Ask A Scientist Chemistry Archive

name         Michelle L. W.
status       student
age          20s

Question -   Why can't tires be broken down chemically and the materials reused?
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Michelle,

Tires can be recycled by chopping them up and separating the metal re-enforcing wires from 
the rubber chunks. The wire (steel) is itself recycled. Instead of using sand or other 
paving materials, the rubber chunks find use as jogging track surfaces and filler around 
playground materials such as swings and slides. Also, there has been some work done on 
using very fine rubber chunks as an additive to molten asphalt used to make paving 
surfaces. This is possible because the molten asphalt partially dissolves the rubber 
polymer.

Tires are not used to make new tires because the process of polymerization and 
vulcanization used to make a tire are not easily reversed chemically to produce 
new starting materials.

Regards,
ProfHoff 724
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Because a tire is a complex product -- not just rubber -- breaking it down chemically 
into useful, economical products is challenging. However, that does not mean that scrap 
tires have no use. Click on the web site: http://www.ciwmb.ca.gov/Tires/Products/ for a 
short list. If you do a Google search on the search terms: "recycled tires uses" you 
will find much more details.

Vince Calder
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