An investigation into interactions between polyacrylic polymers and a non-ionic surfactant: an emulsion...

Area of Science:

• Colloid and Surface Science
• Polymer Chemistry
• Rheology

Background:

• Understanding emulsion stabilization mechanisms is crucial for formulation development.
• Polymeric emulsifiers and surfactants are key components in stabilizing emulsions.
• Investigating polymer-surfactant interactions provides insights into formulation performance.

Purpose of the Study:

• To investigate interactions between acrylates/C10-30 alkyl acrylate crosspolymer (Pemulen TR-2) and polyoxyethylene 20 sorbitan mono-oleate (Polysorbate 80).
• To elucidate the role of hydrophobic groups in polymer-surfactant interactions.
• To understand the impact of these interactions on emulsion rheological properties.

Main Methods:

• Surface tension measurements to analyze interfacial polymer-surfactant interactions.
• Continuous shear rheometry and texture analysis to quantify changes in dispersion network structure.
• Comparison with a hydrophilic polyacrylic acid polymer (Carbopol 934P) to assess hydrophobic influence.

Main Results:

• Pemulen TR-2 demonstrated surfactant desorption from the surface across all tested concentrations.
• Viscosity and texture parameters of Pemulen TR-2 dispersions increased with Polysorbate 80 up to 0.3% w/w, then decreased.
• Carbopol 934P showed no surfactant desorption and minimal changes in network structure.

Conclusions:

• Hydrophobic interactions occur between Pemulen TR-2 and Polysorbate 80 in aqueous dispersions.
• These interactions are concentration-dependent and influence the rheological properties of the dispersion.
• The hydrophobic alkyl groups of Pemulen TR-2 are critical for its interaction with Polysorbate 80.