1、Designation: D5225 17Standard 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, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.For specific hazard statements, see Section 8.NOTE 1There is no known ISO equivalent to this standard.1.6 This international standard w
8、as developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referen
9、ced Documents2.1 ASTM Standards:2D1243 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 MethodE2935 Practice for Conducting Equivalence
10、Testing inLaboratory Applications3. 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 viscosity number.3.1.2 intrinsic viscositylimit of the reduced and inherentvisc
11、osities 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 viscositythe ratio of the specific viscosity tothe concentration. Reduced viscosity
12、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 of the solvent.3.1.5 specific viscositythe relative viscosity minus one.3.1
13、.6 viscosity constant, Kbaseline reading when solventis present in both capillaries.4. Summary of Test Method4.1 Differential 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
14、.Current edition approved Dec. 1, 2017. Published January 2018. Originallyapproved in 1992. Last previous edition approved in 2014 as D5225 - 14. DOI:10.1520/D5225-17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual
15、Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis internation
16、al standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee
17、.112 4.1.1 The viscosity measurement with the differential vis-cometer is based on a 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. Sol
18、u-tion is loaded into the sample reservoir A and then injectedonstream by means of the switching valve SA. The differentialpressure begins 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
19、 strip chartrecorder or computer, providing a baseline where P ismeasured. The equation relating P to specific viscosity is:sp54PPi2 2P(1)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 ca
20、pillaries 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 pressures P2and P1is proportional to theratio o
21、f 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, is 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 throu
22、gh 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 differential pressure P2willincrease due to the high
23、er 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 the viscosity of thesolvent is known.sample! 5 RVsol
24、vent! (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, or Relative Viscometer, DiluteSolution Viscosity (DSV) System,6.2 Glass Vial, 25 m
25、L,6.3 Screw Type Cap, open top, size 24-400,6.4 Septa, aluminum foil (household grade) or acceptablesubstitute,6.5 Balance, capable of weighting to 0.0001 gms,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.
26、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 used on a first-infirst-out basis.NOTE 1R1,R2,R3,R4= Matched SS Capillary TubingA, B = Solution Holdup ReservoirsSA,
27、SB= Switching ValvePi= Solvent Inlet Pressure TransducerP = Differential Pressure TransducerFIG. 1 Differential ViscometerFIG. 2 Relative ViscometerD5225 17212 8.3 Stored solvents prone to develop peroxides should betested on a regular schedule for peroxide development.9. Procedure9.1 Set viscometer
28、 oven temperature to maintain solution ofthe test polymer.9.2 Adjust inlet solvent pressure to obtain the pressuredifferential and test time desired.9.3 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.
29、Cover vialwith an aluminum septa or equivalent and cap.9.5 Program the instrument and processing parameters forthe desired viscosity calculations.9.6 Initiate viscosity acquisition.9.7 After the last sample has been run, flush the sample linesand sample holder with fresh solvent.9.8 Turn off viscome
30、ter, 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 1 is the precision data for eight polymers whichwere measured using this test method. Each result is an averageof three or more independent tests ma
31、de by a single laboratory.(WarningThe following explanations of Irand IR(11.2 thru11.2.3) are only intended to present a meaningful way ofconsidering the approximate precision of this test method. Thedata in Table 1 should not be rigorously applied to acceptanceor rejection of material, as those dat
32、a are specific to the onelaboratory and may not be representative of other lots,conditions, materials, or laboratories.)NOTE 2Users of this test method should apply the principles outlinedin Practice E691 to generate data specific to their laboratory and materials,or between specific laboratories. T
33、he principles of 11.2.1 through 11.2.3would 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 RepeatabilityThe value below which the absolutedifference between two individual test results obtained un
34、derrepeatability conditions is likely to be expected to occur with aprobability of approximately 0.95 (95 %).11.2.2 ReproducibilityThe value below which the abso-lute difference between two test results obtained under repro-ducibility conditions is likely to be expected to occur with aprobability of
35、 approximately 0.95 (95 %).11.2.3 Equivalence testing on numerical data from twosources shall be conducted in accordance Practice E2935 orany known method for judging the equivalence of two means.NOTE 3Example: A t-test.11.3 Bias is systematic error which contributes to thedifference between a test
36、result 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 VISCOMET
37、ERTABLE 1 Precision Data for the Solution Viscosities of Various PolymersAPolymer Solvent ConcentrationRelative Viscosity Inherent Viscosity 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
38、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 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 m
39、Lresin “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 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
40、.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 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 1.03
41、9 0.001 0.003AThis data was generated by a Viscotek Model 100-01 viscometer, Malvern Instruments, 117 Flanders Rd., Westborough, MA.D5225 17312 A1.1 Assume R3is filled with solution and R1,R2,R4arefilled with solvent. The measured quantities are the inletpressure Piand the differential pressure P.PP
42、i5P12 P2Pi(A1.1)P1= pressure drop across R3andP2= pressure drop across R4.A1.2 R2and R4have equal flow resistance, so Pi=2P2,giving the following: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, = vi
43、scosity 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 side 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 spec
44、ific 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 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.
45、SUMMARY OF CHANGESCommittee D20 has identified the location of selected changes to this standard since the last issue (D5225 - 14)that may impact the use of this standard. (December 1, 2017)(1) Revised 6.5 to clarify accuracy of balance being used.(2) Subsections 11.2.1, 11.2.2, and 11.2.3: Removed
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