Can someone explain why rubber - not a plastic - makes up the majority of plastic in the ocean? They do say "synthetic rubber", but from what I am reading those are also not considered a type of plastic. Not that the definition matters too much, but I think it's important not to use language that could be construed as being purposefully disingenuous to make an argument seem more dramatic, since doing so undermines the argument.
Most writing uses "plastic" to mean any synthetic polymer, even non-organic ones like silicone. I don't think this is deliberately disingenuous or even ignorant; it would simply be awkward and mostly irrelevant to use precise technical terms every time.
Technically rubber is elastic, not plastic. But even "thermosetting plastics" aren't physically plastic anymore. Silicone is synthetic but not organic, while lots of organic polymers aren't synthetic. All the public really cares about is "shit that doesn't belong in the ocean".
Elasticity has no bearing on whether something is a plastic or not, and any attempt to use it as a distinction would be pointlessly arbitrary. Silicone is certainly a polymer...
