Detergent Value of Soap Nut Powder J. L. SARIN AND NI. Y. CPPAL Go\-ernmentIndustrial Research Laboratory, P. 0. Shahdara Mills, Lahore, India
4
PREVIOUS paper (5) showed that soap nut (Xapindus mulcorossi) contains 17.2 per cent extractable saponin, other constituents being gums and resins. It was also stated that in India soap nut powder has been used as a washing agent for silk and woolen textiles from ancient times. I n this investigation an attempt is made to measure the detergent efficiency of soap nut powder with a view to its utilization in the textile industry. It was thought that the presence of certain gums in soap nut would also produce a sizing effect on the fiber. The fruit was first air-dried and freed from seeds. The pericarp was then roasted for 3-4 hours at 110" to 130" C., which rendered it friable and readily soluble. It was then powdered and passed through a 60-mesh sieve. The resultant powder was nonhygroscopic and could be safely stored in sacks. The loss in weight was about 5 per cent. A suitable bath was obtained with 15-20 grams of powder per liter of hot water. The pH value of a 2 per cent bath is 3.99.
the weight of oil-coated umber that remains suspended under standard conditions in 100 cc. of the detergent solution. The oil-coated umber was prepared as recommended by Snell
I
1
0.1
0.2
0.3
I
I
0.4
J
0.5
Detergent Efficiency DETERMINATION OF SURFACE TENSION.Measurements of the drop number were carried out against air and transformer oil (density a t 38" C. = 0.8607, viscosity a t 25" C. = 0.210 poise, refractive index, n3z = 1.471). The number of drops were determined in the usual manner in a Traube stalagmometer. For convenience the results were calculated in terms of relative tension-i. e., the drop number of water divided by the drop number of the detergent solution. For comparison, determinations of relative surface and relative interfacial tension were also made with standard soap and some detergents such RS Lissapol C and Lissapol T (probably sodium alkyl sulfonates) made by Imperial Chemical Industries, Ltd. The composition of standard soap was as fO11OTT'S
: Moisture Free alkali Free fatty acid Sodium chloride Glycerol Total alkali (as NazO) Titer of fatty acids
0.1 02 03 0.4 0.5 PER CENT MATERIAL IN SOLUTION
FIGURE1. RELATIVESURFACE INTERFACIAL TENSION AT 35" c.
AND
( 7 ) . One gram of the umber was added in stoppered graduated cylinders to 100 cc. of a 0.1 per cent solution of the detergent a t 18" C., and the mixture was vigorously shaken by hand one hundred times and allowed to stand for 24 hours. At the end of this period 10 cc. of the solution were withdrawn from the middle of the solution and evaporated to dryness a t 110" C. The residue, after ignition a t a dull red heat, was dissolved in concentrated hydrochloric acid (iron-free).
0.72%
o.ooyo
pp$ 12.35% 25.5' C.
Curves were plotted (Figure 1) for concentration against relative surface tension and against relative interfacial tension. Soap nut seems to behave as do other good detergents. The curves for soap nut are broadly similar t o those of soap, though its minimum surface tension is slightly higher. Comparison was also made of the interfacial tension of a 0.04 per cent solution of soap nut powder and other detergents-e. g., sodium hydroxide, sodium carbonate, etc.against benzene and benzene containing 0.1 per cent oleic acid. The results are given in Table I. DEFLOCCULATING AND EMXJLSIFYING POWER.Values for deflocculating and emulsifying power mere determined from
TABLEI. SURFACE AND INTERFACIAL TENSION OF 0.04 PER CENTDETERGENT SOLVTIONS AT 40' C. (IN DYNES PER CM.) Detergent Water Sodium hydroxide Sodium carbonate Standard soap Aodiiim oleate Saponin Soap nut
666
Surface Tension 69.3 69.3 69.3 35.8 34.5 52.5 54.1
-1nterfaoial Benzene 30.6 30.6 30.6 16.0 14.8 8.5 13.4
Tension against:Benzene 0.1% oleic acid 25.8
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