1、Designation: D7309 11D7309 13Standard Test Method forDetermining Flammability Characteristics of Plastics andOther Solid Materials Using Microscale CombustionCalorimetry1This standard is issued under the fixed designation D7309; the number immediately following the designation indicates the year ofo
2、riginal adoption or, in 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, which is similar to thermal analysis techn
3、iques, establishes a procedure for determining flammabilitycharacteristics of combustible materials such as plastics.1.2 The test is conducted in a laboratory environment using controlled heating of milligram specimens and complete thermaloxidation of the specimen gases.1.3 Specimens of known mass a
4、re thermally decomposed in an oxygen-free (anaerobic) or oxidizing (aerobic) environment ata constant heating rate between 0.2 and 2 K/s.1.4 The heat released by the specimen is determined from the mass of oxygen consumed to completely oxidize (combust) thespecimen gases.1.5 The rate of heat release
5、d by combustion of the specimen gases produced during controlled thermal or thermoxidativedecomposition of the specimen is computed from the rate of oxygen consumption.1.6 The specimen temperatures over which combustion heat is released are measured.1.7 The mass of specimen remaining after the test
6、is measured and used to compute the residual mass fraction.1.8 The specimen shall be a material or composite material in any form (fiber, film, powder, pellet, droplet). This test methodhas been developed to facilitate material development and research.1.9 This standard is used to measure and descri
7、be the response of materials, products, or assemblies to heat and flame undercontrolled conditions, but does not by itself incorporate all factors required for fire hazard or fire risk assessment of the materials,products, or assemblies under actual fire conditions.1.10 This standard does not purpor
8、t to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.NOTE 1There is no known ISO equivalent to this tes
9、t method.2. Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD5865 Test Method for Gross Calorific Value of Coal and CokeE176 Terminology of Fire StandardsE177 Practice for Use of the Terms Precision and Bias in ASTM Test MethodsE691 Practice for Conducting an Interlabora
10、tory Study to Determine the Precision of a Test MethodE967 Test Method for Temperature Calibration of Differential Scanning Calorimeters and Differential Thermal AnalyzersE1591 Guide for Obtaining Data for Fire Growth Models1 This test method is under the jurisdiction of ASTM Committee D20 on Plasti
11、cs and is the direct responsibility of Subcommittee D20.30 on Thermal Properties.Current edition approved Oct. 15, 2011Nov. 1, 2013. Published October 2011November 2013. Originally approved in 2007. Last previous edition approved in 20072011as D7309 07a.D7309 11. DOI: 10.1520/D7309-11.10.1520/D7309-
12、13.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only
13、 to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versio
14、nof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13. Terminology3.1 Definitions:3.1.1 For definitions of terms relating to plastics, refer to Terminology D8
15、83.3.1.2 For definitions of terms relating to fire, refer to Terminology E176.3.2 Definitions of Terms Specific to This Standard:3.2.1 combustion residue, nthe non-volatile chemical species remaining after controlled thermal oxidative decomposition ofa specimen.3.2.2 combustion temperature, nthe spe
16、cimen temperature at which the specific combustion rate is a maximum duringcontrolled thermal oxidative decomposition.3.2.3 controlled heating, na controlled temperature program used to effect thermal decomposition or oxidative thermaldecomposition in which the temperature of the specimen is uniform
17、 throughout and increases with time at a constant rate.3.2.4 controlled thermal (or thermal oxidative) decomposition , decomposition, nthermal (oxidative) decomposition undercontrolled heating.3.2.5 heat release capacity, nthe maximum specific heat release rate during a controlled thermal decomposit
18、ion divided bythe heating rate in the test.3.2.6 heating rate, nthe constant rate of temperature rise of the specimen during the controlled temperature program.3.2.7 heat release temperature, nthe specimen temperature at which the specific heat release rate is a maximum duringcontrolled thermal deco
19、mposition.3.2.8 maximum specific combustion rate, nthe maximum value of the specific combustion rate recorded during the test.3.2.9 maximum specific heat release rate, nthe maximum value of the specific heat release rate recorded during the test.3.2.10 net calorific value, nthe net heat of complete
20、combustion of the specimen measured during controlled thermaloxidative decomposition per unit initial specimen mass.3.2.11 oxidative thermal decomposition, na process of extensive chemical species change caused by heat and oxygen (thermaloxidation, oxidative pyrolysis).3.2.12 pyrolysis residue, nthe
21、 fraction of the initial specimen mass remaining after controlled anaerobic thermal decompo-sition.3.2.13 specific combustion rate, nthe rate at which combustion heat is released per unit initial mass of specimen duringcontrolled thermal oxidative decomposition.3.2.14 specific heat of combustion of
22、specimen gases, nnet calorific value of gases.3.2.15 specific heat release rate, nthe rate at which combustion heat is released per unit initial mass of specimen duringcontrolled thermal decomposition.3.2.16 specific heat release, nthe net heat of complete combustion of the volatiles liberated durin
23、g controlled thermaldecomposition per unit initial specimen mass.3.2.17 specimen gases, nthe volatile chemical species liberated during controlled thermal (oxidative) decomposition of aspecimen.3.3 Symbols: = heating rate, K/sE = 13.1 kJ/g-O2 is the average heat released by complete combustion of or
24、ganic compounds per unit mass of oxygenconsumedF = volumetric flow rate of the combustion stream at ambient temperature and pressure measured at the terminal flowmeter, cm3/shc = specific heat release of sample, J/ghco = net calorific value of sample, J/ghc,gas = specific heat of combustion of speci
25、men gases, J/gc = heat release capacity, J/g-Kmo = initial specimen mass, gmc = residual specimen mass after oxidative pyrolysis, gmp = residual specimen mass after the anaerobic pyrolysis, gO2 = the change in the concentration (volume fraction) of O2 in the gas stream due to combustion measured at
26、the oxygensensor at time t, cm3/cm3Q(t) = specific heat release rate at time t, W/gQmax = maximum specific heat release rate, W/gD7309 132Qmax o = maximum specific combustion rate, W/g = density of oxygen at ambient conditions, g/cm3t = time synchronized to temperature, x - , sTmax = heat release te
27、mperature, KTmaxo = combustion temperature, K = transit time of the gas stream between the specimen location and the oxygen analyzer, sx = time at which the oxygen analyzer signal is recorded, sYc = combustion residue, g/gYp = pyrolysis residue, g/g4. Summary of Test Method4.1 This test method provi
28、des two procedures for determining flammability characteristics of materials in a laboratory test usingcontrolled heating (controlled temperature programming) and oxygen consumption calorimetry. This test measures flammabilitycharacteristics using a controlled temperature program to force the releas
29、e of specimen gases, thermal oxidation of the specimengases (and optionally the specimen residue) in excess oxygen, and measurement of the oxygen consumed to calculate the amount,rate, and temperature of heat released by combustion of a solid specimen during controlled heating.4.2 Controlled Thermal
30、 Decomposition, Method AIn this procedure the specimen is subjected to controlled heating in anoxygen-free/anaerobic environment, that is, controlled thermal decomposition. The gases released by the specimen duringcontrolled thermal decomposition are swept from the specimen chamber by a non-oxidizin
31、g/inert purge gas (typically nitrogen),subsequently mixed with excess oxygen, and completely oxidized in a high temperature combustion furnace. The volumetric flowrate and volumetric oxygen concentration of the gas stream exiting the combustion furnace are continuously measured during thetest to cal
32、culate the rate of heat release by means of oxygen consumption. In Method A the heat of combustion of the volatilecomponent of the specimen (specimen gases) is measured but not the heat of combustion of any solid residue. Table X1.1 ofAppendix X1 shows data for c,hc,Yp, and Tmax for 14 different com
33、mercial plastics tested in triplicate (n = 3).4.3 Controlled Thermal Oxidative Decomposition,Method BIn this procedure the specimen is subjected to controlled heating in an oxidizing/aerobic environment, that is,controlled thermal oxidative decomposition. The specimen gases evolved during the contro
34、lled heating program are swept fromthe specimen chamber by the oxidizing purge gas (for example, dry air) and mixed with additional oxygen, if necessary, prior toentering a high temperature combustion furnace where the gases are completely oxidized. The volumetric flow rate and volumetricoxygen conc
35、entration of the gas stream exiting the combustion furnace are continuously measured during the test to calculate thespecific combustion rate by means of oxygen consumption. In Method B the net calorific value of the specimen gases and solidresidue are measured during the test.5. Significance and Us
36、e5.1 This laboratory test method measures thermal combustion properties of materials (1-5).35.2 The test uses controlled thermal decomposition of specimens and thermal oxidation of the specimen gases as they arereleased from the specimen to simulate the condensed and gas phase processes of flaming c
37、ombustion, respectively, in asmall-scale laboratory test (1-7).5.3 The thermal combustion properties measured in the test are related to flammability characteristics of the material (4-7).5.4 The amount of heat released in flaming combustion per unit mass of material is the fire load and the potenti
38、al fire load(complete combustion) is estimated in Method A as hc.5.5 The net calorific value of the material (see Test Method D5865) is determined directly using Method B as hco without theneed to know the atomic composition of the specimen to correct for the latent heat of evaporation of the water
39、produced bycombustion, or to perform titrations to correct for the heat of solution of acid gases. See Table X1.2 for comparison of MicroscaleCombustion Calorimetry (MCC) data with Test Method D5865.5.6 The heat release temperature Tmax of MethodAapproximates the surface temperature at piloted ignit
40、ion in accordance withRef. (5-7) for purposes of fire modeling (See Guide E1591).5.7 The heat release capacity c (J/g-K) is a flammability parameter measured in Method A that is unique to this test method.6. Limitations6.1 The heat release capacity (c) is independent of the form, mass, and heating r
41、ate of the specimen as long as the specimentemperature is uniform at all times during the test (1-5).3 The boldface numbers in parentheses refer to a list of references at the end of this standard.D7309 1336.2 Test results obtained from small (milligram) samples by this method do not include physica
42、l behavior such as melting,dripping, swelling, shrinking, delamination, and char/barrier formation that can influence the results of large (decagram/kilogram)samples in flame and fire tests.6.3 Test results obtained from small (milligram) samples by this method do not include extrinsic factors such
43、as thickness,sample orientation, external heat flux, ignition source, boundary conditions, and ventilation rate that influence the results of large(decagram/kilogram) samples in flame and fire tests.6.4 The specific combustion rate and combustion temperature of Method B are not generally reproducibl
44、e because samplegeometry can affect the rate of surface oxidation and gas phase ignition can occur in the sample chamber at appropriate fuel/oxygenratios. Reproducibility of Qmaxo and Tmaxo are improved by using low oxygen concentration in the purge gas, small samples, andlow heating rates in this t
45、est.7. Apparatus7.1 The equipment used in this test method shall be capable of displaying changes in combustion heat release rate as a functionof specimen temperature during controlled heating and shall have the capability of subjecting the specimen to differentatmospheres of oxygen concentration at
46、 ambient pressure.7.2 Commercial thermogravimetric analyzers, pyrolysis probes, and electrically-heated ceramic tubes in thermal contact witha combustor, or attached gas analyzers, or both, have been found suitable. Detailed apparatus design criteria are given in AnnexA1.NOTE 2In typical materials t
47、ests a material is exposed to a particular set of test conditions and the materials response to those particular testconditions is measured and reported as the test result. In these tests changing the test conditions has an effect on the result of the test. In this test, theheat release capacity (c)
48、 is independent of the test parameters as it is a material property and not a response of a material to a particular set of conditions.Thus, changing the test condition (within certain constraints) will have no effect on the test result. As such, the apparatus required to perform this testshall oper
49、ate to provide test parameters that remain within certain constraints for each section of the device, for example, specimen chamber, mixingsection, combustor. The diameter, length and shape of each section will have no effect on the test result provided the section meets the performance givenin Annex A1.7.3 Figure 1 illustrates the basic components of an apparatus, (1, 5, 8-11), satisfactory for this test method which include:7.4 A specimen chamber (sample chamber) that is capable of holding and heating a small (milligram sized) specimen in ac
