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

Verified step by step guidance

1. Step 1: Initiation - The peroxide (ROOR) decomposes under high pressure to form two alkoxy radicals (RO•).
2. Step 2: Propagation - One of the alkoxy radicals reacts with a propylene molecule (H2C=CHCH3) to form a new radical. This involves the addition of the radical to the double bond of propylene, creating a new carbon-centered radical.
3. Step 3: Propagation - The newly formed carbon-centered radical reacts with another propylene molecule, adding to its double bond and forming a longer carbon chain with a radical at the end.
4. Step 4: Propagation - The process repeats with the radical at the end of the growing chain reacting with another propylene molecule, further extending the polymer chain.
5. Step 5: Termination - The polymerization process can terminate when two radicals combine, either two growing chains or a growing chain and an alkoxy radical, resulting in a stable polymer chain.