| China is the third largest sugarcane gardens in the world.There are a mass of bagasse residue after crushing sugarcane every year and treated as waste.As a biomaterial contains a lot of cellulose,bagasse can be used as a raw material to prepare nanocellulose.And replace traditional fillers of rubber by nanocellulose extracted from bagasse not only can reduce the environmental pressure from traditional fillers,but also provide a new approach for the recycling of bagasse.Bagasse nanocellulose(BNC)with different morphology features and properties were prepared by four ways(an optimized acid hydrolysis way and three kinds of no acid methods)successively from bagasse in this paper.compared with the most common preparation(sulfuric acid hydrolysis)reported in literature,the methods we provided were more facile,less time consuming and better environmental protection.Comprehensive and comparative analysis the processes and the properties of product,the two-step method was the optimum method owing to mild reaction conditions,clean reagents,and the product 2-BNC exhibited higher crystallinity and better thermal stability.The product of sulfuric acid hydrolysis(S-BNC)provided in this paper showed the best dispersibility and reinforcing capabilities in rubber.The morphology of nanocellulose determined by the reagents and preparation conditions,we can prepare nanocellulose with specific morphology by controlling the intensity of reagents,the ultrasonic intensity and the reaction time.The two-step method and sulfuric acid hydrolysis were selected to extract nanocellulose from bagasse,and products 2-BNC and S-BNC were applied in SBR respectively to prepare SBR/2-BNC and SBR/S-BNC composites.The effects of BNC on the performance of SBR were studied,and futher compared with SBR/silica composites with the same amouts of fillers.The results indicated that the addition of BNC can accelerate the curing rate of the system.The most commonly used curing temperature of SBR or SBR/traditional fillers system is 160℃,by contrast,the optimum post curing temperature of SBR/ BNC system is 150℃.As a result,the energy consumption and cost in process was greatly reduced.In addition,we found that interface bonding between BNC and SBR were better than BNC and silica.SBR/BNC composites exhibited higher crosslinking desity,better mechanical properties and abrasion resistance compared with SBR/silica composites with the same amouts of fillers.The modulus at 300% and tear strength of SBR/BNC composites were obviously higher than the SBR/silica composites while both showed close tensile strength and elongation at break.Compared with 2-BNC,S-BNC dispersed more uniform in matrix made the SBR/S-BNC composites present better mechanical properties and dynamical performance than SBR/2-BNC composites.The S-BNC almost can completely replace silica while the filler loading no more than 30 phr.The effects of S-BNC replacing carbon black(CB)partially on the performances of NR/CB/S-BNC composites were studied,and futher compared with vulcanized natural rubber(NR)reinforcing with 45 phr CB.The result indicated that the CB showed better dispersion in NR with the addition of S-BNC,the Payne effect of system was reduced and the processing properties of rubber was improved.Compared with vulcanized NR reinforcing with 45 phr CB,NR/CB/S-BNC composites showed lower heat build-up at dynamic compression.Taken together,the mechanical properties were matained even enhanced and heat build-up at dynamic compression were improved of composites when CB was replaced by S-BNC for not exceeding 10 phr compared with vulcanized natural rubber(NR)reinforcing with 45 phr CB. |
