• Question: How is carbon dioxide turned into plastic?

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      Asked by macdonfr to Helen on 18 Jun 2013. This question was also asked by faithhowson, liamvlotman.
      • Photo: Helen Pritchard-Smith

        Helen Pritchard-Smith answered on 18 Jun 2013:

        There is a molecule called butadiene (http://en.wikipedia.org/wiki/1,3-Butadiene) and two of them can couple or stick together to create a 8 carbon long chain. When palladium (a metal present on the top row in the middle of the periodic table – can you find it?) is added, this 4 carbon molecule coordinates to it. When this happens with carbon dioxide present in large amounts in the atmosphere it can make a 6 atom (5 carbons and 1 oxygen) circular structure called a lactone (http://en.wikipedia.org/wiki/Lactone).

        This lactone has groups sticking out from it called alkenes and these can be thought of as (functional) handles. These handles can connect to other molecules or monomers. When you have two monomers together you can create copolymers (two or more monomers) these are also known as plastics (http://en.wikipedia.org/wiki/Copolymer).

        I will put a picture up of the lactone if i can. The reaction to make it is called telomerisation.

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