Fall_2007_Exam_1 - POLYMER PROCESSING FALL 2007 EMA 4666C...

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POLYMER PROCESSING - FALL 2007 PUT NAME ON LAST PAGE and SIGN HONOR CODE EMA 4666C – EXAM 1 STUDENT No.:______________________ INSTRUCTIONS: Read the entire exam carefully . Answer every question to the best of your ability, based upon the available information. State all assumptions in answers. SECTION I: Polymer Structures/Properties. (2 pts each/12 pts total) 1. Draw the structural repeat units for the following polymers. 2. Indicate the type of polymerization process used to synthesize each of the structures, i.e. condensation, addition, ring opening. 3. State the relative Tg and/or Tm for each polymer. If a Tm is not expected indicate by NA. Polymer Structural Repeat Unit Process Tg Tm 1. poly(ethylene) 2. poly(propylene) 3. poly(hexamethylene adipamide) (Nylon 6,6) 4. poly(methyl methacrylate) 5. poly(styrene) 6. poly(bis phenol A carbonate) rev a
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Student Number:___________________________ Concepts. (2pts ea/12pts total) Answer the following statements with TRUE or FALSE . If the statement is false, state the reason(s). If you believe a statement can be made TRUE by a simple qualifier, then state it clearly. HINT: Normally one word can be modified to correct false statements. 7. Physical aging is increased for an amorphous polymer by heating from Tg-20 ° C to Tg+20 ° C. 8. The crystal growth rate of a linear polyamide increases as the molecular weight is increased. 9. Annealing an amorphous polymer, such as polycarbonate, at ca. 10 degrees below the glass transition temperature decreases the post yield stress drop and elongation to failure. 10. Plastic (viscous) flow in a stress – strain experiment decreases as the Mz value of the polymer increases. 11. The polymer chain diameter in the crystal defines the heat of fusion for a single crystal of polyethylene 12. The tan delta is directly proportional to the storage modulus in a dynamic mechanical analysis. EMA 4666C Fall 2007 Exam 1 rev a 2
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Student Number:___________________________ Graphical Relationships: A. SHOW ALL EQUATIONS. B. EACH GRAPH SHOULD BE A LINEAR RELATIONSHIP. C. LABEL ALL AXES WITH THE APPROPRIATE UNITS . D. CLEARLY STATE ALL ASSUMPTIONS. 13. Sketch the general features of the storage modulus (E’) a function of temperature for poly(ethylene terephthalate) polymer. Label the major transition (s) and their magnitude relative to E’ (This is not a linear function) 3 pts 14. Sketch the DSC output profile for PETE film which was slowly quenched upon extrusion. Show both the heat-up and cool-down profiles of the extruded film.
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Fall_2007_Exam_1 - POLYMER PROCESSING FALL 2007 EMA 4666C...

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