3.064Quiz10/10/03 Sample questions 1. What is the glass transition temperature of a polymer How can it be measured? What molecular characteristics determine its value Illustrate by giving the chemical structure and Tg for polyethylene polyvinyl chloride and polystyrene 2. What is the glass transition temperature" of a polymer How can it be measured? What molecular characteristics determine its value? Illustrate by giving the chemical structure and Tg for polyethylene polypropylene and polystyrer 3. Draw the chemical formulas for polydimethyl siloxane, polyethylene, polypropylene, polyvinyl chloride, polymethyl methacrylate polystyrene, polytetrafluoroethylene, polycarbonate, and polyethylene terephthalate 4. For each of the previous polymers, give the approximate glass transition temperature, the percent crystallinity, and some principal market applications 5. Describe the role of polarity and topology on glass transition temperature 6. Draw plots of modulus versus temperature for various polymers: amorphous, crystalline, crosslinked, non-crosslinked. Explain why the plots have the shape they do 7. Why is Teflon so good as a non-stick surface? How do they get it to stick to the pan? Explain what a spherulite is, and describe the effect of spherulite size on polymer mechanical properties 9. Explain how the molecular weight distribution of a polymer can be measured by size exclusion chromatography. Sketch the form of the raw data obtained from this instrument, and state how the number and ght average me r weight can be obtained from the data 10. Explain the effect of molecular weight on tensile strength and f an of tra-high molecular weight polymer3.064 Quiz 10/10/03 Sample questions 1. What is the “glass transition temperature” of a polymer? How can it be measured? What molecular characteristics determine its value? Illustrate by giving the chemical structure and Tg for polyethylene, polyvinyl chloride and polystyrene. 2. What is the “glass transition temperature” of a polymer? How can it be measured? What molecular characteristics determine its value? Illustrate by giving the chemical structure and Tg for polyethylene, polypropylene and polystyrene. 3. Draw the chemical formulas for polydimethyl siloxane, polyethylene, polypropylene, polyvinyl chloride, polymethyl methacrylate, polystyrene, polytetrafluoroethylene, polycarbonate, and polyethylene terephthalate. 4. For each of the previous polymers, give the approximate glass transition temperature, the percent crystallinity, and some principal market applications. 5. Describe the role of polarity and topology on glass transition temperature. 6. Draw plots of modulus versus temperature for various polymers: amorphous, crystalline, crosslinked, non-crosslinked. Explain why the plots have the shape they do. 7. Why is Teflon so good as a non-stick surface? How do they get it to stick to the pan? 8. Explain what a spherulite is, and describe the effect of spherulite size on polymer mechanical properties. 9. Explain how the molecular weight distribution of a polymer can be measured by size exclusion chromatography. Sketch the form of the raw data obtained from this instrument, and state how the number and weight average molecular weight can be obtained from the data. 10. Explain the effect of molecular weight on tensile strength and viscosity. Give an example of an application of an ultra-high molecular weight polymer