Abstract:

The wax emulsion was prepared by phase inversion method using refined montan wax as oil phase. Both single-factor and orthogonal experimental methods were used, in which emulsion particle size was used as a criterion for judgment. The effects of emulsifier dosage, wax ratio, stirring speed and stirring time on the stability of wax emulsion were studied. The process conditions for preparation of wax emulsions were optimized. Furthermore, the effects of incorporation of beeswax on the stability and particle size of the emulsion were also studied. Then, a composite emulsion of refined montan wax/beeswax with optimal formulation and preparation procedure was obtained. The antibacterial and application properties of the composite wax emulsion were also tested. The results showed that, the influencing factors on the particle size of the wax emulsion was in the descending order of emulsifier dosage>stirring speed>wax ratio>stirring time. The optimized preparation conditions were: The mass fraction of coconut oil fatty acid diethanolamide of 6.30%, Tween60 of 0.75%, Span60 of 2.95%, refined montan wax of 7.00%, beeswax of 3.00%, water of 80.00%, stirring speed of 1 500 r/min, and stirring time of 10 min. The particle size of the emulsion prepared under optimized conditions was 650.2 nm. It was confirmed that the addition of 3.00% beeswax could drastically reduce the particle size of the emulsion, and the particle size distribution became more uniform, which greatly improved the stability of the emulsion. This wax emulsion had good bacteriostatic effects on both Escherichia coli and Staphylococcus aureus. The wax emulsion was applied in leather finishing, indicative of significant improvement in the color change effect, brightness, and feel of the leather.

Key words: montan wax/beeswax, wax emulsion, preparation process, bacteriostatic, leather finishing