将导电微粒与聚合物混合可制备导电聚合物,其室温电阻率可从1Ω·cm到10~7Ω·cm范围进行任意调整,并且其电阻率与温度关系呈线性关系,即PTC(Positive Temperature Coefficient)效应。本文详细讨论不同的掺入导电微粒浓度、聚...将导电微粒与聚合物混合可制备导电聚合物,其室温电阻率可从1Ω·cm到10~7Ω·cm范围进行任意调整,并且其电阻率与温度关系呈线性关系,即PTC(Positive Temperature Coefficient)效应。本文详细讨论不同的掺入导电微粒浓度、聚合物种类以及合成条件对室温电阻率、PTC效应的影响规律,并讨论了这种复合材料在工程技术上的应用前景。展开更多
In this paper, carbon fiber(CF)-filled low density polyethylene(LDPE)composite materials were prepared by conventional melt-mixing method. Wide angle X-ray diffraction(WAXD) observation shows that the addition of CF t...In this paper, carbon fiber(CF)-filled low density polyethylene(LDPE)composite materials were prepared by conventional melt-mixing method. Wide angle X-ray diffraction(WAXD) observation shows that the addition of CF to LDPE does not influence the aggregate structure of the polymer. The change of the resistivity with increasing temperature is determined by two following factors: one is the expansion of the polymer which makes resistivity rise and leads to a positive temperature coefficient(PTC) effect; the other is the agglomeration of filler particles which makes resistivity drop and leads to a negative temperature coefficient(NTC) phenomenon. It is found that the crosslinking under γ-ray radiation can effectively eliminate the NTC phenomenon by forming a network and reducing movement of the CF. And a higher PTC intensity and PTC transition temperature are achieved for the radiated LDPE/CF composites.展开更多
Polymer positive temperature coefficient(PTC) material comprising conductive particles, e.g. carbon black(CB), dispersed in polymer matrix is suitable for use as electrical devices such as circuit overcurrent protecti...Polymer positive temperature coefficient(PTC) material comprising conductive particles, e.g. carbon black(CB), dispersed in polymer matrix is suitable for use as electrical devices such as circuit overcurrent protection device, self-regulation heaters, sensors, etc.. In this paper, the PTC effect of carbon black filled polyethylene and ethylene-propylene-diene terpolymer blends was studied. Effects of raw material ratio and type of carbon black were investigated. The distribution of CB in polymer matrix and the function of crystallites on PTC effect were discussed.展开更多
文摘将导电微粒与聚合物混合可制备导电聚合物,其室温电阻率可从1Ω·cm到10~7Ω·cm范围进行任意调整,并且其电阻率与温度关系呈线性关系,即PTC(Positive Temperature Coefficient)效应。本文详细讨论不同的掺入导电微粒浓度、聚合物种类以及合成条件对室温电阻率、PTC效应的影响规律,并讨论了这种复合材料在工程技术上的应用前景。
文摘In this paper, carbon fiber(CF)-filled low density polyethylene(LDPE)composite materials were prepared by conventional melt-mixing method. Wide angle X-ray diffraction(WAXD) observation shows that the addition of CF to LDPE does not influence the aggregate structure of the polymer. The change of the resistivity with increasing temperature is determined by two following factors: one is the expansion of the polymer which makes resistivity rise and leads to a positive temperature coefficient(PTC) effect; the other is the agglomeration of filler particles which makes resistivity drop and leads to a negative temperature coefficient(NTC) phenomenon. It is found that the crosslinking under γ-ray radiation can effectively eliminate the NTC phenomenon by forming a network and reducing movement of the CF. And a higher PTC intensity and PTC transition temperature are achieved for the radiated LDPE/CF composites.
文摘Polymer positive temperature coefficient(PTC) material comprising conductive particles, e.g. carbon black(CB), dispersed in polymer matrix is suitable for use as electrical devices such as circuit overcurrent protection device, self-regulation heaters, sensors, etc.. In this paper, the PTC effect of carbon black filled polyethylene and ethylene-propylene-diene terpolymer blends was studied. Effects of raw material ratio and type of carbon black were investigated. The distribution of CB in polymer matrix and the function of crystallites on PTC effect were discussed.
