ASTM D3591 Logarithmic Viscosity Number of Poly Vinyl Chloride (PVC)

Scope:

ASTM D3591 test method helps calculate the logarithmic viscosity number of PVC, which provides details about the processing and other applications. The effect of temperature and other severe conditions on the viscosity number of PVC is studied. The purification and compounding techniques for the resins are determined. The resin is freed from plasticizer and insoluble matter.

Test Procedure:

In ASTM D3591 testing, the sample is installed into a thin film and then purified to remove the plasticizer. The sample is passed through a specific temperature and then placed in the Soxhlet extraction apparatus. It is then placed in an evacuated desiccator, and its size is determined. It is then mixed with cyclohexanone to get rid of insoluble matter. The solution is placed in a viscometer to determine the efflux time. The viscosity of the cyclohexanone solution is determined accordingly.

Specimen Size : 

The specimen size should be in accordance with the requirement, i.e. about 2 grams.

Data:

Calculate the logarithmic viscosity number for ASTM D3591 testing as follows:

Logarithmic viscosity number ꞊ ln (t/tₒ)/C

Where:
ln = natural logarithm
t = efflux time of solution
tₒ = efflux time of solvent
C꞊ concentration, the weight of PVC sample used per 100 ml of solution, g/100 ml.

Conclusion:

ASTM D3591 test method helps calculate the logarithmic viscosity number of PVC, which provides details about the processing and other applications.