1、Designation: D 5225 98 (Reapproved 2003)Standard Test Method forMeasuring Solution Viscosity of Polymers with a DifferentialViscometer1This standard is issued under the fixed designation D 5225; the number immediately following the designation indicates the year oforiginal adoption or, in the case o
2、f 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. Scope*1.1 This test method covers the determination of the solu-tion viscosity of polymers using a dif
3、ferential or the modifieddifferential viscometer. It is applicable to all polymers thatdissolve completely without chemical reaction or degradationto form solutions that are stable with time and temperature.Results of the test are usually expressed as specific viscosity,intrinsic viscosity (limiting
4、 viscosity number), inherent viscos-ity (logarithmic viscosity number), or relative viscosity (vis-cosity ratio).1.2 Since there is more than one type of viscometer avail-able to measure a differential pressure, follow the manufactur-ers directions applicable to the equipment being used.1.3 The solu
5、tion viscosity values are comparable with thoseobtained using a glass capillary of Test Method D 2857. Thistest method differs from the glass capillary in that the solventand the solution are compared at the same time that a test isrun. With a glass capillary, each solution must be referencedback to
6、 the solvent run in the same capillary at the sametemperature.1.4 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 safety and health practices and determine the applica
7、-bility of regulatory limitations prior to use. For specific hazardstatements, see Section 8.NOTE 1There is no ISO equivalent method.2. Referenced Documents2.1 ASTM Standards:2D 1243 Test Method for Dilute Solution Viscosity of VinylChloride PolymersD 2857 Test Method for Dilute Solution Viscosity o
8、f Poly-mersE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Terminology3.1 Definitions:3.1.1 inherent viscositythe ratio of the natural logarithmof the relative viscosity to the concentration. The IUPAC termfor inherent viscosity is logarithmic visc
9、osity number.3.1.2 intrinsic viscositylimit of the reduced and inherentviscosities as the concentration of the polymeric solute ap-proaches zero and represents the capacity of the polymer toincrease viscosity. The IUPAC term for intrinsic viscosity islimiting viscosity number.3.1.3 reduced viscosity
10、the ratio of the specific viscosity tothe concentration. Reduced viscosity is a measure of thespecific capacity of the polymer to increase the relativeviscosity. The IUPAC term for reduced viscosity is viscositynumber.3.1.4 relative viscositythe ratio of the polymer solutionpressure to the pressure
11、of the solvent.3.1.5 specific viscositythe relative viscosity minus one.3.1.6 viscosity constant, Kbaseline reading when solventis present in both capillaries.4. Summary of Test Method4.1 Differential Viscometer (Fig. 1):4.1.1 The viscosity measurement with the differential vis-cometer is based on a
12、 fluid analog of the Wheatstone Bridge.Pure solvent at constant inlet pressure Pienters a balancedcapillary network and flows through, producing a zero orbaseline pressure on the differential pressure transducer. Solu-tion is loaded into the sample reservoir A and then injectedonstream by means of t
13、he switching valve SA. The differentialpressure begins to rise until it reaches a steady state value ofDP proportional to the specific viscosity of the solution. Thedifferential pressure is monitored continuously on a strip chartrecorder or computer, providing a baseline where DP ismeasured. The equ
14、ation relating DP to specific viscosity is:hsp54DPPi2 2DP(1)1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.70 on Analytical Methods.Current edition approved November 1, 2003. Published December 2003.Originally approve
15、d in 1992. Last previous edition approved in 1998 as D 5225 -98.2For 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 websi
16、te.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.1.2 Derivation of the equation is in Annex A1.4.2 Modified Differential Viscometer (Fig. 2):4.2.1 The modified dif
17、ferential viscometer has two stainlesssteel capillaries connected in series with a sample loading/injection valve before the second capillary. Two differentialpressure transducers, P1and P2, are connected in parallelacross the capillaries. A pump continuously supplies solventflow. The ratio of the p
18、ressures P2and P1is proportional to theratio of the viscosities of the fluid in capillary 2 to that incapillary 1.P2P15 Kh2h15 K Relative Viscosity (2)4.2.1.1 K, the viscosity constant, is obtained from thebaseline reading when solvent is present in both capillaries, soh2/h1is unity.4.2.1.2 With the
19、 valve in LOAD position, the sample isflushed through the sample loop by the syringe pump. Abaseline reading is established and recorded by the computerdata acquisition system. When the valve is switched to theINJECT position, solvent flowing from capillary 1 pushes thesample into capillary 2. The d
20、ifferential pressure P2willincrease due to the higher viscosity of the sample solution. Thesteady state value of P2/P1then yields the value of relativeviscosity of the sample.Relative Viscosity 5P2KP1(3)4.2.1.3 Absolute viscosity of the sample may be calculatedfrom relative viscosity, RV, assuming t
21、he viscosity of thesolvent is known.hsample! 5 RV hsolvent! (4)5. Significance and Use5.1 Solution viscosity values for polymers are related to theaverage molecular size of that portion of the polymer whichdissolves in the solvent.6. Apparatus6.1 Differential Viscometer, Viscotek Model 100-01 viscom
22、-eter,3or equivalent; or Relative Viscometer, Viscotek ModelY-500,3or equivalent,6.2 Kit for conversion to GPC Detector,6.3 Computer, IBM PC or equivalent, with 640K RAM,coprocessor, and graphics adapter,6.4 PC Based Software, for data acquisition and processing.6.5 PC interface with Data Translatio
23、n Board and externalsignal box and cable,6.6 Printer,6.7 Autosampler, Viscotek #100-06, or equivalent,6.8 Glass Vial,25mL,6.9 Screw Type Cap, open top, size 24-400,6.10 Septa, aluminum foil (household grade) or acceptablesubstitute,6.11 Balance, accurate to 0.0001 grams,6.12 Filter Funnel, and6.13 F
24、ilter medium, coarse filter paper or metal screen of140 mesh or finer.7. Reagents and Materials7.1 Polymer Sample.7.2 Solvent.7.3 Compressed Gas Cylinder of nitrogen or helium.8. Hazards8.1 Flammable solvents are to be used in a hood or a wellventilated area.8.2 Solvents are to be dated and to be us
25、ed on a first-infirst-out basis.8.3 Stored solvents prone to develop peroxides should betested on a regular schedule for peroxide development.9. Procedure9.1 Make solvent and gas cylinder connections as requiredfor the equipment.3Available from Viscotek Corporation, 13600 West Hardy Road, Houston, T
26、X77060.NOTER1,R2,R3,R4= Matched SS Capillary TubingA, B = Solution Holdup ReservoirsSA,SB= Switching ValvePi= Solvent Inlet Pressure TransducerDP = Differential Pressure TransducerFIG. 1 Differential ViscometerFIG. 2 Schematic of Relative ViscometerD 5225 98 (2003)29.2 Connect computer cables to aut
27、osampler, viscometer,PC interface board and external signal box, monitor, andprinter.9.3 Set viscometer oven temperature to maintain solution ofthe test polymer.9.4 Adjust inlet solvent pressure to obtain the pressuredifferential and test time desired.9.5 Prepare polymer solution. Weigh the polymer
28、accuratelyto the nearest 0.0001 g and record weight.9.6 Filter polymer solution into a 25-mL vial. Cover vialwith an aluminum septa or equivalent and cap.9.7 Position vial into autosampler.9.8 Activate the computer and printer.9.9 Program the instrument and processing parameters forthe desired visco
29、sity calculations.9.10 Enter the data for the sample solutions positioned inthe autosampler into the computer acquisition program queue.9.11 Initiate viscosity acquisition.9.12 After the last sample has been run, flush the samplelines and sample holder with fresh solvent.9.13 Turn off viscometer, le
30、aving the sample lines filledwith solvent.10. Report10.1 Report viscosity data for each sample in the run queue.11. Precision and Bias11.1 Table 1 is the precision data for eight polymers whichwere measured using this test method. Each result is an averageof three or more independent tests made by a
31、 single laboratory.NOTE 2Caution: The following explanations of Irand IR(11.2 thru11.2.3) are only intended to present a meaningful way of considering theapproximate precision of this test method. The data in Table 1 should notbe rigorously applied to acceptance or rejection of material, as those da
32、taare specific to the one laboratory and may not be representative of otherlots, conditions, materials, or laboratories.NOTE 3Users of this test method should apply the principles outlinedin Practice E 691 to generate data specific to their laboratory andmaterials, or between specific laboratories.
33、The principles of 11.2.1through 11.2.3 would then be valid for such data.11.2 Concept of Irand IRIf Srand SRhave been calculatedfrom a large enough body of data, then the following applies:11.2.1 RepeatabilityComparing two test results for thesame material, obtained by the same operator using the sa
34、meequipment on the same day, the two test results should bejudged not equivalent if they differ by more than Irfor thatmaterial.Ir5 2.83 3 Sr(5)11.2.2 Reproducibilitycomparing two test results for thesame material, obtained by different operators using differentequipment on different days, the two t
35、est results should bejudged not equivalent if they differ by more than the IRfor thatmaterial.IR5 2.83 3 SR(6)11.2.3 Any judgment per 11.2.1 and 11.2.2 would have anapproximate 95 % (0.95) probability of being correct.11.3 Bias is systematic error which contributes to thedifference between a test re
36、sult and a true (or reference) value.There are no recognized standards on which to base an estimateof bias for this test method.12. Keywords12.1 differential solution viscosity; differential viscometer;polymer solution viscosityANNEX(Mandatory Information)A1. CALCULATIONS FOR DIFFERENTIAL VISCOMETER
37、A1.1 Assume R3is filled with solution and R1,R2,R4arefilled with solvent. The measured quantities are the inletpressure Piand the differential pressure DP.TABLE 1 Precision Data for the Solution Viscosities of Various PolymersPolymer Solvent ConcentrationRelative Viscosity Inherent Viscosity Intrins
38、ic ViscosityMean SrIrMean SrIrMean SrIrpoly(1-butene) decalin 0.1 g/100 mL 1.207 0.007 0.020 1.853 0.054 0.153 1.892 0.057 0.161polycarbonate methylene chloride 0.5 g/100 mL . . . . . . . . . 0.460 0.003 0.0085 0.472 0.003 0.0085poly(ethylene) decalin 0.1 g/100 mL 1.124 0.005 0.014 1.166 0.044 0.125
39、 1.181 0.045 0.127poly(4-methyl-1-pentene) decalin 0.1 g/100 mL 1.280 0.007 0.018 2.294 0.051 0.144 2.361 0.054 0.153poly(propylene) decalin 0.1 g/100 mLresin “A” 1.170 0.005 0.014 1.557 0.042 0.112 1.585 0.044 0.125resin “B” 1.182 0.005 0.014 1.664 0.045 0.127 1.695 0.047 0.133resin “C” 1.254 0.008
40、 0.021 2.240 0.060 0.170 2.299 0.063 0.178resin “D” 1.289 0.007 0.018 2.516 0.052 0.147 2.593 0.056 0.158resin “E” 1.415 0.003 0.008 3.452 0.021 0.059 3.604 0.022 0.062poly(phenylene oxide) chloroform 0.1 g/100 mL 1.053 0.0005 0.001 0.500 0.003 0.0085 0.503 0.003 0.009poly(styrene) toluene 0.1 g/100
41、 mL 1.095 0.0006 0.002 0.726 0.0015 0.004 0.737 0.0025 0.007poly(vinyl chloride) tetrahydrofuran 0.2 g/100 mL 1.225 0.0003 0.0009 1.015 0.001 0.003 1.039 0.001 0.003D 5225 98 (2003)3DPPi5P12 P2Pi(A1.1)P1= pressure drop across R3andP2= pressure drop across R4.A1.2 R2and R4have equal flow resistance,
42、so Pi=2P2,giving the following:DPPi5 1/2FP1P22 1G(A1.2)A1.3 Applying Poiseuelles Law to capillaries R3and R4:P1P25hQ1hoQ2(A1.3)Q1= flow rate through R1,R3,Q2= flow rate through R2,R4,h = viscosity of solution, andho= viscosity of solvent.A1.4 The ratio of flow rates Q1/Q2is equal to the inverseratio
43、 of the total resistance in each side of the bridge.Q1Q25ho1hoho1h52hoho1h(A1.4)A1.5 Combining Eqs (A1.2), (A1.3), and (A1.4), we findthe following:DPPi5 1/2Fh2hoh1hoG(A1.5)A1.6 The definition of specific viscosity of a solution is asfollows:hsp5h2hoho(A1.6)A1.7 Substituting into Eq (A1.5) yields th
44、e following:DPPi5hsp2hsp1 4(A1.7)A1.7.1 Rearrange to give the following:hsp54DPPi2 2DP(A1.8)A1.8 Assumptions in Derivation:A1.8.1 Capillaries have equal flow resistance.A1.8.2 Capillaries obey Poiseuelles Law.SUMMARY OF CHANGESThis section identifies the location of selected changes to this test met
45、hod. For the convenience of the user,Committee D20 has highlighted those changes that may impact the use of this test method. This section also mayinclude descriptions of the changes or reasons for the changes, or both.D 5225 98:(1) An ISO equivalency statement (Note 1) was added andsource reference
46、 (Footnote 5) was updated as part of thefive-year review.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 determination of the validity of any such paten
47、t 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 withdrawn. Your comments are invited eithe
48、r 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 your comments have not received a fair he
49、aring 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 (single 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).D 5225 98 (2003)4
