Slide-Set-3-Chain-Structure

Slide-Set-3-Chain-Structure - Chain Structure and...

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Unformatted text preview: Chain Structure and Configuration: Configuration: Lecture Slide Set #3 Dr. Anthony Brennan University of Florida Tel: 352.392.6281 Email: [email protected] EMA 4161C Phys Prop Poly - University of Florida Copyright 2009 EMA 1 Slide Set #3 – Chain Structure and Slide Configuration Configuration • Learning Objectives: – Understand correlation between chemistry, Understand structure and energy structure • • • • Bond structure Bond rotation PE Distinguish Conformation and Configuration Balance of three energies – Method Specific Properties • Chemical – XPS, FTIR, WAXD, EDAX, Contact Angle, Chemical Radionucleotide, Derivatization Radionucleotide, • Physical – AFM, SEM, TEM, Ellipsometry, DTMA EMA 4161C Phys Prop Poly - University of Florida Copyright 2009 EMA 2 Polymer Structure -Property Behavior Polymer Chain Dimensions • Conformation (model) – – spatial arrangement changes with rotation around bonds • configuration – bonding arrangement – changes only through bond breakage • aspect ratio (L/D) for PE (100kg/mol) – 60,000 EMA 4161C Phys Prop Poly - University of Florida Copyright 2009 3 Isomerism Isomerism H H3C CH3 H H H3C H H3C H H H H H H CH3 H CH2 H3C H H H H H H CH3 H CH2 H3C H2C CH3 CH2 CH3 EMA 4161C Phys Prop Poly - University of Florida Copyright 2009 4 Chain architecture "Branched" or "graft" Blend A A B Block or triblock Network or Crosslinked EMA 4161C Phys Prop Poly - University of Florida Copyright 2009 EMA 5 Balance of Three Energies Balance • Intramolecular – – – PE vs Nylon 6 Nylon 6 vs Kevlar Kevlar vs Nomex • Intermolecular – Nylon vs PE • Thermal – kT per repeat unit • Bond rotation – Nylon 6 : 10 to 20 Nylon kcal/mol (Tm: 220°C) kcal/mol – Kevlar: >20 kcal/mol • Secondary Bonding – H-Bonds, Dipole, Ionic, H-Bonds, van der Waals van – 2 to 11 kcal/mol • Low energy – ~0.6 kcal/mol EMA 4161C Phys Prop Poly - University of Florida Copyright 2009 6 Importance of Chemistry Importance P o ly e th y le n e H o m o p o ly m e r L in e a r H ig h D e n s ity C o p o ly m e r Low D e n s ity L in e a r L o w D e n s ity Low D e n s ity 7 EMA 4161C Phys Prop Poly - University of Florida Copyright 2009 CH3 CH3 CH3 CH3 CH3 CH3 Si Si Si Si Si Si O H3C H3C O H3C O H3C O H3C O H3C O n Tg = -123C, Tm = -60C H H H H H C H H n C C H H H C C H H H C C H H C C H H C H H C H H C H H H Tg = -120C; Tm = 140C EMA 4161C Phys Prop Poly - University of Florida Copyright 2009 EMA 8 CH3 CH3 CH3 CH3 CH3 CH3 Si Si Si Si Si Si O H3C H3C O H3C O H3C O H3C O H3C O n Tg = -123C, Tm = -60C H H H H H C H H n C C H H H C C H H H C C H H C C H H C H H C H H C H H H Tg = -120C; Tm = 140C EMA 4161C Phys Prop Poly - University of Florida Copyright 2009 EMA 9 H H H H H C H H H H n C C H H C C H H C C H H C C H H C H H C H C H H H H Tg = -120C; Tm = 140C H H N H H H H H C C C C C C H H H H H H H H N C O H H H C C C C H H H H Tg = 55C; Tm = 265C Tg EMA 4161C Phys Prop Poly - University of Florida Copyright 2009 EMA O C n 10 H H N H H H H H C C C C C C H H H H H H H H N C O H H H C C C C H H H H O C Tg = 55C; Tm = 265C n H H N N O C C O n Tg > Td EMA 4161C Phys Prop Poly - University of Florida Copyright 2009 EMA 11 EMA 4161C Phys Prop Poly - University of Florida Copyright 2009 EMA 12 Importance of Chemistry Importance B io p o ly m e r s P o ly s a c c h a r id e s P r o te in s G e n e tic C o d in g S tru c tu ra l e g . C o lla g e n S tru c tu ra l e g . C e llu lo s e , C o tto n C a ta ly s is eg. enzym es P o ly n u c le o tid e s eg. D N A, R N A 13 EMA 4161C Phys Prop Poly - University of Florida Copyright 2009 Importance of Chemistry Importance Protein Tertiary Structure Conformational Structure HEAT HEAT COOL COOL HEAT COOL EMA 4161C Phys Prop Poly - University of Florida Copyright 2009 14 Chain Dimensions Chain Rotational Isomers Rotational Ref: Chem Draw Pro – ethane_conformers Ref: • Staggered conformation – Erot~ 0 kJ/mol, Φ = kJ/mol, 60, 180, 300 deg. 60, • Eclipsed - Erot~ 12 kJ/mol, Φ = 0/360, 120, 240 Eclipsed 12 deg. deg. • Staggered 0 kJ/mol < Erot < 0 kJ/mol, Staggered kJ/mol EMA 4161C Phys Prop Poly - University of Florida Copyright 2009 EMA 15 Chain Dimensions Chain Ethanes Rotational Isomer Energies States Ethanes EMA 4161C Phys Prop Poly - University of Florida Copyright 2009 EMA 16 Chain Dimensions Chain n-Butane Conformational States n-Butane Ref: Chem Draw Pro file – butane conformers EMA 4161C Phys Prop Poly - University of Florida Copyright 2009 EMA 17 Chain Dimensions Chain Local Steric Repulsion Local EMA 4161C Phys Prop Poly - University of Florida Copyright 2009 EMA 18 Analytical Analysis of Chain Structure Analytical Method Principle Application Spatial Resolution Analytical Sensitivity Nuclear Magnetic Resonance Magnetic dipole response to induced field Configuration, composition, chemical structure ~0.1 nm High X-ray induced emission of electrons structure Chemical of surface 10-150 Å 0.1 Atom % XPS (Xray photon spectroscopy or ESCA) Auger Spectroscopy Focused ion beam induced emission ofStructure Chemical Auger electrons 100 Å of Surface 0.1 Atom % SIMS (Secondary Ion bombardment induced emission of secondary ions 100 Å Chemical sequence, degradation products ppb Ion Mass Spectrometry) FTIR-ATR (Fourier Transform Infrared Spectroscopy – Attenuated Total Reflectance) UV-Vis IR excitation/adsorbance induces vibrational modes Chemical composition, configuration, conformation 10 μm 1 mol % Adsorption/Transmission proportional to dielectric constant Sequence length, conformation, spatial analysis 1Å ppm EMA 4161C Phys Prop Poly - University of Florida Copyright 2009 19 Chain Dimensions Chain Conformational States Conformational Number of Conformation States is: N = RIS n −1 RIS = Number of Rotational Isomeric States (Gauche+, Trans, Gauche-) n = number of sigma bonds in chain backbone N = 1 x 104770 for PE where Xn ~ 10,000 EMA 4161C Phys Prop Poly - University of Florida Copyright 2009 EMA 20 Chain Dimensions Gaussian Chain • Random Chain Random Conformation Conformation • End-to-End End-to-End Distance <ro> Distance • Radius of Radius Gyration <rg> Gyration EMA 4161C Phys Prop Poly - University of Florida Copyright 2009 EMA 21 Chain Dimensions • Gaussian Chain • End - to - end Gaussian End or random chain: distance and radius or of gyration : – Gaussian of Gaussian distribution of RIS, I.e., trans and gauche states states – characteristic characteristic dimensions based upon molar mass, chain structure and temperature temperature EMA 4161C Phys Prop Poly - University of Florida Copyright 2009 EMA 22 Chain Dimensions Chain n r 2 = mi ri 2 ∑ i =1 n ∑m i =1 s 2 i End to End Distance = r 2 6 Radius of Gyration m - mass of repeat unit (segment) r - vector form center of gravity to atom i EMA 4161C Phys Prop Poly - University of Florida Copyright 2009 EMA 23 Solid-State C13 NMR - HDPE NMR EMA 4161C Phys Prop Poly - University of Florida Copyright 2009 24 Summary • Chain Chemistry defines structure. • Chain bond rotational potential Chain energies dictate properties energies • Balance of three energies defined by Balance structure/processing structure/processing • Characteristic dimensions defined by Characteristic structure and environment structure EMA 4161C Phys Prop Poly - University of Florida Copyright 2009 EMA 25 References • Introduction to Physical Polymer Science, 4th Edition, Lesley H. Sperling, Wiley Interscience (2006) ISBN 13 978-0-471-70606-9 ISBN • Principles of Polymer Chemistry, P.J. Flory (1953) Principles Cornell University Press, Inc., New York. Cornell • The Physics of Polymers, Gert Strobl (1996) The Springer-Verlag, New York. Springer-Verlag, • Figures were reproduced from Polymer Physics, Figures (1996) Ulf Gedde, Chapman & Hall, New York. (1996) EMA 4161C Phys Prop Poly - University of Florida Copyright 2009 EMA 26 ...
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