12 Class Chapter 15- Polymers

Monday, 12 May 2014

Polymer & Polymerization

Condensation Polymer: Nylon-6-6, Terylene.

Addition Polymer: Polythene, Neoprene.

1. Natural Polymer: Protein, Cellulose, Rubber.

2. Semi-synthetic Polymer: Cellulose Derivatives as cellulose acetate (Rayon), Cellulose Nitrate.

3. Synthetic Polymer: Plastic (Polyethene), Synthetic Fibers ( Nylon 6-6), Buna-S.

1. Linear Polymer: High Density Polythene, Polyvinyl Chloride.

2. Branched Chain Polymer: Low Density Polythene.

3. Cross Linked or Network Polymer: Bakelite, Melamine.

1. Elastomers: Weak intermolecular forces. eg.- Natural Rubber, Synthetic Rubber.

2. Fibers: Strong intermolecular forces. eg.- Polyamides (Nylon6-6), Polyesters (Terylene).

3. Thermoplastic: Polythene, Polystyrene.

4. Thermosetting: Bakelite, Urea Formaldehyde Resins.

Lower Density Polyethene (L.D.P.) : prepared at 1000-2000 atm pressure, 350-570 Kelvin Temperature and O₂ peroxide inhibitor.

Higher Density Polyethene (H.D.P.) : prepared at 6-7 atm pressure, 333-343 Kelvin Temperature and Zieglar Natta Catalyst.

Polymers	Monomers	Monomer Formula	Use
1. Teflon	Tetrafluroethene	CF₂=CF₂	Oil seals, Gasket
2. Polyacrylonitrile	Acrylonitrile		Commercial Fibers
3. Terylene or Decron	Ethylene Glycol Teryphthalic Acid	HOCH₂-CH₂OH	Commercial Fibers
4. Nylon 6,6 And 5. Nylon 6	Hexamethylene-diamine Adipic Acid Caprolactum	NH₂(CH₂)₆NH₂ HOOC(CH₂)₄COOH	Making Sheets, bristles of brushes, textile industry, tyre cords, fabrics, ropes etc.
6. Phenol Formaldehyde Polymer
i. Novolac	Phenol + Formaldehyde	HCHO	Used in paints
ii. Bakelite	Phenol + Formaldehyde	HCHO	Comb, Electric switches
7. Malamine Formaldehyde Polymer	Malamine + Formaldehyde	HCHO	Unbreakable crockery
8. Buna S	1,3-Butadiene + Styrene	CH₂=CH-CH=CH₂	Auto tyres, cables insulation, floor tiles