Cellulose derivative, foams

Pectins, produced from fruit wastes are valuable foaming agents for food industry that can substitute various protein and non-protein foaming agents (egg protein, butyric acid ethers, cellulose derivatives, lecithin, glycosides, etc.). 

This material, which is completely amorphous, shows extensive foam formation after treatment. This suggests that high diffiisivity leading to high uptake of carbon dioxide in the material had occurred. Swelling, or extent of foam formation, was more extensive when a shorter decompression time is used. Our experience with this cellulose derivative suggests that such polymers are not very compatible with high pressure carbon dioxide. 

Rivera-Armenta JL, Heinze Th, Mendoza-Martinez AM (2004) New polyurethane foams modified with cellulose derivatives. European Polymer Journal 41 2803-2812. 

Cellulose derivatives, especially methylcellulose and hypromellose, usually cause a strong foam at preparation because they also possess surfactant activity. For the formulation of settling suspensions they are often unsuitable as they create a sediment that is difficult to disperse. They are used in suspensions and emulsions for oral use (see Sects. 5.4.6 and 5.4.7) at concentrations of 0.25-2.5 %. In... 

Water-soluble polymers and proteins [84] can stabilize foam at low concentrations, by increasing the viscoelasticity of the foam film, thus slowing the liquid drainage. Additional benefits like skin feel and mildness to the skin can be obtained with many of these additives. Polymer examples are agar-agar, poly(vinyl alcohol), alginates [85], cationic [86] and nonionic guar [87] derivatives, polyacrylates [88], and cellulose derivatives [89]. Pro-... 

Shampoos normally contain a blend of cleansing agents (usually two anionic surfactants or an amphoteric and an anionic), foam booster (also a surfactant, most often an alkanola-mide), conditioner, viscosity improver (inorganic salts or cellulose derivatives), opacifier, dye, perfume, biostats (often esters of p-hydroxybenzoic acid), and perhaps chelates (EDTA or citric acid). Propylene glycol or glycerin may be present to adjust solubility and viscosity. Depending on current fashion, other compounds will be present, such as vitamins and food or herb extracts (26,27). 

Commercial Disperse Azo Dyes. The first proposal to use insoluble dyes in suspension in an aqueous foam bath, ie, disperse dyes, to dye cellulose acetate was in 1921 (60). Commercialization of disperse dyes began in 1924 with the introduction of the Duranol dyes by British Dyestuffs Corporation (61) and the SRA dyes by British Celanese Company (62). In contrast to the acid monoazo dyes, derivatives of benzene rather than of naphthalene are of the greatest importance as coupling components. Among these components mono- and dialkylariifines (especially A/-P-hydroxyethyl-and A/-(3-acetoxyethylanifine derivatives) are widely used couplers. Nitrodiazobenzenes are widely used as diazo components. A typical example is CeUiton Scarlet B [2872-52-8] (91) (Cl Disperse Red 1 Cl 11110). 

Emulsion Adhesives. The most widely used emulsion-based adhesive is that based upon poly (vinyl acetate)—polytyinyl alcohol) copolymers formed by free-radical polymerization in an emulsion system Poly(vinyl alcohol) is typically formed by hydrolysis of the poly (vinyl acetate). The properties of the emulsion are derived from the polymer employed in the polymerization as well as from the system used to emulsify the polymer in water. The emulsion is stabilized by a combination of a surfactant plus a colloid protection system. The protective colloids are similar to those used paint (qv) to stabilize latex. For poly (vinyl acetate), the protective colloids are isolated from natural gums and cellulosic resins (carboxymethylcellulose or hydroxyethylcellulose). The hydrolized polymer may also be used. The physical properties of the poly (vinyl acetate) polymer can be modified by changing the co-monomer used in the polymerization. Any material which is free-radically active and participates in an emulsion polymerization can be employed. Plasticizers (qv), tackifiers, viscosity modifiers, solvents (added to coalesce the emulsion particles), fillers, humectants, and other materials are often added to the adhesive to meet specifications for the intended application. Because the presence of foam in the bond line could decrease performance of the adhesion joint, agents that control the amount of air entrapped in an adhesive bond must be added. Biocides are also necessary many of the materials that are used to stabilize poly (vinyl acetate) emulsions are natural products. Poly(vinyl acetate) adhesives known as "white glue" or "carpenter s glue" are available under a number of different trade names. Applications are found mostly in the area of adhesion to paper and wood (see VlNYL POLYMERS). 

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