What purpose does Bisphenol A serve in plastics? Does it make it stronger? More flexible?
(This isn’t a debate on whether or not it’s harmful to humans; just wondering why it’s used to begin with.)
In some plastics bisphenol A is an actual building block of the material. Take bisphenol A and another building block and polymerise them into an infinitely long chain / network and you have a plastic. The wiki for polycarbonate explains this in detail.
What the problem is, if in fact there is one, will be similar to the concerns regarding teflon. The polymer itself is very inert - that is often a feature and design point to these polymers. It will however contain tiny amounts of the unreacted monomer trapped in the polymeric structure. Mechanical abrasion, like scratching a teflon frying pan, can in theory release the monomer into the environment. If said monomer is toxic, and they are almost always quite reactive molecules, then that could be a problem.
Bisphenol A seems to be added to a lot of plastics, not just ones that is an obvious building block for. I don’t know what its role is there - maybe a cross-linking agent?
Its also used as a cheap antioxidant
To what end? To make the plastic last longer?