Enhanced positive temperature coefficient in amorphous PS/CSPE‐MWCNT composites with low percolation threshold

Abstract

In this work, amorphous polystyrene/chlorosulfonated polyethylene composites doped with multiwalled carbon nanotubes (PS/CSPE‐MWCNT) were constructed by in situ polymerization to form semi‐interpenetrating networks. The MWCNTs showed excellent dispersion and selective location in the PS regions. High electrical conductivity and low percolation threshold (0.89 wt %) for the composites were achieved. An enhanced positive temperature coefficient (PTC) behavior for amorphous PS/CSPE‐MWCNT composites was first reported, nearly without a negative temperature coefficient (NTC) effect when the conductive fillers were beyond the percolation threshold, similar to those of crystalline polymer composites. Moreover, a PTC intensity of more than five orders of magnitude and excellent repeatability of the PTC effect were achieved. This study offers new insight into the development of novel PTC materials with low percolation threshold. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47053.

Strategies for improving positive temperature effects in conductive polymer composites – a review

“…Lai et al 130 prepared amorphous PTC composites with polystyrene/chlorosulfonated polyethylene (PS/CSPE) as the matrix and MWCNTs as the conductive filler by in situ polymerization, where a semi-interpenetrating network was formed in this PS/CSPE/MWCNT composite and MWCNTs were mainly dispersed in PS. A remarkable microphase separation structure of the composites was gradually observed with the increase of MWCNT content, especially when the MWCNT contents were greater than 3 wt% as shown in Fig.…”

“…This research fills a gap in the field of low-temperature PTC composites. [128][129][130] In addition, the Curie temperature range of this EVA/-LA/CB composite can be adjusted by the addition of a thickener of dioctyl phthalate (DOP), which is an innovative research approach in the field of PTC composites with low Curie temperature points. Different types of functional additives usually result in different effects on the PTC performance of PTC composites.…”

Enhanced positive temperature coefficient effect by crosslinking reaction for silicone rubber/carbon black composites with high pressure sensitivity

“…When the filler content increases to the percolation threshold, the conductive network is easily influenced by external factors, resulting in an obvious change of electrical resistance of the composites. [27][28][29] The relationship between conductivity and filler content of the composites is shown in Figure 1b. With increasing CCB content, the electrical conductivity of the composites increases.…”

Achieving superior pyroresistive reproducibility at HDPE/PVDF composites with tailored conductive phase size

“…To overcome these drawbacks, the combination of immiscible polymer blends [35][36][37][38][39][40][41] could be an alternative strategy based on the following two factors: (i) the PTCs will be confined in the immiscible polymer with higher T m when it is manifesting PTC property and (ii) the binary polymer system has superiority to control resistance of room temperature in practical production due to the expanded ranges of percolation derived from the additional phase morphology percolation transition. Based on immiscible high density polyethylene (HDPE)/ polyvinylidene fluoride (PVDF) system, Zhang et al 37 have reported that the PTCs with "sea-island" morphology exhibited preferable PTC reproducibility.…”