Abstract:

The molecular weight, surface tension, and the particle size distribution of micellar aggregates of a polyether-polyacrylate polymeric surfactant, HS-PA, were characterized on gel permeation chromatograph, surface tension meter, and laser particle size analyzer, respectively. The thickening properties, detergency, liquid crystal morphology, suspension properties, and rheological behaviors of HS-PA in unstructured/structured detergents with LAS/AES/AEO₉ as the main surfactants, respectively, were also investigated. The characterization results showed that, the weight-average molecular weight of HS-PA was 4 244, the critical micelle concentration was 3×10^-7 mol/L, and the equilibrium surface tension was 42.06 mN/m; the average particle size of aggregates was increased when LAS, AES and AEO₉ formed mixed micelles with HS-PA, respectively. The application test in unstructured detergents showed that, HS-PA had viscosity-enhancing effects on all the LAS/AES/AEO₉-based systems, and meanwhile it was beneficial to the improvement of the detergency to sebum. The application test in structured detergents showed that, HS-PA would help the formation of lamellar liquid crystals in the LAS/AES/AEO₉ systems, and the more HS-PA used, the more the liquid crystals in the AES system; the centrifugal separation results showed that the structured detergents containing HS-PA had the ability to stabilize the suspension of microcapsules; HS-PA could increase the yield stress of the LAS formulation system as determined by rotational rheometer.

Key words: polymeric surfactant, structured detergent, unstructured detergent