变温条件下HDPE/CB的正电子湮灭特性  

Study of the size, numerical concentration and size distribution of free volume of carbon filled HDPE composites

作　　者：贾少晋[1] 张志成[1] 范扬眉[2] 张宪峰[2] 韩容典[2] 都志文[1] 翁惠民[2] 

机构地区：[1]中国科学技术大学应用化学系,安徽合肥230026 [2]中国科学技术大学近代物理系,安徽合肥230026

出　　处：《功能材料》2002年第3期335-337,340,共4页Journal of Functional Materials

摘　　要：对掺杂了 2 5份 (phr)导电炭黑 (CB)的样品进行了正电子湮灭寿命谱的变温测量 ,在玻璃化转变温度以上 ,随着温度的增加 ,自由体积的大小线性增加 ,在玻璃化转变温度以下 ,自由体积的大小基本不变。o Ps的强度在 -4 0℃下基本不变 ,从-4 0℃以上开始增加 ,但在 5 0℃以上上升有加快的趋势。The size and numerical concentration of free volume of HDPE/CB composites were estimated by means of positron annihilation lifetime measurement, in which annihilations of positron and positronium were assessed. From the variation of the ortho-positronium (o-Ps) lifetimes with the changes of temperature, It is found that the free volume is a constant at glass transition temperatures and size of free volume rises to when temperature increases above glass transition. It was likely to the test that PTC was probably closely related to hole size and therefore, conductivity may be deduced by the number of holes and the hole size.

关 键 词：HDPE/CB 正电子湮灭 炭黑 PTC 自由体积 

分 类 号：TB332[一般工业技术—材料科学与工程]