Effect of Sodium Methylacrysulfonate upon the Molecular Weight and Performance of Polycarboxylate Superplasticizer

Abstract

The effect of sodium methylacrysulfonate (SMAS) upon the molecular weight, molecular weight distribution and polycarboxylate (PCE)’s dispersion and dispersion-retaining ability were investigated by Gel permeation chromatography (GPC) and test of the fluidity of cement pastes. The results showed that the dosage of SMAS was inversely proportional to the molecular weight of polycarboxylate, and a cubic equation relationship existed between the molecular weight of the polycarboxylate and the reciprocal of SMAS dosage. There was an optimum middle dosage of sodium methylacrysulfonate which could control the molecular weight polycarboxylate, and then affect its dispersion and dispersion maintain performance. The effect of sodium methylacrysulfonate on the monomer conversion rate was also systematically discussed by means of high performance liquid chromatography (HPLC).

Research on the performances of VPEG macromonomer grafted different functional groups to prepare polycarboxylate superplasticizers

“…The GPC test results of the synthesized a series of PCE samples are shown in Table 4. It can be seen that the number average molecular weight ( M n), weight average molecular weight ( M w) and PDI of the synthesized a series of PCE samples are somewhat different, in which the molecules synthesized by doping V‐SMAS have the smallest M n and M w, this is due to the fact that SMAS has a part of the function of chain transfer, 31 and the molecules synthesized by doping V‐AA and V‐AM have not much difference in M n and M w, while the molecules synthesized by doping V‐AMPS and V‐N‐MAM have relatively large M n and M w, which is because the relative molecules of AMPS and N‐MAM are larger than AA and AM. Generally, the molecular weight distributions (PDI) of the synthesized five samples were relatively moderate, and the synthesized conversion rates were in the range of 85% to 95%, which indicated that the process was suitable for the preparation of PCE mother liquid with VPEG macromonomer.…”