ASTM F2466-10(2018)

Standard Practice for Determining Silicone Volatiles in Silicone Rubber for Transportation Applications

SIGNIFICANCE AND USE
4.1 Use of this practice in conjunction with realistic maximum volatility tolerance level can help minimize the risk of oxygen sensor dysfunction from formed-in-place-sealants in transportation applications. This practice provides a method for determination of percentage volatiles in silicone elastomers. The volatile silicones from a commercial silicone are primarily cyclo dimethyl-siloxane. Other species present having GC retention times similar to those of the cyclics are assumed to be silicone as well.
SCOPE
1.1 This practice covers a means to determine the percent silicone-producing volatiles present in heat-cured silicone rubber and room temperature-cured silicones (RTV).  
1.2 Silicone-producing volatiles contribute to fouling of oxygen sensor systems used in the control of vehicle emissions.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Jul-2018
• ICS: 55.020 - Packaging and distribution of goods in general
• Technical Committee: F03 - Gaskets
• Drafting Committee: F03.50 - Analytical Test Methods

Relations

• Replaces: ASTM F2466-10 - Standard Practice for Determining Silicone Volatiles in Silicone Rubber for Transportation Applications
• Effective Date: 01-Aug-2018
• Refers: ASTM E177-14 - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 01-May-2014
• Refers: ASTM E177-13 - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 01-May-2013
• Refers: ASTM E691-13 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-May-2013
• Refers: ASTM E691-11 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-Nov-2011
• Refers: ASTM E177-10 - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 01-Oct-2010
• Refers: ASTM E691-08 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-Oct-2008
• Refers: ASTM E177-08 - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 01-Oct-2008
• Refers: ASTM E177-06b - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 15-Nov-2006
• Refers: ASTM E177-06a - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 01-Nov-2006
• Refers: ASTM E691-05 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-Nov-2005
• Refers: ASTM E177-06 - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 01-Nov-2004
• Refers: ASTM E177-04 - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 01-Nov-2004
• Refers: ASTM E177-04e1 - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 01-Nov-2004
• Refers: ASTM E177-90a(2002) - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 10-Jan-2002

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: F2466 − 10 (Reapproved 2018)
Standard Practice for
Determining Silicone Volatiles in Silicone Rubber for
Transportation Applications
This standard is issued under the fixed designation F2466; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope and measured by gas chromatography (GC), and (4) the GC
results are quantified using a siloxane calibration.
1.1 This practice covers a means to determine the percent
silicone-producing volatiles present in heat-cured silicone
4. Significance and Use
rubber and room temperature-cured silicones (RTV).
4.1 Use of this practice in conjunction with realistic maxi-
1.2 Silicone-producing volatiles contribute to fouling of
mum volatility tolerance level can help minimize the risk of
oxygen sensor systems used in the control of vehicle emis-
oxygen sensor dysfunction from formed-in-place-sealants in
sions.
transportationapplications.Thispracticeprovidesamethodfor
1.3 This standard does not purport to address all of the
determination of percentage volatiles in silicone elastomers.
safety concerns, if any, associated with its use. It is the
The volatile silicones from a commercial silicone are primarily
responsibility of the user of this standard to establish appro-
cyclo dimethyl-siloxane. Other species present having GC
priate safety, health, and environmental practices and deter-
retentiontimessimilartothoseofthecyclicsareassumedtobe
mine the applicability of regulatory limitations prior to use.
silicone as well.
1.4 This international standard was developed in accor-
dance with internationally recognized principles on standard-
5. Apparatus
ization established in the Decision on Principles for the
5.1 Gas Chromatograph, fused silica capillary column sys-
Development of International Standards, Guides and Recom-
tem equipped with a flame ionization detector, split-type
mendations issued by the World Trade Organization Technical
capillary column injector, temperature programming capability
Barriers to Trade (TBT) Committee.
and an appropriate data recording system. An alternative unit
may be an equivalent instrument equipped with a thermal
2. Referenced Documents
conductivity detector, or as agreed upon between producer and
2.1 ASTM Standards:
user. Specific column and operating conditions should be
D3182 PracticeforRubber—Materials,Equipment,andPro-
selected to optimize instrument response and chromatographic
cedures for Mixing Standard Compounds and Preparing
resolution, particularly separation of the internal standard from
Standard Vulcanized Sheets
extracted sample components.
E177 Practice for Use of the Terms Precision and Bias in
5.2 Column, suggested to be used is 30 to 60 m by 0.25 mm
ASTM Test Methods
with 0.25 to 1.5 µm DB-1 or DB-5 fused silica capillary
E691 Practice for Conducting an Interlaboratory Study to
column or equivalent.
Determine the Precision of a Test Method
5.3 Operating conditions are:
3. Summary of Practice
5.3.1 Column—50 to 320°C at 10°C/min (a post-analysis
3.1 This practice consists of four (4) basic steps: (1) the
period may be required to elute higher boiling components
silicone is cured to its elastomeric form, (2) the volatiles are
prior to subsequent analyses).
extracted from the cured material, (3) the extract is separated
5.3.2 Injector—290°C.
5.3.3 Detector—325°C.
5.3.4 Sample Size—1 µL.
ThispracticeisunderthejurisdictionofASTMCommitteeF03onGasketsand
5.3.5 Injector Split Ratio—2:1 to 50:1 (adjusted as needed).
is the direct responsibility of Subcommittee F03.50 on Analytical Test Methods.
Current edition approved Aug. 1, 2018. Published September 2018. Originally 5.3.6 Helium or Nitrogen, for the carrier gas.
approved in 2005. Last previous edition approved in 2010 as F2466 – 10. DOI:
5.3.7 Carrier Gas Flow Velocity—1 to 2 mL/min (adjusted
10.1520/F2466-10R18.
as needed for column dimensions).
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
5.4 Humidity Chamber, or controlled lab environment.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. 5.5 Wrist-Action Mechanical Shaker.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F2466 − 10 (2018)
5.6 Analytical Balance, with glass draft shield capable of
RfDn = the response factor for each siloxane species from
0.0001 g accuracy.
4to10
WtDn = the weight of each siloxane species from 4 to 10
5.7 30-mL Vials, flint glass, with screw cap (polyethylene
used in the standard solution
lined).
ADn = the area under the curve for each siloxane species
5.8 Syringe, capable of accurately delivering 20 6 0.1 µL
from4to10
(no plastic elements used due to solvents used).
DoD = thedodecanestandard,whichisarbitrarilygivena
response factor of “1” (one), and is used as the
5.9 Solvents and standards used are pentane (99 %) and
basis for calculating the response factors of the
dodecane (99 %), both spectral grade.
various know and unknow siloxane species
5.10 Rigid Plates (Glass or Aluminum), 0.90 mm thick, for
ADoD = theareaunderthecurveforthedodecanestandard
cutting the wet formed-in-place sealant.
WtDoD = the weight of the dodecane used in the standard
5.11 Automated devices shall be used for measuring and
solutions
calculating peaks.
7.3 Response factors for cyclic species vary in a relatively
linearmannerfromD throughD ,sothatresponsefactorsfor
6. Test Specimens 5 10
cyclics not in the standard solution can be calculated from the
6.1 Heat-cured silicone rubber samples shall be procured
known response factors of the cyclics in the standard solution.
from either actual production parts, or shall be compression-
A sample calculation for response factors of standards
moldedASTM tensile plaques (Practice D3182, 2.0 6 0.2 mm
available, and a Linear Least Squares Analysis to determine
thick). Cure conditions of the tensile plaques shall mirror cure
response factors of cyclics that are unavailable can be found in
conditions used on the production parts. If actual production
Appendix X1.
parts are used to obtain test samples, best practice would be to
7.4 Alloftheunknownsthatappearintheanalysis(between
cut sample so that it is not thicker than the above stated tensile
D and D ) are assumed to be dimethyl siloxanes. All
plaque thickness.
4 10
unknowns are given, as response factors, the average response
6.2 Room temperature-vulcanized (RTV) samples shall be
factor calculated for the difunctional cyclosiloxane monomers
prepared by spreading the liquid using a suitable device, into
D through D .
4 10
consistent 0.90 6 0.20 mm plaques. Avoid entrapped air and
knit lines when preparing the sample.
8. Conditioning
6.3 Three 1-g samples shall be cut from the plaque. These
8.1 Allow RTV samples to cure for 24 h, but not to exceed
samplesshallbetakenfromnearonecorner,atthecenterofthe
72 h at 25°C and 50 6 10 % relative humidity.
plaque, and near the corner at a diagonal from the first.
7. Standard Solutions 9. Procedure
7.1 Add 0.1 g (weighed to the nearest 0.1 mg) of each pure
9.1 Extraction—Pre-weigh each cured sample to 1.0 6 0.2
cyclic (>98 %) to 1.0 g of dodecane (99 %) (weighed to the
g (record weight to the nearest 0.0001 g) and set aside.
nearest 0.1 mg).Ten millilitres 6 0.1 mLpentane is added and
9.2 Weigh 0.010 6 0.005 g of dodecane (record weight to
the container is sealed to prevent leakage/evaporation. New
the nearest 0.0001 g) and place sample into the 30-mLvial. To
standard mixtures should be prepared if existing one is more
this add 10 mLof pentane. Immediately place the pre-weighed
than seven (7) days old.
sample into the vial, and seal the container to prevent leakage/
7.2 Calibration of the standard solution is achieved by
evaporation. Weight precision of the dodecane and test sample
injecting 1 µL(need verify use with SE 30 column – will need
are extremely important for reproducible results. The sample
to attenuate response or dilute solution) standard solution
vial is placed on a wrist shaker for 16 h.
sample. Response factors for the individual cyclics are calcu-
NOTE1—Thesequenceisimportantduetothevolatilityofthesolvents.
lated using the following equation:
used.
WtDn ADoD
NOTE 2—See 10.1.1 regarding dodecane measurement.
RfDn 5 * (1)
ADn WtDoD
9.3 Inject 1 to 5 µL into the GC injection port. (Injection
where:
volume is dependant on the injector split ratio).
Rf = response factor
9.4 After the elution is complete (about 35 min) identify the
Dn = the cyclic siloxane species from a 4 member to a
peaks and quantify them by integration using the following
10 member ring
equations (sample calculations are shown in Appendix X2):
RfDn*ADn WtDoD
%Dn 5 * *100 (2)
ADoD SaWt
The sole source of supply of the standards solutions known to the committee at
this time is Ohio Valley Specialty Chemicals, 115 Industrial Road, Marietta, OH,
where
45750, 1-800-729-6972, Catalog number 34569/Cyclic Standard Kit D3 through
D10. If you are aware of alternative suppliers, please provide this information to
SaWt = the weight of the silicone part
ASTM International Headquarters. Your comments will receive careful consider-
ation at a meeting of the responsible technical committee, which you may attend. 9.4.1 Perform Eq 2 for D through D .
4 10
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