Preparation Of Sisal Fiber/polypropylene Composites And Its Application In Automotive Industry

With the increasing awareness of environmental protection,the utilization of renewable resources has become more and more important.In recent years,natural fiber reinforced polypropylene composites have attracted more and more attention due to their environmental protection,lightweight and biodegradability,and their applications are more and more widely applied.Sisal fiber(SF)/polypropylene(PP)composites were prepared by hot pressing method using sisal fiber as filling material and polypropylene resin as matrix material.The composites were prepared by changing sisal fiber content,fiber length and fiber surface treatment method.The effects of these variables on interfacial adhesion,mechanical properties and fluidity of sisal fiber/polypropylene composites were studied.At the same time,the application of sisal fiber/polypropylene composites in automobile industry is described,and some Suggestions and methods are given for the possible problems in the process of injection molding.The experimental results show that:(1)the surface treatment of sisal fiber can improve the interfacial compatibility between the fiber and the polypropylene matrix,and improve the adhesion of the two phase interface.The interfacial bonding property of the composite with compatibilizer MAH-g-PP is better than that of the composite material treated by NaOH alkali solution and MAH.(2)the tensile strength and flexural strength of SF/PP composites increase with the increase of fiber content and fiber length,and the impact strength decreases.the length of SF is suitable for 6mm;when the SF length is 6mm and the amount of addition is 15%,the tensile strength and bending strength of PP/SF composites are the most 39.7MPa and 30.2 MPa,while the impact strength is 2.6 kJ/m2.(3)by testing the melt index of sisal.fiber/polypropylene composite,it is found that the fluidity of sisal fiber/polypropylene composite decreases with the increase of fiber mass fraction and length.(4)the thermal deformation temperature of SF/PP composites increased with the increase of SF content.When the amount of SF was 25%,the service temperature of SF/PP composite material was higher than that of pure PP,which was higher than 14 PP.(5)the flame retardancy of SF/PP composites can be improved by adding flame retardant ammonium polyphosphate,and the limit oxygen index can reach 25%,Meet the requirements of automotive industry for plastic injection molding.