Page 86 - Polymer-based Nanocomposites for Energy and Environmental Applications

62 Polymer-based Nanocomposites for Energy and Environmental Applications

Najafi et al. [57] have investigated the effect of nanoclay on the physical and
mechanical properties of nanocomposites based on polypropylene, reed fiber, and
maleated polypropylene (MAPP) as coupling agent. The mass ratio of reed fiber to
polypropylene was controlled at 60/40 for all blends. The concentration was varied
and set to 0, 2, and 4 per hundred compounds (phc) for nanoclay and 0 and 2 phc
for MAPP. Results indicated that the tensile modulus and strength of PP/reed flour
composites significantly increased with nanoclay loading. However, the impact
strength and water uptake of the composites is decreased by 4% addition of nanoclay.
Additionally, they found that the coupling agent has improved the mechanical and
physical properties of the composites by morphological study.
Hybrid composites of polypropylene (PP)/nanoclay (NC)/glass fiber (GF) are pre-
pared by Rahman et al. [58] through extrusion and injection molding process. They
found that the incorporation of nanoclay improves the thermal stability, flexural
strength, flexural modulus, and tensile strength of the hybrid material fabricated. Fur-
ther, Nafchi et al. (2015) have investigated composites based on wood fiber/nanoclay/
polypropylene and found that nanoclay addition improves both the mechanical and
physical properties. It also lowers the water absorption properties in relation to pure
composite.
Manohar and Yoush [59] have studied both mechanical (flexural and tensile
strengths) and physical properties composites based on wood flour/nanoclay/
polypropylene and found improved properties by the incorporation of nanoclay.
The water absorption properties significantly reduced in nanoclay-filled
composite.

2.7 Nanoparticle reinforced recycled thermoplastic
composites

Currently, the growing consumption of polymer products creates a large quantity of
waste materials resulting in the environment and people life. Recently, many
researchers have tried to develop a new science for polymer recycling using nanotech-
nology. In this section, the application of different nanoparticles in the recycled poly-
mers (PET, PP, HDPE, PVC, etc.) with attributed composites and blends is studied.
The present section determines the current status of nanotechnology in the polymer
recycling and their related composite blends.
Basilia et al. [60] have synthesized recycled polyethylene terephthalate (RPET)/
organo-montmorillonite nanocomposites by direct melt intercalation method. They
reported that the thermal degradation has been decreased and tensile strength
increased with the increase in clay loading. Five wt% of synthesized Philippine
MMT (Na-MMT) offered the best improvement of tensile properties. The mechanical
behavior of the nanocomposites at various clay loadings (Fig. 2.30) shows that the
higher the clay content the better is the tensile strength of the samples. Furthermore,
Giraldi et al. [61] have found that the optimized values of strength and toughness are
obtained at 2.5 wt% of nanoclay instead of 5 wt%.