Thermoluminescence (TL) and thermally stimulated conductivity (TSC) glow curves in poly(vinyl chloride), polyethylene, polystyrene, polytetrafluoroethylene, and polyimide have been compared, and many similarities have been observed. Comparison with available NMR, dynamic mechanical loss, and dielectric loss, molecular mobility data shows that most TL and TSC peaks occur at temperatures similar to those assigned to the onset of specific molecular motions, suggesting that the peaks are due to the liberation of electrons from traps formed by the polymer chains themselves, e.g., potential wells or cavities due to chain entanglement in amorphous regions, or main‐chain branching points. Peaks for which correlation with molecular motion is not apparent are tentatively assigned to liberation of electrons from traps centered on impurities. The TSC peak temperatures in PVC were not affected in any consistent fashion by the application of high‐strength electric fields during the warming process, indicating that the electron traps are electrically neutral when empty and charged when filled; the direction of the TSC currents appears to be determined by temperature gradients existing within the samples. The TL glow‐curves are generally in good agreement with the results of other workers. The dark dc conductivity of PVC not exposed to ionizing radiation rises sharply in the temperature region assigned to the β‐relaxation process, suggesting that the electron mobility in that polymer is dominated by molecular chain motion, i.e., the interchain charge transport process is probably best described in terms of a hopping process.

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Apparatus used to measure the Seebeck coefficients of polymer films is described; values are presented for polyvinylchloride and Nylon 66.

SynopsisTransient photocurrents in poly(viny1 chloride) films are shown to be due to photoinjection of electrons from metallic cathodes. Most of the injected electrons are promptly trapped, but some drift across the sample to the anode under the inhence of an external electric field. The mobility of these electrons, determined by transient photoconductivity techniques, is 4.7 f 0.5 X 10-4 cma/V-sec at 27"C, and rises to 3.4 f 0.5 X 10-8 cma/V-sec at 43"C, the measuring cell having been evacuated to a pressure of 10-torr at both temperatures. Diffusion of helium into the samples appears to decrease the electron mobility. It is suggested that electron transport is correctly described by using an energy-band model for intramolecular motion and an activated hopping model for intermolecular transfer. Oscillations observed in the transient photocurrents in the frequency range 101106 HZ are attributed to electron avalanche formation at the anode, with photosuccesson. EXPEWMENTALPolymer films containing no additives were formed by dissolving a commercial PVC powder (I.C.I. Corvic D55/9) in tetrahydrofuran at room temperature and evaporating the solvent at a reduced pressure of about 40 torr. The films, typically 0.05-mm thick, were subsequently outgassed at torr for several days. Electrodes were not evaporated directly onto the samples, since the heat radiated from the evaporator filament was sufficient to cause deformation and slight dehydrochlorination. A Herasil

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