Standard Historical Last Updated: Aug 30, 2018
ASTM D789-15

Standard Test Methods for Determination of Solution Viscosities of Polyamide (PA)

Significance and Use

4.1 These test methods are intended for use as control and acceptance tests. They are also applicable in the partial evaluation of materials for specific end uses and as a means for detecting changes in materials due to specific deteriorating causes.

4.2 The steps involved in running this method are:

4.2.1 Calibration of the viscometers,

4.2.2 Preparation of solutions,

4.2.3 Determination of efflux time,

4.2.4 Calculation of relative viscosity (which requires the following),

4.2.4.1 Determining the density of the polymer/formic acid solution, and

4.2.4.2 Determining the absolute viscosity of the formic acid used.

4.3 Viscosity for groups 03, 04, and 05 (PA11, PA12, and PA6,12) in Classification System D6779 shall be measured using solvents other than formic acid. Relative viscosities for Groups 03 and 04 shall be measured using 0.5 g of polymer dissolved in 99.5 g of m-cresol at 25.0 ± 0.1°C in a Cannon-Fenske No. 200 viscometer. Inherent viscosity of Group 05 shall be measured using 0.5 g of polymer dissolved in 100 mL of m-cresol at 25.0 ± 0.1°C in a Cannon-Fenske No. 200 viscometer. The inherent viscosity is calculated as follows:

Equation D0789-15_1

where:

ts   =   average efflux time for sample solution,
tc   =   average efflux time for solvent, and
C   =   concentration in g/100 mL

Scope

1.1 These test methods cover the determination of solution viscosities as they apply to polyamide (PA).

1.2 The values stated in SI units are to be regarded as standard. The values given in brackets are for information only.

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.

Note 1: This standard and ISO 307 address the same subject, but the technical content is different.

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Details
Book of Standards Volume: 08.01
Developed by Subcommittee: D20.15
Pages: 7
DOI: 10.1520/D0789-15
ICS Code: 83.080.20