Effects Of Silica Contents Of Biomass Based Silicon-Carbon Fillers On Reinforcement Of Natural Rubber

With the challenge of energy crisis in society intensified,it is urgent to develop renewable resources.Biomass is an abundant natural resource.In the field of energy,biomass usually refers to agroforestry waste.The traditional treatment can result in the waste of resources and serious environmental problems.Therefore,the utilization of biomass resources has great economic and environmental benefits.Biomass is rich in lignocellulose,and some biomass also has silica.The hemicellulose and cellulose are important raw materials for sugar and paper industries.However,lignin and SiO2 are often discharged into the river as wastes,which can cause serious environmental pollutions.Due to the different contents of silica,the biomass-based silicon-carbon fillers derived from different types of biomass perform different reinforcing properties.In this paper,three biomass(rice husks,bamboos,corn cobs)with different silica contents was selected to prepare pyrolytic biomass and LS hybrid materials to reinforce natural rubber(NR),and the effects of silica contents on the reinforcement of biomass based silicon-carbon filler were explored.The results are as follows:1.Three biomass was pyrolyzed and then ball-milled at different rotating speeds.The effects of silica contents on the modified conditions and reinforcing properties of pyrolytic biomass were investigated.PRH containing higher silica content demanded more energy to reduce particle size due to the self-agglomeration of silica.Moreover,compared with PC-200,the synergistic effects of silica and carbon in PRH-300 and PB-200 improved the reinforcement of fillers.PRH-300/NR performed the highest elongation at break,because silica could promote the slip of rubber chains on the filler surface.Besides,commercial carbon black was used as the comparison sample,the tensile strength and elongation at break of carbon black/NR were not as desirable as those of PRH-300/NR and PB-200/NR,indicating that PRH-300 and PB-200 had great potential to completely replace commercial carbon black in the field of rubber reinforcement.2.The three biomass above was treated by the method of “alkali dissolved and acid precipitated” and the effects of silica contents on the physicochemical properties and reinforcing properties of LS were discussed.R-LS and B-LS materials extracted from rice husks and bamboos were nano-sized spherical particles with silica as template.Without the template of SiO2,the lignin of C-LS formed self-aggregation and made the particle size larger.Three LS hybrid materials were used as partially substituted fillers of carbon black to reinforce NR.The results showed that the reinforcing effects of 10RLS/40 CB and 10B-LS/40 CB were better than that of 10C-LS/40 CB.Moreover,10RLS/40CB/NR had higher elongation at break,which further proved the promoting effect of silica on elongation at break.However,the decreased content of silica in B-LS inhibited the agglomeration of silica,and the interaction between fillers and rubber was improved,which resulting in higher tensile strength of vulcanizates.