Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Polyethylene naphthalate (poly(ethylene 2,6-naphthalate or PEN) 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.
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 derivative 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. It is also an emerging material for modern electronic devices.
- PEN was the medium for Advanced Photo System film (discontinued in 2011).
- PEN is used for manufacturing high performance fibers that have very high modulus and better dimensional stability than PET or Nylon fibers.
- PEN is used as the substrate for some Linear Tape-Open (LTO) cartridges.
Benefits when compared to 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 polyethylene terephthalate (PET). PEN is intended as a PET replacement, especially when used as a substrate for flexible integrated circuits.
- Nakamura et al., Evidence of deep-blue photon emission at high efficiency by common plastic; Europhysics Letters
- Plastic Processor IEEE