Enhanced thermal conductivity of poly(L lactide) composites with synergistic effect of aluminum nitride and modified multi walled carbon nanotubes
ABSTRACT Poly (ethylene glycol) grafted multi walled carbon nanotubes (PEG MWNTs) were prepared and added into poly(L lactide) (PLLA)/aluminum nitride (AlN) composites to obtain PLLA/AlN/PEG MWNTs nanocomposites. Microstructure and thermal conductivity of the composites were investigated on the basis of the influence of PEG MWNTs incorporated. The results showed that PEG MWNTs were well dispersed in the PLLA matrix and had strong interfacial adhesion with the matrix. The addition of PEG MWNTs improved the thermal conductivity of PLLA/AlN composites. When 3 wt. of PEG MWNTs and 50 wt. of AlN were both added into the PLLA matrix, the thermal conductivity reached 0.7734 W/mK with enhancement almost by 400% as compared to a neat PLLA. However, the thermal conductivity is 0.3401 W/mK for the PLLA composite with 3 wt. of PEG MWNTs and 0.4286 W/mK for the one with 50 wt. of AlN. The synergistic effect of aggregated AlN particles and well dispersed MWNTs could form efficient thermal conductive paths for improving the thermal conductivity of PLLA composites greatly.