Propose a mechanism for reaction of the first three propylene uni...

Question

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

Accepted Answer

Okay. Hi everyone. So for this problem we have to write a mechanism for the polymer ization of the first three units of tetra floral ethylene using an out cock side as the chain initiator. So recall that when you have a polymer ization reaction, what you're doing is you're creating a polymer, right? So you're creating one large molecule made up of monitors, so repeating copies of one smaller molecule. So in this case our monomer here is tetra floral ethylene, which is a carbon carbon double bond With four flooring atoms attached to both. So two on each. So this is our starting material and our chain initiator here is an out cock side. So it's an oxygen with some our group. And because it's a chain initiator, we know that it must have been made into a radical prior to this reaction taking place. So when you have radicals, you have to remember to draw your fishhook arrows, right? So arrows with only one hook to indicate that only one electron is being transferred here. So let's get started with our reaction. When you have a polymer ization reaction, a radical polymer ization reaction, We have a joining of two electrons, one from each material. So what's going to happen first is that this double bond is going to essentially separate one electron is going to move to the left side and the other is going to actually unite with our chain initiator. So something like that. And we end up with a product that looks something like this. So we have our carbon chain Or two florins are still intact. But now we have our o. Are attached to it instead. And on the left side we now have another radical. We now have another radical which is then going to react with our second unit of tetra floral ethylene. Now I'm going to draw the second molecule of tetra floral ethylene in green. But I don't want you to get confused. It's the same molecule. I just want you guys to be able to see how each of the units are being connected to each other. So let's go ahead and repeat this process by having um one electron of the double bond here go towards the right this time and the other is going to join with the first monomer of tetra flora ethylene. So they're going to kind of bridge together like that and we proceed to the next step. So for this one um please bear with me while I'm drawing the next step because these molecules are getting a little complicated. So we have our initial materials, right? That's our f But now we have our florian's like that and we have yet another radical. We have yet another radical which surprise surprise, is going to react with our third um molecule of tetra floral athletes. So I'm going to scroll down and give myself some more space so that we can draw our final polymer ization reaction. So this is tetra floral ethylene but in red so that you guys can see how the units are joining together. And now our electrons are going to join together. Or one electron from this radical and another electron from the double bond of tetra floral ethylene. So the other is going to jump to this other side, the right side. So our final product ends up looking like this. Mhm Yeah. Yeah. Mhm Alright. And this is going to be our final product for the sake of this um example. But we still have a radical right at the very end of the chain. So technically this reaction is going to keep is going to proceed. But because we only have to show the first three units, this is our final answer. So once I finish highlighting, I'm going to do a quick scroll through so that you can see everything that we just did. So this is our final answer. I'm going to grow up to the top here and I'm just going to scroll down right because we have our Alcock side ring as the chain initiator. And then as the radicals form, we have touched a floral ethylene reacting to itself and adding onto this chain. So thanks so much for watching. And I hope this helped

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

Watch next