Sodium formaldehyde

In addition to appHcations in dyeing, sodium formaldehyde sulfoxylate is used as a component of the redox system in emulsion polymerization of styrene—butadiene mbber recipes. 

Sodium formaldehyde sulfoxylate dihydrate (sodium hydroxymethylsulHnate, Rongalite)... 

In the presence of sodium bicarbonate, sodium formaldehyde sulfoxylate (Rongalite) converts perfluoroalkyl iodides and bromides to the corresponding carboxylates Less decarboxylation to the monohydroperfluoroalkanes occurs when the bromides are used [16] (equation 17)... 

About 20 grams of diamino diphenyl sulfone is dissolved in about 500 cc of ethyl alcohol (3A made up of 5 parts methyl alcohol and 100 parts of ethyl alcohol) by placing the ingredients in a flask provided with a reflux condenser and warming over a water bath. About 24 grams of pure grade, very finely powdered (40 to 60 mesh) sodium formaldehyde sulfoxylate Is then rapidly added to the alcohol solution of diamino diphenyl sulfone and the mixture refluxed in the usual manner. It was found that the mixture should be refluxed for a total of 5 hours and that a precipitate starts to form near the 3 hour period. The reaction mixture is then cooled to 15°C and kept at this temperature for about 1 hour. The precipitate formed in the filtrate is filtered off rapidly and drained as much as possible to remove mother liquor and then washed with small amounts of cold alcohol. The solid product is immediately placed in a desiccator and dried over sulfuric acid for about 20 hours. 

Sodium formaldehyde-sulphoxylate (12.46 sodium hy droxy me thane sulphinate) and alkali, although more stable than alkaline dithionite, tends to share the same disadvantages... 

Greater commercial significance is attached to certain derivatives of sodium dithionite, including sodium formaldehyde-sulphoxylate (12.53 hydroxymethanesulphinate) (Scheme 12.23) and the less important sodium acetaldehyde-sulphoxylate (12.54 hydroxye thane -sulphinate). These reducing agents have been of particular interest in printing, especially in the flash-ageing process [228-231]. The formation of sodium formaldehyde-sulphoxylate by reaction of sodium dithionite with formaldehyde is shown in Scheme 12.23 the bisulphite formed can be further reduced with zinc to produce another molecule of the sulphoxylate. 

These reducing agents are much more stable than sodium dithionite at lower temperatures hence they can be used to prepare stable pad liquors and print pastes. At higher temperatures, as in steam fixation treatments, they are capable of bringing about rapid reduction of vat dyes. Sodium formaldehyde-sulphoxylate was used first in conventional steam fixation of vat prints, although the acetaldehyde analogue was initially preferred for the flash-ageing process. As vat dyes are invariably fixed under alkaline conditions, the sodium salts of the sulphoxylates are preferred to the basic salts of zinc (12.55) or calcium (12.56), which are unstable under alkaline conditions. 

Sodium formaldehyde sulfoxylates, 23 677 Sodium glucoheptonate, 4 708 Sodium D-gluconate, 4 708... 

Tellurophene. A mixture of tellurium (4.0 g, 31 mmol), sodium formaldehyde sulphoxylate of 85% (28 g, 200 mmol), sodium hydroxide (17 g, 425 mmol) in 150 mL water is heated at reflux, under N2 atmosphere for 15 min, and then cooled at 20°C. A solution of 1,4-bis(trimethylsilyl)-l,3-butadiene (8.2 g, 42 mmol) in 100 mL of ethanol is slowly added to the stirred sodium telluride solution, the mixture is heated at reflux for 15 min, then stirred at 20°C for 3 h and extracted with ether. The extract is dried (Na2S04), filtered, and 10 mL (200 mmol) of bromine are added dropwise until the bromine colour persists. This solution is concentrated in a water bath under aspiration vacuum to a volume of 50 mL, and the red precipitate of tellurophene dibromide is collected 8.9 g (84%), m.p. 120°C dec. 

Emulsion Polymerizations, eg. vinyl acetate [VAc]/ABDA, VAc/ethylene [VAE]/ABDA, butyl acrylate [BA]/ABDA, were done under nitrogen using mixed anionic/nonlonic or nonionic surfactant systems with a redox Initiator, eg. t-butyl hydroperoxide plus sodium formaldehyde sulfoxylate. Base monomer addition was batch or batch plus delay comonomer additions were delay. 

In the first step a rubbery polymer latex is prepared by emulsion polymerization of styrene and butadiene, the styrene being in an amount of 25%. Divinylbenzene is added as crosslinking agent in an amount of 1%. Diphenyl oxide sulfonate is used as emulsifier in aqueous solution and sodium formaldehyde sulfoxylate acts as a buffer in order to reach a pH of 4. As radical initiator, cumene hydroperoxide is used and the polymerization is conducted 70°C for 9 h. The end of the reaction period is detected as no further pressure drop is observed due to the consumption of butadiene. 

To the latex prepared, 7% of styrene are added followed by sodium formaldehyde sulfoxylate dissolved in water and cumene hydroperoxide. An exothermal reaction is observed. 

One hour after the completion of the exotherm, 7% of methyl methacrylate, 0.07% of butylene dimethacrylate, 0.07% parts sodium formaldehyde sulfoxylate dissolved in water and 0.15% of cumene hydroperoxide are added and the reaction is allowed to completion. 

---