Positive Temperature Coefficient Behavior of the Graphite Nanofibre and Carbon Black Filled High-Density Polyethylene Hybrid Composites

2008 ◽  
Vol 47-50 ◽  
pp. 226-229 ◽  
Author(s):  
Qi Li ◽  
Jong Wan Kim ◽  
Tae Hee Shim ◽  
Yun Ki Jang ◽  
Joong Hee Lee
Keyword(s):  
Carbon Black ◽  
Temperature Coefficient ◽  
High Density Polyethylene ◽  
Hybrid Composites ◽  
Positive Temperature Coefficient ◽  
High Density ◽  
Hybrid Nanocomposites ◽  
Room Temperature Resistivity ◽  
Positive Temperature ◽  
Temperature Resistivity

The graphite nanofiber (GNF) and carbon black filled high-density polyethylene (HDPE) hybrid nanocomposites were prepared by solution mixing and melt blending techniques. The effect of addition of GNF on the positive temperature coefficient (PTC) behavior of the nanocomposites was investigated. The incorporation of small amount of GNF into HDPE/CB composites showed a significant improvement in PTC intensity and repeatability of the hybrid nanocomposites. The maximum PTC intensity was observed for the HDPE/CB/GNF (80/20/0.25) nanocomposite with a relatively low room temperature resistivity.

Tunable temperature-resistivity behaviors of carbon black/polyamide 6 /high-density polyethylene composites with conductive electrospun PA6 fibrous network

2018 ◽  
Vol 53 (14) ◽  
pp. 1897-1906 ◽  
Author(s):  
Yingying Qu ◽  
Ping Xu ◽  
Hu Liu ◽  
Qianming Li ◽  
Ning Wang ◽  
...  
Keyword(s):  
Temperature Coefficient ◽  
Polymer Composites ◽  
High Density Polyethylene ◽  
Conductive Polymer ◽  
Polyamide 6 ◽  
Positive Temperature Coefficient ◽  
High Density ◽  
Positive Temperature ◽  
Conductive Polymer Composites ◽  
Temperature Resistivity

Temperature-resistivity behaviors of carbon black/polyamide 6/high-density polyethylene conductive polymer composites containing electrospun polyamide 6 fibrous network were studied systematically. The positive temperature coefficient intensity of the conductive polymer composites increased firstly and then reduced gradually with increasing heating rate, showing a heating rate-dependent positive temperature coefficient intensity. The fascinating phenomenon was ascribed to the microstructure change of conductive network induced by the volume expansion and the thermal residual stress generated in the composites. During the heating-cooling runs at different top testing temperature of 140, 150 and 180℃, the room-temperature resistivity of sample was observed to be 30, 2.3 and 1.6 orders of magnitude higher than the initial value after one heating-cooling run, respectively. The thermal treatment time above the melting temperature of high-density polyethylene and the viscosity variation of the conductive polymer composites were responsible for the increased resistivity. This study provides a guideline for fabricating conductive polymer composites with tuning positive temperature coefficient property.

scholarly journals Effects of POE and Carbon Black on the PTC Performance and Flexibility of High-Density Polyethylene Composites

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Feng Xue ◽  
Kangcai Li ◽  
Lei Cai ◽  
Enyong Ding
Keyword(s):  
Carbon Black ◽  
High Density Polyethylene ◽  
Crystallization Behavior ◽  
Thermoplastic Elastomer ◽  
Positive Temperature Coefficient ◽  
High Density ◽  
Room Temperature Resistivity ◽  
Positive Temperature ◽  
Lower Temperature ◽  
Micro Morphology

High-density polyethylene (HDPE)/carbon black (CB) is widely used in positive temperature coefficient (PTC) composites. In order to expand its applications to fields that need good flexibility, polyolefin elastomer (POE) was incorporated into HDPE/CB composites as a secondary thermoplastic elastomer phase to provide flexibility. The effects of POE and CB content on the PTC performance and flexibility were investigated. Micro morphology and crystallization behavior are closely related to PTC properties. SEM was conducted to reveal phase morphology and filler dispersion, and DSC was conducted to research crystallization behavior. The results show that the incorporation of 18 wt.% POE can decrease the percolation threshold of conductive carbon black from 22.5 wt.% to 16 wt.%. When the CB content is 30 wt.%, the room temperature resistivity gradually increases with the increasing content of POE because of the barrier effect of POE phase, and the PTC intensity is gradually enhanced. Meanwhile, the PTC switching temperature shifts down to a lower temperature. The incorporation of 18 wt.% POE significantly increases the elongation at break, reaching an ultrahigh value of 980 wt.%, which means great flexibility has been achieved in HDPE/POE/CB composites. This work provides a new method of fabricating PTC composites with balanced electrical and mechanical properties.

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