Paraffin sulphonates

These surfactants are also called alkane sulphonates or secondary alkane sulphonates. They are a versatile class of surfactants with interesting chemistry and are significantly less commercialised than LAS or alkyl sulphates, due to the more complex manufacturing route and the lack of flexibility of a paraffin sulphonate manufacturing unit which can effectively produce only paraffin sulphonates. Compare this to a falling film S03 plant which can be used for the manufacture of a wide range of sulphonated and sulphated surfactants. 

Raw materials. The paraffins used in the manufacture of paraffin sulphonates are essentially the same as those used in the pro duction of LAB but favouring the higher end of the molecular weight range. For paraffin sulphonate manufacture, it is essential to use a normal paraffin, free of any aromatics because branched alkane (especially tertiary) and aromatic species will act as radical traps and reduce the reaction yield. 

Composition vs. performance. Paraffin sulphonates have excellent solubility and surfac-tancy with detergent performance equivalent to LAS and solubility significantly better. As with olefin sulphonates, optimum detergency is found at a chain length of C15. 

There are a number of industrial applications for paraffin sulphonates, such as EOR, leather processing and metal cleaning, which exploit their high solubility, chemical stability and electrolyte tolerance. 

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Low cost Choose from the following most widely used ones soaps, linear alkylbenzene sulphonates (LABS), alcohol ethoxysulphates (AES), alcohol sulphates (AS), alkane or paraffin sulphonate (SAS), and alcohol ethoxylates (AE)... 

Chemistry and general properties. The main challenge in the manufacture of paraffin sulphonates is the lack of a reactive function in the paraffin (alkane) hydrophobe but this is overcome by using the Strecker reaction or a variant of it. The classical Strecker reaction (shown in Figure 4.10) uses a chloroalkane (which can be made by the reaction of a chlorinating agent with an alcohol) and sodium sulphite. 

Marlon PS Series Paraffin sulphonate, sodium salts... 

Paraffin sulphonates are produced by sulpho-oxidation of normal linear paraffins with sulphur dioxide and oxygen and catalyzed with ultraviolet or gamma radiation. The resulting alkane sulphonic acid is neutralized with NaOH. These surfactants have excellent water solubility and biodegradability. They are also compatible with many aqueous ions. 

Uptake of phenobarbitone in a sodium paraffin sulphonate is not a linear function of surfactant concentration [197]. Above the critical micelle concentration there is an inflection, around 1 %, which might result in problems in the dilution of the system. 

Concentrated sulphuric acid. The paraffin hydrocarbons, cych-paraffins, the less readily sulphonated aromatic hydrocarbons (benzene, toluene, xylenes, etc.) and their halogen derivatives, and the diaryl ethers are generally insoluble in cold concentrated sulphuric acid. Unsaturated hydrocarbons, certain polyalkylated aromatic hydrocarbons (such as mesitylene) and most oxygen-containing compounds are soluble in the cold acid. 

Metal stearates such as zinc, magnesium or aluminium stearates are commonly used as lubricants at about 1 % concentration. Other materials that have been used successfully include oxidised paraffin wax and sulphonated castor oil. 

Paraffin and Aromatic Hydi ocarbon may be separated by the action of fuming sulphuric acid, 4iich forms the sulphonic and with the aromatic hydrocarbon. The product is poured into water. The sulphonic acid dissolves readily in water, whereas the paiaffin is insoluble. 

The role of a second liquid phase in photochemical sulphoxidation of paraffins with SO2 and O2 mixtures may also be cited, where water is used to extract sulphonic acid to prevent formation of di- and poly-sulphonic acids (Fischer, 1978). 

The linear olefins are used in the production of biodegradable detergents. The Cq to cuts are fed to alkylation units where the olefins react with benzene to form alkylbenzenes which are subsequently sulphonated. The paraffins present in the feed pass through unconverted. These are then chlorinated and used as plasticizers. The linear olefins can also be converted to linear aldehydes and alcohols by hydroformylation. 

The lower members of the homologous series of 1. Alcohols 2. Aldehydes 3. Ketones 4. Acids 5. Esters 6. Phenols 7. Anhydrides 8. Amines 9. Nitriles 10. Polyhydroxy phenols 1. Polybasic acids and hydro-oxy acids. 2. Glycols, poly-hydric alcohols, polyhydroxy aldehydes and ketones (sugars) 3. Some amides, ammo acids, di-and polyamino compounds, amino alcohols 4. Sulphonic acids 5. Sulphinic acids 6. Salts 1. Acids 2. Phenols 3. Imides 4. Some primary and secondary nitro compounds oximes 5. Mercaptans and thiophenols 6. Sulphonic acids, sulphinic acids, sulphuric acids, and sul-phonamides 7. Some diketones and (3-keto esters 1. Primary amines 2. Secondary aliphatic and aryl-alkyl amines 3. Aliphatic and some aryl-alkyl tertiary amines 4. Hydrazines 1. Unsaturated hydrocarbons 2. Some poly-alkylated aromatic hydrocarbons 3. Alcohols 4. Aldehydes 5. Ketones 6. Esters 7. Anhydrides 8. Ethers and acetals 9. Lactones 10. Acyl halides 1. Saturated aliphatic hydrocarbons Cyclic paraffin hydrocarbons 3. Aromatic hydrocarbons 4. Halogen derivatives of 1, 2 and 3 5. Diaryl ethers 1. Nitro compounds (tertiary) 2. Amides and derivatives of aldehydes and ketones 3. Nitriles 4. Negatively substituted amines 5. Nitroso, azo, hy-drazo, and other intermediate reduction products of nitro com-pounds 6. Sulphones, sul-phonamides of secondary amines, sulphides, sulphates and other Sulphur compounds... 

Method I.—20 gms. of aniline are gradually added to 65 gms. of cone, sulphuric acid placed in a round-bottomed flask. Much heat is developed, and the contents of the flask should be cooled when the aniline is being added. The flask which contains aniline sulphate and excess cone, sulphuric acid is now heated on an oil or paraffin bath to 185° for about 5 hours. When a test portion, treated with dilute caustic soda solution, liberates no free aniline, the sulphonation is complete. The contents of the flask, after cooling, are poured into cold water, when the sulphanilic acid separates, usually as discoloured crystals. These are filtered off and recrystallised from water, adding a little animal charcoal, if necessary. A further crop can be obtained from the mother liquor. 

Toluene obtained from petroleum should contain no more than 4% of paraffinic hydrocarbons. The content of the latter is determined by sulphonation of the toluene with concentrated sulphuric acid or with 20% oleum. Sulphonated aromatic compounds are washed out with water to leave the paraffin hydrocarbon which is not affected by oleum. 

Paraffin-chain salts, similar in general constitution to the soaps but containing a strongly dissociated end group such as a sulphonic acid or a quaternary ammonium atom, are not subject to hydrolysis, and might be expected to behave in a simpler manner. The surface-tension measurements of Adam and Shute,1 R. C. Brown,2 and Lottermoser and others8 indicate, however, a curious, very slow attainment of the final surface tension in solutions so dilute that there are few, if any, ionic micelles present in the interior. The tension may take several days to reach the final value and when the final tension is reached it appears to be independent of the concentration, at least for solutions over 0-003 per cent., i.e. of the order N/10,000. The amount of this final tension depends somewhat on the nature of the end group it is usually about 30 dynes per cm. 

Indicators, if their ionizable groups are present almost exclusively at the surface, and if the colour and optical density of both forms are unaffected by this adsorption, may be used for determining the pH at the surface. Using the triethanolamine salt of cetane sulphonic acid, the pu at the surface of the micelles was found colorimetrically by diphenylazo-o-nitrophenol. p-nitrophenol was employed to find the pu in the solution curiously it was more difficult to find a suitable indicator for the bulk than for the surface pH, since almost all indicators are more or less adsorbed at the surface of these paraffin chain salts. Preliminary experi-... 

A range of single and blended organic sulphonate standards in oil bases is available. These appear to offer excellent stability and may be diluted with paraffinic and aromatic hydrocarbons as well as ketones. These may be obtained from Conostan Division, Continental Oil Company, P.O. Box 1267, Ponca City, Oklahoma 74601, U.S.A. 

General base catalysed halogenation of carbon acids often involves a rate-determining proton transfer from carbon, and halogenation is a technique which is frequently used for obtaining rates of proton transfer. The technique has been developed particularly by Bell [34] to measure rates of proton transfer from ketones. Other carbon acids have been studied, however, for example, esters [35], sulphonates [36], nitro-paraffins [37], and cyanocarbons [38]. Under chosen conditions which may vary depending upon the substrate, the mechanism, illustrated for acetone in eqns. (19) and (20),... 

An alternative method is by sulphonation. Evans describes the following method for toluene. A measured quantity (about 50 c.c.) of toluene is added to 150 c.c. of 98 per cent, sulphuric acid in a 250 c.c. graduated cylinder. The cylinder is carefully shaken, so that the temperature does not exceed 4 and the stopper is lifted frequently to avoid excess pressure. The cylinder is allowed to stand for five minutes and vigorously shaken for three to four minutes. The liquid is transferred to a separating funnel, the neck of which is narrow and graduated in 1/100 c.c. The bottom outlet of the funnel is connected by a rubber tube with a mercury reservoir. By this means the acid can be raised until the paraffin layer is contained in the narrow neck. The volume is read after two to three hours. A correction for solubility of 0 6 of the percentage of paraffins found is allowed. 

Secondary alkane sulphonates, also called paraffinsulphonates, are generated by sulphochlorination or by sulphoxidation of linear paraffins. Sulphochlorination (Reed reaction) means introduction of the SO2-CI moiety in a paraffin molecule by action of CI2 and SO2 under UV-irradiation followed by hydrolysis and neutralization with NaOH. Reaction of SO2 and O2 with n-paraffins under UV light is called sulphoxidation. 

As the long chain olefins produced in the low temperature FT synthesis are almost exclusively linear alpha olefins, they are ideal for producing easily biodegradable detergents. Cuts from the Cg to products are reacted with benzene to produce alkyl benzenes which are sulphonated to give the detergents. The paraffins in the feedstock pass through the process, are chlorinated and used as plasticisers. Linear olefins can also be hydrofor-mulated to yield linear aldehydes and alcohols. 

Paraffin waxes and hydrocarbon waxes, chloro, sulphonated, ammonium salts... 

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