Rubber latex stability

Uses Ethylamine is a colorless, inflammable gas. A variety of manufacturing industries have been associated with this compound (e.g., dyestuff industry, pharmaceuticals, rubber latex stabilizers, oil refining). 

Uses Emulsifier, dispersant and wetting agent used in alkaline cleaning formulations antigelling agents, automotive radiator cleaners, metal, cement, brick, and tile cleaners for crystal growth control plastics, rubber latex stabilizer... 

Synonyms Naphthalenesulfonic acid, bis-(1-methylethyl)-, sodium salt Empirical CieH2oNa03S Properties M.w. 315.39 anionic Uses Emulsifier, dispersant and wetting agent used in alkaline cleaning formulations antigelling agents, automotive radiator cleaners, metal, cement, brick, and tile cleaners for crystal growth control plastics, rubber latex stabilizer Trade Name Synonyms Rhodacal BA-77 t[Rhodia HPCII http //www.rhodia-hpcii.com, Rhodia HPCII France... 

Rubber latex stabilizers Britain 1,555,851 1979 Goodyear Tire Rubber... 

Formula R(OCH2CH2) OH, R = blend of cetyl and stearyl radicals, avg. n = 22 Uses Wetting agent, emulsifier, detergent, solubilizer, dispersant In hydrophobic conditions dye and pigment carriers textile applies. mfg. of wax emulsions and polishes for household and Industrial use antistat rubber latex stabilization emulsifier In cosmetics... 

Amine-containing accelerators and stabilizers used in the polymerisation of rubber latex... 

Foam cement is a special class of lightweight cement. The gas content of foamed cement can be up to 75% by volume. The stability of the foam is achieved by the addition of surfactants, as shown in Table 10-9. A typical foamed cement composition is made from a hydraulic cement, an aqueous rubber latex in an amount up to 45% by weight of the hydraulic cement, a latex stabilizer, a defoaming agent, a gas, a foaming agent, and a foam stabilizer [359,362]. Foamed high-temperature applications are based on calcium phosphate cement [257]. 

The hydrogen ion concentration at which a colloidal system is electrically neutral the addition of acidic substances to, for example, rubber latex causes the pH value to move towards the isoelectric point, which is the region of minimum stability, and coagulation may take place. 

Uses Stabilizer for latex rubber intermediate for dyestuffs and medicinals resin and detergent manufacturing solvent in petroleum and vegetable oil refining starting material for manufacturing amides plasticizer stabilizer for rubber latex in organic synthesis. 

Uses Stabilizing rubber latex solvent for albumin, casein, shellac, and sulfur neutralizing oils in antifreeze as a corrosion inhibitor emulsifier adhesives textile lubricants fungicides manufacturing chelating agents such as EOT A (ethylenediaminetetraacetic acid) dimethylol-ethylene-urea resins organic synthesis. 

Uses. In resin chemistry stabilizer for rubber latex intermediate for dyesmffs, pharmaceuticals in oil refining... 

The compounding technique for latex differs from that of dry mbber and is fundamentally simpler. A critical factor of colloidal stability makes necessary that each ingredient is of optimum particle size, pH, and concentration when added as an aqueous dispersion to the latex. Rubber latex is a colloidal aqueous emulsion of an elastomer and natural mbber latex is the milky exudation of certain trees and plants that of greatest commercial importance is the... 

For some applications, eg, foam rubber, high solids (>60%) latices are required. In the direct process, the polymerization conditions are adjusted to favor the production of relatively large average particle-size latices by lowering the initial emulsifier and electrolyte concentration and the water level in the recipe, and by controlling the initiation step to produce fewer particles. Emulsifier and electrolyte are added in increments as the polymerization progresses to control latex stability. A latex of - 35-40 wt% solids is obtained and concentrated by evaporation to 60—65 wt % solids. 

Ethylenediamine, as such, is used as a solvent for various compds, as a corrosion inhibitor in antifreeze soln, stabilizer in rubber latex, etc. Its use as a colorimetric reagent for expls, such as TNT, etc, is discussed in Vol 3 of Encycl, p C406 L Refs 1) Beil 4, 230, (398), [676] 1478 ... 

Most ABS is made by emulsion polymerization. A polybutadiene or nitrile rubber latex is prepared, and styrene plus acrylonitrile are grafted upon the elastomer in emulsion. The effect of rubber particle size in ABS graft copolymer on physical properties is the subject Chapter 22 by C. F. Parsons and E. L. Suck. Methyl methacrylate was substituted for acrylonitrile in ABS by R. D. Deanin and co-workers. They found a better thermoprocessability, lighter color, and better ultraviolet light stability. 

The purpose of this paper is to summarise results which have recently been obtained for the effects of various soaps and surfactants upon the mechanical and chemical stability of natural rubber latex, and to indicate the inferences which have been drawn in the course of endeavouring to interpret these observations. 

The ability of a soap or surfactant to enhance the chemical stability of natural rubber latex was assessed by ascertaining its effect upon the mechanical stability of natural rubber latices whose stabilities had been reduced by various chemical modifications. Natural rubber latices of reduced stability were produced in three different ways as follows ... 

Wherever possible, the soaps and surfactants were added to the natural rubber latex as dilute aqueous solutions. The cases where this was not possible were (a) ethylene oxide-fatty alcohol condensates of low ethylene oxide fatty alcohol mole ratio, and (b) sparingly-soluble fatty-acid soaps such as lithium laurate and calcium soaps. The former were added as pastes with water, the latter as dry powders. In all cases, the latex samples were allowed to mature for about three days at room temperature before their mechanical stabilities were determined. This allowed some opportunity for the attainment of adsorption equilibrium. 

Effects of added fatty-acid soaps upon mechanical and chemical stability of natural rubber latex (1,2,5)... 

Saturated straight-chain fatty-acid soaps (1). Figure 1 shows the effects of increasing levels of various potassium saturated straight-chain fatty-acid soaps upon the mechanical stability of natural rubber latex. For convenience of making comparisons between the various soaps, the levels of added soap are expressed as moles per 100 g. of latex solids. 

The results summarised in Table I show the effect of equal parts by weight of each of the potassium fatty-acid soaps upon the mechanical stability of each of the three chemically-destabilised latices. For convenience in making comparisons, estimates of the corresponding results for unmodified natural rubber latex are also included. It is clear from these results that the ability of added potassium fatty-acid soaps to enhance the stability of chemically-destabilised natural rubber latex roughly parallels their abilities to enhance the mechanical stability of unmodified natural rubber latex. 

Figure 2. Effect of alkyl chain length of added soap upon mechanical stability of natural rubber latex at four molal levels of addition (A) 0.84 X 10 4 (B) 2 X 10 4 (C) 3.36 X 10 4 (D) 4.20 X 10 4 mol/100 g of latex solids (1)...

Figure 3. Effect of various straight-chain potassium C18 carboxylate soaps upon mechanical stability of natural rubber latex (2) (KCt8) potassium stearate (KC18) potassium oleate (KC18") potassium elaidate (KC18Z) potassium linoleate (KC=ZZ) potassium linolenate (KC1H12(oli)) potassium 12-hydroxy stearate ...

The abilities of the five laurates to protect natural rubber latex against chemical destabilisation appear to be broadly parallel to their effects upon mechanical stability. 

We have also recently discovered that added calcium laurate is able markedly to enhance the mechanical stability of natural rubber latex (2.). This observation is surprising, partly because of the low solubility of calcium laurate in water, and partly because calcium ions are known to be powerful destabilisers of natural rubber latex (j ). It indicates that the stabilising effect of the laurate anion is much greater than the destabilising effect of the calcium cation. 

It is important to point out that our investigation of counterion effects in carboxylate soaps has so far been concerned almost exclusively with laurate soaps. Laurate soaps were chosen partly because they are generally convenient to handle in that many of them are readily soluble in water to give solutions of low viscosity, and partly because, as has been shown above, laurate soaps are very effective in enhancing the mechanical and chemical stability of natural rubber latex. It must therefore be borne in mind that the conclusions which have been drawn from this investigation concerning effects attributable to counterion variation in laurate soaps may not be generally valid for carboxylate soaps as a family. 

The effects of a range of sodium n-alkyl sulphates and sodium n-alkyl sulphonates upon the mechanical stability of natural rubber latex are summarised in Figures 4 and 5 respectively. As in the case of added potassium fatty-acid soaps, small additions of... 

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