Photodegradation and Oxidation of Poly alkylene naphthalate s

Few studies have been undertaken on the photodegradation of poly(ethylene naphthalate) (PEN) [57-60], PEN-PET copolymers [61] and poly(butylene naphthalate) (PEN) [62]. 

It was some time before these studies were superseded by a more comprehensive study of PEN photolysis and photo-oxidation by Scheirs and Gardette [59]. Photolysis mechanisms were postulated as shown next  

Crosslinking and chain extension resulted in gel formation and increased colour due to extended conjugation of directly bonded naphthalene systems. 

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