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TOPIC 7: SOAP & DETERGENT - Coggle Diagram
TOPIC 7: SOAP & DETERGENT
SOAP
a cleaning agent that is composed of one or more salts of fatty acids.
CHARACTERISTIC OF SOAP
Hardness
Cleansing
Conditioner
Lather
Fragrance
RAW MATERIALS
ALKALI
sodium hydroxide (NaOH), also called caustic soda
potassium hydroxide (KOH), also called caustic potash
Fats and oils (fatty acids)
WEAK ACID
o a long hydrocarbon chain at one end
a carboxylic acid group (-COOH) at the other end.
generally represented as RCOOH.
Saturated fatty acids:
stearic acid (C17H35COOH) & palmitic acid
(C15H31COOH)
Unsaturated fatty acids
Oleic acid (C17H33COOH) – mono-unsaturated FA
Linoleic acid – poly-unsaturated FA (2 double bond)
Triglycerides
esters of fatty acids and are formed by combining fatty acids with glycerol
SAPONIFICATION
Saponification is a process in which esters in fats/oils are hydrolysed with sodium or
potassium hydroxide (lye) to produce a carboxylate anion which can act as a surfactant, i.e. soap.
alkaline hydrolysis of esters
TYPE OF SOAP
Soft soap
Hard soap
Novelty soaps
not only for clean but for amusement and enjoyment as well
Medicated soaps
similar to original soap, but the only difference being the addition of antiseptics and disinfectants
Beauty and perfumed soaps
Produced by adding perfume and a few additional ingredients for different skin types
Laundry soaps
Formulated specially to clean grease, solid particles and organic compounds from clothes.
Kitchen soaps
Kitchen soap is a soap intended for use in the kitchen mainly to serve the purpose of dish-washing
LIMITATION OF SOAPS
1.Soaps do not wash well in hard water and does not form much lather or foam
2.Ordinary soaps are not suited for fabrics such as silks, wool etc. The alkalis in them could
damage the fiber.
3.If the water is slightly acidic in nature, soaps cannot be used for cleaning purpose
DETERGENT
a chemical compound or mixture of compounds used as a cleaning agent.
can also be used as surfactants and foaming agents.
a non-soapy cleaning agent that uses a surface-active agent (surfactant) for
cleaning a substance in solution.
SURFACTANTS
a material that can greatly reduce the surface tension of water
The surfactant, usually containing 8 to 18 carbon atoms, has two different ends. One end is water
soluble, called hydrophilic, and the other end is water insoluble, called hydrophobic.
CLASSIFICATION OF SURFACTANTS
Anionic (negative charge)
Cationic (positive charge)
Non-ionic (no charge)
Amphoteric (either positive or negative charge).
ADDED MATERIALS (ADDITIVES) IN DETERGENT/SOAP MANUFACTURING
Builder
effectively soften the water.
Builders removed extra magnesium and calcium ions
Anti-redeposition agents
It prevents fine soil particles from attaching to the fabric,
allowing them to rinse freely out of the wash.
Optical Brighteners
used to make white clothing
“whiter”.
Inert Fillers
Without it, the detergent would stick together and become one big block.
Anti-corrosion Agents
Chemicals such as sodium silicate were added so that metal objects like
buttons and zippers would not rust or corrode
Perfumes
Organic molecules with pleasant smells were added to give the clothes aromas such as floral, summer breeze and lemon
. Enzymes
clean grass and blood stains by destroying the proteins found in them
ADVANTAGES OF DETERGENT
Detergents are more soluble in water than soaps.
Detergents have a stronger cleansing action than soaps.
Detergents are the salts of strong acids so they do not decompose in acidic medium. Thus
detergents can effectively clean fabric even if the water is acidic.
Detergents can lather well even in hard water. There is no scum formation.
DISADVANTAGES OF DETERGENT
Some of detergents are not biodegradable.
Detergent can cause a variety of water pollution problems.
CLEANING ACTION OF SOAP AND DETERGENT
When grease or oil are mixed with a soap- water solution, the fatty acid anions work as a
"bridge" between polar water molecules and non-polar oil molecules.
The hydrophobic tails dissolve in the greasy dirt and the hydrophilic heads dissolve in
water. ☞ micelles are form
This action drawing water onto the dirt and fabric. As the water is swirled around it pulls
the grease out of the fabric
Once the dirt and oils are removed from the clothes, surfactants keep them suspended in
the water (emulsion) and are washed away with excess of water leaving the fabric clean.
DIFFERENCES BETWEEN SOAPS AND DETERGENTS
Diff between soap and detergent