and there is an urgent need for localization.

Polyethylene naphthalate (PEN) is one of the important members of the polyester family. It is composed of 2,6-dimethyl naphthalate (NDC) or 2,6-naphthalenedicarboxylic acid (2,6-NDA). ) and ethylene glycol (EG), which is an emerging excellent polymer. Its chemical structure is similar to that of PET, except that the molecular chain of PEN is replaced by a…