Latex laurates

In supplying a calender with a strip of warmed compound by means of a narrow conveyor belt, the final section of the belt may be arranged to oscillate back and forth across the calender nip the device is termed a pendulum feed. Pentachlorophenyl Laurate PCPL, latex auxiliary. 

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. 

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. 

Table II Effects of added laurate soaps of various counterions upon mechanical stability of natural rubber latex (5)...

Some data are also available for the effect of the counterion of a dodecyl sulphate upon its ability to enhance the mechanical stability of natural rubber latex. As in the case of the laurates the lithium, sodium, potassium and ammonium salts are similar in behaviour, but the morpholinium salt is slightly less effective. Again, the latter effect is attributed to specific adsorption of the morpholinium cation. Calcium and magnesium dodecyl sulphates are also effective in enhancing mechanical stability, their abilities being similar to that of morpholinium dodecyl sulphate. 

In an emulsion polymerization of isoprene with 0.10 M potassium laurate at 50°C the estimated time required for 100% conversion at steady rate is 30 h. The final latex has 40 g of polymer per 100 mL with particles of 450 A diameter. During stage II, the growing swollen polymer particles contain 20 g of monomer per 100 mL of swollen polymer. Assuming that there is no change in total volume on polymerization, estimate the polymerization rate constant from these data. Assume that the polymer has a density of 0.90 g/cm . 

Chem. Descrip. PEG-8 laurate CAS 9004-81-3 EINECS/ELINCS 253-458-0 Uses Emulsifier dispersant detergent lubricant vise, control agent in plastisol formulations wetting agent and defoamer in latex paint cosmetics ingred. 

Nonoxynol-1 Nonoxynol-3 Pegosperse 100 0 Surfonic N-10 Surfonic N-31.5 Surfonic N-40 Surfonic N-60 Surfonic N-85 Teric N2 Teric N4 Teric N5 Teric N6 emulsifier, w/o latex/aq. paints PEG-2 oleate SE emulsifier, w/o leather finishes Beeswax, synthetic emulsifier, w/o paints Crill 43 Crill 45 PEG-2 laurate, PEG-2 laurate SE PEG-17 sorbitan Iriole, PEG-18 sorbitan triolet Propylene glycol myristate... 

Sodkm C14-16 olefin sulfonate foam builder, latex POLYSTEP B-7 foam builder, latex emulsions Cocaminobutyric acid, Supragil WP foam builder, latex foam coatings Disodtm takoi/v sulfosuccinamate foam builder, paint strippers Rhodafac La529 foam builder, paints Disodtm nonoxynol-10 sulfosuccinate, oaoxynoTSO PEG-80 sorbitan laurate. 

N8 Teric N9 Teric N10 Teric Nil Teric N12 Teric N13 Teric N15 Tetronic 901 Trldeceth-15 solubilizer, emulsions Alrosperse 100 solubilizer, floor finishes DelONIC NPE-40 Surfonic N-550 Surfonic N-700 solubilizer, industrial Ceteareth-20, Chemax DNP-150/50 ChemaxOP-10 C12-15pareth-10, Nonoxynol-2 Nonoxynol-4 Nonoxynol-5 Nonoxynol-6 Nonoxynol-8, Nonoxynol-10, Nonoxynol-15 Nonoxynol-100 Nonyl nonoxynol-18, Octoxynol-5 Octoxynol-12, PEGS castor oil, PEG-15 castor oil PEG-8 dllaurate PEG-20 glyceryl stearate PEG-4 laurate, PEG-8 laurate PEG-12 oleate Sorbitan laurate solubilizer, latex... 

Caearerit-20, Magnesium ririnum slllcale PEG-5 castor ori, PEG-15 castor oil PEG-8 laurate viscosity contrd agent, latex... 

Meroxapol 174 Meroxapol 178 Meroxapol 251 Meroxapol 252 Meroxapol 254 Meroxapol 255 Meroxapol 258 Meroxapol 311 Meroxapol 312 Meroxapol 314 defoamer, rubber latex PEG-2 laurate... 

PEG-10 lanolin PEG-20 lanolin PEG-30 lanolin Polyquatemium-6 emollient, rubber 2-Tetradecyloctadecanol emollient, rubber latex PEG-2 laurate SE emollient, salves Beeswax, synthetic emollient, shampoo... 

PEG-2 laurate SE PPG-2 laurate PPG-2 oleate PPG-2 stearate TEA-oleate emulsifier, w/o polymerization Sorbitan sesguioleate emulsifier, w/o resins Laureth-6 phosphate emulsifier, w/o rubber latex Glyceryl dilaurate SE Glycol distearate Glycol stearate SE PEG-2 dilaurate PEG-2 dilaurate SE... 

PPG-40 butyl ether PPG-53 butyl ether Rapeseed (Brassica campestris) oil Silicone emulsion Sodium ricinoleate Stearyl/aminopropyl methicone copolymer lubricant, rubber latex PEG-2 laurate SE lubricant, rubber molds PEG-4 PEG-6 PEG-8 PEG-9 PEG-12 PEG-14 PEG-16 PEG-20 PEG-32 PEG-40 PEG-75 PEG-100 PEG-150 PEG-180 PEG-200 PEG-350... 

Several preservative systems have been developed for NR latex to suppress the proliferation of bacteria. Ammonia is the most common preservative used for NR field latex. It is a known mild bactericide and also functions as an alkali to increase the pH of the latex. The normal practice is to add some ammonia to the field latex upon arrival at the factory to prevent auto-coagulation before further treatment. Since the field latex contains only about 30% solids, it is unsuitable for most technical appKcations. Thus field latex needs to be further preserved, purified and concentrated to about 60% sohds in many commercial technical grade latex concentrates. Long-term preservation requires strong preservatives and/or higher dosages of these. Latex concentrate is preserved usually with about 0.7% of ammonia at a pH of about 10.5. This is known as HA latex concentrate. Alternatively a low ammonia concentration of 0.2% is used in conjunction with tetramethylthiuram disulfide (TDTM) as copreservative. This latex concentrate, known as LA-TZ, contains 0.025% TMTD/ZnO and 0.05% ammonium laurate. HA and LA-TZ latex concentrates are the two most common latex concentrates marketed. 

A whole range of inorganic and organic bases can be used to adjust the pH of NR field latex. However, ammonia remains the most common and the cheapest option and hence is widely used. Additional preservatives are sometimes used to further boost the stability of NR latex concentrates. Very often they function as bactericides, enzyme inhibitors, sequestering agents or stabilizers and are often used in combination. Some early preservative systems that were discontinued mainly because of safety and health hazard concerns are 0.2% sodium penta-chlorophenate and 0.2% ammonia 0.1% sodium pentachlorophenate and 0.1% ethylenediaminetetraacetic acid (EDTA) and 0.1% ammonia 0.2% zinc di-ethyldithiocarbamate (ZDTC) and 0.2% ammonia 0.2% boric acid, 0.05% ammonium laurate and 0.2% ammonia. 

The preservatives may function as bactericides, enzyme inhibitors, sequestering agents or stabilizers. They are often used in combination. A system widely used today is zinc oxide/TMTD 0.025% lauric acid or ammonium laurate 0.05% and ammonia (NH3) 0.2%. This is the low ammonia LA-TZ centrifuged latex corresponding to Type III. 

Potassium laurate and sodium abietate are often used as emulsifiers that are attached to the surfae of the latex particles. There are also emulsifiers such as maleic acid monoesers, methacrylic acid, and vinyl benzene sulfonic acid that are built into the polymer, thus improving the tensile strength of the final rubber coating [483]. The nature and concentration of the emulsifier is also a means to controlling the particle size distribution of the products. In monodisperse lattices the particle size varies by less than 1% which can be achieved by short polymerization times [484,485]... 

Another point is the presence of carboxyl groups. Ottewill and Shaw (14, 15) found a large proportion of these groups on latex particles prepared with hydrogen peroxide initiator and sodium laurate emulsifier, and cleaned by dialysis. On the other hand, we did not find appreciable concentrations of carboxyl groups in our latexes, whether prepared with sulfonate or carboxylate emulsifier, as evidenced by both conductometric and potentiometric titration curves, infrared spectra of the polymer, and electrophoretic mobility of the particles (however, the infrared spectra gave evidence for hydroxyl groups). 

The number of resin emulsions and rubber latexes suitable for use as raw materials for adhesives is very large. Emulsions of homopolymers and copolymers of vinyl acetate are the most important. The comonomers for vinyl acetate include maleic esters, acrylates, ethylene and vinyl chloride, unsaturated carboxylic acids, and vinyl esters of relatively long-chain fatty acids, such as vinyl laurate. Apart from these products, polyacrylate homopolymers and copolymers and also styrene copolymers are particularly important in adhesives [42]. 

Testa and Vianello [101] applied the HLB method to the emulsion polymerization of VC. They plotted the rate of polymerization and some properties of the latex against the HLB of anionic emulsifiers or their blends with non-ionic emulsifiers (Empicol (HLB = 40), sodium laurate (20.8), Atlas G 3300 (11.7) and Span 20 (8.6)). No bell-shaped curves were obtained, as one would have expected. The properties of polymer latexes and/or the rate of polymerization seemed to be rather dependent upon the amount of the emulsifier. 

Uses Emulsifier, dispersant, antistat for textiles, paper processing, cutting oils, polishes, emulsion cleaners, rubber latexes, wool lubricants Manuf/Distrib. ChemService Glycol laurate SE EINECS/ELINCS 237-725-9 Synonyms Dodecanoic acid, ester with 1,2-ethanediol Ionic Nature Anionic... 

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