为了开发高性能聚合物基NTC热敏电阻,将石墨烯均匀地分散在868环氧树脂聚合物基体中并固化成型,制备得到一种具有负温度系数(Negative Temperature Coefficient,NTC)的环氧树脂/石墨烯复合材料,研究了石墨烯含量、固化工艺对复合材料体...为了开发高性能聚合物基NTC热敏电阻,将石墨烯均匀地分散在868环氧树脂聚合物基体中并固化成型,制备得到一种具有负温度系数(Negative Temperature Coefficient,NTC)的环氧树脂/石墨烯复合材料,研究了石墨烯含量、固化工艺对复合材料体积电阻率及NTC强度的影响,并考察了复合材料的稳定性和附着力。结果表明,石墨烯质量分数为5%的样品,当固化温度为40℃,时间为9 h时,在50℃测试条件下,其体积电阻率为9.32×10^(6)Ω·cm,当测试温度升高到100℃,体积电阻率下降为4.35×10^(3)Ω·cm;同时,NTC强度最高可达到3.33,并且其在PET膜上表现出优异的附着力;经过3次重复加热测试后石墨烯在基体内部发生轻微的不可逆变化,初始体积电阻率有所降低,后续导电结构趋于稳定,并表现出优异的循环稳定性。本研究为聚合物基NTC热敏电阻的研究提供一定理论基础,有助于推动其在电子、通信、新型储能等行业的应用。展开更多
Polyacrylate-based conductive coatings were prepared from polyacrylate emulsion as matrix and carbon black (CB) whose surface was treated with titanate coupling agent as conducting particles.One kind of organic crysta...Polyacrylate-based conductive coatings were prepared from polyacrylate emulsion as matrix and carbon black (CB) whose surface was treated with titanate coupling agent as conducting particles.One kind of organic crystal was added to study its effects on the electrical conductivity and PTC(positive temperature coefficient)effect of the conductive coatings.Experimental results show that the coatings containing only polyacrylate emulsion and CB exhibit an excellent electrical conductivity but bad PTC effect,and when organic crystal is added,PTC effect is characterized and can increase by 2 orders of magtitude.The critical transformation temperature of polyacrylate emulsion/CB PTC composites is decided by melting point of organic crystals.展开更多
BaTiO3∶Mn0.006Smx(x=0.001, 0.002, 0.003, 0.004, 0.006 respectively) ceramics were prepared by using sol-gel method and their resistivities at different temperatures were measured. The results showed that Mn element m...BaTiO3∶Mn0.006Smx(x=0.001, 0.002, 0.003, 0.004, 0.006 respectively) ceramics were prepared by using sol-gel method and their resistivities at different temperatures were measured. The results showed that Mn element may enhance the PTC characteristics of BaTiO3 ceramics. But the doped Mn element deteriorated the room temperature resistivities of the modified BaTiO3 ceramics which were greater than 105 Ω·m. Then, rare earth element Sm was penetrated into BaTiO3∶Mn0.06Smx ceramics in gaseous state, which largely decreased the room temperature resistivity to 3.20 Ω·m, and appeared as a NTC effect instead of PTC effect. The forming mechanism of NTC effect was explored through analyses of SEM and electric properties of Sm-penetrated BaTiO3∶Mn0.006Smx ceramics.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
文摘为了开发高性能聚合物基NTC热敏电阻,将石墨烯均匀地分散在868环氧树脂聚合物基体中并固化成型,制备得到一种具有负温度系数(Negative Temperature Coefficient,NTC)的环氧树脂/石墨烯复合材料,研究了石墨烯含量、固化工艺对复合材料体积电阻率及NTC强度的影响,并考察了复合材料的稳定性和附着力。结果表明,石墨烯质量分数为5%的样品,当固化温度为40℃,时间为9 h时,在50℃测试条件下,其体积电阻率为9.32×10^(6)Ω·cm,当测试温度升高到100℃,体积电阻率下降为4.35×10^(3)Ω·cm;同时,NTC强度最高可达到3.33,并且其在PET膜上表现出优异的附着力;经过3次重复加热测试后石墨烯在基体内部发生轻微的不可逆变化,初始体积电阻率有所降低,后续导电结构趋于稳定,并表现出优异的循环稳定性。本研究为聚合物基NTC热敏电阻的研究提供一定理论基础,有助于推动其在电子、通信、新型储能等行业的应用。
文摘Polyacrylate-based conductive coatings were prepared from polyacrylate emulsion as matrix and carbon black (CB) whose surface was treated with titanate coupling agent as conducting particles.One kind of organic crystal was added to study its effects on the electrical conductivity and PTC(positive temperature coefficient)effect of the conductive coatings.Experimental results show that the coatings containing only polyacrylate emulsion and CB exhibit an excellent electrical conductivity but bad PTC effect,and when organic crystal is added,PTC effect is characterized and can increase by 2 orders of magtitude.The critical transformation temperature of polyacrylate emulsion/CB PTC composites is decided by melting point of organic crystals.
文摘BaTiO3∶Mn0.006Smx(x=0.001, 0.002, 0.003, 0.004, 0.006 respectively) ceramics were prepared by using sol-gel method and their resistivities at different temperatures were measured. The results showed that Mn element may enhance the PTC characteristics of BaTiO3 ceramics. But the doped Mn element deteriorated the room temperature resistivities of the modified BaTiO3 ceramics which were greater than 105 Ω·m. Then, rare earth element Sm was penetrated into BaTiO3∶Mn0.06Smx ceramics in gaseous state, which largely decreased the room temperature resistivity to 3.20 Ω·m, and appeared as a NTC effect instead of PTC effect. The forming mechanism of NTC effect was explored through analyses of SEM and electric properties of Sm-penetrated BaTiO3∶Mn0.006Smx ceramics.
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.
