Abstract
We describe palm-based methyl ester sulphonate premixes, which are mixtures of methyl ester sulphonates (MES) and fatty alcohol ethoxylate sulphonates (FAES), and their application in liquid detergent formulations. The best ratios of these compounds were obtained from ternary phase diagrams of MES, FAES and deionised water at 70 degrees C. The phase changes - from isotropic to liquid crystalline regions were observed visually using polarised film, and the liquid crystalline birefringent optical patterns - were subsequently confirmed using a polarising microscope. Based on the phase diagrams obtained, the optimal liquid crystalline region was selected for the preparation of a palm oil-based premix. Stable premixes can be used to produce liquid detergent products such as dish-washing liquids, laundry detergents, hand washes, kitchen cleaners and floor cleaners. The active levels of the palm-based MES premixes were measured using an autotitrator for dish-washing liquid formulation. The physical stability of the model dish-washing liquids (DWL) was assessed by conducting stability tests at room temperature (24 degrees C) and also at 45 degrees C, over a three-month period. Other properties such as detergency, foaming power, pH and viscosity were measured, and comparisons were made with current typical commercial products. A dermal irritation assay confirmed that the product is non-irritant to the skin.