Rubber Surface-active agents

Dimeihylamine, C2H7N, (CH3)2NH. Colourless, inflammable liquid with an ammoniacal odour, mp -96" C, b.p. 7°C. Occurs naturally in herring brine. Prepared in the laboratory by treating nitrosodimetbyl-aniline with a hot solution of sodium hydroxide. Dimethylamine is largely used in the manufacture of other chemicals. These include the solvents dimethylacetamide and dimethyl-formamide, the rocket propellant unsym-metrical dimethylhydrazine, surface-active agents, herbicides, fungicides and rubber accelerators. 

Rubber processed in latex form accounts for about 10% of new mbber consumption. Rubber latex is a Hquid, oil-in-water emulsion which is used to make foam or thin-walled mbber articles. The same accelerators and antidegradants used in dry mbber are used in latex, with longer-chain versions preferred for greater oil solubiHty. To prepare these and other additives for addition to latex, they must be predispersed in water and the surface of the powder or oil droplet coated with a surface-active agent to prevent destabilization (coagulation) of the latex. 

Wet anti-tack agents can be soap or detergent solutions or suspensions of the dry agents in water. For example, dissolved polymers with non-ionic surface active agents which form a thin layer of polymer on unvulcanised rubber sheets magnesium stearate in water zinc stearate dispersion and aqueous dispersions of fatty acid salts. 

Uses Intermediate in the synthesis of rubber accelerators, dyes, pharmaceuticals, insecticides, bactericides, textiles, and surface-active agents solvent dehairing agent solubilizer for 2,4-D. 

The octylphenol condensate is used as an additive to lubricating oils and surface-active agents. Other uses of dimer are amination to octylamine and octyldiphenylamine, used in rubber processing hydroformylation to nonyl alcohol for phthalate production and carboxylation via Koch synthesis to yield acids in formulating paint driers (see Drying). 

Lower aliphatic amines are widely used as intermediates for the synthesis of herbicides, insecticides and drugs or can be applied as rubber accelerators, corrosion inhibitors, surface active agents etc. [l]. The most widespread method for the preparation of lower aliphatic amines involves the reaction of ammonia with an alcohol or a carbonyl compound in the presence of hydrogen. The most common catalysts used for reductive amination of alcohols, aldehydes and ketones contain nickel, platinum, palladium or copper as active component [ I — 3 ]. One of the most important issues in the reductive amination is the selectivity control as the product distribution, i.e. the ratio of primary to secondary or tertiary amines, is strongly affected by thermodynamics. 

The rubber particle size in the final product increases several fold if the prepolymerization is carried out in the presence of a dilute aqueous solution of an alkane sulfonate or polyvinyl alcohol in place of pure water. The addition of a surface-active agent converts the coarsely dispersed oil-water mixture—obtained as above in the presence of pure water—into an oil-in-water emulsion. In this case even prolonged stirring during prepolymerization does not decrease the rubber particle size appreciably in the final product. The stabilization of the droplets of the organic phase in water by the emulsifier obviously impedes or prevents agitation within the polymeric phase. Figure 1 shows the influence of these three prepolymerization methods (under otherwise equal reaction conditions) on the dispersion of rubber particles in polystyrene. 

Typical examples of stress corrosion are crack formation in strained rubber vulcanizates under the influence of ozone, hair cracks in PE under stress in the presence of a surface active agent (see also 7.4.2), crack formation in PC, when exposed to e.g. CCI4, within a few seconds after the application of a small stress. 

TEA is used as an intermediate for surface-active agents used in textile specialties, waxes and polishes, herbicides, petroleum demulsifiers, toilet goods, cement additives, cutting oils, and photograph-film developers as corrosion inhibitors as a dispersant for dyes, casein, shellac, and rubber latex as sequestering agents and as a rubber chemicals intermediate123. 

The degree of dispersion depends on the degree of grafting, where the graft acts almost as a surface-active agent to keep the rubber in a colloidal dispersion in the matrix. The effectiveness of the graft appears... 

Squalene and phytosterols are components present in the unsaponifiable lipid fraction of foods (as tocopherols). Squalene is an intermediary in cholesterol biosynthesis, and 33.9-58.4 mg/100 g of it was found in the lipid fraction of quinoa (Jahaniaval et al., 2000 Ryan et ah, 2007) squalene is the biochemical precursor of the whole family of steroids, and besides their effective antioxidant activity, tocotrienols have other important functions, in particular in maintaining a healthy cardiovascular system and a possible role in protection against cancer (Nesaretnam, 2008). Squalene is used as a bactericide and as an intermediate in many pharmaceuticals, organic coloring materials, rubber chemicals, and surface-active agents (Ahamed et ah, 1998). 

Use Intermediate, synthetic-rubber processing, surface-active agent, corrosion inhibitor. 

Use Surface-active agents, lubricant additives, rubber chemicals, flotation agents, antifoam agent. 

Use Solvent, intermediate for surface-active agents, oil additives, resins, fungicides, bactericides, dyes, pharmaceuticals, adhesives, rubber chemicals. 

Tariff Commission, Synthetic Organic Chemicals—U. S. Production and Sales, annual, 1917 to date (except 1931-1932). Production, sales, and unit values of dyes, lakes, and toners, medicinal chemicals, flavor and perfume chemicals, plastics and resins, elastomers, rubber-processing chemicals, plasticizers, surface active agents, pesticides, and many individual organic chemicals. Lists producers of all commercially important organic chemicals. Formerly Dyes and Other Synthetic Organic Chemicals (1917-1937). 

Diethanolamine is used in the production of surface-active agents and lubricants for the textile industry as an intermediate for rubber chemicals as an emulsifier as a humectant and softening agent as a detergent in paints, shampoos, and other cleaners and as an intermediate in resins and plasticizers. 

CNSL is obtained as a by-product of the cashew nut industry, mainly containing anacardic acid 80.9%, cardol 10-15%, cardanol, and 2-methyl cardol (Fig. 10). CNSL occurs as a brown viscous fluid in the shell of cashewnut, a plantation product obtained from the cashew tree, Anacardium oxidentale (Bhunia, et al., 2000). CNSL is used in the manufacture of industrially important materials such as cement, primers, specialty coatings, p)aints, varnishes, adhesives, foundry core oils, automotive brake lining industry, laminating and rubber compounding resins, epoxy resins, and in the manufacture of anionic and non-ionic surface active agents. CNSL modified phenolic resins are suitable for many applications and perform improved corrosion and insulation resistance. 

As epoxy and silicone rubber are completely immiscible, the addition of a compatibilizer is necessary to obtain a satisfactory dispersion of the rubber in the resin. The main objective of Kasemura and coworkers [216] was to find an appropriate surface-active agent to reduce the interfacial tension between the resin and the rubber, in order to compatibilize the two components. These authors achieved adequate compatibility in the epoxy resin with the use of a polyester-modified silicone oil to disperse an RTV (room temperature vulcanizing) silicone rubber or silicone diamine. The results showed that the impact fracture energy of the resin was increased by the addition of the RTV silicone rubber, up to two times that of the unmodified resin, whereas the addition of silicone diamine had almost no effect, possibly because the molecular weight was too low. Moreover, T-peel strengths of aluminum plates bonded by epoxy resin filled with RTV silicone rubber and with silicone diamine effectively increased with the silicone content, showing a maximum at 10-20 pph. By scanning electron microscopy, many particles of silicone rubber, 1-20 xm, were observed across the whole of the fracture surface. 

The standard spectra are run using pure compounds and include the common organic reagents. The commercial series includes dyes, stains, plasticizers, monomers, polymers, polyols, resins, rubbers, soaps, fatty acids and drying oils, solvents, surface-active agents, textile chemicals, waxes, petroleum chemicals, intermediates, and pharmaceuticals. These spectra reflect the materials as they are available commercially, and list their trade as well as chemical names. 

Formulations based on thermoplastic rubbers can be made into emulsions by dispersing solutions or melts into water containing appropriate surface active agents. Normally, any organic solvent present would be stripped from the emulsion. High shear devices, such as colloid mills or centrifugal pumps, have been successfully used for the emulsifying step. 

Code 28 is the most interesting for chemists. See the complete product code in Manual Predicasts User s Manual. The main advantage is the opportunity to search for product categories as a whole e.g. Surface Active Agents or Plastic and Rubber Chemicals. In the context of usual substance-orientated indexing, such queries are difficult to search, because the complete list of substance names must then be entered individually. 

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