1、Designation: D5227 13Standard Test Method forMeasurement of Hexane Extractable Content of Polyolefins1This standard is issued under the fixed designation D5227; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revis
2、ion. 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 describes an extraction/gravimetricprocedure for determination of the amount of hexane solublelow molecular we
3、ight material present in polyethylene,polypropylene, ethylene-propylene copolymers, and ethylene-vinyl acetate copolymers. This test method is a modification ofthe Food and Drug Administration (FDA) procedure fordetermining hexane extractables of polyolefins. This testmethod is based upon the presum
4、ption that the weight of theresidue extract present in the solvent is equal to the amountextracted from the film sample and could therefore be quanti-fied by measuring the weight loss of the extracted film,eliminating the complex and time-consuming evaporationprocess described in 21 CFR 177.1520.1.2
5、 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-bility of regulatory limitations prior to use.1.3 The values sta
6、ted in SI units are to be regarded as thestandard. Units used in 21 CFR 177.1520 are also used in thistest method. Units are in conformance with Federal Code 21CFR 177.1520, from which this test method is derived.NOTE 1There is no known ISO equivalent to this standard.2. Referenced Documents2.1 ASTM
7、 Standards:2D883 Terminology Relating to PlasticsD1239 Test Method for Resistance of Plastic Films toExtraction by ChemicalsD1600 Terminology forAbbreviated Terms Relating to Plas-ticsE131 Terminology Relating to Molecular SpectroscopyE691 Practice for Conducting an Interlaboratory Study toDetermine
8、 the Precision of a Test Method2.2 Federal Document:321 CFR 177.15203. Terminology3.1 The definitions given in Terminology D883, D1600, andE131 are applicable to this test method.3.2 Abbreviations:3.2.1 EVAethylene-vinyl acetate copolymer.3.2.2 LDPElow-density polyethylene.3.2.3 HDPEhigh-density pol
9、yethylene.3.2.4 LLDPElinear low-density polyethylene.3.2.5 FDAFood and Drug Administration.3.2.6 PPpolypropylene.4. Summary of Test Method4.1 Film samples are extracted with hexane for 2 h at 49.56 0.5C, dried, and weighed.4.2 The loss in weight of the film is presumed to be equal tothe extractable
10、content determined by solvent evaporation inthe FDA protocol.5. Significance and Use5.1 FDA requirements for maximum extractables are speci-fied for resin and uses. This test method provides a means todetermine the amount of hexane-soluble low molecular weightmaterial present in polyolefins. It is a
11、pplicable to resinscontaining greater than 0.20 % extractables.6. Apparatus6.1 Water Bath, maintained at 49.5 6 0.5C.6.2 Resin Kettle, 1500-mL.6.3 Kettle Head, 3-neck, with one 45/50 and two 24/40female joints, and appropriate stoppers.6.4 Clamp.6.5 Allihn Condenser, Size C, with 45/50 male joint.1T
12、his 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 June 1, 2013. Published July 2013. Originally approvedin 1992. Last previous edition approved in 2008 as D5227 - 01(2008)1
13、. DOI:10.1520/D5227-13.2For 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.3Available from Standardization Docume
14、nts Order Desk, DODSSP, Bldg. 4,Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http:/www.dodssp.daps.mil.*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 States16.6 P
15、lastic Sleeves, tetrafluoroethylene (TFE), to fit Allihncondenser 45/50 male joint.6.7 Vacuum Oven, capable of maintaining 80 6 5C and aminimum of 25-in. Hg pressure.6.8 Magnetic Stirring Bar, egg-shaped, TFE-coated, 112 by58 in.6.9 Submersible Magnetic Stirring Motor, with power sup-ply.6.10 Analyt
16、ical Balance, capable of weighing to 0.1 mg.7. Reagents and Materials7.1 n-Hexane, aromatic free (1 mg/L), minimum 85 %n-Hexane-reagent grade or equivalent. The solvent must befree of aromatic compounds that would significantly increasethe solubility of the resin. The solvent grade specified repre-s
17、ents the minimum required purity.8. Materials8.1 Blown Film, compression molded films, or cast films aresuitable for testing.8.2 Film, approximately 2.5 g, with a thickness not exceed-ing 4 mil is required for a single determination.9. Procedure9.1 Assemble the resin kettle setup with glass stopper,
18、clamp, and magnetic stirring bar. (See Fig. 1.)9.2 Add 1000 mL of n-Hexane to the kettle assembly.9.3 Stopper the kettle and clamp the assembly into the waterbath set at 49.5 6 0.5C.NOTE 2Temperature is a critical factor in this analysis and must notvary more than 1C. If the temperature exceeds thes
19、e limits, the test mustbe discontinued and restarted. The FDA protocol also states the tempera-ture of the contents must be brought to 49.5 6 0.5C within 20 to 25 min.NOTE 3The level of water in the bath must be kept at least 2 cm abovethe level of the solvent in the kettle to ensure the temperature
20、 equilibrium.Position the kettle so that the center bottle of the kettle is sitting on asubmersible stirrer. Start stirring and allow the hexane to heat for 1 h.9.4 Using gloves and metal tweezers to avoid samplecontamination, cut 2.7 g of the prepared film sample (4 mil orless in thickness) into 1-
21、in. squares using clean sharp scissors.NOTE 4Care must be exercised when cutting the samples to avoidragged edges on the specimen. Small shards of film or contaminationpresent at initial weighing can easily be lost during the test, adverselyaffecting the test results.9.5 Weigh 2.5 6 0.05 g of film s
22、quares and record the initialfilm weight to the nearest 0.1 mg. Also record the number offilm pieces.NOTE 5Forty or more squares will be obtained depending on the filmthickness. Some laboratories have found that a basket assembly, as shownin Appendix X1, eliminates the need to count the film pieces
23、before andafter the solvent extraction step.9.6 Add the film sample to the hexane making sure allsquares become immersed in the solvent. (Use tweezers.)Replace the kettle head with condenser column. Extract for 2 h.9.7 After the extraction period:9.7.1 Filter the contents of the resin kettle through
24、 the frittedporcelain funnel.9.7.2 Transfer the film squares, using tweezers, to a 200-mLBerzelius beaker and recount the film pieces to verify that nonewere lost during transfer.9.7.3 Cover the beaker with a watchglass and place it in avacuum oven at 80 6 5C for 2 h.9.7.4 After 2 h, remove the cove
25、red beaker from the vacuumoven and place it in a desiccator to cool to room temperature(estimated 1 h).9.8 Remove the film squares using tweezers and weigh themto the nearest 0.1 mg.9.9 Repeat 9.7.3 and 9.7.4 until a constant weight isobtained.10. Calculation10.1 Calculate the weight percent of extr
26、actables present inthe original sample as follows:hexane extractables, % 5A 2 B! 3100 30.935A(1)where:A = weight of original sample film, g,B = weight of the film after extraction, g, and0.935 = correlation factor to eliminate the bias between theoriginal FDA technique and this alternate testmethod.
27、11. Report11.1 Report the hexane extractables to the nearest 0.01 % ascalculated in 10.1.12. Precision and Bias412.1 Hexane Extractable Content of Polyolefins:12.1.1 Table 1 is based on a round robin conducted in 1990in accordance with Practice E691, involving five materials4Supporting data are avai
28、lable from ASTM Headquarters. Request RR:D20-1173.FIG. 1 Resin Kettle SetupD5227 132tested by ten laboratories. The materials were supplied by onelaboratory. Each test result was an individual determination.Each laboratory obtained six test results for each of the fivematerials. Each laboratory obta
29、ined two test results for eachmaterial tested each day for three days.NOTE 6Caution: The following explanations of r and R(12.1.2-12.1.2.3) are only intended to present a meaningful way ofconsidering the approximate precision of this test method. The data inTable 1 should not be rigorously applied t
30、o acceptance or rejection ofmaterial, as those data are specific to the round robin and may not berepresentative of other lots, conditions, materials, or laboratories. Users ofthis test method should apply the principles outlined in Practice E691 togenerate data specific to their laboratory and mate
31、rials, or between specificlaboratories. The principles of 12.1.2-12.1.2.3 would then be valid forsuch data.12.1.2 Concept of r and RIf Sr and SR have beencalculated from a large enough body of data, and for test resultsthat were averages from testing five specimens.12.1.2.1 Repeatability Limit, r(Co
32、mparing two test resultsfor the same material, obtained by the same operator using thesame equipment on the same day.) The two test results shouldbe judged not equivalent if they differ by more than the r valuefor that material.12.1.2.2 Reproducibility Limit, R(Comparing two test re-sults for the sa
33、me material, obtained by different operatorsusing different equipment in different laboratories.) The twotest results should be judged not equivalent if they differ bymore than the R value for that material.12.1.2.3 Any judgment in accordance with 12.1.2.1 or12.1.2.2 would have an approximate 95 % (
34、0.95) probability ofbeing correct.12.1.3 BiasThere are no recognized standards by which toestimate bias of this test method.13. Keywords13.1 ethylene-propylene copolymers; ethylene-vinyl acetatecopolymers; extractables; FDA; hexane; plastics; polyethyl-ene; solvent extractionAPPENDIX(Nonmandatory In
35、formation)X1. BASKET ASSEMBLY FOR n -HEXANE EXTRACTABLESX1.1 If one uses the basket assembly shown in Fig. X1.1,the following steps should be performed after the 2-h hexaneextraction (9.6) Also, the sample and basket must be weighedtogether and recorded before starting the extraction:X1.1.1 Rinse th
36、e basket and contents by immersing severaltimes in fresh n-hexane contained in a small beaker, allowingthe basket to drain between rinsings.X1.1.2 Remove the excess solvent by briefly blowing thebasket with a stream of nitrogen or dry air.X1.1.3 Place the basket in a vacuum oven for 2 h at 8065C, th
37、en cool to ambient temperature in a desiccator (esti-mated 1 h).X1.1.4 Reweigh the basket and its contents to the nearest0.1 mg.TABLE 1 Hexane Extractable Content of Polyolefins, WeightMaterial Average Sr SR r RHDPE 0.26 0.03 0.05 0.09 0.15LLDPE 0.88 0.11 0.16 0.31 0.46LDPE 1.74 0.08 0.15 0.21 0.42E
38、VA 3.54 0.28 0.33 0.78 0.93PP 3.80 0.29 0.35 0.81 0.98D5227 133SUMMARY OF CHANGESCommittee D20 has identified the location of selected changes to this standard since the last issue (D5227 01(2008)1) that may impact the use of this standard. (June 1, 2013)(1) Removed permissive language.(2) Removed m
39、aterials manufacturers information.(3) Revised X1.1.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 rig
40、hts, 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 either for
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42、 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
43、 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/).FIG. X1.1 Basket for n-Hexane Extractables1D5227 134
