PVC - K-Value - ISO 1628-2

The PSL Rheotek RPV-3 determines the reduced viscosity (viscosity number) and K-value of Polyvinyl Chloride (PVC) resins (in powder form) in dilute solution using glass capillary viscometers in accordance with ISO 1628 Part 2. The test method requires a 0.5% concentration. The PVC powder is dissolved in Cyclohexanone. Solvent and solution flow times are measured at 25 deg. C using a size 1C suspended-level Ubbelohde type viscometer for both measurements.

Step by step

The method requires that two successive flow times are obtained within a 0.25% precision. It should be noted that two complete determinations are required, each starting with a fresh test portion. K-value results from the two determinations should agree within +/- 0.4% from the mean value.

Instrument options

For this application the dual position RPV-3 (2) is an ideal configuration as well as the four position RPV-3 (4). The iSP-1 Sample Preparation system can be used in conjunction with the RPV-3 to prepare samples on a precise weight to weight basis. Dissolution is carried out using a reaction block with stirring and heating at a closely controlled temperature (80 to 85 deg. C) with a programmable timer (SD-BM). Software options include: ISO 1628 Part 2: K value; DIN 53726: K value; JIS K 6721 Mean Polymerization Degree.