Chemical properties of cotton:

Chemical properties of cotton:

                                I     Effect of Acid: .        Cotton fibers are not affected by cold week acids. Cotton fiber are fully dissolved in high concentration mineral acid.

                              II.            Effect of Alkalis: The  fiber is affected by hot alkali particularly in the presence of air. In this case NaOH Promotes cellulose  oxidation by atmospheric oxygen resulting in the formation of oxycellulose. The boiling of cotton with 1% Solution of caustic soda causes weight loss of cotton due to the removal of non-cellulosic substance from the fibre.   

                            III.            Effect of Organic Solvent: Some solvents are fully dissolved cotton completely . It has high resistance to normal solvents but disperse by the copper complexes cuprammonium  hydroxide and cupriethylene diamine and concentrated 70% H2SO4. 

                            IV.            Effect of Oxidizing Agent:  Cotton is readily attacked by oxidizing agents .some oxidizing agents name Hypochlorite , sodium perborate, hydrogen peroxide , sodium chlorite.  

                              V.            Action of Micro Organism :  Cotton fibers can resist moths and most insects , but it can be attacked by fungi and bacteria.

                            VI.            Action of Water: Easily attacked by polar –OH  groups of the cotton fiber. Cotton fiber shows greater strength in wet state than dry .

Others properties

Effect of Heat: Cotton fiber shows an excellent resistance to thermal decomposition .Dehydration and decomposition by general heating.Heating 250 affects only the amorphous regions since no change in crystalline structure . The crystalline structure of cotton cellulose has been shown to be lower when heated at 250 to 270 C and then disappear on further heating to 300C  .Further heating can cause instant decomposition with the formation of liquid and gaseous produces of different composition

Effect of Light: There is a gradual loss strength  when cotton exposed to sunlight for a long time and the fiber turns yellow. It losses its 50% strength into 940 hours.  The effect of light may vary depending on the type and structure of the goods. For the example the heavy fabrics are more resistant to daylight than the  light fabrics . The sensitivity of cotton goods to daylight can increase with the presence of metal content (e,.g., copper , manganese , iron ) added to the fiber during processing.  

Chemical structure:

Cotton is the most pure form of cellulose , so that chemical structure of cotton is characterized by cellulose  structure.

  Bangladesh  Textile depend on cotton fibre . Cotton fiber is most important for our country.