Polyester is a polymer as well. All plastics are polymers. It's just one subcategory.
And continuing on the late to the party trend:
There are currently 6,106 results for 'ABS' in the materials database I use, many are base resins with different fillers (glass, minerals, lubricants, etc) and multiple manufacturers are listed which may have the exact same chemical makeup, so I could very conservatively estimate close to a thousand unique additive formulations.
Afterall, the additives define most of your processing parameters.