Preparation And Properties Of Modified Jute Fibers/Polypropylene Composite

With the increasing demand for resources and the enhancement of green and environmental protection concepts,natural plant fiber reinforced polymer composites are receiving more and more attention and application.But the application of natural plant fiber reinforced polymer composites is limited because the interface between natural fiber and polymer matrix are poor.In this paper,jute fiber(JF)was used as the reinforcing material and polypropylene resin(PP)was used as the matrix material.The surface modification of JF was carried out by sodium lignosulfonate(SL)and alkali lignin(AL),respectively.JF/PP composites(JF-Untreated/PP,JFSL/PP and JF-AL/PP)were prepared by injection molding techniques.The effects of SL and AL treatment on the properties of JF and JF/PP composites were studied.The main conclusions are as follows:1.The effects of SL and AL solution concentration and treatment time on the properties of JF and JF/PP composites were investigated by single factor test,respectively.The results showed that with the increase of solution concentration and treatment time,the content of SL and AL adsorbed on the surface of JF increased,and the tensile strength of single fiber and the mechanical properties of composites increased at first and then decreased.The preferred processing parameters were:solution concentration was 2 %,treatment time was 12 h.2.The effects of treatment of SL and AL on the surface morphology,surface chemistry,thermal properties and mechanical properties of JF were analyzed by SEM,FTIR,XPS,TGA,dynamic contact angle and fiber monofilament tensile test,respectively.The results showed that SL and AL which were treated could be adhered to the smooth surface of JF.The surface roughness of JF was greatly increased.At the same time,the wetting property of the fiber was improved.The contact angle of fiber was reduced and the surface energy was increased to 57.2 % and 30.1 %,respectively.The tensile strength of single fiber treated by SL and AL were increased to 24.4 %and 6.6 %,respectively.Compared with AL treatment,SL treatment had a more significant effect on the performance of JF due to the strong chemical interaction between SL and JF and the increasing in the ratio of fiber surface O/C.3.The effects of SL and AL treatment on the structural morphology,static mechanics and dynamic mechanical properties of JF/PP composites were investigated by SEM,universal testing machine and DMA,respectively.The results showed that the static mechanical properties of the composites were significantly improved after SL and AL treatment.Compared with JF-AL/PP,the mechanical properties of JF-SL/PP composites were greatly improved because the JF-SL/PP material with JF treatment had good interface bonding strength.The tensile strength,fracture elongation,bending modulus and bending strength of JF-SL/PP composites were improved by16.8 %,13.0 %,16.9 % and 19.7 %,respectively.4.The effects of SL and AL treatment on the thermal properties,water absorption performance and hydrothermal aging properties of JF/PP composites were analyzed by DSC,TGA,contact angle experiment,water absorption experiment and hydrothermal aging experiments,respectively.The results showed that the weight loss rate of the composite material was reduced and the melting temperature,initial decomposition temperature and pyrolysis activation energy of the composite were increased when the fiber was treated by SL and AL.So the thermal stability of the composite was improved.However,since the SL and AL treatments reduced the hydrophobic properties of the composite,its resistance to hydrothermal aging was decreased.In summary,the surface roughness of JF increases after the JF is treated by SL and AL.It provids a favorable condition for achieving better physical meshing between JF and PP matrix,and improves the surface chemical properties of JF,which can be used as a "bridge" for chemical interactions between JF and PP.Therefore,the interfacial compatibility between the JF and PP matrices is significantly improved,which in turn significantly enhances the overall performance of the JF/PP composite.