Polyethylene naphthalate

Structure of Polyethylene naphthalate

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.[1]

Production

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.

Applications

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.

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 intended as a PET replacement, especially when used as a substrate[2] for flexible integrated circuits.

It is prepared from ethylene glycol and one or more naphthalene dicarboxylic acids by condensation polymerization.

External links

References

  1. Nakamura et al., Evidence of deep-blue photon emission at high efficiency by common plastic; Europhysics Letters
  2. Plastic Processor IEEE