# HW1f10 - c. isotactic polypropylene or atactic...

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Homework 1 Due Tuesday 8/31/10 1. Calculate Mn, Mw, and PDI for the following sample of polystyrene: mass used (g) DP 10 1000 2 1500 8 2000 5 2500 2. You are designing a crane with a steel cable that will be used to pick up objects. The radius of the cable is 10 cm, and the yield strength of the steel is 1070 MPa. Assuming a design factor of 2, what is the maximum force that can be sustained by this cable? 3. The density of PET with 74.3 wt% crystallinity is 1.408 g/cm 3 , and the density of PET with 31.2 wt% crystallinity is 1.343. g/cm 3 . a. Calculate the densities of completely amorphous and completely crystalline PET. b. Calculate the wt% crystallinity of PET with a density of 1.382 g/cm 3 . 4. For each of the following indicate which is more crystalline, or if they are the same, or if you cannot determine, and provide a brief (1-2 sentence) explanation why. a. HDPE or LDPE b. atactic polystyrene or atactic polypropylene
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Unformatted text preview: c. isotactic polypropylene or atactic polypropylene d. isotactic polypropylene or isotactic PVC e. PET heated to 270˚ C and then rapidly cooled to room temperature, or PET heated to 270˚ C, cooled to 150˚ C, held there for 30 minutes, then rapidly cooled to room temperature. 5. For each of the following indicate which has the higher Tg, or if they are the same, or if you cannot determine, and provide a brief (1-2 sentence) explanation why. a. HDPE or LDPE b. atactic polystyrene or atactic polypropylene c. isotactic polypropylene or atactic polypropylene d. isotactic polypropylene or isotactic PVC e. polystyrene with Mn of 100,000 g/mol or polystyrene with Mn of 200,000 g/mol 6. Explain why it is a mistake to name a compound 3-pentene. What would be the correct name of the compound?...
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## This note was uploaded on 11/16/2011 for the course EMA 3066 taught by Professor Douglass during the Fall '10 term at University of Florida.

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