Anomalous characteristics of ion emission during fracture of polymers

Current–voltage characteristics of ion emission during mechanical fracture of polymer films (polyethylene terephthalate, polyimide, polyphenylene ether) in high vacuum have been studied. Positive ions appear at a pulling potential of 100–200 V, after which their number monotonically increases with potential until saturation. Negative ion emission starts at $\ll$ 200 V and exhibits resonance behavior within the 0–50 V interval, whereby the resonance peak position depends on the nature of polymer. The resonance character of negative ion emission found corresponds to the proposed physical mechanism of ion formation.