What are synthetic Polymers? Write the method of preparation and uses.

Polymers are large molecules made up of many small and identical repeating units joined together by covalent bonds. Synthetic polymers are the polymers made artificially in industries from chemical industries. Synthetic polymers include :

i) Nylon-66: Nylon 66 is synthesized by polycondensation of hexamethylenediamine and adipic acid.

n HOOC-(CH₂)₄-COOH + n H₂N-(CH₂)₆-NH₂→ [-OC-( CH₂)₄-CO-NH-(CH₂)₆-NH-]_n + (2n-1) H₂O

It is used in fibers for textiles and carpets and molded parts.

ii) Terylene: It is formed by esterification of ethylene glycol and terephthalic acid is conducted directly at moderate pressure and high temperature. Water is eliminated in the reaction, and it is also continuously removed by distillation
n C₆H₄(CO₂H)₂ + n HOCH₂CH₂OH→[(CO)C₆H₄(CO₂CH₂CH₂O)]_n + 2n H₂O

It is used to make plastic bottles which contain water and soft drinks.

iii) Plastic: Plastic is a synthetic material made up of a wide range of organic polymers like polythene, PVC, nylon etc. that can be molded in any shape while it is soft.

Main plastic polymers are:

Polythene: Polythene is formed by polymerization of ethene molecules. It is used to make bags, tubes, pipes.

Poly Vinyl Chloride (PVC) : It is formed by polymerization of vinyl chloride. It is used to make tubes and pipes.

Poly Acrylin Nitrile : It is formed by polymerization of vinyl cyanide. It is used to make wool and fibres.

iv) Synthetic Rubber: Synthetic rubber is any artificial elastomer which is durable as well as has greater resistance. They are made up of 2,1-dimethyl-1,3-butadiene and carbon dioxide in presence of sodium as a catalyst. It is used to make tyres-tubes, medical instruments, tanks, tubes etc.