1、Designation: E 1952 06Standard Test Method forThermal Conductivity and Thermal Diffusivity by ModulatedTemperature Differential Scanning Calorimetry1This standard is issued under the fixed designation E 1952; the number immediately following the designation indicates the year oforiginal adoption or,
2、 in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method describes the determination of thermaldetermination of thermal
3、 conductivity of homogeneous, non-porous solid materials in the range of 0.10 to 1.0 W/(K m) bymodulated temperature differential scanning calorimeter. Thisrange includes many polymeric, glass, and ceramic materials.Thermal diffusivity, which is related to thermal conductivitythrough specific heat c
4、apacity and density, may also be derived.Thermal conductivity and diffusivity can be determined at oneor more temperatures over the range of 0 to 90 C.1.2 SI units are the standard. The values given in paren-theses are provided for information purposes only.1.3 This standard does not purport to addr
5、ess all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E 473 Terminol
6、ogy Relating to Thermal Analysis and Rhe-ologyE 967 Test Method for Temperature Calibration of Differ-ential Scanning Calorimeters and Differential ThermalAnalyzersE 968 Practice for Heat Flow Calibration of DifferentialScanning CalorimetersE 1142 Terminology Relating to Thermophysical PropertiesE 1
7、231 Practice for Calculation of Hazard PotentialFigures-of-Merit for Thermally Unstable Materials3. Terminology3.1 Definitions:3.1.1 Specific technical terms used in this document aredefined in Terminologies E 473 and E 1142.3.2 Definitions of Terms Specific to This Standard:3.2.1 modulated temperat
8、ure differential scanningcalorimetera version of differential scanning calorimetrythat provides a sinusoidally varying temperature program to thetest specimen in addition to the traditional isothermal ortemperature ramp programs. Results from analysis shall in-clude apparent and specific heat capaci
9、ty.4. Summary of Test Method4.1 The heat capacity of a test specimen may be determinedusing the modulated temperature approach in which an oscil-latory or periodically repeating temperature program (aroundan average temperature) is imposed upon a test specimenproducing an oscillatory (periodic) heat
10、 flow into or out of thespecimen. The heat capacity of the test specimen may beobtained from the amplitude of the resultant heat flow dividedby the amplitude of the oscillatory (periodic) temperature thatproduces it. Specific heat capacity is obtained by normalizingthe heat capacity to specimen mass
11、.4.1.1 The accuracy of the heat capacity thus obtaineddepends upon experimental conditions. When a thin testspecimen encapsulated in a specimen pan of high thermalconductivity is treated with temperature oscillations of longperiod (low frequency), the test specimen is assumed toachieve a uniform tem
12、perature distribution and the resultantheat capacity information will be comparable with those ofother non-oscillatory test methods.4.1.2 When one end of a thick test specimen is exposed tothe temperature oscillations of short period (high frequency),the test specimen will achieve a temperature dist
13、ribution overits length related to its thermal diffusivity.1This test method is under the jurisdiction of Committee E37 on ThermalMeasurements and is the direct responsibility of Subcommittee E37.01 on ThermalTest Methods and Practices.Current edition approved Dec. 1, 2006. Published January 2007. O
14、riginallyapproved in 1998. Last previous edition approved in 2001 as E 1952 01.The process described in this test method is covered by a patent (Marcus, S. M.and Reading, M., U. S. Patent 5 335 993, 1994) held by TA Instruments, Inc., 109Lukens Drive, New Castle DE 19720. Interested parties are invi
15、ted to submitinformation regarding the identification of acceptable alternatives to this patentedmethod to the Committee on Standards, ASTM Headquarters, 100 Barr HarborDrive, West Conshohocken PA 19428-2959. Your comments will receive carefulconsiderations at a meeting of the responsible technical
16、committee which you mayattend.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International,
17、100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.1.3 The apparent heat capacity information thus obtainedis lower than that of the uniform temperature distribution casedescribed above and is proportional to the square root ofthermal conductivity of the test speci
18、mens.3The thermalconductivity of the test specimen may be derived from theapparent heat capacity of a thick specimen, the actual heatcapacity of a thin specimen, and a series of geometric andexperimental constants.4.2 If the thermal conductivity of the test specimen is low,approaching that of the pu
19、rge gas surrounding it, a correctionto the measured thermal conductivity is required to compensatefor heat losses from the thick test specimen.4.3 Thermal diffusivity is derived from the determinedthermal conductivity, specific heat capacity, and density of thetest specimen.5. Significance and Use5.
20、1 Thermal conductivity is a useful design parameter forthe rate of heat transfer through a material.5.2 The results of this test method may be used for designpurposes, service evaluation, manufacturing control, researchand development, and hazard evaluation. (See PracticeE 1231.)6. Interferences6.1
21、Because the specimen size used in thermal analysis is onthe order of 10 to 100 mg, care must be taken to ensure it ishomogeneous or representative of the material, or both.6.2 The calculation of thermal conductivity requires knowl-edge of this specimen geometry. This test method requires aspecific s
22、pecimen size and shape. Other geometries may beused with the appropriate modifications to the calculatingequations.7. Apparatus7.1 A modulated temperature differential scanning calorim-eter consisting of:7.1.1 A Differential Scanning Calorimetry (DSC) TestChamber, of (1) a furnace to provide uniform
23、 controlledheating/cooling of a specimen and reference to a constanttemperature or at a constant rate within the applicable range ofthis test method; (2) a temperature sensor (or other signalsource) to provide an indication of the specimen temperaturereadable to 0.01 C; (3) a differential sensor to
24、detect a heatflow difference between the specimen and reference equivalentto 0.001 mW; and (4) a means of sustaining a test temperatureenvironment of inert nitrogen purge gas at a rate of 50mL/min6 10 mL/min.7.1.2 A Temperature Controller, capable of executing aspecific temperature program by (1) op
25、erating the furnacebetween selected temperature limits at a rate of temperaturechange of 1C/min, (2) holding at an isothermal temperatureover the temperature range of 0 to 90 C within 6 0.1C, and(3) sinusoidal varying temperature with an amplitude of 60.2to 0.7C and a period of 60 to 100 seconds (fr
26、equency of 10 to16 mHz).NOTE 1The upper thermal conductivity achievable by this method isextended to 4 W (K m) for instruments capable of 20 s periods(frequency of 50 mHz)47.1.3 A Calculating Device, capable of transforming theexperimentally determined modulated temperature and modu-lated specimen h
27、eat flow signals into the required continuousoutput forms of heat capacity (preferably in units of mJ/C),specific heat capacity (preferably in units of J/(g C), andaverage test temperature to the required accuracy and preci-sion.7.1.4 A Recording Device, to record and display heat capac-ity, specifi
28、c heat capacity, and average temperature on theordinate (Y axis) and elapsed time (preferably in units ofminutes) on the abscissa (X axis) with a sensitivity of 0.001mJ/K for heat capacity, 0.001 J/(g K) for specific heatcapacity, 0.1 C for average temperature, and 0.1 min for time.7.1.5 A Coolant S
29、ystem, to provide oscillatory heating andcooling rates of at least 3 C/min.7.1.6 Inert Nitrogen, or other low conductivity purge gasflowing at a rate of 50 mL/min (see 7.1.1).NOTE 2Helium, a commonly used purge gas, is unacceptable for thispurpose, due to its very high thermal conductivity which res
30、ults in reducedrange, precision, and accuracy.7.2 A Balance, with a range of at least 200 mg to weighspecimens or containers, or both, (pans, crucibles, etc.) to60.01 mg.7.3 Calipers or other length-measuring device with a rangegreater than 4 mm, readable to 0.01 mm.7.4 Sapphire Disk Calibration Mat
31、erial,20to30mg.7.5 Polystyrene Thermal Conductivity Calibration Mate-rial, of known thermal conductivity and specific heat capac-ity, in the shape of a right circular cylinder, 6.3 6 0.2 mm indiameter and 3.5 6 0.3 mm thickness.7.5.1 Polystyrene Specific Heat Capacity Reference Mate-rial, composed o
32、f the same material as the thermal conductiv-ity calibration material, in the shape of a right circular cylinderor disk, 6.3 6 0.2 mm in diameter and 0.4 6 0.1 mm inthickness.7.6 Circular Aluminum Disk, 6.3 mm in diameter and 0.01mm or thinner in thickness.7.7 Containers (pans, crucibles, etc.) that
33、 are inert to thespecimen and are of suitable structural shape and integrity tocontain the specimen in accordance with the specific require-ments of this test method.7.8 Silicone Heat Transfer Fluid, with no thermal transi-tions over the temperature range from -10 to 100C.NOTE 3Silicone oil with a v
34、iscosity of about 1 Pa s (10 poise) hasbeen found satisfactory for this application.7.9 While not required, users may find the following op-tional apparatus and materials useful for this determination.7.9.1 Polymeric Thermal Conductivity Performance Mate-rial, a right circular cylinder, 6.3 6 0.2 mm
35、 in diameter and 3.56 0.3 mm in length.3Marcus, S.M., and Blaine, R.L., Thermochim. Acta, Vol 243, 1994, pp.231-239.4E. Verdonck, R.L. Blaine, G. Dreezer, :Thermal Conductivity Measurements ofConducive EpoxyAdhesives by MDSCt,” Proceedings of the 31stConference of theNorth American Thermal Analysis
36、Society, 2003.E19520627.9.2 Polymeric Specific Heat Capacity Reference Material,composed of the same material as the thermal conductivitystandard reference material, a right circular cylinder or disk,6.3 6 0.2 mm in diameter and 0.4 6 0.1 mm in thickness.8. Sampling8.1 Select two right circular cyli
37、nders, both nominally 6.3mm in diameter. The first of these test specimens is nominally0.4 mm thick and the second is nominally 3.5 mm thick. Thesetest specimens are most conveniently obtained by cutting from0.25 in. diameter rod, a common material form.NOTE 4Other fabrication techniques, such as cu
38、tting from sheet stockusing cork borers, machining from stock, or molding may also be used.8.1.1 Polish the circular end surfaces of the test specimenssmooth and parallel to within 6 30 m with 600 grit emerypaper.9. Calibration9.1 Calibrate the temperature signal from the apparatus inaccordance with
39、 Practice E 967 using an indium referencematerial and a heating rate of 1 C/min.9.2 Calibrate the heat flow signal from the apparatus inaccordance with Practice E 968 using an indium referencematerial.9.3 Calibrate the apparatus for heat capacity measurementsin accordance with the instructions of th
40、e manufacturer asdescribed in the instrument manual using isothermal tempera-ture conditions (at the mid point of the temperature range ofinterest), the sapphire calibration material (from 7.4) 60.5 Camplitude and 80 s period (12.5 mHz frequency).10. Procedure10.1 Measure thermal conductivity under
41、quasi-isothermalconditions at an operator-selected temperature within the rangefrom 0 to 90 C. If measurements at additional temperaturesare desired, repeat the procedure at those additional tempera-tures.10.2 A common set of experimental conditions are used foreach measurement:10.2.1 Select the mod
42、ulated mode on the DSC and recordthe heat capacity signal. Equilibrate the apparatus at the testtemperature selected by the operator. Modulate the temperaturewith an amplitude of 60.5 C and a period (P) of 80 s (12.5mHz). (See Note 5).After 15 min equilibration time, record theaverage test temperatu
43、re (T) and the specific heat capacity (Cp)or apparent heat capacity (C) as called for in the appropriatesection.10.3 Determine the thermal conductivity calibration factor,D.10.3.1 Weigh the thin (0.4 mm) polystyrene (or other)calibration disk (from 7.5.1); record the mass as m. Enter it asan experim
44、ental parameter into the apparatus calculator. En-capsulate the thin polystyrene calibration disk in a standardaluminum sample container with lid.10.3.2 Place the encapsulated test specimen in the DSC onthe specimen sensor. Use an empty aluminum container and lidon the reference side.NOTE 5Matching
45、the combined weights of the reference containerand lid to those of the specimen container and lid within 60.1 mgproduces the best results.10.3.3 Measure the heat capacity of the thin polystyrenecalibration material using the conditions of 10.2.1. Record thespecific heat capacity (Cp) in units of J/(
46、g K).NOTE 6This value for the specific heat capacity of polystyrene maybe compared against the literature values listed in Table 1 as a perfor-mance criteria test.10.3.4 Weigh the thick (3.5 mm) polystyrene calibrationdisk (from 7.5); record the mass as m; and enter it into theexperimental parameter
47、s screen on the measuring apparatus.10.3.5 Measure and record the diameter (d) and length (L)of the polystyrene calibration test specimen.10.3.6 Moisten the DSC sample and reference sensors withsilicone oil. Place a thin aluminum disk over each sensor.Carefully place the thick sample (which has been
48、 moistenedwith oil on the bottom side) on the aluminum disk covering thesample sensor.NOTE 7Ensure that silicone oil does not change the characteristics ofthe test specimen.NOTE 8A cotton swab may be wetted with silicon oil and the pressedbetween the fingers to remove any excess oil. The “moist” cot
49、ton swabmay be passed once over the surface to “wet” it with the oil.10.3.7 Measure the apparent heat capacity of the specimenin accordance with the conditions of 10.2.1. Record theapparent heat capacity (C) in the units of mJ/C.10.3.8 Using the values of P (from 10.2.1), Cp(from10.3.3); and m, L, and d (from 10.3.4 and 10.3.5), calculate theobserved thermal conductivity (lo) for polystyrene using Eq 1(see 11.1).NOTE 9An example calculation is presented in 11.5.1.10.3.9 Determine the value for thermal conductivity ofpolystyrene (lr) for the corres
