Polymers

1. Have high molecular mass and formed by union of monomers.

2. Chain growth polymers or addition polymers are formed by successive addition of monomers without loss of simple molecules like H₂O, NH₃ etc.

3. Step growth or condensation polymers : These are formed through series of independent steps. Each step involves condensation between two monomers leading to formation of

polymers. More than one monomer unit is involved.

4. Homopolymers : Polymers made of same monomer.

5.Copolymers : Polymers made of different types of monomers.

6. Elastomers : The strands of polymer are held together by weak inter molecular forces (van der waal's). e.g.- vulcanised rubber.

7. Fibres are held together by hydrogen bonds, e.g.- nylon, polyester, polyamide.

5. Thermoplastics can be easily moulded on heating. They don't have cross-links, e.g.- polyctlicnc.

9. Thermosetting polymers have cross links, cannot be remolded on heating, e.g.- Bakelite.

10. Plastisizer are high boiling esters which are added to plastic to make it soft and rubber like.

11. Synthetic rubbers :

(a) Buna-S or styrene-Butadiene rubber (SBR)

Addition copolymer of CH₂ = CH -CH = CH₂ and C₆H₅CH = CH₂ 1,3-butadiene Styrene

(b) Buna-N or (Nitrile rubber)

Addition copolymer of CH₂ = CH -CH = CH₂ and CH₂ = CHCN 1,3-butadiene acrylonitrile

(c) Neoprene




13. Polyesters:

(a) Terylene or dacron




(b) Glyptal or alkyd resin



14. Polyamides:

(a) Nylon 66

Copolymer of adipic acid + hexamethylenediamine

COOH(CH₂)COOH + NH₂ - (CH₂)₄ - NH₂

(b) Nylon 6




(c) Nylon 610

Copolymer of NH₂(CH₂)₄NH₂ + HOOC(CH₂)₈COOH

hexamethylenediamine sebacic acid


15. Polyacrylates :

(a) Poly methyl methacrylate (PMMA)

Addition homopolymer of CH₂ = COOCH₃

(Methyl methacrylate)


(b) Polyacrylonitrile (PAN) or Orion

Addition homopolymer of CH₂ = CHCN

(acrylonitrile)


16. Polyolefins

(a) Polystyrene (or styron)

Addition homopolymer of C₆H₅CH = CH₂

(styrene)


(b) Polythene or polyethylene

Addition polymer of ethylene CH., = CH,.



17. Polyhalolefins

(a) Poly vinyl chloride (PVC)

Chain growth homopolymer of vinyl chloride (CH-, = CH - Cl).

(b) Polytetrafluoroethylene or Teflon (PTFE)

Chain growth homopolymer of tetrafluoroethylene (F₂C = CF₂).

(c) Polymonochlorotrichloroethylene (PCTFE)

Homopolymer of C1FC = CF₂ (monochlorotrifluoroethylene)


18. Bakelite : Copolymer of phenol + formaldehyde.


19. Melamine : Copolymer of formaldehyde and melamine (2,4, 6-triamino-l, 3, 5-triazine)