Alireza Hosseinmardi, Nasim Amiralian, Pratheep K Annamalai, Darren Martin* 


Australian Institute for Bioengineering and Nanotechnology (AIBN)
University of Queensland, St. Lucia, Brisbane, QLD, Australia


Reinforcement of natural rubber (NR) using renewable nanomaterials and sustainable pathways remains a challenge. Recently, through the use of easily-deconstructed spinifex-derived cellulose nanofibres we have demonstrated that having residual lignin and hemicellulose in the cellulose nanofibres (CNF) can significantly influence the surface chemistry and enhance the dispersion of CNF in the aqueous colloidal mixture and the subsequent mechanical properties of dried NR nanocomposite films. 1 This has necessitated further investigation of the influence of residual lignin and hemicellulose components. In this study, we have prepared a systematic series of CNF from T. pungens, spinifex arid grass, by varying the concentration of sodium hydroxide solution (0.5 to 14 w/v %) in the early stage pulping treatment. This has resulted in nanofibres with different chemical composition, thermal stability and hydrophilicity, as analysed by spectroscopic methods (such as FTIR and XPS), thermogravimetry and contact angle measurements. We found that with decreasing the concentration of NaOH in the treatment, the hydrophobicity increases (as per the increasing the contact angle in Figure 1a) and the tensile strength of the 0.1 wt % CNF/NR nanocomposites increases (Figure 1b). The nanocomposite with 0.1 wt.% CNF/NR, which was treated with 0.5 w/v % NaOH, improved the tensile strength by 15 % (~42 MPa) and more importantly its elongation at break was not considerably diminished (Figure 1b). A detailed discussion on the structure-property-processing relationship will be given in the presentation.

Figure 1: (a) water contact angle values and (b) tensile properties of NR nanocomposites with 0.1 wt % of the spinifex-derived CNF as a function of NaOH concentration in the pretreatment of fibres.


  1. A. Hosseinmardi, P. K. Annamalai, L. Wang, D. Martin and N. Amiralian Nanoscale, 2017. DOI: 10.1039/C7NR02632C