Polyethylene naphthalate (PEN) (Poly(ethylene 2,6-naphthalate) is a polyester with good barrier properties (even better than Polyethylene terephthalate). Because it provides a very good oxygen barrier, it is particularly well-suited for bottling beverages that are susceptible to oxidation, such as beer. It is also used in making high performance sailcloth. It also has been found to show supreme scintillation properties and is expected to replace classic plastic scintillators.
Polyethylene Naphthalate (PEN, Poly(ethylene-2,6-naphthalene dicarboxylate, CAS No: 25853-85-4) is a polyester polymer of naphthalene-2,6-dicarboxylate and ethylene glycol.
There are two major manufacturing routes for PEN, i.e. an ester or an acid process, named according to whether the starting monomer is a diester or a diacid of naphthalene, respectively. In both cases for PEN, the glycol monomer is ethylene glycol.
Solid-state polymerization (SSP) of the melt-produced resin pellets is the preferred process to increase the average molecular weight of PEN.
Significant commercial markets have been developed for its application in textile and industrial fibers, films, and foamed articles, containers for carbonated beverages, water and other liquids, and thermoformed applications.
Benefits when compared to PET (Polyethylene Terephthalate) 
The two condensed aromatic rings of PEN confer on it improvements in strength and modulus, chemical and hydrolytic resistance, gaseous barrier, thermal and thermo-oxidative resistance and ultraviolet (UV) light barrier resistance compared to PET.
PEN is also the medium for Advanced Photo System film.
PEN is also used for manufacturing high performance fibers that have very high modulus and better dimensional stability than Polyester or Nylon fibers.
PEN is used as the substrate for some LTO tape cartridges.
PEN is being used as a substrate for flexible integrated circuits.
Advansa Sasa Polyester San A.S. 
DuPont Teijin Films TEONEX Q83 Data sheet 
- Nakamura et al., Evidence of deep-blue photon emission at high efficiency by common plastic; Europhysics Letters
- Plastic Processor IEEE
|This article about polymer science is a stub. You can help Wikipedia by expanding it.|