Which plastics are you refering to? In a PLA plastic for example (which is derived from lactic acid, derived from startch) there is no distinction between "bind

Which plastics are you refering to? In a PLA plastic for example (which is derived from lactic acid, derived from startch) there is no distinction between "binder" and "plastic", and there is no starch left in the resulting production. Granted the biodegradability of many formulations is still far too long and requires unrealistic circumstances to happen in the wild (hot composting for example).