Polyethylene terephthalate chemical reactivity

Polymer preparation is based on chemical reactions (polymerisation) of gas (e.g. ethylene) or liquid (e.g. styrene) substances with low molecular weight. These molecules (monomers) are bi- or poly-functional because they show two or more reactive moieties [Nicholson and Royal Society of Chemistry (Great Britain), 2006]. As an example, the reaction between ethylene glycol and terephthalic acid promotes the formation of polyethylene terephthalate (PET, a polyester), (Fig. 2.5) (Liangbin et al., 2001). 

Reactive compatibilizing agents of the type A-C can also compatibilize an A/B blend as long as C can chemically react with B. Such studied systems include polyethylene (PE)/nylon-6 blends compatibilized with carboxyl functional PE, polypropylene (PP)/poly(ethylene-terephthalate), with PP-g-acrylic acid, nylon-6,6/EPDM with poly(styrene-co-maleic anhydride), and nylon-6/PP with PP-g-maleic anhydride. 

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