制备工艺对TiB_2-CB/PE复合材料PTC性能的影响  

Effect of Preparation Processes on PTC Performance of TiB_2-CB/PE Composite

作　　者：施文照 杜晓东[1] 詹马骥 王夫成 郎经纬 

机构地区：[1]合肥工业大学材料科学与工程学院,合肥230009

出　　处：《机械工程材料》2015年第7期77-81,共5页Materials For Mechanical Engineering

基　　金：国家重点基础研究计划("973"计划)资助项目(2011CB013402);安徽省科技攻关计划重大项目(1301021006);安徽省教育厅自然科学重点项目(KJ2012A232)

摘　　要：采用熔融共混法制备了TiB2-CB/PE复合材料,在130,160,180℃以及3,6,8 MPa的条件下热压成型后,分别进行退火处理(120,130℃)和硅烷交联处理,研究了热压工艺、退火温度和交联工艺对复合材料PTC性能的影响以及相关机理。结果表明:随着热压压力和温度升高,复合材料的PTC性能呈先上升再下降的趋势;在合适的热压温度和压力成型后空冷处理可以提升复合材料的结晶度,且结晶度越高,PTC性能越好;在压力为6 MPa、温度为160℃下热压并于空气中冷却制得复合材料的结晶度为48.4%,室温电阻率为4.47Ω·m,PTC强度高达5.1;退火处理后,复合材料的峰值电阻率和PTC转变温度都有所提高;硅烷交联处理使复合材料的热循环稳定性得到显著提高,NTC效应也基本得以消除;复合材料PTC效应的产生与聚乙烯基体结晶区的熔融与再结晶密切相关。A TiB2-CB/PE composite was prepared by melt-blending process.After hot pressing molding under the conditions of temperature of 130,160,180 ℃and pressure of 3,6,8 MPa,annealing treatment（120,130 ℃）and silane crosslinking were carried out respectively.The effects of hot pressing process,annealing temperature and crosslinking process on PTC performance and PTC mechanism were investigated.The results show that PTC properties of the composite increased at first and then decreased with the increase of hot-pressing pressure and hot-pressing temperature.An appropriate hot-pressing temperature and cooling mode could increase the crystallinity of the composite,and the higher crystallinity corresponded to the more obvious PTC effect.The composite with crystallinity of 48.4%,room temperature resistivity of 4.47Ω·m and PTC intensity of 5.1could be obtained by hot-pressing with pressure of 6MPa,temperature of 160 ℃ and cooling in the air.The peak resistivity and PTC transition temperature of the composite all could be increased after annealing treatment.After silane crosslinking treatment,the composite could get more stable thermal cycling property and lower NTC effect.The PTC effect of the composite was closely related to the crystallization area melting and recrystallization of polyethylene matrix.

关 键 词：PTC性能 热压工艺 结晶度 退火 硅烷交联 热循环稳定性 

分 类 号：TB32[一般工业技术—材料科学与工程]