Chemical and Mechanical Evaluation of Bio-composites Based on Thermoplastic Starch and Wood Particles Prepared by Thermal Compression

Abstract

The present work inspects the preparation of bio-composites of cassava starch with particles of eucalyptus wood through the application of a novel method of thermal compression. Bio-composites with different amounts of wood particles (5 to 30%), with particle sizes of 4 and 8 mm, were obtained. Chemical and mechanical evaluation of these samples was carried out using optical microscopy, infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and the moisture absorption effect. The effect of the amount and size of the wood particles was tested by comparison with a thermoplastic matrix sample. Results from these evaluations demonstrated that the thermocompression method produced bio-composites with a distribution of particles in the matrix that contributed to an increase in their tensile strength. This mechanical property is also enhanced by interfacial adhesion between the matrix and particles, as confirmed by SEM. Furthermore, the maximum amount of particles in the bio-composites (30%) showed the maximum resistance to moisture absorption. Temperature and time parameters contributed to the formation of diffraction patterns V H and E H as a consequence of the structural disruption of native starch. Finally, FTIR showed the chemical compatibility between the starch, glycerol, and wood particles.

Antibacterial Effectiveness of Rice Water (Starch)‐Capped Silver Nanoparticles Fabricated Rapidly in the Presence of Sunlight

“…) of rice starch showed a broad band centered at 3304 cm −1 due to the O–H stretching of starch. Other band at 2922 cm −1 was attributed by the C–H stretching vibrations of aliphatic groups, the band at 1643 cm −1 could be contributed by the O–H bending of water, bands at 1076 cm −1 and 835 cm −1 could be due to the C–O–C symmetric stretching, and the one at 1004 cm −1 was due to the C–O–H bending vibration . However, the FTIR spectrum of sAgNPs showed a similar spectrum as that of rice starch with a slight deviation in peaks associated with O–H functional group.…”

Utilization of ramon seeds (Brosimum alicastrum swarts) as a new source material for thermoplastic starch production

“…The FTIR spectrum of the TPS‐RS also presents two bands, which cannot be observed in the native starch: 1743 and 1261 cm −1 . The presence of these bands has been reported previously, when the spectra of native starch and thermoplastic starch of cassava were compared . The first sign was attributed to compounds with carbonyl groups originating from a slight decomposition of the glycerol, and the second to the CH 2 ‐OH link of glycerol.…”

Development of bio-derived and biodegradable polyhydroxyalkanoate (PHA)-based wood plastic composites (WPCs)

“…uncompatibilised composites with wood fibre; Open circles (○) represent uncompatbilised composites with WF; Solid line is the trend-line for composites with wood fibre and dashed line is the trend-line for composites with WF [Agnantopoulou et al, 2012;Cobut et al, 2014;De Carvalho et al, 2002;Lomelí-Ramírez et al, 2014;Müller et al, 2014;Zhang et al, 2015] Muller et al used a mechanical strength model to quantify the interfacial adhesion between corn starch and wood fibres and found that such an interface demonstrated a stronger adhesion than that of PP and PLA [Müller et al, 2014]. Also, fourier-transform infrared spectroscopy (FTIR) analyses demonstrated compatibility between cassava starch and wood particles, which was attributed to the association by hydrogen bonding of OH groups [Lomelí-Ramírez et al, 2014]. Therefore, unlike the focus for PLA and PHA, research into TPS-based WPCs has been concentrated on understanding the reinforcing effects of various wood reinforcements rather than improving the interfacial adhesion through the addition of compatibilisers.…”

“…It was also shown that the tensile strength of wood fibres/plasticised corn starch composites improved with increasing wood content then deteriorated when the wood content was above 40 wt% [Müller et al, 2014;Zhang et al, 2015]. Other types of starches, including potato [Cobut et al, 2014] and cassava starch [Lomelí-Ramírez et al, 2014], have also been used in composites. The addition of wood reinforcements to plasticised (using 30% glycerol) potato and cassava starch resulted in similar improvement in tensile strength and modulus as seen in corn starch-based WPCs [Cobut et al, 2014;Lomelí-Ramírez et al, 2014].…”

“…Other types of starches, including potato [Cobut et al, 2014] and cassava starch [Lomelí-Ramírez et al, 2014], have also been used in composites. The addition of wood reinforcements to plasticised (using 30% glycerol) potato and cassava starch resulted in similar improvement in tensile strength and modulus as seen in corn starch-based WPCs [Cobut et al, 2014;Lomelí-Ramírez et al, 2014]. One commercially available TPS/polyester copolymer is Mater-Bi®.…”