FOURIER-TRANSFORM INFRARED OBSERVATION OF THE ORIENTATION OF DIPOLAR UREA BONDS IN POLYUREA DURING CORONA POLING

Polyurea thin films were prepared using 4,4-diaminodiphenyl methane (M DA) and 4,4-diphenyl methane diisocyanate (MDI), by vapor deposition p olymerization. Polyureas include urea bonds which contain NH and CO di polar groups. The dipole orientation which was caused by corona poling was observed by Fourier Transform Infra-Red [FT-IR] reflectance. In d iode corona poling, the dipoles are aligned best in the area directly below the needle electrode, with the degree of dipole orientation decr easing in proportion to increasing distance from this electrode. In tr iode corona poling, a grid electrode is set up between the needle elec trode and planar electrode, and orientation is accomplished uniformly over the entire surface. Contrary to this assumption, however, we foun d, through FT-IR mapping analysis, that dipole orientation follows the form of a net mesh structured like a grid electrode.