LDPE/carbon black conductive composites: Influence of radiation crosslinking on PTC and NTC properties

✍ Scribed by Hongfeng Xie; Pengyang Deng; Lisong Dong; Jiazhen Sun

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 471 KB
• Volume: 85
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.10720

✦ Synopsis

Abstract

The electrical resistivity of low‐density polyethylene/carbon black composites irradiated by ^60^Co γ‐rays was investigated as a function of temperature. The experimental results obtained by scanning electron microscopy, solvent extraction techniques, and pressure‐specific volume‐temperature analysis techniques showed that the positive temperature coefficient (PTC) and negative temperature coefficient (NTC) effects of the composites were influenced by the irradiation dose, network forming (gel), and soluble fractions (sol). The NTC effect was effectively eliminated when the radiation dose reached 400 kGy. The results showed that the elimination of the NTC effect was related to the difference in the thermal expansion of the gel and sol regions. The thermal expansion of the sol played an important role in both increasing the PTC intensity and decreasing the NTC intensity at 400 kGy. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2742–2749, 2002