Abstract
Biopolymer blend materials of PLLA/PHB/TBC/MWCNT have been prepared by solvent casting and then melted to form films. The electrical conductivity, thermal properties, crystal structure, and morphology of new blends were studied. The AC conductivity is still constant in the case of low frequency or high frequency, and is increased with rising temperature like semiconductor materials and the conductivity of the blends can be increased from 10(-17) S cm(-1) (pure PLLA) to 10(-1) S cm(-1) (blend 5). It is observable that the dielectric loss (epsilon aEuro(3)) is improved after adding MWCNT to PLLA matrix and its values reach 10(13) which decrease as frequency increase to 10(4) in comparing the blend of PLLA/PHB/TBC as the reference without MWCNT. Thermal behavior and crystalline behavior were investigated by DSC. The lower Tg decreased from 60 A degrees C for pure PLLA to 20 A degrees C for the blend 5 due to an active interaction between all components. WAXD found the existing peak at 2 I = 25A degrees and 44A degrees for MWCNT. The good interface structure between the MWCNT and PLLA was examined by TEM. It is found the dispersion of MWCNT in the PLLA matrix uniformly, no aggregation; therefore, the electrical conductivity increased.