ASTM D4878-98
(Test Method)Standard Test Methods for Polyurethane Raw Materials Determination of Viscosity of Polyols
Standard Test Methods for Polyurethane Raw Materials Determination of Viscosity of Polyols
SCOPE
1.1 These test methods (A and B) determine the viscosities of polyols in the range from 10 to 100000 cP at 25°C or at 50°C. Test Method A also applies to more viscous samples that are soluble in -butyl acetate. (See Note.)
1.2 The values stated in SI units are to be regarded as the standard.
1.3 This standard does not purport to address all of the safety problems, 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-There is no equivalent ISO standard.
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NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 4878 – 98
Standard Test Methods for
Polyurethane Raw Materials: Determination of Viscosity of
Polyols
This standard is issued under the fixed designation D 4878; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 4.2 Viscosity measures the resistance of a fluid to uniformly
continuous flow without turbulence or other forces.
1.1 These test methods (A and B) determine the viscosities
of polyols in the range from 10 to 100 000 cP at 25°C or at
5. Sampling
50°C. Test Method A also applies to more viscous samples that
5.1 Polyesters and polyethers usually contain molecules
are soluble in n-butyl acetate. (See Note.)
covering an appreciable range of molecular weights. These
1.2 The values stated in SI units are to be regarded as the
have a tendency to fractionate during solidification. Unless the
standard.
material is a finely ground solid it is necessary to melt (using
1.3 This standard does not purport to address all of the
no higher temperature than necessary) and mix the resin well
safety concerns, if any, associated with its use. It is the
before removing a sample for analysis. Many polyols are
responsibility of the user of this standard to establish appro-
hygroscopic and care should be taken to provide minimum
priate safety and health practices and determine the applica-
exposure to atmospheric moisture during the sampling.
bility of regulatory limitations prior to use.
NOTE 1—There is no equivalent ISO standard for Test Method A TEST METHOD A—BROOKFIELD VISCOSITY
although ISO 3219 is similar. Test Method B is equivalent to ISO 3104.
6. Summary of Test Method
2. Referenced Documents
6.1 The viscosity of resins is measured by determining the
2.1 ASTM Standards:
torque on a spindle rotating at constant speed in the liquid
D 445 Test Method for Kinematic Viscosity of Transparent
sample which is adjusted to 25 6 0.1°C. Samples with viscosi-
and Opaque Liquids (and the Calculation of Dynamic
ties exceeding 100 000 cP at 50°C are dissolved in n-butyl
Viscosity)
acetate (or other solvent) and the viscosity is determined at
D 883 Terminology Relating to Plastics
25 6 0.1°C.
E 1 Specification for ASTM Thermometers
7. Apparatus
2.2 ISO Standards:
ISO 3104
7.1 Constant-Temperature Bath, capable of maintaining
ISO 3219
temperatures of 25 6 0.1°C and 50 6 0.1°C should be used.
Water, water and glycerin, or oil may be used as the heating
3. Terminology
medium and the batch should be provided with heating,
3.1 For definitions of terms used in these test methods see
stirring, and thermostating devices.
Terminology D 883.
7.2 Bath and Sample Thermometers, graduated in 0.1°C
subdivisions and standardized for the range of use to the
4. Significance and Use
nearest 0.01°C. ASTM Saybolt Viscosity Thermometers hav-
4.1 These test methods are suitable for research or as quality
ing ranges from 19 to 27°C and 49 to 57°C, as specified, and
control or specification tests.
conforming to the requirements for Thermometers 17C and
19C, respectively, as prescribed in Specification E 1 are rec-
ommended.
These test methods are under the jurisdiction of ASTM Committee D-20 on 7.3 Brookfield Synchrolectric Viscometer —Model LVF
Plastics and is the direct responsibility of Subcommittee D20.22 on Cellular
with speeds of 60, 30, 12, and 6 r/min is to be used when
Plastics.
available. It is applicable to the range of 10 to 100 000 cP. If
Current edition approved July 10, 1998. Published January 1999. Originally
this model is not available, Model RVF or HAF may be
published as D 4878 – 88. Last previous edition D 4878 – 93.
Annual Book of ASTM Standards, Vol 05.01.
substituted. However, samples should be heated or dissolved in
Annual Book of ASTM Standards, Vol 08.01.
Annual Book of ASTM Standards, Vol 14.03.
5 6
Available from American National Standards Institute, 11 West 42nd Street, Obtainable from Brookfield Engineering Laboratories, 240 Cushing Street,
13th Floor, New York, NY 10036. Stoughton, MA 02072.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 4878
TABLE 1 Correction Factors Corresponding to Various
the standard way to keep the measured viscosity below
Combinations of Spindles and Rotational Speeds
100 000 cP so that the test may be repeated in other laborato-
Spindle
ries under similar conditions with Model LVF. The calibration
Model Correction Factors
Number
of the instrument should be checked periodically by measuring
Rotational speed, r/min 6 12 30 60
the viscosity of Brookfield Engineering Laboratories viscosity
LVF 1 2 1 0.4 0.2
standard fluids. Standard fluids L-2, L-3, R-1, R-2, H-1 are
2 10 521
suitable for the usual range. The calibration corrections should
340 20 8 4
be applied to sample measurements.
4 200 100 40 20
Rotation speed, r/min 2 4 10 20
8. Solvent
RVF 1 10 521
8.1 n-Butyl Acetate, reagent grade.
240 20 8 4
3 100 50 20 10
4 200 100 40 20
9. Preparation of Sample
5 400 200 80 40
9.1 The preparation of a homogeneous sample is of primary
6 1 000 500 200 100
7 4 000 2 000 800 400
importance in viscosity measurements. A nonuniform tempera-
ture distribution as well as the presence of air bubbles and
Rotational speed, r/min 1 2 5 10
traces of extraneous material should be avoided. Resins are not
HAF 1 40 20 8 4
2 160 80 32 16
easily made homogeneous with respect to temperature, there-
3 400 200 80 40
fore, the sample should be thoroughly mixed and the tempera-
4 800 400 160 80
ture measured at several locations in the sample vessel before
5 1 600 800 320 160
6 4 000 2 000 800 400
determining the viscosity.
7 16 000 8 000 3 200 1 600
10. Preparation of Appar
...
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