Nylon (polyamides), Chemistry

Nylon (polyamides): Synthetic fibre forming polyamides are also termed as Nylons. Therefore, Nylon is well known in the textiles. Nylons are those polymers which contains a repeating amide linkage. The nylons have been named on the basis of the number of carbon atoms in the monomer molecules. Usually four types of nylons are prepared:

1.                 Nylon6: This is prepared by ring opening polymerization by self: polyconensation of caprolactum which contains 6 carbon atoms. The process occurs in 4 steps.  

(1)                         Cyclohexane is oxidized to cyclohexanone

(2)                         Cyclohexanone converts cyclohexanoneoxime by treatment with hydroxylamine NH2OH.

(3)                         This cyclohexanoneoxime undergoes Backmann rearrangement to give caprolactum in presence of H2SO4

(4)                         Ring opening polymerization of caprolactum to give Nylon: 6.

2.                 Nylon: 66: This is prepared by the condensation of polymerization of Adipic acid and hexamethylene diamine in 1: 1 molar ratio.  

3.                 Nylon:6, 10: This is prepared by self condensation of polymerization of hexamethylene diamine and sebasic acid.

4.                 Nylon: 11: This is prepared by self: condensation of W. It is more expensive than other nylons.

Properties:

1.                 They are soluble in phenol and formic acid, while insoluble in common organic solvents like benzene, ethylated spirit, acetone etc.

2.                 The polymer chains are held together by hydrogen bonds. Thus nylons possesses high crystalline which imparts high strength, high melting point (160 to 2640C) elasticity, toughness etc.

3.                 Nylons are whitish, translucent and possess good high thermal stability and good abrasion-resistance.

4.                 It can retain good mechanical properties up to 150 degree centigrade.

5.                 They are sterilizable.

Uses:

1.                 Nylon-6 is mainly used for making tyre cords and non woven fabrics.

2.                 Due to sterilisability, they are used in medicine and pharmacy.

3.                 Nylon-6, 6 is used for manufacture of fibre cloth, ropes, carpets and undergarments, socks, etc.

4.                 Nylon-6, 6 is used in gears, bearings, brushes etc.

5.                 Nylon-6, 10 is suitable for monofilaments which are used for bristles, brushes and sporting equipments.

6.                 Nylon-11 is used in the preparation of textile fibres and threads; it is also used for making bearing and gears due to its self lubricating properties.

Posted Date: 7/21/2012 8:20:27 AM | Location : United States







Related Discussions:- Nylon (polyamides), Assignment Help, Ask Question on Nylon (polyamides), Get Answer, Expert's Help, Nylon (polyamides) Discussions

Write discussion on Nylon (polyamides)
Your posts are moderated
Related Questions


how hyperconjugation accued in branched molecules?

Iodoform or tri-iodomethane, CHI 3 Industrial preparation Iodoform is ready on large scale by electrolysis of a solution consisting of ethanol, potassium iodide and sodium

how a catalyst perform its work

environmental pollution caused by nitrogen

Disaccharides - Biomolecules The disaccharides give in on hydrolysis two monosaccharides. Those disaccharides that generates two hexoses on hydrolysis contain a general formul

When 100 ml of M/10 H2SO4 is mixed with 500 ml of My/10 NaOH then nature of resulting solution and normality of excess reactant left is

polonium crystallizes in a simple cubic unit cell with an edge length of 3.36A. 1. what is the volume of the unit cell? 2. what is the volume of atom in the unit cell? 3. what i

The electrochemical cell contains two half cells. The electrodes in these cells have different electrode potentials. When the circuit is completed the loss of electrons occurs at t