Answer to Question #95568 in Organic Chemistry for Bruno

Question

i) Polyethylene exists either as a linear (straight-chain) polymer or as a branched polymer. Which is in high-density form? Explain.
ii) Draw how H2C=CH2 can be polymerized. What type of polymerization is method is used?

Answer 1

1. Polyethylene with linear structure can easily crystallize, while branched polyethylene cannot, it has amorphous structure (up to 70%). That is why linear structured ethylene is higher in density than branch structured.

2. Linear polymer is made by polymerization of ethylene, branched is made by copolymerization with alkyl-branched comonomer. See the picture attached.