Lecture20 - EMA 6165 - Polymer Physics Glass Transition...

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Unformatted text preview: EMA 6165 - Polymer Physics Glass Transition Trends Lecture 20 Dr. Anthony Brennan University of Florida Department of Materials Science & Department Engineering Engineering EMA 6165 Polymer Physics – AB Brennan EMA 1 Agenda • Glass Transition values – Organic Organic – Inorganic Inorganic • • • Thermodynamic Treatment of Tg Kinetics of Tg Physical Aging Behavior EMA 6165 Polymer Physics – AB Brennan EMA 2 Structural: Tacticity, etc. Temperature Transitions Suggested Mechanisms 433 K (1600 C) Tl,l Liquid-liquid2 Tg Long-range chain motions Torsional vibrations of phenyl groups 373 K (1000 C) 325 + 4K (~500 C) β EMA 6165 Polymer Physics – AB Brennan EMA 3 Tables Polymer • Polyethylene • Polypropylene • Polybutene-1 Tg -1200 C -80 -13 -13 -8 -8 atactic isotactic syndiotactic -25 EMA 6165 Polymer Physics – AB Brennan EMA 4 Tables Polymer Tg • Polyisobutylene -73 • Polystyrene +100 isotactic, syndiotactic • Poly(vinyl chloride) (PVC) (PVC) +80 EMA 6165 Polymer Physics – AB Brennan EMA 5 Tables Tg Polymer • Polydimethyl siloxane Polydimethyl (PDMS) -123 • Polybutadiene -85 • Polycaprolactone -60 EMA 6165 Polymer Physics – AB Brennan EMA 6 Tables Polymer • Poly(vinylidene Poly(vinylidene fluoride) fluoride) Tg -45 • Polyoxymethylene, Polyoxymethylene, Poly(ethylene oxide) Poly(ethylene -85 • Poly(vinyl alcohol) +85 EMA 6165 Polymer Physics – AB Brennan EMA 7 Tables Polymer • Polytetrafluoroethylene Tg none • Poly(hexamethylene Poly(hexamethylene adipamide) Nylon 6,6 adipamide) +49 • Poly(ethylene Poly(ethylene terephthalate) terephthalate) +69 EMA 6165 Polymer Physics – AB Brennan EMA 8 Tables Tg Polymer • Polycarbonate +150 • Polysulfone +190 • Cis-1,4-polyisoprene -73 -73 EMA 6165 Polymer Physics – AB Brennan EMA 9 Tables Polymer • Poly(vinyl acetate) Tg +30 • Poly(methyl Poly(methyl methacrylate) methacrylate) +105 atactic • Poly(2,6-dimethyl1,4-phenylene oxide) +220 +220 EMA 6165 Polymer Physics – AB Brennan EMA 10 Glass Transition Side Chain Methyl Ethyl n-Propyl Iso-Propyl n-Butyl Iso-Butyl Sec-Butyl Cyclohexyl Isotactic 10 -25 -11 -23 12 Syndiotactic 8 -24 -44 -6 -49 -24 -22 19 EMA 6165 Polymer Physics – AB Brennan EMA 11 Effect of Tacticity on Polymethacrylates Side Chain Isotactic Syndiotactic 100% Methyl 43 105 160 Ethyl 8 65 120 n-Propyl 35 Iso-Propyl 27 81 139 n-Butyl -24 20 88 Iso-Butyl 8 53 120 Sec-Butyl 60 Cyclo_hexyl EMA 6165 Polymer Physics – AB Brennan 51 104 163 12 EMA Structural: Tacticity, etc. • Crystallinity: Variable q Molecular weight: Increases to limiting of persistant Tg q Diluents q Thermal History q Pressure: ∂ Tg 0 ≈ 0.025 C bar ∂P EMA 6165 Polymer Physics – AB Brennan EMA 13 Structural: Tacticity, etc. Increase T Decrease Tg • In-chain groups In-chain promoting flexibility (double bonds and ether linkages ether • Flexible side groups • Symmetrical Symmetrical substitution substitution EMA 6165 Polymer Physics – AB Brennan EMA 14 Structural: Tacticity, etc. Temperature Transitions 130 K γ Suggested Mechanisms Motions due to four carbon backbone moieties δ Oscillation or wagging of phenyl groups 38-48 K EMA 6165 Polymer Physics – AB Brennan EMA 15 Summary • Glass Transition behavior is Glass characteristic of all glasses characteristic • Glass transition behavior is Glass dependent upon structure, thermal history, pressure and rate history, • Short range and long range molecule Short diffusion differentiate glass transition from other thermodynamic transitions transitions EMA 6165 Polymer Physics – AB Brennan EMA 16 References • Introduction to Physical Polymer Science, 3rd Edition, Lesley Introduction H. Sperling, Wiley Interscience (2001) ISBN 0-471-32921-5 • Principles of Polymer Chemistry, P.J. Flory (1953) Cornell Principles University Press, Inc., New York. University • The Physics of Polymers, Gert Strobl (1996) Springer-Verlag, The New York. New Some figures were reproduced from Some • Principles of Polymer Chemistry, P.J. Flory (1953) Cornell Principles University Press, Inc., New York. University EMA 6165 Polymer Physics – AB Brennan EMA 17 ...
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