The Research Of In Situ Deposited Nano-SiO₂ On The Surface Of Jute Fiber And Its Polypropylene Matrix Composites

Jute fiber reinforced polypropylene?PP?composites?JFP?had attracted much attention because of their light weight,low cost and biodegradability.However,the disadvanges of JFP include poor comprehensive performance.In this paper,nano-SiO₂ was deposited on the surface of pretreatment jute fiber,and jute fiber/nano SiO₂/PP composites were prepared.The optimum pretreatment of jute fiber was studied,the deposition process of nano-SiO₂ on the surface of jute fiber surface was explored,and the interfacial properties between jute fiber and resin matrix with in situ deposition of nano-SiO₂ was analyzed.The jute fiber through alkali treatment,ethylenediamine/urea treatment and carboxymethylation treatment was studied by infrared spectrum analysis,X-ray diffraction analysis,X analysis,value analysis of barium suspension performance and microstructure analysis.The influence of pretreatment on activation properties of jute fiber was discussed.The results showed that the three kinds of pretreatment may remove the pectin from the jute fiber,and destroy the intermolecular hydrogen bonds,reduce crystallinity and improve reaction activity of jute fiber.The reaction activity of jute fiber through the carboxymethylation treatment was the best,followed by alkali treatment,and the reaction activity of jute fiber through ethylenediamine / urea was minimum.Nano-SiO₂ particlulates were deposited on the surface of the pretreated jute fibers by ultrasonic-sol-gel method using tetraethyl orthosilicate?TEOS?as the precursor solution.The deposition mechanism and interfacial bonding mechanism of nano-SiO₂ on the surface of jute fibers were investigated by single factor method.Finally,the optimum deposition process was determined by orthogonal test.When the volume ratio of TEOS to distilled water was 1:1,the concentration of ammonia was 1.8mol/L,the reaction time was 16 h and the reaction temperature was 40?,the deposition amount of nano-SiO₂ was 11.4%,and the particle size was 80 nm.The size distribution of nano-SiO₂ is considerably narrow,and the controllable size and deposition of nano-SiO₂ on the surface of jute fiber were realized.Besides,the comprehensive properties of the single fiber were the best.Jute fiber/nano-SiO₂/PP composites were prepared by melt-blending with the jute fiber of in situ deposition of nano-SiO₂ and PP.The results showed that the tensile strength of composites,flexural strength and impact strength compared to the undeposition increased by 38.55%?30.31% and 26.03%.At this time the content of jute fiber was 24wt%,the deposition of nano-SiO₂ was 11.4wt%,and the particle size was 80 nm.At the same time,the water absorption of the composites decreased obviously.When the soaking time was 360 h,the water absorption and thickness swelling decreased by 23.84% and 34.30% respectively,which indicated that in situ deposition of nano-SiO₂ particles can significantly improve the interfacial bonding strength of the jute fiber composites.