Standard Reference Material 2881 - National Institute of Standards ...

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NISTIR 7512A Report on the Certification of anAbsolute Molecular Mass DistributionPolymer Standard:Standard Reference Material 2881Charles M. GuttmanKathleen M. FlynnWilliam E. WallacePolymers DivisionMaterials Science and Engineering LaboratoryNational Institute of Standards and TechnologyGaithersburg, MD 20899-8541Anthony J. KearsleyMathematical and Computational Sciences DivisionInformation Technology LaboratoryNational Institute of Standards and TechnologyGaithersburg MD 20899-8910October, 2008U.S. Department of CommerceCarlos M. Gutierrez, SecretaryNational Institute of Standards and TechnologyPatrick Gallagher, Deputy Director
ABSTRACTThe certification of an absolute molecular mass distribution polymer Standard ReferenceMaterial, SRM 2881, is described. SRM 2881 is an n-octyl-initiated, proton-terminated, narrowpolydispersity, low mass, atactic polystyrene. The absolute molecular mass distribution (MMD)was obtained by matrix-assisted laser desorption ionization time-of-flight mass spectrometry(MALDI-TOF MS). The certification includes estimates of uncertainties, both Type A (random)and Type B (systematic), for each oligomer in the sample having a concentration of at least0.18 % of the total of all oligomers on the low mass tail of the MMD and 0.02 % on the highmass tail. The bottle-to-bottle variation of the packaged SRM was checked by size exclusionchromatography and found to be negligible.DISCLAIMERSCertain commercial materials and equipment are identified in this paper in order to specifyadequately the experimental procedure. In no case does such identification implyrecommendation or endorsement by the National Institute of Standards and Technology, nordoes it imply necessarily the best available for the purpose.According to ISO 31-8, the term “molecular mass” has been replaced by “relative molecularmass,” symbol M r . Thus, if that nomenclature and notation were followed in this publication, oneshould write M r,w instead of the historically conventional M w for the weight-average molecularmass with similar changes for M n , and M z . M w would be called the “mass-average relativemolecular mass.” The conventional notation, rather than the ISO notation, has been used in thispublication.2
Page 1: NISTIR 7512A Report on the Certific
Page 5 and 6: 1. IntroductionThe certification of
Page 7 and 8: BHT), was used as the solvent. The
Page 9 and 10: anticipated to be a useful material
Page 11 and 12: sample using a separate method, or
Page 13 and 14: 6.0. Signal Axis Calibration Proced
Page 15 and 16: 6.2 Mathematical Model for Gravimet
Page 17 and 18: Here Q is a function of all the exp
Page 19 and 20: Let us consider this final equation
Page 21 and 22: GGexpTAexpTBGG0TA0TB=⎧⎨1+⎩0(
Page 23 and 24: were also used in this experiment:
Page 25 and 26: The matrix was all-trans retinoic a
Page 27 and 28: educes the data set to groups of th
Page 29 and 30: atios of the two sets of data is ag
Page 31 and 32: An analysis of variance (ANOVA) 5 w
Page 33 and 34: 11. Discussion of Type B Uncertaint
Page 35 and 36: Two other methods were used to chec
Page 37 and 38: certified by this method with the u
Page 39 and 40: References1. S. D. Hanton, I. Z. Hy
Page 41 and 42: Figures1. MALDI-TOF mass spectra of
Page 43 and 44: Figure 242
Page 45 and 46: Figures 5 (inset) and 6 (main)44
Page 47 and 48: Figure 946
Page 49 and 50: Tables1. Q/k 0 with its estimated u
Page 51 and 52: Table 2Instrument Parameter Optimal
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103 10840.42 0.0063 8.93 % 14.72 %
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99 10423.86 0.0139 0.0008 93.9 %100
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INSTRUCTIONS FOR USEStorage: The SR
Page 59:
REFERENCES[1] See ASTM D5296 05 “
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