Why Salt Tolerance Decides Which Carbomer You Specify

A conventional carbomer thickens by neutralising its acid groups so the cross-linked network opens up and holds water. Add electrolyte and the same charges are screened: the network collapses, and viscosity falls even though nothing in the formula has changed.

There are three ways around it. Hydrophobically modified grades add associative side chains, so the network is partly held by hydrophobic interaction rather than charge alone; NM-Carbomer 21 and 60 are in this group. Pre-neutralised polymers such as NM-PA 6 arrive already neutralised and rely on a dual mechanism, tolerating up to 10 wt.% sodium chloride from pH 2 to 10. Liquid dispersions such as NM-Carbomer SF-1 avoid the swelling step altogether and tolerate moderate electrolyte levels.

Which one fits depends on where the electrolyte comes from. A surfactant system is different from an aloe-based gel, and both differ from a high-pH cleaner with builders. Send us the formulation and the target viscosity and we will say which route holds.