Studies On The Preparation And Composite Applications Of The Bagasse Nanocrystalline Cellulose

Nano-materials used in composites has been industrialization as a reinforcing agent, although there are many synthetic polymers used to prepare nanocomposites, but they are restricted in many places such as Treatability,biocompatibility and biodegradability compared with natural polymers.The cellulose nanocrystals in the field of polymer-based nanocomposites as a natural、new high-strength reinforcing agent has been studied partly.It has great significance to prepare nanocrystalline cellulose (NCC) used the bagasse pulp in this study.In this paper, NCC was prepared with acid degradation of bleached bagasse pulp.Composite poly alcohol (PVA) film was prepared with this NCC and the enhanced roles of different preparation conditions of composite film were studied. At the same time, the NCC blend with cationic starch is used for bleached bagasse pulp papermaking enhancement study and the enhancement of NCC for bleached bagasse pulp was explored. The results show that:(1) NCC particle size of50nm, length200nm around was obtained used64%of concentrated sulfuric acid at a temperature45℃, reaction time30min,acid pulp rate10:1. After determination of infrared spectroscopy and X-ray diffraction, The functional groups structure of obtained NCC is similar to the original bagasse pulp but has different content, and degree of crystallinity was increased from69.2%to80.2%.(2) NCC was used as nano-materials in compound polyvinyl alcohol film, the film properties were investigated under different preparation conditions. It has low water absorption and will not cause too low elongation at break of the composite films when the amount of NCC is0.5%, the crosslinking time1hour, drying heating temperature70℃.The tensile strength is Increased to57.0Mpa, breaking elongation was reduced to8.2%and water absorption is also reduced to89.1%.(3)NCC and modified starch enhancer used in bleached bagasse pulp and papermaking, when the amount of NCC at0.6%, tensile index increased by97%,tear index increased by43.7%, burst index increased by8.3%, folding strength increase of66.7%.(4)Adding NCC in different beating degree has a great impact of the paper’s strength, of which the tensile index’s increase is the most obvious. With the improvement of beating degree, paper’s tensile index, tear index, burst index and folding strength all have the trend first increases and then decreases. The turning point is in the beating degree of70°SR.Tensile index, tear index, burst index and folding strength increase437%,17.4%,120%and340%respectively.(5)Scanning electron microscopy analysis shows that, the NCC are evenly distributed in the surface of paper fibers when added0.6%; when pulp beating degree is70°SR, paper fibers has the apparent phenomenon of wire broom and this is conducive to the retention and uniform distribution of NCC.