PA - Relative Viscosity - ASTM D789

The PSL Rheotek RPV-2 determins the Relative Viscosity of polyamides using glass capillary viscometers in accordance with ASTM D789. The test method requires a high 8.4% concentration. The viscosity of the polyamide solution is related to the solvent (90% Formic Acid). Flow times are measured at 25 deg. C using calibrated suspended-level Ubbelohde type viscometers - size 1 for the solvent and a larger size 2B or 3 for the Polyamide Solution.

The method requires that two successive flow times are obtained within 0.2% of the mean. The four position RPV-2 (4) is an ideal configuration for ASTM D789 allowing for one position to be dedicated to the measurement of solvent flow times. Cleaning is carried out in-situ using Formic Acid followed by Acetone. The iSP-1 Sample Preparation system can be used in conjunction with the RPV-2 to prepare samples on a precise weight to weight basis. Dissolution is carried out using a wrist action shaker (WAS).