1、Designation: E1952 11Standard Test Method forThermal Conductivity and Thermal Diffusivity by ModulatedTemperature Differential Scanning Calorimetry1This standard is issued under the fixed designation E1952; the number immediately following the designation indicates the year oforiginal adoption or, i
2、n the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method describes the determination of thermalconductivity of homogeneous
3、, non-porous solid materials inthe range of 0.10 to 1.0 W/(K m) by modulated temperaturedifferential scanning calorimeter. This range includes manypolymeric, glass, and ceramic materials. Thermal diffusivity,which is related to thermal conductivity through specific heatcapacity and density, may also
4、 be derived. Thermal conductiv-ity and diffusivity can be determined at one or more tempera-tures over the range of 0 to 90 C.1.2 SI units are the standard. The values given in parenthe-ses are provided for information purposes only.1.3 This standard does not purport to address all of thesafety conc
5、erns, 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:2E473 Terminology Relating to Thermal An
6、alysis and Rhe-ologyE967 Test Method for Temperature Calibration of Differen-tial Scanning Calorimeters and Differential Thermal Ana-lyzersE968 Practice for Heat Flow Calibration of DifferentialScanning CalorimetersE1142 Terminology Relating to Thermophysical PropertiesE1231 Practice for Calculation
7、 of Hazard Potential Figures-of-Merit for Thermally Unstable MaterialsE2161 Terminology Relating to Performance Validation inThermal Analysis3. Terminology3.1 Definitions:3.1.1 Specific technical terms used in this document aredefined in Terminologies E473, E1142, E2161 including cali-bration, diffe
8、rential scanning calorimetry, heat capacity, modu-lated temperature, precision, reference material, relative stan-dard deviation, repeatability, reproducibility, specific heatcapacity, standard deviation, thermal analysis, thermal con-ductance, and thermal conductivity.3.2 Definitions of Terms Speci
9、fic to This Standard:3.2.1 modulated temperature 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 sha
10、ll in-clude apparent and specific heat capacity.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 spe
11、cimenproducing an oscillatory (periodic) heat 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
12、normalizingthe heat capacity to specimen mass.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 tes
13、t specimen is assumed toachieve a uniform temperature distribution and the resultant1This test method is under the jurisdiction of Committee E37 on ThermalMeasurements and is the direct responsibility of Subcommittee E37.10 on Funda-mental, Statistical and Mechanical Properties.Current edition appro
14、ved Aug. 1, 2011. Published September 2011. Originallyapproved in 1998. Last previous edition approved in 2006 as E1952 11. DOI:10.1520/E1952-11.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.,
15、 159Lukens Drive, New Castle DE 19720. Interested parties are invited 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 receiv
16、e carefulconsiderations at a meeting of the responsible technical 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 Docume
17、nt Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.heat 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 to
18、the temperature oscillations of short period (high frequency),the test specimen will achieve a temperature distribution overits length related to its thermal diffusivity.4.1.3 The apparent heat capacity information thus obtainedis lower than that of the uniform temperature distribution casedescribed
19、 above and is proportional to the square root ofthermal conductivity of the test specimens (1).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 consta
20、nts.4.2 If the thermal conductivity of the test specimen is low,approaching that of the purge 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 condu
21、ctivity, specific heat capacity, and density of thetest specimen.5. Significance and Use5.1 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,
22、 researchand development, and hazard evaluation. (See Practice E1231.)6. Interferences6.1 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 conduct
23、ivity requires knowl-edge of this specimen geometry. This test method requires aspecific specimen 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
24、A Differential Scanning Calorimetry (DSC) TestChamber, of (1) a furnace to provide uniform 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
25、an indication of the specimen temperaturereadable to 0.01 C; (3) a differential sensor to 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 50 mL/min 6 10 mL/min.
26、7.1.2 A Temperature Controller, capable of executing aspecific temperature program by (1) operating 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 60.1 C, and(3) sinusoida
27、l varying temperature with an amplitude of 60.2to 0.7 C and a period of 60 to 100 seconds (frequency of 10 to16 mHz).NOTE 1The upper thermal conductivity achievable by this method isextended to 4 W (K m) for instruments capable of 20 second periods(frequency of 50 mHz) (2).7.1.3 A Calculating Device
28、, capable of transforming theexperimentally determined modulated temperature and modu-lated specimen heat 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 re
29、quired accuracy and preci-sion.7.1.4 A Data Collecting Device, to provide a means ofacquiring, storing, and displaying measured or calculatedsignals, or both. The minimum output signals required are heatflow, temperature, time, heat capacity, specific heat capacity,and average temperature with a sen
30、sitivity of 0.001 mJ/K forheat capacity, 0.001 J/(g K) for specific heat capacity, 0.01 Cfor average temperature, and 0.1 min for time.7.1.5 A Coolant System, 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 rat
31、e 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 results in reducedrange, precision, and accuracy.7.2 A Balance, with a range of at least 200 mg to weighspecimens or containers, or both, (pans, crucib
32、les, 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 Material,20to30mg.7.5 Polystyrene Thermal Conductivity Calibration Material,of known thermal conductivity and specific heat capacity, inthe shape of a
33、right circular cylinder, 6.3 6 0.2 mm in diameterand 3.5 6 0.3 mm thickness.7.5.1 Polystyrene Specific Heat Capacity Reference Mate-rial, composed of 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.
34、4 6 0.1 mm in thick-ness.7.6 Circular Aluminum Disk, 6.3 mm in diameter and0.01 mm or thinner in thickness.7.7 Containers (pans, crucibles, etc.) that are inert to thespecimen and are of suitable structural shape and integrity tocontain the specimen in accordance with the specific require-ments of t
35、his test method.7.8 Silicone Heat Transfer Fluid, with no thermal transi-tions over the temperature range from 10 to 100 C.NOTE 3Silicone oil with a viscosity 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 app
36、aratus and materials useful for this determination.3The boldface numbers in parentheses refer to a list of references at the end ofthis standard.E1952 1127.9.1 Polymeric Thermal Conductivity Performance Mate-rial, a right circular cylinder, 6.3 6 0.2 mm in diameter and3.5 6 0.3 mm in length.7.9.2 Po
37、lymeric 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 cylinders, both nominally6.3 mm in
38、 diameter. The first of these test specimens isnominally 0.4 mm thick and the second is nominally 3.5 mmthick. These test specimens are most conveniently obtained bycutting from 0.25-in. diameter rod, a common material form.NOTE 4Other fabrication techniques, such as cutting from sheet stockusing co
39、rk 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 630 m with 600 grit emerypaper.9. Calibration9.1 Calibrate the temperature signal from the apparatus inaccordance with Practice E967 using an indium
40、referencematerial and a heating rate of 1 C/min.9.2 Calibrate the heat flow signal from the apparatus inaccordance with Practice E968 using an indium referencematerial.9.3 Calibrate the apparatus for heat capacity measurementsin accordance with the instructions of the manufacturer asdescribed in the
41、 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-second period (12.5 mHz frequency).10. Procedure10.1 Measure thermal conductivity under quasi-isothermalconditions a
42、t 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 modulated mode on the DSC and r
43、ecordthe 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 seconds(12.5 mHz). (See Note 5.) After 15 min equilibration time,record the average test temperature (T) and the specif
44、ic heatcapacity (Cp) or apparent heat capacity (C) as called for in theappropriate section.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 experimental parameter into
45、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 the combined weights
46、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/(g K).NOTE 6This value
47、 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 parameters screen on the measu
48、ring 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 moistenedwith oil on
49、 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” cotton 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
