ASTM D2115-92(1997)

Standard Practice for Oven Heat Stability of Poly(Vinyl Chloride) Compositions

SCOPE
1.1 This practice lists procedures for determining the relative thermal stability of sheet or molded poly(vinyl chloride) compounds as indicated by discoloration due to exposure to an elevated temperature at controlled oven conditions.  
1.2 A specimen preparation technique using a two-roll mill is provided for compositions that are not in molded or sheeted form.  
1.3 This practice is not intended for use in purchasing specifications because the conditions of processing plastic compounds vary widely, and the degree of correlation of data obtained by this practice to process exposure has not been determined. However, despite this limitation, this practice does yield data of value in judging the comparative service quality of poly(vinyl chloride) compositions.
1.4 The values stated in SI units are to be regarded as the standard. The values in parentheses are given for information only.
1.5 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 1-This standard is similar in content, but not technically equivalent to ISO305-1990.

General Information

• Status: Historical
• Publication Date: 09-Nov-1997
• ICS: 83.080.20 - Thermoplastic materials
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.15 - Thermoplastic Materials

Relations

• Replaced By: ASTM D2115-92(2003) - Standard Practice for Oven Heat Stability of Poly(Vinyl Chloride) Compositions
• Effective Date: 10-Jul-2003

Standards Content (Sample)

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.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 2115 – 92 (Reapproved 1997)
Standard Practice for
Oven Heat Stability of Poly(Vinyl Chloride) Compositions
This standard is issued under the fixed designation D 2115; 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 Discoloration Method
1.1 This practice lists procedures for determining the rela-
3. Terminology
tive thermal stability of sheet or molded poly(vinyl chloride)
3.1 General—Definitions are in accordance with Terminol-
compounds as indicated by discoloration due to exposure to an
ogy D 883 and abbreviations with Terminology D 1600, unless
elevated temperature at controlled oven conditions.
otherwise indicated.
1.2 A specimen preparation technique using a two-roll mill
is provided for compositions that are not in molded or sheeted
4. Significance and Use
form.
4.1 Poly(vinyl chloride) compositions degrade by discolora-
1.3 This practice is not intended for use in purchasing
tion on prolonged exposure to heat. The degree of discoloration
specifications because the conditions of processing plastic
is related to the condtion of exposure, such as length of period
compounds vary widely, and the degree of correlation of data
and temperature. When the conditions of exposure are fixed
obtained by this practice to process exposure has not been
and controlled, then the relative resistance to discoloration due
determined. However, despite this limitation, this practice does
to heat of two or more compositions may be determined. The
yield data of value in judging the comparative service quality
precision of heat stability testing is also dependent on the
of poly(vinyl chloride) compositions.
thickness of the specimens and the history of heat exposure
1.4 The values stated in SI units are to be regarded as the
prior to testing. This practice allows for control or the reporting
standard. The values in parentheses are given for information
of these variables.
only.
4.2 This practice is particularly applicable for determining
1.5 This standard does not purport to address all of the
gross differences in the heat stabilities of poly(vinyl chloride)
safety concerns, if any, associated with its use. It is the
compositions that are detectable as a color change. It is not
responsibility of the user of this standard to establish appro-
intended to measure absolute thermal stability. Although the
priate safety and health practices and determine the applica-
observed color changes may be evidence of degradation,
bility of regulatory limitations prior to use.
molecular degradation phenomena such as chain-scission or
NOTE 1—This standard is similar in content, but not technically
cross-linking may not be identifiable.
equivalent to ISO 305–1990.
NOTE 2—While discoloration caused by exposure to elevated tempera-
2. Referenced Documents ture is commonly regarded as evidence of degradation in poly(vinyl
chloride) compositions, it must be borne in mind that some vinyl
2.1 ASTM Standards:
compositions may undergo substantial change in color without appre-
D 883 Terminology Relating to Plastics
ciable loss of mechanical strength, chemical resistance, etc., whereas
D 1600 Terminology for Abbreviated Terms Relating to
others may resist change in color yet undergo substantial change in other
Plastics
properties. Therefore, resistance to discoloration should not be taken as
sole evidence of thermal stability. It is recommended that this test be
2.2 ISO Standard:
supplemented by others such as tensile strength and elongation, impact
ISO305–1990 Plastics—Determination of Thermal Stability
strength, and deflection temperature under load (for rigid compositions),
of Poly(Vinyl Chloride), Related Chlorine-Containing
Durometer hardness (for nonrigid compositions), and dilute solution
Polymers and Copolymers and Their Compounds—
viscosity, and that the test results before and after oven exposure be
compared to determine the degree of degradation which has been
produced in each of the properties measured.
4.3 This practice may be used to predict the relative
This practice is under the jurisdiction of ASTM Committee D-20 on Plastics
discoloration in processing, provided that the compositions in
and is the direct responsibility of Subcommittee D20.15 on Thermoplastic Materials
(Section D20.15.07).
Current edition approved Oct. 15, 1992. Published December 1992. Originally
e1 3
published as D 2115 – 62 T. Last previous edition D 2115 – 67 (1988) . Available from American National Standards Institute, 11 W. 42nd St., 13th
Annual Book of ASTM Standards, Vol 08.01. Floor, New York, NY 10036.
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.
D2115
1 1
question are tested at the relative maximum temperatures 12.7 mm ( ⁄4 to ⁄2 in.) in diameter is obtained across the face
developed in processing. of the mill with the rolls set to give a sheet 0.816 6 0.08 mm
4.4 This practice is not applicable to materials that will (0.040 6 0.004 in.) thick.
cross-contaminate during oven exposure.
NOTE 6—Other specimen thicknesses may be used. However, heat
stability is affected by thickness, and all comparative tests shall be made
5. Apparatus
on specimens of the same nominal thickness.
5.1 Mill—A two-roll laboratory plastic or rubber mill (for
6.1.2 Weigh all components to an accuracy of 6 1% of
use for preparing specimens from the basic ingredients or from
their nominal weight.
molding or other compounds). Provision shall be made for
6.1.3 Premix the solid and liquid components separately in
heating the rolls to the desired temperature and for maintaining
suitable containers until homogeneous in appearance. Add dry
this temperature constant over the surfaces of both rolls within
components to the container holding the liquid components,
63°C.
then blend together until homogeneous.
5.2 Oven—The oven shall be of the forced-air type and shall
6.1.4 Charge the batch or composition to the mill rolls
have the following additional requirements:
which have been preheated to a temperature suitable for
5.2.1 The oven temperature shall be controlled by an
complete fluxing of the compositions. A temperature of 149 6
accurate, reliable thermoregulator maintaining the set po
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