Well polyethylen terephthalate (PET) is a themoplastic. (it melts when heated to a high temperature about 500 F instead of charring like thermosets) It is used mostly for films and pop bottles. It is used mostly for non structual applications, but there are engineering grades. The make up of it is 9 Hydrogen, 4 Oxygon, 10 Carbon. I would display the way it goes together, but I lost my copy of Autocad. Also, PET is cystalline.
What exactly do you want to know? Is this the one you want or did you want a different polymer? I can help there too. Oxides are only on metals, such as iron oxide (rust) etc... I will help you any way I can.
Ben