Abstract: Chemical modifier (Acrylic Acid) is used as filler treatment to improve mechanical properties and swelling behavior of polypropylene/coconut fiber (PP/CF) composites by creating more adherent bonding between CF filler and PP Matrix. Treated (with chemical modifier) and untreated (without chemical modifier) composites were prepared in the formulation of 10 wt%, 20 wt%, 30 wt%, and 40 wt%. The mechanical testing indicates that composite with 10 wt% of untreated composite has the optimum value of tensile strength, and the composite with chemical modifier shows the tensile strength was increased. By increasing of filler loading, elastic modulus was increased while the elongation at brake was decreased. Meanwhile, the swelling test discerned that the increase of filler loading increased the water absorption of composites and the presence of chemical modifier reduced the equilibrium water absorption percentage.
Abstract: In this study, structural, mechanical, thermal and
electrical properties of poly (lactic acid) (PLA) nanocomposites with
low-loaded (0-1.5 wt%) untreated, heat and nitric acid treated multiwalled
carbon nanotubes (MWCNTs) were studied. Among the
composites, untreated 0.5 wt % MWCNTs and acid-treated 1.0 wt%
MWCNTs reinforced PLA show the tensile strength and modulus
values higher than the others. These two samples along with pure
PLA exhibit the stable orthorhombic α-form, whilst other samples
reveal the less stable orthorhombic β-form, as demonstrated by X-ray
diffraction study. Differential scanning calorimetry reveals the
evolution of the mentioned different phases by controlled cooling and
discloses an enhancement of PLA crystallization by nanotubes
incorporation. Thermogravimetric analysis shows that the MWCNTs
loaded sample degraded faster than PLA. Surface resistivity of the
nanocomposites is found to be dropped drastically by a factor of 1013
with a low loading of MWCNTs (1.5 wt%).