Documents about Glass Transition Temperature
ps_3
Stevens, PS 344
Excerpt: ... Problem Set 3 Due: Thursday, 10 February, 2005 at beginning of lecture From Sections 3 and 4 Problems posted on the Core. 3.19 BCC unit cell 3.20 - Nickel 3.21 Fe atomic size 4.4 - Glass transition temperature 4.6 fused silica and soda lime glass 4.8 - viscosity E-344 Spring 2005 ...
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5t
Stevens, E 344
Excerpt: ... What is the difference between the melting temperature of a polymer and the glass transition temperature of a polymer. ...
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P4_10
Stevens, E 344
Excerpt: ... Is the glass transition temperature for a piece of window glass above or below room temperature? Why? ...
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4f
Stevens, E 344
Excerpt: ... Is the glass transition temperature for a piece of window glass above or below room temperature? Why? ...
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5o
Stevens, E 344
Excerpt: ... Is the glass transition temperature of an elastic band above or below room temperature? Briefly justify your answer. ...
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Problem core 5.16
Stevens, E 344
Excerpt: ... Is the glass transition temperature of an elastic band above or below room temperature? Briefly justify your answer. ...
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5t
Stevens, E 344
Excerpt: ... What is the difference between the melting temperature of a polymer and the glass transition temperature of a polymer. ...
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Problem core 4.10
Stevens, E 344
Excerpt: ... Is the glass transition temperature for a piece of window glass above or below room temperature? Why? ...
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Problem core 5.20
Stevens, E 344
Excerpt: ... What is the difference between the melting temperature of a polymer and the glass transition temperature of a polymer. ...
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Hmwk02
Utah, MSE 6481
Excerpt: ... n: C p = R = 1 2 TV() 3. The Tait equation is an empirical equation which can be used as an equation of state for equilibrium polymer melts or for quasi-equilibrium polymer glasses. A paper by Zoller, Bolli, Hershe, and Pahud (Kunststoffe, 66, 363 (1976) gives a fit to the Tait equation for polystyrene melts and for low-pressure solidified polystyrene glasses. The fits are: a. Tait Equation: V(T,P) = V(0,T) [ 1 - C ln (1 + P )] B(T) (Note: C = 0.0894 and T will always be in C) b. Polystyrene Melt: 1 V(0,T) = A0 + A1T B(T) = B0 exp(-B1T) c. Polystyrene Glass: V(0,T) = A0 + A1T B(T) = B0 exp(-B1T) with A0 = .9181 cm3/g and A1 = 0.5443e-3 cm3/g/C with B0 = 234.1 MPa and B1 = 3.41e-3 C-1 with A0 = .9481 cm3/g and A1 = 0.2243e-3 cm3/g/C with B0 = 353.5 MPa and B1 = 2.999e-3 C-1 Plot volume versus temperature for pressures of 0, 50, 100, 150, and 200 MPa. Graphically find the glass transition temperature as a function of pressure and also evaluate the pressure dependence of the glass ...
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Lab6-PolymerStrengthF06-1
Cal Poly, MATE 215
Excerpt: ... Laboratory 6 Polymers: Structure-Property Relationships with Tensile Testing Goal: To relate how a polymer's mechanical strength and ductility are linked to its molecular structure and to predict & explain the transition in strength above the glass transition temperature . Learning Objectives: 1. Define a polymer, and give some properties and applications of polymers. 2. Give situations or applications in which a polymer might be used to replace a metal or ceramic. 3. Discuss how the bonding within the molecular chains vs. between the chains can affect properties. 4. Sketch, model, and describe the molecular structure (e.g., bonding, pendant groups) of polyethylene, polycarbonate, and polystyrene. 5. Explain how the structure of a thermoplastic affects its mechanical properties. 6. Rank the relative mechanical properties (such as stiffness, strength and ductility) of different polymers, based on their structure. 7. Explain the changes that take place at and then above the glass transition temperature (Tg ...
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MSE3003-StudyGuide-II
UConn, MSE 3003
Excerpt: ... MSE 3003: Study Guide Midterm II 1. Fick's first law (12.1) a. Diffusivity for various crystal structures (12.1 & 12.8) 2. Kirkendall effect (12.2) 3. Darken's equation (12.4) a. This leads to Fick's second law, and helps determine the diffusivities of components by solving 2 equations b. A good description of marker velocity can be found in (12.7). You will need this to solve Darken's equations. Section 12.7 also contains a nice worked out problem 4. Temperature dependence of D, dependence on grain boundary versus bulk (12.9, 12.12) 5. Diffusion in non-isomorphous alloy systems (12.14) 6. Interstitial diffusion a. Snoek effect (13.2 first half) b. Measurement of time constant or relaxation time using torsional pendulum (13.3) 7. Phases of matter [The liquid phase (14.1)] a. Liquid closer to solid than to gas b. Radial distribution function (short-range vs. long-range order) c. Phase diagram vs. free energy curves 8. metallic glasses (14.3) a. glass transition temperature b. metallic glasses deep eutecti ...
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4_mc
Stevens, E 344
Excerpt: ... The glass transition temperature of window glass is: a) the same as the melting temperature; b) greater than the melting temperature; c) above room temperature; d) below room temperature; e) none of the above. ...
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4_mc
Stevens, E 344
Excerpt: ... The glass transition temperature of window glass is: a) the same as the melting temperature; b) greater than the melting temperature; c) above room temperature; d) below room temperature; e) none of the above. ...
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Term_Paper
Stanford, CHEME 160
Excerpt: ... echanism of small molecule diffusion in glassy polymers Physical aging in glassy polymers Morphology and conformational structure of polysilanes (or other polymers) Molecular structure-property relationships in side-chain liquid crystal polymers Application of fluorescence spectroscopy to studies of polymer morphology Application of solid-state NMR to studies of polymer dynamics Structure and Dynamics of Polymer Interfaces Surface-initiated polymerization Adhesion of polymers to metal substrates Theory of polymer adsorption from solution Effect of constrained geometry on glass transition temperature Surface segregation in block copolymers Monte Carlo simulation of polymer interfaces Rheology and Procesing Dynamics of polymers in dilute solution Lyotropic solution properties and processing of polyamic acids Constitutive equations and director tumbling in flow of liquid crystal polymers Structure-property-processing of polyetherimides (or other engineering polymer) Rheology of polymers in pseudo-two-dimension ...
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F98mtm
Youngstown, CHEM 824
Excerpt: ... a random coil from a rigid rod 5 5. (a) What is end group analysis (i.e. what specific information about the polymer does end group analysis tell you and why)? (b) Briefly describe three specific techniques for doing end group analyses. (c) What are the strengths and weaknesses of end group analysis compared to other techniques. 6 (6) (a) Clearly explain what happens to the structure of a polymer as one approaches its glass transition temperature . (b) What is the likely level of agreement between Tg values measured on identical samples in different labs using different techniques? Clearly explain your reasoning. (c) A sample of polypropylene has a glass transition temperature of +5 while a sample of polyvinyl chloride has a glass transition temperature of +81. Clearly explain this difference. ...
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CA81
Norwich, CH 104
Excerpt: ... ature of the polymer increases it approaches T g , the glass transition temperature . The glass transition temperature is the temperature above which the polymer chains can move with respect to each other. The polymer is now a flexible thermoplastic, bendable and rubbery. Finally, the temperature reaches the melting point, T m , and a liquid is formed. At this point the polymer is easily molded or extruded. The fact that both T g and T m are reached before the polymer undergoes chemical decomposition makes the polymer a thermoplastic rather than a thermoset plastic. Thermoplastic Properties Depending on Temperature Decomposition Products T g and T m of Common Polymers in /C polymer polyisoprene (rubber) teflon polyethylene (linear) polypropylene polyvinylchloride polyvinylalcohol polystyrene polycarbonate Tg ! 75 ! 65 ! 60 ! 10 81 85 90 150 Tm 30 325 135 165 273 265 230 265 - Td -Liquid - Tm -Flexible Thermoplastic - Tg -Crys ...
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ps_3
Stevens, E 344
Excerpt: ... al reaction. 9. a. b. c. d. e. A thermoplastic polymer: melts or softens when heated; becomes brittle if cooled below its glass transition temperature ; does not involve covalent crosslinks; may be amorphous, semicrystalline, or crystalline, depending on the polymer; all of the above. 10. A good example of a metallic alloy is: a. a sample of pure aluminum (Al); b. a sample consisting of a small amount of pure copper (Cu) dissolved into pure Al; c. a sample of aluminum oxide (Al2O3); d. a single alumium atom; e. none of the above. Page - 3 ...
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259 11-16-05
Penn State, EMS 259
Excerpt: ... gions - alignment gives greater strength to fiber Kevlar is highly aligned Breaking strength of polymer fibers (tenacity) 1. measure denier (wt. in grams of 9000 meters of fiber) 2. run tensile test Tenacity also increases w/ chain length - fewer crystal defects Glass transition temperature (Tg) Molecular wt. Glass transition temperature (Tg) Chemical structure Glass transition temperature (Tg) Chain stiffness Glass transition temperature (Tg) Chain stiffness Glass transition temperature (Tg) Bulky side groups Assignment: Review today's classnotes a. crystallinity in polymers b. chain folding c. spherulites d. tenacity e. glass transition temperature ...
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603a01
RIT, SCHM 703
Excerpt: ... SCHM-503/703: Assignment #1 Polymer Chemistry: Bulk Materials due 9/14/04 Fall 04-1 Problem #1: Getting Familiar With Your Resources A) Sketch the monomers and polymers given in the table on pg. 2-12. B) Use the internet to find: a) the melt temperature, Tm, of poly(ethylene terephthalate) b) the glass transition temperature , Tg, of PMMA. C) Use SciFinder to find an article on one of the following topics, and print the abstract for the article. a) Core-Shell Emulsion particles containing polystyrene b) Polymers incorporating "nanotubes" c) Polymers for fuel cell membranes d) Polymers from biomass D) Use the internet to find an application of: (give the URL): a) a polymer/clay composite b) a block copolymer c) a polymer IPN Problem #2: The Main Concepts A) Briefly discuss the difference between step-growth and chain-growth polymerization. Include characteristics of the monomer used in the two processes. B) The repeat structure for oil, grease, candle wax and polyethylene are identical. Briefly describe why ...
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Quiz-5-soln
Texas A&M, ENGR 213
Excerpt: ... Name_ Team No._ ENGR 213 Quiz 5 16 OC 02 CLOSED BOOK and NOTES, INDIVIDUAL WORK 1. List the four mechanisms of metal strengthening. 4 pts solid solution alloying grain size reduction precipitation hardening (introducing second phase) cold working/strain hardening 2. Grain growth is a method to restore material properties. What is the driving force for grain growth? 2 pts Increasing grain size lowers the potential energy of the system because of the reduction in surface area If the grain structure is too coarse (ie grains too large) in a single-phase alloy, what procedure can be applied? 2 pts Applying plastic deformation followed by heating to produce recrystallisation 3. Why does plastic deformation not occur for some ceramics? 3 pts Noncrystalline ceramics do not have a regular atomic structure, so deformation Occurs by flow rather than dislocation movement 4. What is the glass transition temperature (1 pt), its typical range of values (1 pt), and describe why a polym ...
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short
Maryville MO, KOESTERE 120908
Excerpt: ... PROPERTIES OF EXTRUDED WHITE CORN FLOUR HIGH AMYLOSE CORN STARCH PUFFS Elizabeth Koester Fu-hung Hsieh, Thesis Supervisor ABSTRACT This study was conducted to determine the effect of high-amylose corn starch in corn puffs on the extrusion parameters, product and textural properties and the glass transition temperature . The data was analyzed in a randomized complete block design (RCBD) in which the treatments were arranged in a 4 x 3 x 3 {high-amylose content (0, 20, 40 and 60%) x moisture content (20, 22, and 18 or 24%) x extruder screw speed (200, 300 and 400 rpm)} factorial arrangement of treatments with two replicants. The collected results indicate that the maximum amount of expansion occurs when the screw speed and moisture content are both decreased and the high-amylose corn starch content is increased. The puff density increased and the specific volume decreased when screw speed and starch content decreased and moisture content increased. While the original puff breaking strength and hardness were ...
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HW05
Case Western, ENGR 145
Excerpt: ... ENGR 145 Chemistry of Materials Spring 2007; rev. 2/16/07 Homework Assignment #5 covering lectures 12 - 15 Due Tuesday, February 27, 2007 Show your work or otherwise explain how you arrived at your answers. 1) Callister problem 15.25 2) Callister problem 15.27 3) Callister, problem 6.12 4) Callister, problem 6.14. What additional mechanical property of the alloy must be known, and what value must it have, to ensure that the deformation will be only elastic? 5) Callister, problem 6.29 6) Callister, problem 13.41 7) Callister, problem 16.1 Also estimate the modulus of elasticity for this material at 4 C and 40 C. 8) Based on the data shown in Callister Figure 16.3, estimate the glass transition temperature for polymethyl methacrylate. Justify your answer. 9) Callister, problems 4.1 and 4.3 10) Callister, problem 4.4 Case School of Engineering 1 of 1 Case Western Reserve University ...
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3_mf
Stevens, E 344
Excerpt: ... An amorphous solid: a. b. c. d. e. is also referred to as a glass; is not crystalline; does not deform at appreciable rates below its glass-transition temperature, Tg; flows under stress at temperatures above Tg; all of the above. ...
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