THERE IS SUBSTANTIAL RISK IN MELTING/HEATING PLASTICS [ =POLYMERS ]Originally Posted by Sporqster
WITHOUT A FUME HOOD AND WITHOUT KNOWING EXACTLY WHAT IS IN THE PLASTICS.
IT IS NOT RECOMMENDED FOR THE REASONS LISTED BELOW AND SOME THAT DON'T
COME TO MIND:
1. There are two classes of polymers: thermoplastic and thermosetting.
The former will soften when heated; the latter will never soften, just
decompose, when heated. Bakelite is an example of the latter.
2. Some polymers produce toxic gases when heated. For example, vinyl
chloride produces HCl gas when heated.
3. Plastics are not pure materials; they are formulated products. Some
of the chemicals used to give the plastics their desired mechanical and
physical properties also form toxic vapors when heated. An example are the
common phthalate plasticizers.
4. Some polymers "unzip" when heated evolving monomer vapors. Acrylates
polymers are notorious for this. Acrylate monomers are toxic.
A safer route would be to use water dispensable gums [ e.g. algenates ]
like dentists use to form a denture. These harden and can be used to form
models from plaster of Paris, or self-reacting styrene formulations
available at hobby stores. Even in this case adequate ventilation is
necessary because styrene vapor is also toxic.