将不同体积分数的定向碳纳米管(A—MWNT)通过溶液共混的方法填充到天然橡胶中,经过室温交联硫化,得到A-MWNT填充的天然橡胶复合材料。对比普通非定向碳纳米管(MWNT),观察了A-MWNT在天然橡胶基体中的分散情况,研究了A—MWNT对橡胶复合材料玻璃化转变温度(正)、高温交联放热和导热性能的影响,并进行了机理分析。研究表明:A-MWNT在与天然橡胶溶液共混过程中经超声波振荡和搅拌后会被部分打乱。但是在微区单元内是定向的,在整体上呈非定向。随着A—MWNT填充量的增加,正逐渐下降后又有回升之势,高温交联固化放热逐渐增大,复合材料的导热率较之同条件下MWNT填充的复合材料的导热率大,且增长速度较快,在填充分数为10%时,导热率跃增到0.735W/(m·K),增加了222.4%。
In this paper, aligned multi-walled carbon nanotubes (A-MWNT) and non-aligned multi- walled carbon nanotubes(MWNT) of different volume fractions were dispersed into natural rubber (NR) via solution blending, and subsequently NR nano-composites were prepared through ambient cross-linking. Then the dispersions of A-MWNT and MWNT in rubber matrix were observed, and the effects of A- MWNT and MWNT on the glass transition temperature (Tg) of rubber composites, cross-linking heat release under high temperature and heat conduction performances were analyzed. Research showed that parts of the A-MWNT would be disorganized in the process of solution blending, ultrasonic oscillation and stir, be aligned in micro-area units but isotropic on the whole. As the fraction of A-MWNT increased, Tg gradually decreased then increased, heat release under high temperature gradually increased. Compared with composite materials filled with MWNT in the same condition, the thermal conductivity of the composites filled with A-MWNT increased quickly with the enhancement of A-MWNT fraction, jumping to maximum of 0.735 W/(moK) when filled with 10% A-MWNT, which was increased by 222.4%.