1、Designation:D 2703 95Standard Practice forRubber ChemicalsDetermination of Ultraviolet AbsorbanceCharacteristics1This standard is issued under the fixed designation D 2703;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of l
2、ast revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice2covers the measurement of the ultravioletabsorption spectrum of any rubber chemical that is soluble ina spect
3、roscopic solvent.The rubber chemical may possessabsorption maxima in this region(approximately between 200and 400 nm).1.2 The recommended practice further differentiates be-tween rubber chemicals on the basis of differences in theirabsorption spectra,both in the spectral position of the absorp-tion
4、bands and in the absorptivities at selected wavelengths.1.3 The use of this practice implies that the conditions ofmeasurement and sample preparation be reported for a rubberchemical under examination(see 13.2).1.4 This standard does not purport to address all of thesafety concerns,if any,associated
5、 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.2.Referenced Documents2.1 ASTM Standards:D 4483 Practice for Determining Precision for Test MethodStandards
6、 in the Rubber and Carbon Black Industries3E 131 Terminology Relating to Molecular Spectroscopy4E 169 Practices for General Techniques of Ultraviolet-Visible Quantitative Analysis4E 275 Practice for Describing and Measuring Performanceof Ultraviolet,Visible,and Near Infrared Spectrophotom-eters43.Te
7、rminology3.1 Definitions:3.1.1 For definitions of terms and symbols used,see Termi-nology E 131.4.Summary of Practice4.1 The ultraviolet absorbance spectrum of a rubber chemi-cal,or some specified portion of the spectrum,is determined bymeasuring the absorbance of a solution of known concentrationat
8、 specified wavelengths,in a cell of known sample pathlength,using a spectrophotometer for measurement.5.Significance and Use5.1 The ultraviolet light absorbing characteristics of a rub-ber chemical are useful for identification,comparison pur-poses,quality-control,and research and development studie
9、s(see 11.4.6 and 13.2).6.Apparatus6.1 Spectrophotometer,manual or recording,single-ordouble-beam equipped to handle liquid samples in cells andcapable of covering the spectral region from 200 to 400 nm.Acell with a sample path length of 1 cm is desirable.Cells withlonger or shorter sample path lengt
10、hs may be used.Theinstrument shall be operated in accordance with the practicesrecommended by the manufacturer for obtaining optimuminstrument performance.6.2 If the performance of the spectrophotometer must beevaluated,refer to Practice E 275.6.3 Micro Balance with a capacity of 0 to 25 mg and asui
11、table tare for increasing capacity to 50 mg is desirable.If amicro balance is not used,dilutions necessary to bring thesample solution to the necessary concentration must be ap-plied.6.4 Red Glassware of the low actinic type or brown glassvolumetric flasks should be used for sample solutions tominim
12、ize the effects of light.6.5 One or more pairs of fused silica cells are required.Suitable procedures for testing and cleaning cells are describedin Practice E 275.7.Reagents7.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unless otherwise indicated,it is intended thatall reag
13、ents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,1This practice is under the jurisdiction ofASTM Committee D-11 on Rubber andis the direct responsibility of Subcommittee D 11.11 on Chemical Analysis.Current edition approved Feb.15,199
14、5.Published April 1995.Originallypublished as D 2703 68.Last previous edition D 2703 94.2Based on Kress,K.E.,“Absorption Spectroscopy as an Analytical Method inRubber Chemistry”in the book Frey,H.E.,Methoden zur Chemischen Analyze vonGumminischungen,Springer-Verlag,Berlin,1960,p.135.3Annual Book of
15、ASTM Standards,Vol 09.01.4Annual Book of ASTM Standards,Vol 03.06.1AMERICAN SOCIETY FOR TESTING AND MATERIALS100 Barr Harbor Dr.,West Conshohocken,PA 19428Reprinted from the Annual Book of ASTM Standards.Copyright ASTMNOTICE:This standard has either been superseded and replaced by a new version or d
16、iscontinued.Contact ASTM International(www.astm.org)for the latest information.where such specifications are available.5Other 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 Some common,commercially available solvents usedfor spectral analysis of rubber chemicals are distilled water,methylene chloride,methyl alcohol,isooctane,and cyclohex-ane.The analyst should be aware of a