Thursday, August 9, 2012

Thermal Stability of Dry Blended PVC Compound

Test Method for Thermal Stability test of Dry Blended PVC Compound.


Instruments


Sample of Blended Compound
Glycerin Bath ( Heated to 200°C )
Test Tube
Glass Stopper
Glass rods
Piece of Congo Red
Test Tube Stand
Stop watch


Procedure


Setup all instruments following given image.

Test Method for Thermal Stability test of Dry Blended PVC Compound


The temperature of Glycerin Bath must be Constant. When you put sample added test tube in to the glycerin bath, immediately start the stop watch. Then wait until colour change of Congo red. When start colour changing, stop the stop watch and get the time. That's the time for Decomposition of PVC Compound.

Colour range of Congo Red






Colour range of Congo Red






Approximate pH range for color change : 3.0-5.0
Color of acid form : Blue
Color of base form : Red


So when PVC  Compound decomposed pH value will decrease (HCl gas content will increase). Then colour of Congo Red will change Red to Blue.






8 comments:

  1. Replies
    1. Pvc Extrusion Tutorial: Thermal Stability Of Dry Blended Pvc Compound >>>>> Download Now

      >>>>> Download Full

      Pvc Extrusion Tutorial: Thermal Stability Of Dry Blended Pvc Compound >>>>> Download LINK

      >>>>> Download Now

      Pvc Extrusion Tutorial: Thermal Stability Of Dry Blended Pvc Compound >>>>> Download Full

      >>>>> Download LINK Am

      Delete
  2. This method refer to the IEC 60811-3-2 standard? According to the standard glass tube (borosilicate grade) with inner diameter 4mm is used for this test method.

    ReplyDelete
    Replies
    1. Thank you for sharing your knowledge with us. Our company use ISO 182-1:1990 standard for that. I think these standards may not different.

      Of course we use Borosilicate Glass Tube (4 mm) for this test. Because after decomposing the PVC compound, we must immediately clean the glass tube without cooling (not for all type of PVC compounds). At this temperature, normal glass tubes break easily.

      Delete