ASTM D3591-97(2003)

The logarithmic viscosity number provides information on the effect of compounding or processing of PVC.

Exposure of PVC compositions to shear or to high temperatures can result in a change in the logarithmic viscosity number of the resin.

1.1 This test method covers the determination of the logarithmic viscosity number of poly(vinyl chloride) (PVC) homopolymers after compounding or processing.

1.2 It is the basic assumption of this technique that the formulation of the compounded resin is known and that any additives present can be separated from the resin by extraction with diethyl ether. This is necessary to permit adjustment of the amount of sample used in the test to give a resin concentration in cyclohexanone of 0.2 ± 0.002 g/100 mL.

1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in 7.3 and 8.4.1.