Electrical conductivity and positron annihilation characteristics of ternary silicone rubber/carbon black/TiB₂ nanocomposites

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• 作者：A.M. Ismail^a ; K.R. Mahmoud^b ; ^{kamalreyad@hotmail.com" class="auth_mail" title="E-mail the corresponding author} ; M.H. Abd-El Salam^a
• 关键词：Ternary silicone rubber ; Carbon black ; Nanocomposites ; Electrical conductivity ; Positron annihilation ; Doppler broadening
• 刊名：Polymer Testing
• 出版年：2015
• 出版时间：December 2015
• 年：2015
• 卷：48
• 期：Complete
• 页码：37-43
• 全文大小：619 K

文摘

The effect of TiB₂ nano-powder content on the electrical conductivity and positron annihilation characteristics of ternary silicone rubber/CB/TiB₂ nanocomposites was studied. The endothermic enthalpy of melting (ΔH_m) and melting temperature of the composites (T_m) were determined by differential scanning calorimetery (DSC). The addition of 12 phr TiB₂ leads to a maximum shift in T_m toward higher temperature. Also, χ_c values of the investigated composites were found to decrease with increasing TiB₂ content. The dc conductivity has reached maxima in the region of 12 phr TiB₂ followed by a decrease with increasing TiB₂ content. The temperature dependence of the conductivity showed peaks at certain temperatures and shifted to higher temperature with increasing TiB₂ content up to 12 phr. Two types of free volume cavities were detected by positron annihilation lifetime, ranging from V₁ (8.77–18.18 ų) and V₂ (270.68–274.48 ų). A correlation between positron annihilation parameters was also used to discuss the properties of the investigated composites.