Dispersing carbomers, mixing technology matters

Mixing dry carbomer powder with water using magneto-hydrodynamic mixing yielded carbomer dispersions with higher viscosity and increased storage modulus as compared to conventional high shear mixing. 1H NMR spectroscopy demonstrated this to be induced by a different water distribution, accompanied by lower ionization and higher degradation of the polymer in case of high shear mixing. This investigation reveals 1H MAS NMR to provide suitable sensitivity and resolution to detect structural changes induced in organic polymers during their hydration.