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Free notes of Polymers short revision part 1

 Polymers:

  • The fibres have strong hydrogen bond.            
  • Examples of elastomers :- buna-s , buna - N , neoprene.                                                                  
  • Examples of the fibres:-polyamide ( nylon 6,6) , polyester ( terelyne).                                    
  • Concept of thermoplastic:- which substance which is soft on heating and hardening on cooling.                                                                    
  • Examples of thermoplastic are polythene , polystyrene , polyvinyl .                                            
  • Thermoplastic are not heavily branched.         
  • Trend of force of attraction i.e bond attraction : fibre > thermoplastic > elastomers.                                                              
  • Thermosetting plastic are heavily branched.                                                                 
  • Examples of thermosetting plastic are bakelite , urea - formaldehyde resins etc.         
  • Thermosetting plastic are not soften on heating .                                                                    
  • Addition or chain growth polymers are having free radicals mechanism. In these mechanisms the initiator use are benzoyl peroxide , tert butyl peroxide , acetyl peroxide are used.                                                 
  • For formation of Low density polyethene peroxide is use as the catalyst .                           
  • Low density polymer (LDP) are chemically inerts and they are poor conductor of electricity ,so they are used as insulators .       
  • High density polymer is form in presence of the zigler natta catalyst . The zigler natta catalyst is the triethyl aluminium and titanium tetrachloride .                                        
  • Polyacryonitrile is use for substitution of wool and also use for preparation of Orlon fibre.                                                                         
  • Terelyene is a condensation polymer  and it has monomers are ethylene glycol , terephatahallic acid.                                               
  • Chloroprene is converted in to neoprene in presence of oxygen benzoyl peroxide.
  • Some important structures and reactions:
  • 1) terelyene:
    2) nylon 6,6


     3) nylon 6
     


      4) PHBV:
      

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