Soap vs detergents

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  • Prepared By : Mazadul Hasan sheshir ID: 2010000400008 13th Batch (session 2009-2013) Department : Wet Processing Technology Email: Blog : www. (visit) Southeast University Department Of Textile Engineering I/A 251,252 Tejgaon Dhaka Bangladesh Prepared By : right
  • INTRODUCTION: SOAP VS DETERGENTS Water that contains calcium ions, Ca2+, and magnesium ions, Mg2+, is said to be hard water. These ions are leached from ground water flowing over rock formations containing limestone and other minerals. Hard water interferes with the cleaning action of soaps. When soap is added to hard water, insoluble compounds form which appear as sticky scum. This scum leaves a deposit on clothes, skin, and hair. You could have ring around the collar! When boiled, hard water leaves a deposit of calcium carbonate, CaCO3. This scale builds up in tea kettles and inside hot water heaters. Detergents have replaced soap for many cleaning jobs around the home. The development of synthetic detergents by chemists was a great advantage for people with relatively hard tap water in their homes.
  • DETERGENTS DEFINITION : Detergents are soap-like compounds which are used for cleaning purpose. They are sodium salts of long chain alkyl benzene sulphonic acids or sodium salts of long chain alkyl hydrogen sulphate, whereas, soaps are sodium salts of long chain carboxylic acids. STRUCTURE OF DETERGENTS
  • Hydrophilic part: Hydrophilic part is sodium salt which is readily soluble in water. e.g. SO3-, OSO3-, OH- or NR4. This part of a detergent is ionic and is attracted by polar water molecules. Hydrophobic part: hydrocarbon part of detergent is called hydrophobic part. It is non- polar. Hydrophobic part is insoluble in water but it is soluble in oil. This part consists of a hydrocarbon segment and can dissolve oil or grease. Hydrophilic part (water soluble) Hydrophobic part (oil soluble ) DETERGENTS
  • By combining animal or vegetable fats with aqueous sodium hydroxide soap is made. Soaps are advantageous because they are made from biodegradable renewable resources. Therefore, soaps are not polluting the environment. These factors are outweighed by the negative affects of hard water and the cost of the raw materials. Soaps react with calcium and magnesium ions in hard water leading to the formation of precipitates. Increased household use of alkylbenzene sulfonates (ABS), a former compound used in laundering with soaps, resulted in large bodies of water covered in foam. The synthesis of ABS is shown below in Figure 1. Figure: Synthesis of ABS PREPARATION OF DETERGENT:
  • 1. Detergents are carbonic compounds which are not alkaline. 2. They are costly. 3. They are suitable for delicate clothes. 4. They clean both in hot and cold water. 5. They clean the cloth even in hard water. 6. They are removed very easily so less quantity of water is needed. GENERAL PROPERTIES OF DERERGENT:
  • Chemical classification of detergents 1. Anionic detergents 2. Cationic detergents 3. Non-ionic and zwitterionic detergents Chemical classification of detergents
  • 1. Anionic: Those that develop a negative charge on the water solubilizing end. 2. Cationic: Those that develop a positive charge on the water solubilizing end. 3. Non-Ionic: Those that develop no ionic charge on the water solubilizing end. 4. Amphoteric : Those that have both a positive and negative charged group on the molecule. Chemical classification of detergents By Ionic Charge
  • Anionic detergents Typical anionic detergents are alkylbenzenesulfonates. The alkylbenzene portion of these anions is lipophilic and the sulfonate is hydrophilic. Two varieties have been popularized, those with branched alkyl groups and those with linear alkyl groups. The former were largely phased out in economically advanced societies because they are poorly biodegradable. An estimated 6 billion kilograms of anionic detergents are produced annually for domestic markets. Bile acids, such as deoxycholic acid (DOC), are anionic detergents produced by the liver to aid in digestion and absorption of fats and oils. Anionic detergents
  • Cationic detergents : Cationic detergents are similar to the anionic ones, with a hydrophobic component, but, instead of the anionic sulfonate group, the cationic surfactants have quaternary ammonium as the polar end. The ammonium center is positively charged Cationic detergents
  • Non-ionic and zwitterionic detergents Non-ionic detergents are characterized by their uncharged, hydrophilic headgroups. Typical non- ionic detergents are based on polyoxyethylene or a glycoside. Common examples of the former include Tween,Triton, and the Brij series. These materials are also known as ethoxylates or PEGylates). Glycosides have a sugar as their uncharged hydrophilic headgroup. Examples include octyl-thioglucoside and maltosides. HEGA and MEGA series detergents are similar, possessing a sugar alcohol as headgroup. Zwitterionic detergents possess a net zero charge arising from the presence of equal numbers of +1 and -1 charged chemical groups. Examples include CHAPS. Non-ionic and zwitterionic detergents
  • SOAP STRUCTURE OF SOAP: Soap is a substance called a surfactant that is used with water for washing and cleaning a variety of objects. Detergent refers to any substance, soapy or not, that aids in cleaning. DEFINITION
  • All soaps and detergents are polar molecules, which allow for the cleansing action of dirt in water. One end consists of a large non-polar hydrocarbon group that is hydrophobic i.e., repels water but attracts oil and dirt particles. The other end has a highly polar short group that is hydrophilic i.e., attracts water and not oil or dirt. MECHANISM OF SOAP & DETERGENT:
  • Soap forms a colloidal solution in water and when soap is applied to the surface of a wet dirty cloth, the non-polar long end hydrocarbon of soap attaches itself to the dirt and grease. The short polar or ionic end of the soap molecule remains attached to water molecules. The latter form very small globules or structures called 'micelles' in which the oily dirt particle is surrounded with the tails of soap molecules carrying negative charge, while the polar head with positive charge interacts with the water. The subsequent mechanical action of rubbing or tumbling dislodges the dirt and grease. These are washed away with excess of water leaving the fabric clean. MECHANISM OF SOAP & DETERGENT:
  • In the industrial manufacture of soap, tallow (fat from animals such as cattle and sheep) or vegetable fat is heated with sodium hydroxide. Once the saponification reaction is complete, sodium chloride is added to precipitate the soap. The water layer is drawn off the top of the mixture and the glycerol is recovered using vacuum distillation. PREPARATION OF SOAP: PREPARATION OF SOAP: One of the organic chemical reactions known to ancient man was the preparation of soaps through a reaction called saponification. Natural soaps are sodium or potassium salts of fatty acids, originally made by boiling lard or other animal fat together with lye or potash (potassium hydroxide). Hydrolysis of the fats and oils occurs, yielding glycerol and crude soap.
  • 1. Soap are made from fat and alkali by specification method 2. There are cheap. 3. There are not suitable for delicate clothes. 4. They are clean better in hot water. 5. They don't produce lather with hard water and are not able to clean the cloth. 6. Lot of water is needed to remove soap from the cloth. GENERAL PROPERTIES OF SOAP:
  • Part I: Soap vs. Detergent in Hard Water 1. Add 100 mL of distilled (soft) water to a 250 mL beaker. Then add 2.0 g of magnesium sulfate, MgSO4, and stir. Label this beaker hard water. You now have prepared a stock solution of hard water. 2. Arrange three test tubes in a test-tube rack. Half-fill the first test tube with distilled water (soft water). Half-fill the second tube with tap water. Half-fill the third with hard water from the stock solution. 3. Using a metal spatula, add a pea-sized sample of solid soap from a bar of commercial hand soap to each of the three test tubes. (Caution: Remember after shaking several times to stop, release the pressure, re-stopper, and shake.) Stopper and shake the first test tube. Ten shakes is adequate. On your data sheet record the height of suds in the test tube as measured with a centimeter scale. Draw a picture of the test tube; record all your observations in the picture. Part I: Soap vs. Detergent in Hard Water
  • 1. Repeat Step 3 for the other two test tubes. Shake each test tube in an identical manner. 2. Dump and rinse the test tube contain