Polymer positive temperature coefficient composites with room-temperature Curie point and superior flexibility for self-regulating heating devices

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

“…Based on the classical thermodynamic, it can be calculated that the conductive filler is mainly dispersed in one of the phases of the non-homogeneous system or at the interface between the two phases, which can significantly reduce the percolation threshold of the conductive filler in the PTC composite. [80][81][82] In addition, the PTC composite can exhibit good electrical conductivity while maintaining the excellent mechanical properties of the polymer matrix and effectively reducing the cost of the PTC composite. 80,83 In the nonhomogeneous polymer systems, the continuous phase is mainly the polymer with low crystallinity, low melting point, and excellent mechanical properties, such as LDPE, HDPE, and polypropylene (PP), which is generally used as the main matrix to provide a certain PTC intensity.…”

PVDF Hybrid Nanocomposites with Graphene and Carbon Nanotubes and Their Thermoresistive and Joule Heating Properties

“…XRD and DSC analyses were performed to obtain information for the MWCNT-doped PEG and PU blend, and the results led to the conclusion that the physical mixing of PU and PEG decreases the crystallinity of PEG, which results in improved thermoresistive behavior for the crosslinked nanocomposites [ 19 ]. On the other hand, graphene was analyzed for its self-regulating effect (an equilibrium of the generated temperature reached at applied voltage) [ 20 ] and embedded in poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) [ 21 ]. The self-regulating heating devices were prepared using crystalline polymer EVA mixed with amorphous polymer (PS or PVAc) [ 20 ].…”

“…On the other hand, graphene was analyzed for its self-regulating effect (an equilibrium of the generated temperature reached at applied voltage) [ 20 ] and embedded in poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) [ 21 ]. The self-regulating heating devices were prepared using crystalline polymer EVA mixed with amorphous polymer (PS or PVAc) [ 20 ]. Several carbon black (CB) hybrid compositions were also reported for improved positive temperature coefficient (PTC) characteristics and piezoresistive properties [ 22 , 23 ].…”

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

“…[1][2][3][4][5][6][7][8][9][10] This pyroresistive property has fascinating applications in the field of electrical industry, such as self-regulating heater, the over current protective device, and high sensitive temperature sensors, etc. [11][12][13][14][15][16][17][18][19][20][21] Meanwhile, the crystalline polymer matrix also has a variety of selectivity during the melting temperature (T m ) ranging from 20 to 300 C to perfectly meet the requirements of temperature sensitive characteristics in specific temperature ranges. 6 In order to realize satisfactory room temperature resistivity and pyroresistive property, a suitable concentration of conductive fillers is needed to be introduced into the crystalline polymer matrix.…”

“…Polymer‐based positive temperature coefficient materials (PTCs) are a typical conductive polymer composites (CPCs) that present a tremendous increase in resistivity followed by the melting of the crystalline polymer matrix 1–10 . This pyroresistive property has fascinating applications in the field of electrical industry, such as self‐regulating heater, the over current protective device, and high sensitive temperature sensors, etc 11–21 . Meanwhile, the crystalline polymer matrix also has a variety of selectivity during the melting temperature ( T m ) ranging from 20 to 300°C to perfectly meet the requirements of temperature sensitive characteristics in specific temperature ranges 6 .…”