Extraction Microfibrillated Cellulose From Spinifex Grass Using High Energy Milling and Chemical Pretreatment Nasim Amiralian* 1 , Paul Memmott 2 ,Grant Edwards 1 , John Milne 1 , Kevin Jack 3, Isabel Morrow 1,3 and Darren Martin 1 1 Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, 75, Corner College and Cooper Road, Brisbane 4072, QLD, Australia 2 Aboriginal Environmental Research Centre, University of Queensland, St. Lucia, QLD 4072, Australia 3 Centre for Microscopy & Microanalysis, University of Queensland, St. Lucia, QLD 4072, Australia Email Id of Corresponding Author: n.amiralian@uq.edu.au Spinifex grasses are the dominant vegetative component in Australian grassland habitats, covering approximately 27% of the Australian landmass. Spinifex is the long-established common name for 3 genuses and over 70 species. They produce highly resilient prickly leaves which based on the stiffness of the leaves and the production of resin, they divided to two different category: the hard non-resinous species and the soft resinous species. Current research efforts are focused on investigation and characterisation of producing micro fibrillated cellulose (MFC) form “Triodia Pungens”, a soft spinifex grass, using a mechanical method combined with chemical pre-treatment. Chopped fibre were subjected to chemical process like delignification and bleaching to eliminate lignin, hemicelluloses and the other waxy components from fibres then MFC were obtained from never dried fibre suspension in water by “ High Energy Milling “. The effect of milling time on MFC thermal property and crystallinity was investigated by FTIR, XRD and TGA. Spinifex fibres showed the crystalline nature of typical cellulose I structure. Furthermore, through XRD and FTIR analysis, chemical purification caused to increasing crystallinity due to removal cementing materials like lignin, hemicelluloses and pectin which exist in amorphous regions and causes to realignment of intermediate ordered region. After mechanical treatment, the crystallinity index slightly declines for 30 min and 1 h milling due to damaging the cell walls and disordering oriented domains. It appears that for longer milling times, the crystalline regions of cellulose undergo some degree of reordering in fibres, as evidenced by XRD graphs. Interestingly, after chemical and mechanical treatments, the thickness of crystalline domains increases due to intermolecular rearrangement during these processes.These quantitative results were confirmed by TGA analysis by measurement of the amount of water absorbed by cellulose, and temperature associated with the onset of thermal degradation. All the cellulose samples after chemical and mechanical treatments had almost the same weight loss (about 5.5% in the range of 30-150 o C), and the degradation behaviour was almost the same for chemically-treated and milled samples. There was only a slight change in maximum decomposition temperature for milled samples as a function of different milling times. References [1] H.K . Gamage, S.Mondal, L.A. Wallis, P. Memmott, L. Wallis, D. Martin. B. R. Wright, S. Schmidt. Australian Journal of Botany 2012, 60:114-127 [2] R. Avolio, I. Bonadies, D. Capitani, M.E. Errico, G. Gentile, M. Avella . Carbohydrate Polymers 2012, 87: 265– 273 [3] S. Alila, I. Besbes, M. R. Vilar, P. Mutjé, Sami Boufi. Industrial Crops and Products 2013, 41: 250– 259 [4] E. Abraham, B. Deepa, L.A. Pothan, M. Jacob, S. Thomas, U. Cvelbar, R. Anandjiwala. Carbohydrate Polymers 2011, 86: 1468– 1475.