11. Radical Reactions

Propose a mechanism for reaction of the first three propylene units in the polymerization of propylene in the presence of a peroxide.

When styrene (vinylbenzene) is commercially polymerized, about 1–3% of 1,4-divinylbenzene is often added to the styrene. The incorporation of some divinylbenzene gives a polymer with more strength and better resistance to organic solvents. Explain how a very small amount of divinylbenzene has a marked effect on the properties of the polymer.