PET… (Polyethylene terephthalate)
PET consists of polymerized units of the monomer ethylene terephthalate, with repeating (C10H8O4) units. PET is commonly recycled, and has the number 1 as its recycling symbol.
Polyethylene terephthalate is produced from ethylene glycol and dimethyl terephthalate (C6H4 (CO2CH3)2) or acid. The former is a transesterification reaction, whereas the latter is an esterification reaction.
Because PET is an excellent water and moisture barrier material, plastic bottles made from PET are widely used for soft drinks (see carbonation)Biaxially oriented PET film (often known by one of its trade names, "Mylar") can be aluminized by evaporating a thin film of metal onto it to reduce its permeability, and to make it reflective and opaque (MPET). These properties are useful in many applications, including flexible food packaging and thermal insulation