1,2 Hexanediol as an Alternative Cosurfactant for Preparing Palm Based Microemulsions for Practical Applications
Microemulsions (uE) were prepared with palm fatty acid esters (PFAME) as solvents stabilised by fatty alcohol ethoxylates (hydrophilic lipophilic balance, HLB value ~12.8) and 1,2 hexanediol as a co surfactant. The effects of co surfactant on the ternary phase systems were studied only at 10, 15, 20, 25, and 30% (w/w) of surfactant concentrations. The ratio of PFAME/water was chosen at 30:70 only. The mixtures were mixed vigorously and then kept at ambient temperature (25degC) for few days. The emulsions (two phase) uE and liquid crystalline phases were observed using the polarised light. In addition, the physical stability (accelerated test/month at 45degC),conductivity and viscosity for uE solutions were measured. The effects of co surfactant on the ternary phase systems for PFAME/non ionic surfactant/water were constructed at 25 and 45degC. The result showed that larger uE region was formed with PFAME 1 than the PFAME 2 at 30:70 ratio of oil to water. The minimum concentration of surfactant for producing clear, low viscosity and thermodynamically stable uE solutions was 10% (w/w) for both PFAME 1 and PFAME 2 at 25degC. However, the concentration of co surfactant used to produce uE solutions was 12.5% for PFAME 1 but was 30% (w/w) for PFAME 2. Furthermore, the conductivity and viscosity measurements indicated types of uE, that is, O/W or W/O formed.