Plastic is a synthetic organic polymer. Meaning that they can be made from any type of organic polymer, but most are made from petrochemicals. These are the molecular structures of the most common plastics we find around us.
PET – polyethylene terephthalate
HDPE – high density polyethylene
V – polyvinyl chloride
LDPE – low density polyethylene
PP – polypropylene
PS – polystyrene