A new finding is reported of the magnetic orientation of poly(ethylene-2,6-naphthalate) (PEN) near its melting point, evidenced by X-ray analyses and magnetic birefringence measurements. Since PEN does not exhibit features characteristic of liquid-crystalline polymers under a polarization microscope, the magnetic orientation was unexpected. The orientation is probably due to some ordered structure susceptible to a magnetic field, but the detail of the structure is not fully understood at present.
