1、Designation: D7977 14Standard Test Methods forPolymer Content of AMS (-Methylstyrene)1This standard is issued under the fixed designation D7977; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in
2、 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 determination of the poly-mer content of AMS (-Methystyrene). Dimers and trimers arenot measured by these test metho
3、ds.1.2 This test method has been found applicable to determin-ing the polymer content of AMS in concentrations up to 15mg/kg. Samples containing more than 15 mg/kg of polymermust be suitably diluted before measurement.1.3 In determining the conformance of the test results usingthis method to applica
4、ble specifications, results shall berounded off in accordance with the rounding-off method ofPractice E29.1.4 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 concern
5、s, 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-bility of regulatory limitations prior to use. For specific hazardstatements, see Section 8.2. Referenced Documents2.1 ASTM Standar
6、ds:2D3437 Practice for Sampling and Handling Liquid CyclicProductsD6367 Specification for AMS (-Methylstyrene)D6809 Guide for Quality Control and Quality AssuranceProcedures for Aromatic Hydrocarbons and Related Ma-terialsE29 Practice for Using Significant Digits in Test Data toDetermine Conformance
7、 with Specifications2.2 Other Document:3OSHA Regulations, 29 CFR paragraphs 1910.1000 and1910.1200TEST METHOD ADETERMINATION OF POLYMERIN -METHYLSTYRENE VIASPECTROPHOTOMETER3. Summary of Test Method3.1 This test method utilizes the fact that AMS polymerspresent in the monomers are insoluble in metha
8、nol. Thepolymer content of AMS monomer is determined by measure-ment of the degree of turbidity produced by the addition of drymethanol to the AMS sample.4. Significance and Use4.1 This test method can be used for determining polymerconcentrations in AMS monomer.4.2 This test method will not detect
9、dimers and trimers.4.3 This test method can be used for plant control and forspecification analysis.5. Interferences5.1 Small changes in turbidity may occur with time. It is,therefore, important that the absorbance of calibration mixturesand samples be determined after standing the same length oftim
10、e.5.2 Hexane is used for two reasons:5.2.1 To block out any color in the AMS, and5.2.2 To indicate high levels of dissolved water in the AMS.5.3 Water content was found to have a slight impact on themeasurement of polymer in AMS solution. When the waterconcentration is below 260 ppm, its effect on t
11、he measurementof polymer in AMS solution is negligible.6. Apparatus6.1 Class A Volumetric Pipets, 10 and 15-mL.1These test methods are under the jurisdiction of ASTM Committee D16 onAromatic Hydrocarbons and Related Chemicals and is the direct responsibility ofSubcommittee D16.07 on Styrene, Ethylbe
12、nzene and C9 and C10 AromaticHydrocarbons.Current edition approved Dec. 1, 2014. Published March 2015. DOI: 10.1520/D7977-14.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information,
13、refer to the standards Document Summary page onthe ASTM website.3Available from U.S. Government Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http:/www.access.gpo.gov.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Co
14、nshohocken, PA 19428-2959. United States16.2 Bottles or Flasks, of suitable size equipped with glassstoppers.6.3 Spectrophotometer or Photometer Cells, with 100 to150-mm light path.6.4 Spectrophotometer of Photometer, capable of absor-bance measurements in wavelength region of 330 nm andsensitive to
15、 1 mg polymer/kg monomer.7. Reagents and Materials7.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where s
16、uch specifications are available.4Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.7.2 Hexane, dry.7.3 Methanol, dry.7.4 Poly-AMS: Commercially available high-purity poly-AMS
17、can be used; low-molecular weight poly-AMS (150 000molecular weight) was found to work and was used in thedevelopment of this standard.7.4.1 Be aware of possible error when the molecular weightof the polymer measured is different from that of the polymerused for calibration curves.8. Hazards8.1 AMS
18、(-Methylstyrene) monomer is flammable andpolymerizes exothermically on contact with peroxides, mineralacids and aluminum chloride.8.2 AMS monomer both in liquid and vapor state, when insufficient concentrations, acts as an irritant to the eyes andrespiratory tract.8.3 Consult current OSHA regulation
19、s, local regulations,and suppliersSafety Data Sheets for all materials used in thesetest methods.9. Sampling and Handling9.1 Sample the material in accordance with Practice D3437.10. Calibration10.1 ApparatusPrepare and operate the spectrophotom-eter or photometer in accordance with the manufacturer
20、sinstructions.10.2 Reference Standards and Blanks:10.2.1 Dissolve 0.0910 g of poly-AMS in 1000 mL of AMSmonomer measured at 25C. This serves as the 100 mg/kgstandard solution.10.2.2 Make standard solutions containing 1, 3, 6, 9, 12, and15 mg/kg of polymer by diluting 1, 3, 6, 9, 12, and 15 mL ofthe
21、100 mg/kg standard solution to 100 mL with AMS in avolumetric flask at 25C.10.3 Calibration Curves and Tables:10.3.1 Into each of a series of 25 mL volumetric flasksequipped with glass stoppers pipet 15 mL of dry methanol and10 mL of a polymer standard and mix thoroughly. Into anotherseries of flask
22、s pipet 15 mL of hexane and 10 mL of eachpolymer standard and mix thoroughly. Other volumes may beused, depending on the capacity of the spectrophotometer cellas long as the 3:2 proportions are maintained.10.3.2 Allow the solutions to stand in the stoppered bottlesfor 15 min. (Note 1). At the end of
23、 this time, pour the solutionsinto the spectrophotometer cells and measure the absorbance ofeach at a wavelength of 330 nm using the hexane/polymerstandard as the blank (Note 2).NOTE 1Small changes in turbidity may occur with time. It is,therefore, important that the absorbance of calibration mixtur
24、es andsamples be determined after standing the same length of time.NOTE 2The hexane is used for two reasons: (1) to blank out any colorin theAMS, and (2) to indicate high levels of dissolved water in theAMS.10.3.3 Prepare a calibration curve by plotting the absor-bance against the milligrams per kil
25、ogram of polymer (Note 3).NOTE 3Background levels of poly-AMS absorbance may existdepending on the quality of AMS monomer used. In such cases, preparecalibration curves using the method of standard additions, effectivelysubtracting out the background level.11. Procedure11.1 Pipe 15 mL of hexane into
26、 a 25 mL volumetric flaskequipped with a glass stopper.11.2 Into a second bottle, pipet 15 mL of dry methanol.11.3 Add 10 mL of AMS to each bottle and mix thoroughly.11.4 Proceed as described in 10.3.2 using the hexanemixture as the blank.12. Calculation12.1 Read the milligrams per kilogram of polym
27、er directlyfrom the calibration curve (Note 4).NOTE 4Milligrams per kilogram can be converted to weight percentby dividing by 10 000.13. Report13.1 Report the polymer content of the sample as milli-grams of polymer per kilogram of monomer to the nearestmg/kg. For results less than 1 mg/kg, report 1
28、mg/kg.14. Precision and Bias514.1 A single sample containing 4.8 mg/kg polymer wasanalyzed 20 times by one person using one instrument over theshortest practical time. Details are given in Research ReportRR:D16-1054.4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Socie
29、ty, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.5
30、Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D16-1054. ContactASTM CustomerService at serviceastm.org.D7977 14214.2 Repeatability:14.2.1 The average of the 20 results was 4.65. Repeatability“r” was 0.2. Results should not be s
31、uspect unless they differ bymore than “r”. Results that differ by less than “r”havea95%probability of being correct.14.3 Reproducibility has not been determined and will bedetermined within five years.14.4 Bias:14.4.1 Since there is no accepted reference material suitablefor determining the bias in
32、this test method, bias has not beendetermined.15. Quality Guidelines15.1 Laboratories shall have a quality control system inplace.15.1.1 Confirm the performance of the test instrument ortest method by analyzing a quality control sample followingthe guidelines of standard statistical quality control
33、practices.15.1.2 A quality control sample is a stable material isolatedfrom the production process and representative of the samplebeing analyzed.15.1.3 When QA/QC protocols are already established inthe testing facility, these protocols are acceptable when theyconfirm the validity of test results.1
34、5.1.4 When there are no QA/QC protocols established inthe testing facility, use the guidelines described in GuideD6809 or similar statistical quality control practices.TEST METHOD BVISUAL EVALUATION OFPOLYMER CONTENT OF -METHYLSTYRENE16. Summary of Test Method16.1 This test method utilizes the fact
35、that AMS polymersare insoluble in methanol. The polymer content of a sample ofAMS is evaluated by visual observation of the degree ofturbidity produced by the addition of methanol to the sample.The order of magnitude of the polymer content of AMS in theincremental steps 0.001, 0.01, 0.1, and 1.0 wei
36、ght % mayreadily be differentiated visually. For 0 % observe pure drymethanol.17. Apparatus17.1 Test Tube, 25 by 150-mm.17.2 Class A Volumetric Pipets, 2 and 10-mL.17.3 Daylight Fluorescent Tube, equipped with curved re-flector.18. Reagents18.1 Methanol, dry.18.2 Poly-AMS, uncolored, unfilled, unlub
37、ricated (see 7.4).18.3 Toluene, dry.19. Procedure19.1 Pipet 2 mL of sample into a clean, dry test tube, add 10mL of dry methanol by means of a pipet, stopper the test tubewith a cork covered with aluminum foil, and shake vigorouslyfor a few seconds.19.2 After shaking the test tube, inspect the mixtu
38、re visuallyby looking through it toward a source of artificial daylight.Compare the observed turbidity of the mixture with thedescriptions of turbidity given in Table 1 or against knownstandards. If standards are desired, they may be prepared usingpoly-AMS and toluene.20. Report20.1 From Table 1 sel
39、ect the turbidity description that mostnearly approximates that of the sample, and report the corre-sponding polymer content.21. Keywords21.1 -methylstyrene; AMS; polymer; polymer contentASTM International takes no position respecting the validity of any patent rights asserted in connection with any
40、 item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent 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
41、committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at
42、 a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing 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 D
43、rive, 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
44、.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 1 Relationship Between Polymer Content of AMS andTurbidity of Mixture of Two Parts by Volume AMS and Ten Partsby Volume Dry Me
45、thanolPolymer Content ofAMS mg/kgADescription of Turbidity ofStyrene-Methanol Mixture10 000 or greater milk-white opaque liquid with heavy white precipitate1000 milk-white opaque liquid with no evidence ofsedimentation100 cloudiness readily visible, but mixture still transparent10 faint trace of clo
46、udiness; detectable only bycomparison with pure dry methanol1 no cloudiness discernible by comparison with pure drymethanolAIt is suggested that the analyst initially perform the test using reference mixturesdescribed in this table as a guide. An experienced analyst can estimate thepolymer content reliably without the use of reference mixtures.D7977 143
