1、Designation: D7605 11Standard Test Method forThermoplastic ElastomersMeasurement of Polymer MeltRheological Properties and Congealed Dynamic PropertiesUsing Rotorless Shear Rheometers1This standard is issued under the fixed designation D7605; the number immediately following the designation indicate
2、s the year oforiginal 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 covers the use of a rotorless
3、 oscillatingshear rheometer for the measurement of the flow properties ofpolymer melts and their respective congealed dynamic prop-erties for thermoplastic elastomers (TPE) which includesthermoplastic vulcanizates (TPV). These flow properties andcongealed dynamic properties are related to factory pr
4、ocessingand product performance.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of
5、 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:2D1349 Practice for RubberStandard Temperatures forTestingD3896 Practice for Rubber From Synthetic SourcesSamplingD44
6、83 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustriesD6600 Practice for Evaluating Test Sensitivity for RubberTest Methods3. Terminology3.1 Definitions:3.1.1 complex shear modulus, G*, nratio of peak ampli-tude shear stress to peak ampli
7、tude shear strain; mathemati-cally, G* = (S*/Area)/Strain = (G2+G”2)1/2.3.1.2 complex torque, S*, npeak amplitude torque re-sponse measured by a reaction torque transducer for a sinusoi-dally applied strain; mathematically, S* is computed by S* =(S2+S”2)1/2.3.1.3 congealed thermoplastic, nthermoplas
8、tic polymerthat when cooled from the melt state exhibits a substantialportion of the physical properties of the solid state.3.1.4 dynamic complex viscosity, h*, nratio of the com-plex shear modulus, G* to the oscillation frequency, v,inradians per second.3.1.5 elastic torque, S, npeak amplitude torq
9、ue compo-nent which is in phase with a sinusoidally applied strain.3.1.6 loss angle, d, nphase angle by which the complextorque (S*) leads a sinusoidally applied strain.3.1.7 loss factor, tan d, nratio of loss modulus to storagemodulus, or the ratio of viscous torque to elastic torque;mathematically
10、, tan d = G”/G = S”/S.3.1.8 loss shear modulus, G”, nratio of (viscous) peakamplitude shear stress to peak amplitude shear strain for thetorque component 90 out of phase with a sinusoidally appliedstrain; mathematically, G” = (S”/Area) /Peak Strain.3.1.9 real dynamic viscosity, h, nratio of the loss
11、 shearmodulus, G” to the oscillation frequency, v, in radians persecond.3.1.10 storage shear modulus, G, nratio of (elastic) peakamplitude shear stress to peak amplitude shear strain for thetorque component in phase with a sinusoidally applied strain;mathematically, G = (S/Area) /Peak Strain.3.1.11
12、viscous torque, S”, npeak amplitude torque com-ponent which is 90 out of phase with a sinusoidally appliedstrain.4. Summary of Test Method4.1 A thermoplastic elastomer test specimen is contained ina sealed die cavity which is closed and maintained at anelevated temperature. The cavity is formed by t
13、wo dies, one ofwhich is oscillated through a rotary amplitude. This actionproduces a sinusoidal torsional strain in the test specimenresulting in a sinusoidal torque, which measures a viscoelasticquality of the test specimen. The test specimen can be athermoplastic elastomer such as a thermoplastic
14、vulcanizate1This test method is under the jurisdiction of ASTM Committee D11 on Rubberand is the direct responsibility of Subcommittee D11.12 on Processability Tests.Current edition approved Nov. 1, 2011. Published November 2011. Last previousedition approved in 2010 as D7605 10. DOI: 10.1520/D7605-
15、11.2For 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, 100 Barr Harbor Drive, PO B
16、ox C700, West Conshohocken, PA 19428-2959, United States.(TPV), a styrenic blocked copolymer (SBC), a copolyester, athermoplastic polyurethane, a thermoplastic polyolefin, orother TPE forms.4.2 These viscoelastic measurements can be made based on(1), a frequency sweep in which the frequency is progr
17、ammedto change in steps under constant strain amplitude and tem-perature conditions, (2), a strain sweep in which the strainamplitude is programmed to change in steps under constantfrequency and temperature conditions, or (3), a temperaturesweep in which the temperature is programmed to eitherincrea
18、se or decrease under constant strain amplitude andfrequency conditions. A timed test may also be performed inwhich a sinusoidal strain is applied for a given time periodunder constant strain amplitude, frequency and temperatureconditions.4.2.1 For a frequency sweep test, the instrument is typicallyp
19、rogrammed to increase the frequency with each subsequentstep change. For a strain sweep test, the instrument is usuallyprogrammed to increase the strain amplitude with each subse-quent step change. This is done to minimize the influence ofprior test conditions on subsequent test steps. For temperatu
20、resweeps, the temperature may be programmed either to increaseor decrease with each subsequent step change, depending onthe effects to be studied. The results from increasing frequency,strain amplitude or temperature may not be the same as resultsfrom decreasing these test parameters.4.3 Rheological
21、 properties are measured for each set offrequency, strain and temperature conditions. These propertiescan be measured as combinations of elastic torque S, viscoustorque S”, storage shear modulus, G, loss shear modulus G”,tan d, complex dynamic viscosity h*, and real dynamicviscosity h.5. Significanc
22、e and Use5.1 This test method is used to measure viscoelastic prop-erties of thermoplastic elastomer polymer melts at elevatedtemperatures as well as the dynamic properties of the respec-tive congealed thermoplastic elastomer specimens measured atlower temperatures. These polymer melt viscoelastic p
23、ropertiesmay relate to factory processing behavior while the dynamicproperties of the respective congealed specimen may relate toproduct performance.5.2 This test method may be used for quality control inthermoplastic elastomer manufacturing processes, for qualitycontrol of received shipments of the
24、rmoplastic elastomers, andfor research and development testing of thermoplastic elasto-mers. This method may also be used for evaluating processingand product performance differences resulting from the use ofdifferent compounding materials and process conditions in themaking of these thermoplastic e
25、lastomers.6. Apparatus6.1 Torsion Strain Rotorless Oscillating Rheometer with aSealed CavityThis type of rheometer measures the elastictorque S and viscous torque S” produced by oscillatingangular strain of set amplitude and frequency in a completelyclosed and sealed test cavity.6.2 Sealed Die Cavit
26、yThe sealed die cavity is formed bytwo parallel plate dies. In the measuring position, the two diesare fixed a specified distance apart so that the cavity is closedand sealed (see Fig. 1).6.3 Die GapFor the sealed cavity, no gap should exist atthe edges of the dies. The die gap for these parallel pl
27、ate diesshall be set at 2.58 6 0.1 mm.6.4 Die Closing MechanismFor the sealed cavity, a pneu-matic cylinder or other device shall close the dies and holdthem closed during the test with a force not less than 11 kN(2500 lbf).6.5 Die Oscillating SystemThe die oscillating systemconsists of a direct dri
28、ve motor which imparts a torsionaloscillating movement to the lower die in the cavity plane.6.5.1 The oscillation amplitude can be varied, but a selec-tion of 60.5 arc (7.0 % shear strain) is preferred for frequencysweep tests. The oscillation frequency can be varied between0.03 Hz and 30 Hz.6.6 Tor
29、que Measuring SystemThe torque measuring sys-tem shall measure the resultant shear torque.6.6.1 The torque measuring device shall be rigidly coupledto one of the dies, any deformation between the die and deviceshall be negligibly small, and the device shall generate a signalwhich is proportional to
30、the torque. The total error resultingfrom zero point error, sensitivity error, linearity, and repeat-ability errors shall not exceed 1 % of the selected measuringrange.6.6.2 The torque recording device shall be used to record thesignal from the torque measuring device and shall have aresponse time f
31、or full scale deflection of the torque scale of 1s or less. The torque shall be recorded with an accuracy of60.5 % of the range. Torque recording devices may includeanalog chart recorders, printers, plotters, or computers.FIG. 1 Typical Sealed Torsion Shear Rotorless Rheometer withParallel Plate Die
32、sD7605 1126.6.3 A reference torque device is required to calibrate thetorque measurement system. A torque standard may be used tocalibrate the torque measuring system at the selected angulardisplacement by clamping a steel torsion rod to the oscillatingand the torque measuring dies of the torsion sh
33、ear rheometer(see Fig. 2). The reference values for angular displacement andcorresponding torque shall be established by the manufacturerfor each torque standard.6.7 Reference Test TemperatureThe standard referencetest temperature for thermoplastic elastomer polymer meltsdepend on the melt transitio
34、n temperature of the specific classof TPE being tested. For example, measurements of therheology of the polymer melts of thermoplastic vulcanizatesbased on EPDM rubber and polypropylene are commonlytested at 215C with dynamic property measurements of thecongealed specimen performed at 60C. For styre
35、nic blockedcopolymer thermoplastic elastomers, measurements of thepolymer melts are performed at 200C with dynamic propertymeasurements of the congealed specimen performed at 60C.For thermoplastic vulcanizates based on polyacrylate rubberand nylon, measurements of the polymer melts are performedat 2
36、50C with dynamic property measurements of the con-gealed specimen performed at 60C. Tests may be carried outat other temperatures if required. Temperatures should beselected, when practical, in accordance with Practice D1349.6.8 Temperature Control SystemThis system shall permitthe reference tempera
37、ture to be varied between 40C and250C with an accuracy of 60.3C or better.6.8.1 The dies shall heat to the set point temperature in 1.0min or less from closure of the test cavity. Once the initialheating up time has been completed, die temperature shall notvary by more than 60.3C for the remainder o
38、f a test at a settemperature. When the set temperature is changed in a pro-grammed temperature sweep, rheological measurementsshould not be recorded until the die temperatures are within60.3C of the new set temperature for at least 30 s.6.8.2 Temperature distribution within the test piece shall beas
39、 uniform as possible. Within the deformation zone, a toler-ance of 61C of the average test piece temperature shall not beexceeded.6.8.3 Die temperature is determined by a temperature sensorused for control. The difference between the die temperatureand the average test piece temperature shall not be
40、 more than2C. Temperature measurement accuracy shall be 60.3C forthe die temperature sensor.7. Test Specimen7.1 A test specimen taken from a sample shall be carefullycut to within 60.02 g of the target mass, which is equal to massrepresenting 105 % of the fill factor for the die cavity. Themass for
41、100 % fill factor can be empirically determined bytesting a specimen from the sample that has a mass greater thanthe 100 % fill factor. After completing this test, the testspecimen is carefully removed from the cavity, the film iscarefully removed, and the flash is carefully cut away from thisspecim
42、en. The sample is weighed to the nearest one hundredthof a gram. This weight is then multiplied by 1.05 to determinethe target mass for all future tests for this thermoplasticelastomer series of materials. Once a target mass for a desiredTPE series (all with the same specific gravity) has beenestabl
43、ished, all future specimen masses for this family ofthermoplastic elastomers should be controlled to within60.02 g for best repeatability. The initial test specimen shapeshould fit well within the perimeter of the test cavity.7.2 Thermoplastic Elastomer SpecimensCondition thespecimen obtained in acc
44、ordance with Practice D1349 until ithas reached room temperature (23 6 2.0C (73.4 6 3.6F)throughout. The thermoplastic elastomer test specimen shouldbe tested as received, that is unmassed (not milled).7.2.1 Thermoplastic elastomer specimens in a sealed cavityoscillating rheometer must be pre-condit
45、ioned in the instru-ment before rheological measurements are made to improvetest repeatability. A programmed pre-conditioning step shallconsist of oscillating the specimen at 0.5 Hz, 62.8 % strain, atthe predetermined polymer melt temperature for the timeinterval of 0.5 min.FIG. 2 Typical Torque Sta
46、ndard Calibration Device for TorsionShear CuremetersD7605 1138. Procedure8.1 Select the frequency, strain, temperature and time for theconditioning step as listed for thermoplastic elastomer melt inTable 1.8.2 Select the frequency steps and the strain and tempera-ture conditions for the frequency sw
47、eep for thermoplasticelastomer melt as listed in Table 1.8.3 Select the strain steps and the frequency and tempera-ture conditions for the strain sweep for the thermoplasticelastomer melt in Table 1.8.4 Select the strain steps and frequency and temperatureconditions for the two “back to back” strain
48、 sweep for thecongealed thermoplastic elastomer in Table 1.8.5 Program a test configuration which incorporates allthese conditions and store on the instrument computer operat-ing system.8.6 Quantitatively weigh and cut a specimen from thethermoplastic elastomer sample to within 60.02 g of the target
49、mass for the thermoplastic elastomer, which is based on themass of the subject material at 105 % cavity fill factor(reference 7.1).8.7 Load the test configuration to run the test.8.8 Enter specimen identification.8.9 Wait until both dies are at the initial test temperature.Open the test cavity and visually check both upper and lowerdies for cleanliness. Clean the dies if necessary. Place a sheetof 23-micron thick film over the lower die (use nylon 6,6 filmif the temperature is below 225C). Place the test specimen onthe
