1、Designation: D 5028 96 (Reapproved 2003)e1Standard Test Method forCuring Properties of Pultrusion Resins by ThermalAnalysis1This standard is issued under the fixed designation D 5028; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision,
2、 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.e1NOTEReinserted Figure 1 in March 2007.1. Scope1.1 This test method covers determination of curing param-eters of p
3、ultrusions resins by differential scanning calorimetry.1.2 This test method is applicable to pultrusion resin solu-tions with adequate initiator(s).1.3 The normal operating temperature range is from 0 to200C.NOTE 1Resin systems which do not form an adequate baseline are notcovered by this test metho
4、d.1.4 Computer or electronic based instruments or data treat-ment equivalent to this practice may also be used.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safe
5、ty and health practices and determine the applica-bility of regulatory limitations prior to use. For specific hazardstatements, see Note 1.NOTE 2There is no similar or equivalent ISO standard.2. Referenced Documents2.1 ASTM Standards:2D 3418 Test Method for Transition Temperatures of Poly-mers By Di
6、fferential Scanning CalorimetryD 3918 Terminology Relating to Reinforced Plastic Pul-truded ProductsE 473 Terminology Relating to Thermal Analysis and Rhe-ologyE 967 Test Method for Temperature Calibration of Differ-ential Scanning Calorimeters and Differential ThermalAnalyzers3. Terminology3.1 Defi
7、nitions:3.1.1 onset temperaturean extrapolated point representingan intersection of the baseline and the front slope of theexothermic curing curve.3.1.2 peak temperaturean extrapolated point representingan intersection of both front and rear slopes of the exothermiccuring curve.4. Summary of Test Me
8、thod4.1 The test method consists of heating of the test materialat a controlled rate of temperature increase in a controlledatmosphere and continuously monitoring with a suitable sens-ing device the difference in heat input between a referencematerial and a test material due to changes of state in t
9、hematerial. A curing transition is marked by a release of energyby the specimen resulting in a corresponding exothermic curve.NOTE 3Toxic or corrosive effluents, or both, may be released whenheating the material, and could be harmful to the personnel or to theapparatus.5. Significance and Use5.1 Dif
10、ferential scanning calorimeters are used to determinechemical reaction thermal profiles of materials. One suchreaction is the curing of thermosetting resins.5.2 This test method is useful for both specification accep-tance and for research.6. Apparatus6.1 Differential Scanning Calorimeter, capable o
11、f heating atest specimen and a reference material at a controlled rate up toat least 20C/min and of automatically recording the differen-tial heat flow.1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.18 on Reinforced T
12、hermoset-ting Plastics.Current edition approved Nov. 1, 2003. Published December 2003. Originallyapproved in 1989. Last previous edition approved in 1996 as D 5028 - 96.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annua
13、l Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.2 Specimen Holders, composed of clean aluminum or ofother high thermal cond
14、uctivity material.6.2.1 Specimen holders may be open, covered, or sealedtype.6.3 Nitrogen, or other inert purge gas supply.6.4 Flowmeter, for purge gas.6.5 Recording Charts, for temperature recording apparatuswith suitable graduation for measurements of energy differen-tial against temperature or ti
15、me.7. Technical Hazards7.1 An increase or decrease in heating rate from thosespecified may alter the test results. This practice assumes lineartemperature indication.7.2 Since milligram quantities of sample are used, it isessential to ensure that samples are homogeneous and repre-sentative.7.3 Sampl
16、e sizes larger than those specified in the testmethod may alter the test results.7.4 For comparison, the same heating rate, the same samplesize and the same type of pan and lid shall be used.7.5 For low viscosity resin systems, a sealed type of pan andlid shall be used to prevent excessive volatile
17、componentevaporation during the test.8. Test Specimen8.1 Thermoset resin system containing initiator(s) capableof curing in range from room temperature to 200C.8.2 Following the addition of initiator, the sample shall beheld for a minimum of12 h before commencing the test.9. Calibration9.1 Using the
18、 same heating rate to be used for samples,calibrate the apparatus with appropriate standard referencematerials. For temperature range of this standard, the followingmaterial may be used (NIST or equivalent quality):Standard_Melting Point, C_Indium 156.410. Procedure10.1 Weigh a sample of 5 to 10 mg.
19、10.1.1 Crimp a flat metal cover against the pan with thesample sandwiched between them to ensure good heat transfer.Take care to ensure that the cover contacts the resin surface.Place sample in the DSC cell.10.1.2 Intimate thermal contact between the sample andclean thermocouple or other temperature
20、 probe is essential forreproducible results.10.1.3 It is recommended to balance the energy flow into orout of the sample. Start the heating cycle when no movementof the recording pen is visible.10.2 Select appropriate x and y axis sensitivities to yield anarea of 30 to 60 cm3(5 to 10 in.2) under the
21、 curing exotherm.10.3 Purge the cell with nitrogen at 60 to 80 mL/min gasflow rate.10.4 Perform and record the thermal cycle by heating thesample at a rate of 10C/min under the nitrogen atmospherefrom ambient to temperature high enough to achieve the entireexothermic curing curve information.10.5 Me
22、asure the corrected temperatures for the desiredpoints on the curves: To, Tp(see Fig. 1),where:To= extrapolated onset temperature, C, andTp= extrapolated peak temperature, C.11. Report11.1 Report the following information:11.1.1 Complete identification and description of the mate-rial tested, includ
23、ing source, and manufacturers code,11.1.2 Description of instrument used for the test,11.1.3 Statement of the mass, dimension, geometry, andmaterials of the sample holder, and the heating rate used,11.1.4 Description of calibration procedure,11.1.5 Identification of the sample atmosphere by gas flow
24、rate, purity, and composition, and11.1.6 Values of the transition measured using the tempera-ture parameters (To, Tp) cited in Fig. 1.12. Precision312.1 This precision data was generated as part of an industryround-robin between eight participating laboratories usingresins from various suppliers sta
25、ndard inventory.12.2 Repeatability (r)the critical difference within whichtwo averages of three observations each, obtained on the samematerial by a single operator using the same instrument, can beexpected to lie 95 % of the time because of random variationwithin a laboratory.3Supporting data are a
26、vailable from ASTM Headquarters. Request RR:D20 1160.FIG. 1 Typical Exothermic Curing CurveD 5028 96 (2003)e1212.2.1 The following criteria were established from tests ofthe resins indicated:IsophthalicPolyester AIsophthalicPolyester B Vinyl EsterOn-setTemperature, C Unfilled: 2.2 2.0 2.6Filled: 2.0
27、 1.6 1.2PeakTemperature, C Unfilled: 1.4 2.9 2.4Filled: 1.3 2.2 1.112.2.2 If the results and average working data on a givensample tested in the same laboratory differ by more than thevalues indicated in 12.2.1, the averages can be consideredsignificantly different.12.3 Reproducibility (R)the critic
28、al difference withinwhich two averages of three observations each, obtained bytwo different operators using different instruments in differentlaboratories, can be expected to lie 95 % of the time because ofvariation within and between laboratories.12.3.1 The following criteria were established for t
29、he resinsindicated:IsophthalicPolyester AIsophthalicPolyester B Vinyl EsterOn-setTemperature, C Unfilled: 3.8 3.4 3.1Filled: 2.6 4.6 2.3PeakTemperature, C Unfilled: 2.8 5.2 3.9Filled: 2.7 3.9 4.312.3.2 If the results and average working data on a givensample test from different laboratories differ b
30、y more than thevalues indicated in 12.3.1, the averages can be consideredsignificantly different.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determi
31、nation of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or wi
32、thdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that y
33、our comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (si
34、ngle or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).TABLE 1 DSC Indium Calibration SummaryParticipantMeasured IndiumMelting PointCorrect
35、ionFactorDSC InstrumentationAshland 157.8 1.2 duPont 9900Cargil 156.3 +0.3 Perkin Elmer DSC 4Dow Chemical 158.8 2.2 duPont 1090Koppers 157.7 1.1 Perkin Elmer DSC-2CMMFG 156.4 +0.2 Omnitherm QC .25OCF 156.0 +0.6 duPont 1090PPG 157.0 0.4 Perkin Elmer 7R. D. Werner 155.6 +1.0 Omnitherm QC .25Indium Sta
36、ndard 156.6 TABLE 2 On-Set Temperature Precision Data Calculations Basedon “Original” Test ValuesMaterialMeanAverage, XOverall RelativeStandardDeviation ofPrecision TestMethod, VR,%RepeatabilityInterval, IrRepeatabilityInterval, IR1 93.07 0.815 2.148 4.3812 92.47 0.751 1.967 4.1713 95.32 0.729 1.967
37、 4.3704 96.35 0.582 1.585 5.6975 102.82 0.878 2.558 4.2226 102.41 0.400 1.160 4.590TABLE 3 Peak Temperature Precision Data Calculations Basedon “Adjusted Test ValuesMaterialMeanAverage, XOverall RelativeStandardDeviation ofPrecision TestMethod, VR,%RepeatabilityInterval, IrRepeatabilityInterval, IR1
38、 92.72 0.818 2.148 3.7842 92.12 0.754 1.967 2.6353 94.97 0.731 1.967 3.3544 96.00 0.584 1.585 4.5875 102.47 0.882 2.558 3.0686 102.06 0.401 1.160 2.270TABLE 4 Peak Temperature Precision Data Calculations Basedon “Original Test ValuesMaterialMeanAverage, XOverall RelativeStandardDeviation ofPrecision
39、 TestMethod, VR,%RepeatabilityInterval, IrRepeatabilityInterval, IR1 105.57 0.454 1.356 3.5432 105.45 0.418 1.248 3.5693 107.85 0.958 2.929 5.5524 107.36 0.725 2.202 4.5055 112.28 0.759 2.408 4.6276 111.62 0.344 1.087 6.011TABLE 5 Peak Temperature Precision Data Calculations Basedon “Adjusted Test V
40、aluesMaterialMeanAverage, XOverall RelativeStandardDeviation ofPrecision TestMethod, VR,%RepeatabilityInterval, IrRepeatabilityInterval, IR1 105.35 0.455 1.356 2.8332 105.10 0.420 1.248 2.7343 107.50 0.961 2.929 5.2074 107.01 0.727 2.202 3.9035 111.93 0.762 2.408 3.9396 111.27 0.345 1.087 4.299D 5028 96 (2003)e13
