1. Write out the detailed mechanism for the radical chain polymerization of styrene (vinylbenzene), designating the three stages of the chain mechanism, and giving the repeat structure for the polymer. What is the significance of the subscript "n" in the repeat structure? Why is this an average value? What term is used to describe the extent to which a polymer product contains individual polymer molecules which have a wide or narrow range of molecular weights?

2. Draw the dotted line/partial radical character strucutre for the TS of a typical propagation step for this reaction and explain, using the Method of Competing TS's (draw both competing TS's), the preferred regiochemistry of the polymerization. What terminology is used to describe this specific type of regiochemistry?

3. In the radical chain polymerization of ethene, the polyethylene obtained is referred to as "low density" polyethylene (LDPE). Explain, both in mechanistic/chemical terms, including structural depictions, and in solid state/physical structural terms why this polyethylene is "low density". What effect does this have on the physical properties of the polymer?

4. Explain why the polymers obtained from the radical chain polymerization of vinyl chloride, styrene, or acrylonitrile are unbranched.

5. Write out a rough mechanism for the Ziegler-Natta polymerization of ethylene and explain why this polymer is termed "high density" polyethylene (HDPE).

6. Write out a mechanism for the radical chain polymerization of isoprene (2-methyl-1,3-butadiene). Draw the repeat structures for both natural rubber and the polyisoprene which results from radical polymerization.Then explain how these structures differ and why the Ziegler-Natta catalytic system is able to polymerize isoprene to a polymer which is identical to natural rubber.

7. Write the mechanism for the anionic polymerization of oxirane (ethylene oxide). Use ethoxide ion as the base. Name and write the structures of two other monomers which are readily polymerizable by the anionic method. Name and write the structures of two monomers which can be polymerized by the cationic method.

8.Sketch the mechanism for the thermal copolymerization of 1,6-hexanediamine and adipic acid, showing the structure of the nylon salt obtained upon mixing the two monomers and then the structure of the first "dimer" and one of the two possible "trimers" obtained upon heating. Then draw the repeat structure of Nylon 66. Why is it called "66"? What is Nylon 6 and how is it obtained?

9.Describe the difference between chain growth and step growth polymerizaiton. Specify one experimental test for making this distinction.

10. Explain why polystyrene is soluble in organic solvents, but the copolymer of styrene with a few percent of 1,4-divinylbenzene is highly insoluble. What term is used to describe this kind of polymer?