20
1 Introduction to PVA-Based Bionanocomposite Films
Fig. 1.12 Schematic diagram of in situ polymerisation of styrene in the presence of HNTs [150]
melt intercalation is likely to be the most popular method to disperse nanoparticles
into polymer matrices in nanocomposite systems owing to its environmental friendliness and cost-effectiveness in the absence of solvents. This technique involves heating
the mixture of polymer pellets and nanoparticles up to a melting temperature T m of
semicrystalline polymers or above T g of amorphous polymers [151, 152]. Using this
process, nanofillers such as HNTs can be mixed with a molten polymer under high
shear forces with a variety of mixing devices. At this stage, the molten polymeric
chains start to interact with HNTs due to mechanical shearing mechanism, leading to
interfacial compatibility with the aid of compression moulding, injection moulding
and screw extrusion to manufacture final polymer/HNT nanocomposites. Nonetheless, the combination of high-processing temperature and high shear forces often
results in polymer oxidation and degradation with detrimental polymer properties
[45].
Moreover, a variety of nanocomposites based on thermoplastics have been
successfully fabricated using this method such as PLA/BC composites [31], wood
plastic (WP)/BC composites [34] PCL/MMT composites [153] and PLA/MMT
composites [154]. The characteristics of resulting nanocomposite structures are
known to be influenced by factors such as the type and nature of polymers and
modified layered silicates in terms of surfactants, chain length and packing density
[155].
The fourth method for bionanocomposite fabrication is electrospinning. As previously mentioned, it involves the application of a high-voltage electrical field into polymeric solutions with the provision of the formation of continuous micro-/nanofibres.
These fibres can be used to produce fabric networks with high porosity, small
pore sizes and high surface-to-volume ratios. The electrospinning method has been
1 Introduction to PVA-Based Bionanocomposite Films
Fig. 1.12 Schematic diagram of in situ polymerisation of styrene in the presence of HNTs [150]
melt intercalation is likely to be the most popular method to disperse nanoparticles
into polymer matrices in nanocomposite systems owing to its environmental friendliness and cost-effectiveness in the absence of solvents. This technique involves heating
the mixture of polymer pellets and nanoparticles up to a melting temperature T m of
semicrystalline polymers or above T g of amorphous polymers [151, 152]. Using this
process, nanofillers such as HNTs can be mixed with a molten polymer under high
shear forces with a variety of mixing devices. At this stage, the molten polymeric
chains start to interact with HNTs due to mechanical shearing mechanism, leading to
interfacial compatibility with the aid of compression moulding, injection moulding
and screw extrusion to manufacture final polymer/HNT nanocomposites. Nonetheless, the combination of high-processing temperature and high shear forces often
results in polymer oxidation and degradation with detrimental polymer properties
[45].
Moreover, a variety of nanocomposites based on thermoplastics have been
successfully fabricated using this method such as PLA/BC composites [31], wood
plastic (WP)/BC composites [34] PCL/MMT composites [153] and PLA/MMT
composites [154]. The characteristics of resulting nanocomposite structures are
known to be influenced by factors such as the type and nature of polymers and
modified layered silicates in terms of surfactants, chain length and packing density
[155].
The fourth method for bionanocomposite fabrication is electrospinning. As previously mentioned, it involves the application of a high-voltage electrical field into polymeric solutions with the provision of the formation of continuous micro-/nanofibres.
These fibres can be used to produce fabric networks with high porosity, small
pore sizes and high surface-to-volume ratios. The electrospinning method has been