SynopsisElectron spin resonance (ESH) of y-irradiated poiy(viny1 alcohol) (PVA) a t room temperature has been used to identify the radiation damage products. The FSR spectrum is analyzed by using least-squares fits between observed and calculated spectra, assuming various free radical species. T h e best theoretical fit, together with W absorption data, enabled the assignment of the observed ESR spectrum. T h e existence of carbonyl macrofree radicals, probably with aldehyde functional groups, i s proposed in irradiated PVA. 9. Y. 'Ikuchiya and K. Sumi, J. l'olym. Scr. Part A -I , 7, 31.51 (1969).

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Studies on the surface micromorphology and surface conductivity in thin polymer films of poly vinyl alcohol (PVA) and poly ethylene oxide (PEO) in both as-grown and ion-implanted polymer films have been carried out to reveal certain specific features of the ordered state in these materials. Optical microscopic investigations revealed the existence and enhanced formation in number of spherulites and dendrites in ionimplanted films relative to the as-grown films. The number and rate of formation of spherulites indicated an increase in the degree of crystallinity in these films. Measurements of surface conductivity of as-grown and ion-implanted polymer films, employing four-point probe method, indicated a decrease in electrical conductivity on ion-implantation. Photomicrographic analysis of the PVA and PEO thin film surfaces, has enabled to propose a temperature-stress induced mechanism of crystallization in conjunction with the surface conductivity measurements. The decrease in surface conductivity on ion-implantation in both PVA and PEO thin films, is attributed to a decrease in mobility of macromolecular charged species due to an increase in degree of crystallinity as has been observed by optical microscopy.

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