In the following multiple-choice problems, circle the one answer which best completes the Sentence (i) (iii) (iv) (v) The glass transition temperature of polystyrene is about 110 °C. Relative to a sample at 120 °C, at room temperature polystyrene is: a. orders of magnitude more viscous b. slightly more viscous c. equally as viscous less viscous d. e. none of the above. The glass transition temperature of polystyrene is about 110 °C. Relative to a sample at 120 °C, a sample of polystyrene at 130 °C is: a orders of magnitude more viscous b. slightly more viscous c. equally as viscous d. less viscous e. none of the above. Suppose a tensile test is performed on two identical materials except that one has a deep scratch on its surface whereas the other is perfectly smooth. Relative to the smooth specimen, the test will find that the scratched specimen has a lower. a. elasticity b. yield stress c. tensile stress d. elongation to failure e. none of the above. Thermoplastic polymers such as…

V. Using the figure/data below, answer the following questions for polystyrene: (a) What is the specific free volume at 120°C? (b) What is the specific free volume at 80°C? ag "24 x 104 1ºc OR "55x 104 10C Spacific Volume 100°C Temperature, OC

Identify reagents A and B in the following reaction scheme. This synthetic sequence was used to prepare the C16 juvenile hormone (Figure 20.6). он OH (excess) (excess) several steps several steps čo,CH3 OH OH C18 juvenile hormone