Abstract:
Polypropylene (PP) and PP-talc composites with compositions of9'1, 8:2, 7:3, 6:4, and
5:5 wt, ratio were prepared by extrusion Cumcompression molding methods, Surface
morphology of the composites wag observed by a scanning electilln microscope (SEM)
Various properties such as bulk density, water absorption, tensile strength, flexural
strcngth, Young modulus, microhardness and electrical properties of these composites
were investigated
SEM micrographs ofPP and PP-tale composites show that illuglmess of the surface of the
composites gradually increases as the amount of talc increases. The bulk density of the
composites decreases with the increase of talc content. With the increase of the
percentage of talc and period of immersion, the water absorption increascs
The tensile strength and elongation-at-break (%) of PP-talc composites decrease with the
increase of talc content whereas Young moduli.!s(YM) of the composites increases with
talc content. The YM value of the composites with JOwt% tale is the highest. The
flexural strength increases with the addition of talc up to 30wt% and after that it
decreases but flexural break (%) decreases with the increase of talc content. Flexural
modulus increases slowly up to 20wt% talc and then it increases rapidly for JOwt% talc.
With the increase of talc content, the microhardness (H) value increases up to JOwt%talc
and after that it decreases for PP- talc composites.
The thermal bchavior ofPP-talc composites was analyzed by TGA, Dr A, and DTG It is
seen that composites become thermally more stable than the neat PP, The current-voltage
(I-V) charactenstics of the composites wer'e recorded in the voltage range from 0 to 120
V DC at different temperatures. It is evident that currem-voltage curves show ohmic
behavior in the lower voltage region. Conductivity has been calculated and is found to
incrcase with increasing temperature but with the increase % of talc, conductivity
decreases for PP-talc composites, The activation energy of all the samples has higher
value in high temperature region than those at low temperature region
