The behavior of most synthetic polymers during pyrolysis may be described as one of three general cases. Either the polymer breaks apart into smaller versions of the macromolecule, producing oligomers, unzips all the way to monomer, or eliminates side groups and then fragments. Polyolefins like polyethylene and polypropylene are examples of polymers which produce a large array of oligomeric material, including monomers, dimers and trimers, but also fragments with ten or more monomeric units. Poly methacrylates, such as poly methyl methacrylate, unzip to produce a large peak for the monomer and very little else. Vinyl polymers like PVC and poly vinyl acetate first strip away the side group, making HCl or acetic acid, then produce aromatic compounds from the remaining backbone of the polymer. In all cases, these degradation products are reproducible and characteristic and may be used to identify polymers in an unknown formulation.
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