the abnormal analysis of number average molecular weight of sulfonated melamine formaldehyde (smf)

Smf, a water-soluble polymer and superplasticizer, was synthesized in four controlled steps: methylolation, sulfonation, and polymerization in low and high ph. the implemented specific bonds at each step were identified by ftir. in addition, the intrinsic viscosity and average hydrodynamic radius of synthesized smf by dilute solution viscometry (dsv) and dynamic light scattering (dls), respectively were combined in the flory’s theory based equation to overcome the observed anomaly and acquire its number-average molecular weight, 227,000 g/mol. the experimental results were consistent with the reported data from the literature using appropriate modifications regarding the unusual behavior of polyelectrolytes in aqueous solutions