Original Article Improving cellulose/polypropylene nanocomposites properties with chemical modified bagasse nanofibers and maleated polypropylene Mohammad L Hassan 1,2 , Aji P Mathew 3 , Enas A Hassan 2 , Shiamaa M Fadel 2 and Kristiina Oksman 3 Abstract The properties of cellulose/polypropylene (PP) nanocomposites with n-octadecyl-modified bagasse nanofibers (MBNF) were compared to those with maleated polypropylene (MAPP) coupling agent. The nanocomposites were prepared by twin-screw extrusion with bagasse nanofiber (BNF) content varying from 2.5 to 10 wt%. The compression molded nanocomposites sheets were characterized regarding their tensile strength properties, dynamic mechanical thermal properties, crystallinity, water absorption, transparency and loss of strength due to composting in soil. As a compati- bilizer to improve the tensile strength properties and transparency of PP/cellulose nanofibers nanocomposites, MAPP was more effective than n-octadecyl-modified cellulose nanofibers. The crystallinity of the nanocomposites was lower than that of neat PP except for those prepared using high loading of MBNF. Dynamic mechanical thermal analysis (DMTA) of the prepared materials showed that adding the different nanofibers (treated or untreated) resulted in better mech- anical thermal properties above glass transition temperature (T g ) of PP. Water absorption capability in all nanocompo- sites was weakened while that in PP/MBNF was the lowest. No significant differences were found between the nanocomposites with different kinds of nanofibers regarding the loss of their tensile strength after compositing in soil up to six months. Keywords Bagasse, nanofibers, polypropylene, nanocomposites Introduction Using of nanocellulosic materials to replace man-made and oil-based fibers as reinforcing elements in polymer composites is expected to be the next generation trend for high performance environmentally friendly nanocomposites. 1 The problem of compatibility of cellulose fibers with hydrophobic polymers has been thoroughly investi- gated; it results in poor dispersion of the fibers in hydrophobic polymer matrices and low fiber/matrix interaction resulting in poor performance of the pre- pared composites. 2 Surface modification of cellulosic fibers or use of coupling agents, known as compatibili- zers, has been investigated to overcome the compatibil- ity problem between cellulose fibers and hydrophobic polymer matrices. Chemical modification of cellulose fibers is not easily applicable at the industrial level while the use of coupling agents are more practical because they are usually added in small amounts (1– 3 wt% of polymer matrix). 2,3 Coupling agents can modify the interface by inter- acting with both the fiber and the matrix, thus forming links between the components. 1,2 One of the most com- monly used coupling agents is maleic anhydride grafted 1 Cellulose and Paper Department, National Research Center, Dokki, Cairo, Egypt 2 Center of Excellence for Advanced Sciences, Advanced Materials and Nanotechnology Group, National Research Center, Dokki, Cairo, Egypt 3 Division of Materials Science, Lulea ˚ University of Technology, Sweden Corresponding author: Mohammad L Hassan, Center of Excellence for Advanced Sciences, Advanced Materials and Nanotechnology Group, National Research Center, Dokki, Cairo, Egypt. Email: mlhassan2012@yahoo.com Journal of Reinforced Plastics and Composites 2014, Vol 33(1) 26–36 ! The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/0731684413509292 jrp.sagepub.com at Lulea Univ. of Technology on April 15, 2015 jrp.sagepub.com Downloaded from