ChemistryInvestigatoryProject

INDEX1.Certificate 2. Acknowledgements.3.Aim 4.Introduction5.Mechanism of cleansing of soap6.Soap making processes7.Imp. points to measure ingredients8.Preparation of soap by cold process9.Soap prepared by cold process10. Preparation of soap by hot process11. Soap prepared by hot process12. Merits and demerits of soap13. Bibliography

AIMManufacture of soaps using different

oils and methods.

Soaps are sodium or potassium salts of higher fatty acids like stearic, palmitic and oleic acids can be either saturated or unsaturated. They contain a long hydrocarbon chain of about 10-20 carbon with one carboxylic acid group as the functional group.

A soap molecule a tadpole shaped structure, whose ends have different polarities. At one end is the long hydrocarbon chain that is non-polar and hydrophobic, i.e., insoluble in water but oil soluble. At the other end is the short polar carboxylate ion which is hydrophilic i.e., water soluble but insoluble in oil and grease.

Long Hydrocarbon Chain Hydrophobic end Hydrophilic end

Mechanism of Cleansing Of SoapAction of soap

Structure of a micelle

(

M

+

When soap is shaken with water it becomes a soap solution that is colloidal in nature. Agitating it tends to concentrate the solution on the surface and causes foaming. This helps the soap molecules make a unimolecular film on the surface of water and to penetrate the fabric. The long non-polar end of a soap molecule that are hydrophobic, gravitate towards and surround the dirt ( fat or oil with dust absorbed in it). The short polar end containing the carboxylate ion, face the water away from the dirt. A number of soap molecules surround or encircle dirt and grease in a clustered structure called 'micelles', which encircles such particles and emulsify them.

Cleansing action of soaps decreases in hard water. Hard water contains Calcium and magnesium ions which react with sodium carbonate to produce insoluble carbonates of higher fatty acids.

2C17H35COONa +Ca2+ (C17H35COO) 2 Ca

+2Na+ . (Water soluble) (ppt.)

2C17H35COONa + Mg2+ C17H35COO) 2 Mg

+2Na+

This hardness can be removed by addition of Sodium Carbonate.

Ca2++ Na2CO3 CaCO3 2Na+

Mg2++ Na2CO3 gCO3 + 2Na+

Effect of the alkaliThe type of alkali metal used determines the kind of soap product. Sodium soaps, prepared from sodium hydroxide, are firm, whereas potassium soaps, derived from potassium hydroxide, are softer or often liquid. Historically, potassium hydroxide was extracted from the ashes of bracken or other plants. Lithium soaps also tend to be hard—these are used exclusively in greases.

Effects of fatsSoaps are derivatives of fatty acids. Traditionally they have been made from triglycerides (oils and fats).Triglyceride is the chemical name for the triesters of fatty acids and glycerin. Tallow, i.e., rendered beef fat, is the most available triglyceride from animals. Its saponified product is called sodium tallowate. Typical vegetable oils used in soap making are palm oil, coconut oil, olive oil, and laurel oil. Each species offers quite different fatty acid content and, hence, results in soaps of distinct feel. The seed oils give softer but milder soaps. Soap made from pure olive oil is sometimes called Castile soap or Marseille soap, and is reputed for being extra mild. The term "Castile" is also sometimes applied to soaps from a mixture of oils, but a high percentage of olive oil.

Soap making processesThe industrial production of soap involves continuous processes, such as continuous addition of fat and removal of product. Smaller-scale production involves the traditional batch processes. The three variations are: the 'cold process', wherein the reaction takes place substantially at room temperature, the 'semi boiled' or 'hot process', wherein the reaction takes place near the boiling point, and the 'fully boiled process', wherein the reactants are boiled at least once and the glycerol is recovered.

Typically soapmakers choose the hot process methods if they wish to remove the cure time to a three-day air dry process. Most soapmakers, however, continue to prefer the cold process method. The cold process and hot process (semi boiled) are the simplest and typically used by small artisans and hobbyists producing handmade decorative soaps. The glycerine remains in the soap and the reaction continues for many days after the soap is poured into moulds. The glycerine is left during the hot-process method, but at the high temperature employed, the reaction is practically completed in the kettle, before the soap is poured into moulds. This simple and quick process is employed in small factories all over the world.

Important points to measure .. the ingredients Saponification values of Fats (oils) used:

1. Coconut oil – 0.1912. Soya bean oil – 0.1363. Castor oil – 0.128

Calculations to measure ingredients1. Amount of Lye = Amt. of Oil × Saponification value of Oil2. Total amt. of Lye-Water solution = Amt. of Lye × 0.33. Amt. of Water = Amt. of Lye-Water solution ― Amt. of Lye

Note : 1.To make the soap harder add more amount . of lye then the calculated one.

2. Temperature of the lye-water solution and . the oils should be nearly equal.

Preparation of Soap by

Cold Process

Ingredients and Requirements:Coconut oil and Soya bean oilLye (NaOH)GlycerolBlenderMould Measuring cupsLab thermometerDigital scalePerfume and colours

Steps Involved:1. Measure the amount of lye and mix with water.

2.Measure the amount of hard and soft oils . Melt the

hard oil and then mix it with the soft oil.

3.Watch that the temp. of the lye-water solution and the melted oils are nearly same using lab thermometer . If the temp. of both are nearly same then mix them using a blender or rod.

4.After blending mix glycerol , perfume and colour and mix them and put it in a mould.

5.Leave the soap for 2-3 days and then

demould it.

6.Cut out the soap into pieces.

Preparation of Soap by Hot Process

Ingredients and Requirements:Castor oil and coconut oilLye (NaOH)GlycerinCrockpot Silicon mouldWooden spoon Glass measuring cupsDigital scaleBlenderPerfume and colours

Steps Involved:1. Measure the amount of oils . Melt the hard oil and mix

it with the soft oil.

2. Measure the amount of lye and mix with water .

3.Watch that the temp. of the lye-water solution and the melted oils. They should be nearly same using lab thermometer .

4. Put the lye solution in the oil pot and mix them till it starts to thicken up.

5. Keep on stirring the mixture till it looked like

applesauce and after like mashed potatoes .

6. Add a glycerin , perfume and colours and mix them as

fast you can.

7.Put it in the mould and leave for a day or two and after that put out them out.

Qualities of Soaps

Preparation of soap is cheap. Soap is biodegradable. Easily soluble in polar protic solvents. It can be molded into various shapes, sizes

and various kinds of fragrances and medical properties can be added to it.

Demerits of Soaps Soaps do not work in hard water , they

form salts with calcium and magnesium ions which are insoluble and thus a lot of soap gets wasted.

The cleansing abilities are poorer than detergents