In this video I have discussed the answers of L6 , Plastics, Types of Plastics like Thermoplastics and Thermosetting Plastics and Fibers. The details of the lecture is as follows:
Plastics
When unsaturated hydrocarbons e.g. ethylene, propylene, butylene etc. undergo polymerization under specific conditions then higher polymer plastic is obtained.
These are of two types :
(i) Thermoplastics are liner in structure can be soften on heating and becomes harden on cooling. This character is
maintained through out its existence. e.g. polythene, polystyrene, polyvinylchloride, teflon.
(ii) Thermosetting plastics undergo permanent change on heating due to excessive cross linking and cannot be
remoulded and reused, e.g. bakelite, melmac.
Fibres
The Solid substance which has thin long chain structure is called fibre. Cotton, jute, silk, wool are natural fibres whereas rayon, nylon, polyster are synthetic fobres. Fibres possess strong intermolecular forces like hydrogen bonding e.g. nylon -66 dacron, orlon.
Rayon (acetate rayon and viscose rayon) is called artificial silk.
• Orlon is obtained by polymerization of cyanide.
• Carbon fibres are made from long chains of carbon atoms in which corrosion does not take place. These are used in making parts of space vehicles and sports items.
At last I have given you questions and discussed three answers.
Please answer the same in the comment box.
Thank You
Chaput Chakma
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