1、Designation: D5225 14Standard Test Method forMeasuring Solution Viscosity of Polymers with a DifferentialViscometer1This standard is issued under the fixed designation D5225; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year
2、 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. Scope*1.1 This test method covers the determination of the solu-tion viscosity of polymers using a differential or the modi
3、fieddifferential 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 viscosity number), i
4、nherent 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 solution viscosity values
5、 are comparable with thoseobtained using a glass capillary of Test Method D2857. 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 the solvent run in th
6、e same capillary at the sametemperature.1.4 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the
7、 user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For specific hazardstatements, see Section 8.NOTE 1There is no known ISO equivalent to this standard.2. Referenced Documents2.1 ASTM Standards:2D1243
8、Test Method for Dilute Solution Viscosity of VinylChloride PolymersD2857 Practice for Dilute Solution Viscosity of PolymersE691 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 lo
9、garithmof the relative viscosity to the concentration. The IUPAC termfor inherent viscosity is logarithmic viscosity 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 t
10、oincrease viscosity. The IUPAC term for intrinsic viscosity islimiting viscosity number.3.1.3 reduced viscositythe 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
11、viscosity is viscositynumber.3.1.4 relative viscositythe ratio of the polymer solutionpressure to the pressure 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 D
12、ifferential Viscometer (Fig. 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 May 1, 2014. Published June 2014. Originallyapproved in 1992. Last previous edition appr
13、oved in 2009 as D5225 - 09. DOI:10.1520/D5225-14.2For 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.*A Summary o
14、f Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14.1.1 The viscosity measurement with the differential vis-cometer is based on a fluid analog of the Wheatstone Bridge.Pure solvent at
15、 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 the switching valve SA. The differentialpressure begins
16、 to rise until it reaches a steady state value ofP proportional to the specific viscosity of the solution. Thedifferential pressure is monitored continuously on a strip chartrecorder or computer, providing a baseline where P ismeasured. The equation relating P to specific viscosity is:sp54PPi2 2P(1)
17、4.1.2 Derivation of the equation is in Annex A1.4.2 Modified Differential Viscometer (Fig. 2):4.2.1 The modified differential viscometer has two stainlesssteel capillaries connected in series with a sample loading/injection valve before the second capillary. Two differentialpressure transducers, P1a
18、nd P2, are connected in parallelacross the capillaries. A pump continuously supplies solventflow. The ratio of the pressures P2and P1is proportional to theratio of the viscosities of the fluid in capillary 2 to that incapillary 1.P2P15 K215 KRelative Viscosity (2)4.2.1.1 K, the viscosity constant, i
19、s obtained from thebaseline reading when solvent is present in both capillaries, so2/1is unity.4.2.1.2 With the 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 val
20、ve is switched to theINJECT position, solvent flowing from capillary 1 pushes thesample into capillary 2. The differential 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 Visco
21、sity 5P2KP1(3)4.2.1.3 Absolute viscosity of the sample may be calculatedfrom relative viscosity, RV, assuming the viscosity of thesolvent is known.sample! 5 RVsolvent! (4)5. Significance and Use5.1 Solution viscosity values for polymers are related to theaverage molecular size of that portion of the
22、 polymer whichdissolves in the solvent.6. Apparatus6.1 Differential Viscometer, or Relative Viscometer, DiluteSolution Viscosity (DSV) System,6.2 Glass Vial, 25 mL,6.3 Screw Type Cap, open top, size 24-400,6.4 Septa, aluminum foil (household grade) or acceptablesubstitute,6.5 Balance, accurate to 1.
23、0 6 0.1 mg,6.6 Filter Funnel, and6.7 Filter medium, coarse filter paper or metal screen of 140mesh 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
24、 Solvents are to be dated and to be used on a first-infirst-out basis.8.3 Stored solvents prone to develop peroxides should betested on a regular schedule for peroxide development.NOTE 1R1,R2,R3,R4= Matched SS Capillary TubingA, B = Solution Holdup ReservoirsSA,SB= Switching ValvePi= Solvent Inlet P
25、ressure TransducerP = Differential Pressure TransducerFIG. 1 Differential ViscometerFIG. 2 Relative ViscometerD5225 1429. Procedure9.1 Set viscometer oven temperature to maintain solution ofthe test polymer.9.2 Adjust inlet solvent pressure to obtain the pressuredifferential and test time desired.9.
26、3 Prepare polymer solution. Weigh the polymer accuratelyto the nearest 1.0 6 0.1 mg and record weight.9.4 Filter polymer solution into a 25-mL vial. Cover vialwith an aluminum septa or equivalent and cap.9.5 Program the instrument and processing parameters forthe desired viscosity calculations.9.6 I
27、nitiate viscosity acquisition.9.7 After the last sample has been run, flush the sample linesand sample holder with fresh solvent.9.8 Turn off viscometer, leaving the sample lines filled withsolvent.10. Report10.1 Report viscosity data for each sample in the run queue.11. Precision and Bias11.1 Table
28、 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 single laboratory.(WarningThe following explanations of Irand IR(11.2 thru11.2.3) are only intended to present a meaningful way ofconsidering t
29、he approximate precision of this test method. Thedata in Table 1 should not be rigorously applied to acceptanceor rejection of material, as those data are specific to the onelaboratory and may not be representative of other lots,conditions, materials, or laboratories.)NOTE 2Users of this test method
30、 should apply the principles outlinedin Practice E691 to generate data specific to their laboratory and materials,or between specific laboratories. The principles of 11.2.1 through 11.2.3would then be valid for such data.11.2 Concept of IrandIRIf Srand SRhave been calculatedfrom a large enough body
31、of data, then the following applies:11.2.1 RepeatabilityComparing two test results for thesame material, obtained by the same operator using the sameequipment 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 Re
32、producibilityComparing two test results for thesame material, obtained by different operators using differentequipment on different days, the two test 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 in accordance with 11.2
33、.1 and 11.2.2would have an approximate 95 % (0.95) probability of beingcorrect.11.3 Bias is systematic error which contributes to thedifference between a test result and a true (or reference) value.There are no recognized standards on which to base an estimateof bias for this test method.12. Keyword
34、s12.1 differential solution viscosity; differential viscometer;polymer solution viscosityANNEX(Mandatory Information)A1. CALCULATIONS FOR DIFFERENTIAL VISCOMETERTABLE 1 Precision Data for the Solution Viscosities of Various PolymersAPolymer Solvent ConcentrationRelative Viscosity Inherent Viscosity
35、Intrinsic 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 0.04
36、4 0.125 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” 1.25
37、4 0.008 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.
38、1 g/100 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 0.003AThis data was generated by a Viscotek Model 100-01 viscometer, Malvern Instruments, 117 Flanders Rd., Westborough, MA.D5225 143
39、A1.1 Assume R3is filled with solution and R1,R2,R4arefilled with solvent. The measured quantities are the inletpressure Piand the differential pressure P.PPi5P12 P2Pi(A1.1)P1= pressure drop across R3andP2= pressure drop across R4.A1.2 R2and R4have equal flow resistance, so Pi=2P2,giving the followin
40、g:PPi5 1/2FP1P22 1G(A1.2)A1.3 Applying Poiseuelles Law to capillaries R3and R4:P1P25Q1oQ2(A1.3)Q1= flow rate through R1,R3,Q2= flow rate through R2,R4, = viscosity of solution, ando= viscosity of solvent.A1.4 The ratio of flow rates Q1/Q2is equal to the inverseratio of the total resistance in each s
41、ide of the bridge.Q1Q25o1oo152oo1(A1.4)A1.5 Combining Eqs (A1.2), (A1.3), and (A1.4), we findthe following:PPi5 1/2F 2 o1oG(A1.5)A1.6 The definition of specific viscosity of a solution is asfollows:sp5 2 oo(A1.6)A1.7 Substituting into Eq (A1.5) yields the following:PPi5sp2sp14(A1.7)A1.7.1 Rearrange
42、to give the following:sp54PPi2 2P(A1.8)A1.8 Assumptions in Derivation:A1.8.1 Capillaries have equal flow resistance.A1.8.2 Capillaries obey Poiseuelles Law.SUMMARY OF CHANGESCommittee D20 has identified the location of selected changes to this standard since the last issue (D5225 - 09)that may impac
43、t the use of this standard. (May 1, 2014)(1) Removed specific equipment models from 6.1.(2) Removed old subsections 6.2, 6.3, 6.4, 6.5, 6.6, and 6.7.(3) Removed old subsections 9.1, 9.2, 9.7, 9.8, and 9.10.(4) Revised 6.5 and 9.3 to replace 0.0001 g with 1.0 6 0.1 mg.(5) Moved and reworded supplier
44、footnote to table footnote inTable 1.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 patent rights, and the ri
45、skof 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 either for revision of th
46、is 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 hearing you shouldmake
47、 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D5225 144
