There was some discussion at last year’s Mars Society Conference on the use of locally-synthesized plastics — polyethylene in particular — for a variety of construction and other uses in a Mars settlement.
The Macrogalleria has introductory-level overviews on all the major/common plastic materials, including the basics on how they are synthesized.
For those who’ve never studied polymers, it may come as a surprise to learn just how simple plastics really are, in terms of the elements involved. Polyethylene, for example, is simply a long chain of ethylene monomers — two carbon atoms flanked by two hydrogens each.
Polypropylene, another common but more thermally-stable plastic, is a slightly more complex arrangement of the same elements, with a methyl (CH3)group replacing one of the hydrogens in the ethylene monomer.
Taking it one step further, replacing the second hydrogen atom on the same carbon with another methyl group, gives you polyisobutylene, also known as butyl rubber — the only rubber which is gas impermeable. Imagine the potential uses for a material with thatproperty in a Martian settlement.
So, three common and useful polymer materials can be produced from elements which are known to exist in substantial and available quantities on Mars. How do we aquire these elements from their available forms, and what is required to turn them from feedstocks into polymers?