Effects of Cellulose Nanowhiskers on Mechanical, Dielectric, and Rheological Properties of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/Cellulose Nanowhisker Composites

Abstract

The thermal, mechanical, dielectric, and dynamic mechanical properties of polymer nanocomposites strongly depend on nanoparticles' content and aspect ratio. In this study, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/ cellulose nanowhisker (CNW) composite films with various CNW concentrations (0−4.6 wt %) were prepared by solution casting. Bulge, tensile, and dynamic mechanical tests showed that mechanical properties of the films increased with increasing CNW content until the content reached 2.3 wt %. Real permittivity of the composites also peaked at 2.3 wt % CNWs over a wide spectrum of frequencies (0.01−10 6 Hz). These property transitions occurring at 2.3% CNW content were due to the transition of CNW dispersion from homogeneous dispersion to agglomeration. Rheological results of the composites, however, indicated a transition point lower than 2.3%. This was attributed to the existence of a polymer−CNW network in the composite melt, which required no physical touching or geometrical overlapping between CNWs.

Characterization of Ultrafine Cellulose-filled High-Density Polyethylene Composites Prepared using Different Compounding Methods

“…3c). This implies that the composites from EFM compounding became substantially less viscous and dissipated less energy during shear deformation compared to the other composites (Ten et al 2012). Figure 4 shows the apparent viscosity as a function of shear rate at 170 °C for the neat HDPE and its composites.…”

Bacterial cellulose nanowhiskers to enhance the properties of plastics and bioplastics of interest in food packaging

“…for 1 wt.-% BCNW. Glass transition temperature was also seen to increase up to 4 ºC for PHBV (12%HV) nanocomposites loaded with plant-derived CNW (Ten et al, 2012). Thus, the addition of highly crystalline cellulose nanowhiskers reduces the mobility of PHBV molecular chains provided that interactions are established between the matrix and the nanofiller.…”

“…However, it can also be extracted from algae and marine animals, such as tunicin, as well as have not been reported previously. However, the reinforcement of commercial PHBV grades with plant-derived CNW has been already reported in several studies (Jiang et al, 2008b;Ten et al, 2012;Yu et al, 2012).…”

“…In contrast, it was possible to attain a good level of dispersion for nanocomposites prepared by solution casting with loadings of up to 2.3 wt.-% CNW (Ten et al, 2012) and up to 5 wt.-% CNW containing ca. 30 wt.-% PEG as compatibilizer (Jiang et al, 2008b) and the incorporation of CNW gave rise to improved mechanical properties.…”

“…The incorporation of nanoparticles, such as nanoclays and cellulose nanocrystals, is an efficient strategy to tailor the properties of polymeric materials and, consequently, many works have already reported on the production of PHBV nanocomposites (Jiang et al, 2008b;Ten et al, 2012;Yu et al, 2012). The reinforcement of PHBV with cellulose nanowhiskers (CNW) may present particular interest since it would allow the development of fully biodegradable nanocomposites produced from renewable resources.…”