Phase Analysis And Formula Design Of Compound Soap Made By Sodium Acyl Isethionate

The synthesis and phase analysis of mono-carbon chain acyl isethionate sodium (SAI) was studied in this paper; then the compound soap phase analysis of mixed carbon chain SAI was researched; the formula of compound soap and neural soap was designed based on the former result of phase analysis.According to orthogonal test, the optimal synthesis conditions of mono-carbon chain SAI were: feeding ratio 1.3:1, titration time 50min, reaction time 150min and the nitrogen feeding after reaction is 60min .The result of X-Ray diffraction, thermal gravimetric analyzer, differential scanning calorimeter and polarized light microscope with heat stage showed that the mono-carbon chain SAI was heat-stable below 250℃and maybe have one crystalline phase.The compound soap of sodium fatty acid and mixed carbon chain SAI was prepared. The effect of parameters on phase and property showed that the optimum conditions of compound soap were grinding time 20min, moisture content around 13%, electrolyte around 3%. There are at least three phases in the compound soap in this condition. The soap had good foam property and moderate hardness. CAB, K12 and Tween 20 were added in the soap in order to improve hard water tolerance and mildness. The optimum formula of the compound soap using response surface methodology were: grain of soap 8820 55g, mixed carbon chain SAI 20g, lauric acid 7g, sodium isethionate 3.5g, titamium dioxide 0.3g, BHT 0.1g, flavor 1.0g, katonh 0.1g, water 13g, CAB 3.80g, K12 4.35g, Tween20 2.35g. The foamability of this formula was 30mm, foam stability 2.5mm, hardness 69.3, pH 9.38, hard water tolerance 4.94ml, mildness 200.57mg/100ml.The neutral soap made by mixed carbon chain and mono-carbon chain SAI were compared, optimum formula was as follows:mixed carbon chain SA(I65%)70g, grain of soap 8820 2g, paraffin wax 8g, starch 6g, sodium isethionate 4g, titamium dioxide 0.3g, BHT0.1g, flavor 1.0g, katonh 0.1g, water 8.5g. The foamability of this formula was 84mm, stability of foam 76mm, pH 6.56, hardness 64.9, hard water tolerance 10.15ml, mildness 85.42mg/100ml. It's foam and hard water tolerance was higher than Dove, hardness and pH value was smaller than Dove, but mildness was weaker than Dove.