Identification of Polystyrene (PS) | chemwifi

Identification of Polystyrene 

Identification of Polystyrene chemwifi


This Article prescribes, the requirements and the methods of test for identification of Polystyrene .


  • Filter paper
  • Test tube 
  • Bunsen burner


  • 2,6-dibromoquinone-4-chlorimide
  • Ether
  • Diluted Ammonia
  • Nitric acid

Method for prepare filter paper- Prepare the paper by drenching it in a concentrated solution of 2,6-dibromoquinone-4-chlorimide in ether and then drying it in air .


  • Polystyrene and most styrene-containing copolymers can be identified by this method.
  • placing a small sample in a small test tube, adding a few drops of fuming nitric acid, and evaporating the acid without having the polymer decompose.
  • The residue is then heated over a small flame for approximately 1 min.
  • Fasten the test tube with its open end tilted slightly down and covered with
  • a piece of filter paper(prepared before ).
  • When the paper is moistening with a drop of dilute ammonia, the paper turns blue if polystyrene is present.
  • If the sample still contains some free nitric acid, the test is affected and the paper turns brown, which may conceal the blue color.


If the filter paper is change in blue color confirm for polystyrene.


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