1、Designation:D501796(Reapproved 2009)1Standard Test Method forDetermination of Linear Low Density Polyethylene(LLDPE)Composition by Carbon-13 Nuclear Magnetic Resonance1This standard is issued under the fixed designation D5017;the number immediately following the designation indicates the year oforig
2、inal adoption or,in the case of revision,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.1NOTEReapproved with editorial changes in April 2009.1.Scope1.1 This test method
3、determines the molar composition ofcopolymers prepared from ethylene(ethene)and a secondalkene-1 monomer.This second monomer can include propene,butene-1,hexene-1,octene-1,and 4-methylpentene-1.1.2 Calculations of this test method are valid for productscontaining units EEXEE,EXEXE,EXXE,EXXXE,and ofc
4、ourse EEE where E equals ethene and X equals alkene-1.Copolymers containing a considerable number of alkene-1blocks(such as,longer blocks than XXX)are outside the scopeof this test method.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is the
5、responsibility 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.See Section 8 for aspecific hazard statement.NOTE1There is no equivalent ISO standard.2.Referenced Documents2.1 ASTM Standards:2E1
6、77 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE386 Practice for Data Presentation Relating to High-Resolution Nuclear Magnetic Resonance(NMR)Spec-troscopyE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodIEEE/ASTM SI-10 Standard
7、for Use of the InternationalSystem of Units(SI):The Modern System33.Terminology3.1 Some units,symbols,and abbreviations used in this testmethod are summarized in IEEE/ASTM SI-10 and PracticeE386.Other abbreviations are listed as follows:3.2 Abbreviations:3.2.113Ccarbon 13,3.2.2 LLDPElinear low-densi
8、ty polyethylene,3.2.3 T1relaxation time,and3.2.4 TRpulse repetition time.3.3 Definitions of Terms Specific to This Standard:3.3.1 With a few modifications,terms used to designatedifferent carbon types were suggested by Carman.4Methinecarbons are identified by CH and branch carbons are labeledaccordi
9、ng to branch type as summarized in Table 1.Branchcarbons are numbered starting with the methyl as number one.3.3.2 Backbone methylene carbons are designated by a pairof Greek letters that specify the location of the nearest methinecarbon in each direction.For example,-methylene carbon isbetween two
10、methine carbons or an,+methylene carbon hasone immediate methine neighbor and the second methinecarbon is located at least four carbons away.4.Summary of Test Method4.1 Polymer samples are dispersed in hot solvent andanalyzed at high temperatures using Carbon-13 nuclear mag-netic resonance(NMR)spect
11、roscopy.4.2 Spectra are recorded under conditions such that theresponse of each chemically different carbon is identical.Integrated responses for carbons originated from the differentcomonomers are used for calculation of the copolymer com-position.1This test method is under the jurisdiction of ASTM
12、 Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.70 on Analytical Methods.Current edition approved April 1,2009.Published June 2009.Originallyapproved in 1991.Last previous edition approved in 2003 as D5017 96(2003)1.DOI:10.1520/D5017-96R09E01.2For referenced ASTM stand
13、ards,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 ASTM International Headquarters,100 Barr Harbor Drive,C700,West Conshohocken
14、,PA 19428.4Carman,C.J.,Harrington,R.A.,and Wilkes,C.E.,Macromolecules 1977,Vol10,p.536.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.Significance and Use5.1 Performance properties are dependent on the numberand type of short chain bra
15、nches.This test method permitsmeasurement of these branches for ethylene copolymers withpropylene,butene-1,hexene-1,octene-1,and4-methylpentene-1.6.Apparatus6.1 NMR Spectrometer,13C pulse-Fourier transform spec-trometer with a field strength of at least 2.35 T.NOTE2The system should have a computer
16、size of at least 32 K for50-MHz carbon frequency with digital resolution of at least 0.5 Hz/pointin the final spectrum.6.2 Sample Tubes,510-mm outside diameter.NOTE3Sample tube size can be varied;however,the samplepreparation procedure described in 10.1 may need to be altered tomaintain the minimum signal-to-noise requirement of 9.4.7.Reagents and Materials7.1 Ortho-dichlorobenzene or 1,2,4-trichlorobenzene,re-agent grade7.2 Deuterated o-dichlorobenzene or p-dichlorobenzene.This material is used