Abstract
The following five oligomers of polymethylene naphthalenesulfonates with plasticizing properties of cement grouts were synthesized by the modified procedure. Condensation of sodium salt of α- and β-naphthalenesulfonic acid with formaldehyde in a ratio of 1: 1 leads to the formation of α-PNS-1 (2,7-polymethylenenaphthalene-α-sulfonate of sodium), and b-PNS-3 (5-7-polymethylenenaphthalene-b-sulfonate of sodium), increase of the ratio of 1: 3 - to trisubstituted cycle of α-PNS-2 (5-7,3-3-polymethylenenaphthalene-α- sulfonate of sodium), b-PNS-4 (5-7, 6-6-polymethylene-naphthalen-b-sulfonate of sodium), which modification leads to the formation of b,b¢-PNS-5 (b,b¢-PNS-5 4-4, 8-8-polymethylenenaphthalene-1,5-oxymethylene-2,6(β,β’)-disulphonate of sodium). Testing the synthesized additives on the plasticizing properties, on the strength and kinetics of the hardening cement grouts showed that PNS-1 by PNS-4 all proposed types of PNS increase the plasticity from P1 to P3 and in accordance with the State Standard 24211-2008 are plasticizers,increasing the concrete strength from 27 to 30%. PNS5 increases the plasticity from P1 to P5 and in accordance with the State Standard 24211-2008 are superplasticizer, increasing the concrete strength up to 60%.