SYNTHESES OF SOAP AND DETERGENT Adolfo, Angela Angela Nicole G., Alcaraz Frances Jillian Jillian Kaye F., Aliman, Stephani Stephanie e T., Astor, Jashmin D., Bauzon, Franchesca D., Cabral, Danica Rose G.
Department of Pharmacy, Faculty of Pharmacy University of Santo Tomas
ABSTRACT The synthesis of soap and detergent is an experiment detailing the process of creating soap and detergent. Soap, by chemical definition, refers to a cleaning agent that is a mixture of sodium salts of various naturally occurring fatty acids. Detergents, on the other hand, are structurally similar to soaps but differ in terms of water-solubility. The cleaning action of both soaps and detergents results from their ability to emulsify or disperse water-insoluble materials and hold them in suspension in water. In the experiment, experi ment, soap and detergent are synthesized and later compared their solubility in hard water. Soap is synthesized by usage of solutions and solvents such as NaOH, coconut oil, cold saturated NaCl solution. Detergent is synthesized by means of solutions such as dodecanol, H 2SO4, NaOH, and a detergent sample. INTRODUCTION Soap is a salt of a compound known as a fatty acid. A soap molecule consists of
combine with the alkali to form crude soap and
is
confirmed
in
the
method
saponification.
a long hydrocarbon chain (with 12 to 18 carbon atoms) with a carboxylic acid group on one end which is ionic bonded to a metal ion, usually a sodium or potassium. A soap serves as a surfactant in conjunction to water. Soaps for cleansing are obtained by treating vegetable or animal oils and fats with a strongly alkaline solution. Fats are first
Figure 1. Condensed 1. Condensed Structural and
hydrolyzed into free fatty acids, which then
Skeletal Formula of Soap
of
As seen from the Figure above the
By adding oil, the water is polar. The
fatty acid usually contains 12 to 18 carbon
water and oil has a bi-polar reactivity and
atoms, this formula consists of 16 carbon
water will mix through suspension of oil in
atoms. Solid soaps usually consist of sodium
soap as soap is to water. The micelle’s “tail”
salts of fatty acids whereas liquid soaps
may extend or become highly branched for
usually are potassium salts of fatty acids.
as long as it still dissolves in non-polar
Soap consists of a polar end and a non-polar
substances like oil. This function of soap is
end. Soaps are called amphipathic molecule
attributed to micelles which have coats of
due to this dual nature. In this case, sodium
polar carboxylate groups on the outside,
salts were used for the experiment.
encasing a hydrophobic pocket that can surround any grease particles.
Glycerol (glycerine) is liberated and is either leftin or washed out and recovered as a useful by-product, depending on the process employed.
and common way of creating soap is through the cold process method. The common product of this modern homemade soap production is the "Lye". The rationale behind the oil or grease is removed when the garment stained with oil is dictated by the
explains this function in a diagram.
A. Preparation of Soap First, a mixture of 30 mL of 6M
As done in the experiment, the best
“like dissolves like” principle.
METHODOLOGY
Micelles’
NaOH and 50 mL water was prepared. The mixture was transferred into a 500 mL beaker and heated over a low flame with frequent stirring. 15 mL of coconut oil was added in portions to the mixture and it was heated for 15-20 minutes with frequent stirring to replace the water lost by evaporation. Then, the test for complete saponification was done by adding a drop of mixture to 1 mL of water. When the saponification was complete, the mixture
was
stirred
until
it
became
homogeneous. The hot solution was poured into a 50 mL cold, saturated solution of NaCl. The precipitated soap was filtered through a cheesecloth and the collected soap was washed twice with 5 mL portions of ice-cold Figure 2. A Micelle
water. Then, the soap was placed in a large evaporating dish and 10-20 mL of water was
added to completely dissolve the soap. It was
RESULTS AND DISCUSSION
evaporated until a jelly consistency was seen. The soap was cooled partially and poured into a molder.
The following results are observed during the performed experiment. Table 1 - Properties of Soap & Detergent
B. Extraction of Glycerol
SOAP
DETERGENT
White Gelatin
White Amorphous
Insoluble
Soluble
Insoluble
Soluble
Slightly Emulsified
Slightly Emulsified
(less suds)
(less suds)
The filtrate collected from the previous procedure was neutralized with diluted HCl.
Color & Appearance
It was evaporated to a small volume or to a syrupy consistency and it was allowed to
Solubility in
cool. Then, the residue was extracted with 10
1% CaCl2
mL of 95% ethanol and it was filtered. The
Solubility in
alcoholic extract was evaporated in a water
1% MgCl2
bath.
Emulsifying Ability
C. Test for Glycerol the
Table 1 shows that detergent and
glycerol, a pinch of powdered potassium
soap are color white solid in appearance.
bisulfate was added. It was heated over a
This is because of their chemical nature;
high flame and the odor was observed.
soaps are alkaline salts, and detergents are
To
the
residue
containing
sodium dodecyl sulfate. D. Behavior in Hard Water An amount of 5 mL of soap solution was placed in each of two test tubes. 2 mL of 1% CaCl2 was added into one soapcontaining tube and 2 mL of 1% MgCl 2 in another test tube. The contents of each test tube was mixed several times and the precipitation (very large, little, none) was noted. Then, 4 drops of cooking oil was added into each test tube. A cork stopper was plugged and the mixture was shaken vigorously. The emulsifying ability of soap in each test tube was observed and recorded.
Figure 3. Saponification Reaction Sequence
The
sequence
states
that
oil
dissolved in their respective alkyl groups and
underwent alkaline hydrolysis in NaOH. It
the ionic ends made the molecules soluble in
yielded soap and glycerol. Soap has sodium
water.
salts that affects the appearance and solubility in water. Hard water contains Ca2+ and Mg2+ ions, both insoluble in water, its interaction
with
sodium
salts
yielded
insoluble solids due their different solubility. The by-product glycerol, was observed by heating the mixture and also by adding a pinch
amount
of
powdered
potassium
bisulphate. The reaction produced a sweet, butter-like odor due to the fatty acid present in the mixture.
Figure 5. Filtered Soap As seen from the figure above, the Figure 4. Reaction Sequence for Detergent
finished product of soap was obtained through filtration of the made mixture of
Preparation
water, Sodium Hydroxide, Coconut Oil, and The reaction of dodecyl alcohol
(cold) Sodium Chloride.
(dodecanol) and sulfuric acid formed dodecyl sulfate and water. It was further converted to a sodium salt by hydrolysis with NaOH. The
CONCLUSION Through the Syntheses of Soap and
result yielded a sodium dodecyl sulfate salt,
Detergent
which notes to the appearance and solubility
encountered. The first aspect observed from
in water. Detergents, when added to a 1%
them was their color and appearance,
CaCl2 and 1%MgCl 2, were more soluble than
another aspect is their solubility with different
soap. Soaps and detergents both showed
inorganic chemicals (Calcium Chloride and
emulsifying ability. The detergents produced
Magnesium
more
the
experiment, it has been observed that soap
emulsified products proved that the oil was
is insoluble with both reagents and detergent
suds
compared
to
soaps,
several
Chloride).
aspects
And
we’re
in
this
is the soluble. Giving an idea of their
http://www.chymist.com/Soap%20and%20d
common use. Soaps are use as bath soap,
etergent.pdf
and intended to last longer. That’s why they were considered as insoluble, but in the use of soaps it could be said that they are considered as very slightly soluble (with water). And as for detergents, that are used in laundry; giving the fact that they have to be
Making Soaps and Detergents. (2016). Retrieved
from
http://www.rsc.org/learn-
chemistry/resource/res00001746/makingsoaps-anddetergents?cmpid=CMP00005261
freely soluble with water for the clothes to be completely suspended or soaked in the soapy liquid produced by the water and
Books:
detergent. One more aspect observed from
Bathan, G.I., Bayquen, A.V., Crisostomo,
the soap and detergent we’re also through
A.B.C., Cruz, C.T., de Guia, R.M., Farrow,
their emulsifying ability, projecting a similar
F.L., Peña G.T., Sarile, A.S., Torres, P.C..
result, wherein both are contemplated to be
(2014). Laboratory Manual in Organic
slightly emulsified.
Chemistry Revised Edition. Quezon City,
In this experiment, the members have encountered the syntheses of soap and detergent. Giving an accomplishment for the first objective of the experiment. And through the results from the experiment, the behavior of soap and detergent in hard water have been
totally
compared.
Giving
another
accomplishment to the second objective. Concluding that the objectives have been accomplished.
REFERENCES Website: Katz, D.A.. (2000). The Science of Soaps and
Detergents.
Retrieved
from
Manila: C & E Publishing, Inc.
