Thermal and mechanical behavior of carbon-nanotube-filled latex

Composite films were prepared from a mixture of poly(vinyl acetate) latex and SWNTs. SEM images reveal a segregated SWNT network that grows heavier with increasing concentration. Nanotube segregation is the result of excluded volume created by the much larger polymer particles in the latex. Thermal conductivity exhibits a sharp rise with increasing quantity of nanotubes, although the maximum value is only 10% greater than that of the polymer matrix due to large thermal interface resistance. Storage modulus exhibits a peak and subsequent drop due to pore formation. In the absence of porosity, the Halpin-Tsai model accurately predicts the composite modulus at 25 degrees C. The segregated network improves the composite modulus above T-g by nearly an order of magnitude with only 2 wt.-% SWNT.