Synthesis and Properties of Sodium Secondary Alkyl Sulfates for Concentrated Laundry Sheets

Abstract

Sodium secondary alkyl sulfates (SASs) with C₁₂, C₁₄, and C₁₆ chains were synthesized from linear α-olefins and H₂SO₄. Using 1-dodecene as the model substrate, optimal conditions (H₂SO₄/olefin molar ratio of 1.1, 10°C, 30 min addition) achieved >93% conversion, which was successfully applied to C₁₄ and C₁₆ homologues. SAS-12 and SAS-14 have Krafft points below 0°C, indicating favorable low-temperature solubility. Conductivity measurements confirmed that the critical micelle concentration (CMC) of all three homologues increases with temperature. Among the homologues, SAS-14 shows the best balance of wetting and foaming performance. In laundry sheet applications, SAS-based formulations achieved overall detergency comparable to alcohol ether sulfate (AES), with superior removal of sebum and protein soils at both 30°C and 20°C. With its favorable low-temperature solubility, competitive surface activity, and validated performance, SAS-14 is a promising candidate for high-performance concentrated laundry sheets.