.88]    [Pg.410]    [Pg.239]    [Pg.7168]    [Pg.208]    [Pg.240]    [Pg.436]    [Pg.192]    [Pg.227]    [Pg.358]    [Pg.7]    [Pg.88]    [Pg.12]    [Pg.135]    [Pg.258]    [Pg.354]    [Pg.359]    [Pg.257]    [Pg.171]    [Pg.167]    [Pg.311]    [Pg.408]    [Pg.68]    [Pg.67]    [Pg.200]    [Pg.107]    [Pg.350]    [Pg.271]    [Pg.588]   
See also in sourсe #XX -- [ Pg.137 ]




SEARCH



Cellulose and carboxymethylcellulose sodium

Cellulose ethers carboxymethylcellulose

Water-soluble Carboxymethylcellulose (Cellulose Glycolic Acid)

© 2024 chempedia.info