Acids lignosulphonate

Fig. 14. Solid-state NMR spectrum of an acetylated lignosulphonic acid (A) and corresponding spectrum of its demethylated sulfur derivative (B), 441...

S. V. Martyanova, A. A. Chezlov, A. G. NigmatuUina, L. A. Rskareva, and R. D. Shamsutdinov. Production of lignosulphonate reagent for drilling muds—by initial heating with sulphuric acid, condensation with formaldehyde, and neutralisation of mixture with sodium hydroxide. Patent RU 2098447-C, 1997. 

P. Ya. Zeltser. Plugging solution for oil and gas industry—contains plugging Portland cement, lignosulphonate(s), waste from formic acid production obtained at stage of decomposition of sodium formate, and water. Patent SU 1730431-A, 1992. 

Chen, R. and Kokta, B.V. (1982). Graft copolymerisation of lignosulphonate with methacrylic acid and acrylate monomers. In Graft Polymerisation of Lignocellulosic Fibers, Hon, D.N.S. (Ed.). ACS Symposium Series, 187, pp. 285-299. 

Kojima Y, Hayashi A, Tachi I (1960) Studies on lignosulphonic acid (VI) Conductometric titration with weak base 7pn Tappi 14 831-834 Kolthoff IM, Sandell EB (1952) Textbook of quantitative inorganic analysis Macmillan, New York, 759pp... 

Samuelson O (1948) A contribution to the ehemistry of the sulphite process. III. A comparison between the sulphur content and the amount of sulphonic acid groups in lignosulphonic acid. Sven Kern Tidskr 60 128-130... 

Salts of lignosulphonic acids Salts of hydroxycarboxylic acids... 

Analytical data of lignosulphonate fractions after ultrafiltration of a technical softwood acid sulphite pulping liquor [92]... 

Various compounds are used as set-retarders based on sugar, lignosulphonic or hydroxy-carboxylic acids and salts, and also inorganic salts. For example, sugar added as 0.05% of cement mass may delay the set by approximately four hours. The long-term concrete strength is not modified by set-retarders. 

The plasticizers are produced on the basis of several organic compounds lignosulphonic and hydroxylated carboxylic acids and salts, polyols and others. Usually between 0.2% and 0.5% of cement mass is added in an appropriate way, more often directly to the mixing water. The increased amount of a plasticizer may cause retardation effects and longer setting times. 

Poly(acrylic acid), -(CH2-CH-COOH) -, at pH > 5, the carboxylic acid groups ionise to form an anionic polydectrolyte poly(acrylic acid)/poly(methacrylic acid), (CH2-CH-COO ) -(CH2-C(CH3)-COO ) naphthalene formaldehyde sulpho-nated condensates, lignosulphonates. 

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