1、Designation: D5225 14D5225 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,
2、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. Scope*1.1 This test method covers the determination of the solution viscosity of polymers using a differential or t
3、he modifieddifferential viscometer. It is applicable to all polymers that dissolve completely without chemical reaction or degradation to formsolutions that are stable with time and temperature. Results of the test are usually expressed as specific viscosity, intrinsic viscosity(limiting viscosity n
4、umber), inherent viscosity (logarithmic viscosity number), or relative viscosity (viscosity ratio).1.2 Since there is more than one type of viscometer available to measure a differential pressure, follow the manufacturersdirections applicable to the equipment being used.1.3 The solution viscosity va
5、lues are comparable with those obtained using a glass capillary of Test Method D2857. This testmethod differs from the glass capillary in that the solvent and the solution are compared at the same time that a test is run. Witha glass capillary, each solution must be referenced back to the solvent ru
6、n in the same capillary at the same temperature.1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsib
7、ilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use. For specific hazard statements, see Section 8.NOTE 1There is no known ISO equivalent to this standard.1.5 This standard does not purport to ad
8、dress all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability ofregulatory limitations prior to use. For specific hazard statements, see Sect
9、ion 8.NOTE 1There is no known ISO equivalent to this standard.1.6 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations
10、issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D1243 Test Method for Dilute Solution Viscosity of Vinyl Chloride PolymersD2857 Practice for Dilute Solution Viscosity of PolymersE691 Practice for Conducting an Interlaborato
11、ry Study to Determine the Precision of a Test MethodE2935 Practice for Conducting Equivalence Testing in Laboratory Applications3. Terminology3.1 Definitions:3.1.1 inherent viscositythe ratio of the natural logarithm of the relative viscosity to the concentration. The IUPAC term forinherent viscosit
12、y is logarithmic viscosity number.1 This test method is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.70 on Analytical Methods.Current edition approved May 1, 2014Dec. 1, 2017. Published June 2014January 2018. Originally approved in 199
13、2. Last previous edition approved in 20092014 asD5225 - 09.D5225 - 14. DOI: 10.1520/D5225-14.10.1520/D5225-17.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the sta
14、ndards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurat
15、ely, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Dr
16、ive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.2 intrinsic viscositylimit of the reduced and inherent viscosities as the concentration of the polymeric solute approacheszero and represents the capacity of the polymer to increase viscosity. The IUPAC term for intrinsic viscosit
17、y is limiting viscositynumber.3.1.3 reduced viscositythe ratio of the specific viscosity to the concentration. Reduced viscosity is a measure of the specificcapacity of the polymer to increase the relative viscosity. The IUPAC term for reduced viscosity is viscosity number.3.1.4 relative viscosityth
18、e ratio of the polymer solution pressure to the pressure of the solvent.3.1.5 specific viscositythe relative viscosity minus one.3.1.6 viscosity constant, Kbaseline reading when solvent is present in both capillaries.4. Summary of Test Method4.1 Differential Viscometer (Fig. 1):4.1.1 The viscosity m
19、easurement with the differential viscometer is based on a fluid analog of the Wheatstone Bridge. Puresolvent at constant inlet pressure Pi enters a balanced capillary network and flows through, producing a zero or baseline pressureon the differential pressure transducer. Solution is loaded into the
20、sample reservoir A and then injected onstream by means of theswitching valve SA. The differential pressure begins to rise until it reaches a steady state value of P proportional to the specificviscosity of the solution. The differential pressure is monitored continuously on a strip chart recorder or
21、 computer, providing abaseline where P is measured. The equation relating P to specific viscosity is:sp5 4PPi 2 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 stainless steel capillaries connected
22、in series with a sample loading/injectionvalve before the second capillary. Two differential pressure transducers, P1 and P2, are connected in parallel across the capillaries.A pump continuously supplies solvent flow. The ratio of the pressures P2 and P1 is proportional to the ratio of the viscositi
23、es ofthe fluid in capillary 2 to that in capillary 1.P2P1 5K21 5KRelative Viscosity (2)4.2.1.1 K, the viscosity constant, is obtained from the baseline reading when solvent is present in both capillaries, so 2/1 isunity.NOTE 1R1, R2, R3, R4 = Matched SS Capillary TubingA, B = Solution Holdup Reservo
24、irsSA, SB = Switching ValvePi = Solvent Inlet Pressure TransducerP = Differential Pressure TransducerFIG. 1 Differential ViscometerD5225 1724.2.1.2 With the valve in LOAD position, the sample is flushed through the sample loop by the syringe pump.Abaseline readingis established and recorded by the c
25、omputer data acquisition system. When the valve is switched to the INJECT position, solventflowing from capillary 1 pushes the sample into capillary 2. The differential pressure P2 will increase due to the higher viscosityof the sample solution. The steady state value of P2/P1 then yields the value
26、of relative viscosity of the sample.Relative Viscosity5 P2KP1(3)4.2.1.3 Absolute viscosity of the sample may be calculated from relative viscosity, RV, assuming the viscosity of the solventis known.sample!5RVsolvent! (4)5. Significance and Use5.1 Solution viscosity values for polymers are related to
27、 the average molecular size of that portion of the polymer whichdissolves in the solvent.6. Apparatus6.1 Differential Viscometer, or Relative Viscometer, Dilute Solution 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)
28、or acceptable substitute,6.5 Balance, accurate to 1.0 6 0.1 mg,capable of weighting to 0.0001 gms,6.6 Filter Funnel, and6.7 Filter medium, coarse filter paper or metal screen of 140 mesh or finer.7. Reagents and Materials7.1 Polymer Sample.7.2 Solvent.7.3 Compressed Gas Cylinder of nitrogen or heliu
29、m.8. Hazards8.1 Flammable solvents are to be used in a hood or a well ventilated area.8.2 Solvents are to be dated and to be used on a first-in first-out basis.8.3 Stored solvents prone to develop peroxides should be tested on a regular schedule for peroxide development.9. Procedure9.1 Set viscomete
30、r oven temperature to maintain solution of the test polymer.9.2 Adjust inlet solvent pressure to obtain the pressure differential and test time desired.9.3 Prepare polymer solution. Weigh the polymer accurately to the nearest 1.0 6 0.1 mg and record weight.9.4 Filter polymer solution into a 25-mL vi
31、al. Cover vial with an aluminum septa or equivalent and cap.9.5 Program the instrument and processing parameters for the desired viscosity calculations.FIG. 2 Relative ViscometerD5225 1739.6 Initiate viscosity acquisition.9.7 After the last sample has been run, flush the sample lines and sample hold
32、er with fresh solvent.9.8 Turn off viscometer, leaving the sample lines filled with 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 which were measured using this test method. Each result is an
33、average ofthree or more independent tests made by a single laboratory. (WarningThe following explanations of Ir and IR (11.2 thru 11.2.3)are only intended to present a meaningful way of considering the approximate precision of this test method. The data in Table 1should not be rigorously applied to
34、acceptance or rejection of material, as those data are specific to the one laboratory and maynot be representative of other lots, conditions, materials, or laboratories.)NOTE 2Users of this test method should apply the principles outlined in Practice E691 to generate data specific to their laborator
35、y and materials, orbetween specific laboratories. The principles of 11.2.1 through 11.2.3 would then be valid for such data.11.2 Concept of IrandIRIf Sr and SR have been calculated from a large enough body of data, then the following applies:11.2.1 RepeatabilityComparing two test results for the sam
36、e material, obtained by the same operator using the sameequipment on the same day, the two test results should be judged not equivalent if they differ by more thanThe value below whichthe absolute difference between two individual test results obtained under repeatability conditions is likely to be
37、expected to occurwith a probability of approximately 0.95 I(95 %).r for that material.Ir 52.833Sr (5)11.2.2 ReproducibilityComparing two test results for the same material, obtained by different operators using differentequipment on different days, the The value below which the absolute difference b
38、etween two test results should be judged notequivalent if they differ by more than the obtained under reproducibility conditions is likely to be expected to occur with aprobability of approximately 0.95 (95 %).IR for that material.IR 52.833SR (6)11.2.3 Any judgment in accordance withEquivalence test
39、ing on numerical data from two sources shall be conducted inaccordance Practice 11.2.1E2935 andor 11.2.2 would have an approximate 95 % (0.95) probability of being correct. any knownmethod for judging the equivalence of two means.NOTE 3Example: A t-test.11.3 Bias is systematic error which contribute
40、s to the difference between a test result and a true (or reference) value. There areno recognized standards on which to base an estimate of bias for this test method.12. Keywords12.1 differential solution viscosity; differential viscometer; polymer solution viscosityANNEXTABLE 1 Precision Data for t
41、he Solution Viscosities of Various PolymersAPolymer Solvent Concentration Relative Viscosity Inherent Viscosity Intrinsic ViscosityMean Sr Ir Mean Sr Ir Mean Sr Irpoly(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 .
42、. . . . . . . . 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 mLresin “A” 1.170 0.005 0
43、.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 3.604 0.022 0.062poly(phe
44、nylene 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 1.039 0.001 0.003AThis data
45、was generated by a Viscotek Model 100-01 viscometer, Malvern Instruments, 117 Flanders Rd., Westborough, MA.D5225 174(Mandatory Information)A1. CALCULATIONS FOR DIFFERENTIAL VISCOMETERA1.1 Assume R3 is filled with solution and R1, R2, R4 are filled with solvent. The measured quantities are the inlet
46、 pressure Pi andthe differential pressure P.PPi 5P12P2Pi (A1.1)P1 = pressure drop across R3 andP2 = pressure drop across R4.A1.2 R2 and R4 have equal flow resistance, so Pi = 2P2, giving the following:PPi 51/2FP1P2 21G (A1.2)A1.3 Applying Poiseuelles Law to capillaries R3 and R4:P1P2 5Q1oQ2 (A1.3)Q1
47、 = 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/Q2 is equal to the inverse ratio of the total resistance in each side of the bridge.Q1Q2 5o1oo1 52oo1 (A1.4)A1.5 Combining Eqs (A1.2), (A1.3), and (A1.4), w
48、e find the following:PPi 51/2F2o1o G (A1.5)A1.6 The definition of specific viscosity of a solution is as follows:sp52oo(A1.6)D5225 175A1.7 Substituting into Eq (A1.5) yields the following:PPi 5sp2sp14 (A1.7)A1.7.1 Rearrange to give the following:sp5 4PPi 2 2P(A1.8)A1.8 Assumptions in Derivation:A1.8
49、.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 - 09D5225 - 14) that may impact the use of this standard. (DecemberMay 1, 2014) 1, 2017)(1) Removed specific equipment models fromRevised 6.5 to clarify accuracy 6.1.of balance being used.(2) Removed old subsections 6.2, 6.3, 6.4, 6.5, 6.6, and 6.7.Subsections 11.2.1, 11.2.2, and 11.2.3: Removed passive languag
