The Effect Of Surface Modification Of Ramie Fiber On The Mechanical Properties Of Its Composites

With the rapid development of technology,composites with superior performance advantage were widely used in materials industry.Because of its excellent performance,ramie fibers are deemed one of the preferred reinforcing fibers of the composite.However,the outer pectin impurity covering of ramie fibers could greatly impact the adhesion with epoxy resin,the stability of the composite interface is affected,so that the performance of the composites is fallen.Therefore,the surface modification of ramie fibers is the key to the manufacture of composites.In order to improve the interface performance between ramie fibers and epoxy resin,from the perspective of green and environmental protection,this present study adopts low temperature treatment to treat ramie fiber,which is energy saving and efficient modification method.Then molding process was used to make ramie fiber reinforced composites.Through the test of the properties of fibers and composites analyzed the influence of the low temperature plasma treatment of ramie fiber and its composite.The research item of this file includes 4 parts:(1)Influence of plasma treatment condition on properties of ramie fibers.Through the testing of wettability,surface morphology,tensile property and friction property of ramie fiber,the pectin and impurities are separated effectively by low-temperature plasma treatment and the fine fiber with irregular striations is revealed,the surface roughness reasonably increases.(2)The determination of the optimal parameters.Ramie fibers were treated under various low-temperature plasma conditions such as different output powers and treatment times.By analysis of the surface energy and tensile property,the parameters were chosen to do orthogonal experiment,which effect obviously.At last,1min-100w treated,2min-150w treated,and 3min-200w treated were selected as output power and treatment time.(3)The comparison of low-temperature plasma treatment and alkali treatment on properties of ramie fibers.Comparing with alkali treatment,the influence of on wettability and friction property of ramie fibers is more remarkable.Among a certain scope of parameters,low-temperature plasma treatment causes less damage to ramie fibers.With the growth of output powers and treatment times,ramie fibers were damaged seriously after low-temperature plasma treatment,the tensile property decreased seriously.(4)The influence of ramie fiber modification on mechanical properties of the composite.Epoxy resin was chosen as base material.Ramie fiber reinforced composites were made by molding process,which volume fraction of fiber was 30%.Through the analysis ofinechanical test,Comparing with untreated fibers,the surface energy of plasma-treated ramie fibers and adhesion work with epoxy resin were increased 124.5%and 59.1%after 3min-200w,respectively.From the analysis of SEM and AFM,it is discovered that fibers were etched by plasma treatment.The contact area between fibers and resin was increased so that fibers adhered with resin effectively and fibers were not easy to pull out.Fibers were damaged by treatment,while the adhesion between fibers and resin were improved,so that the tension strength,bending strength and shearing strength of composites were increased 29.2%,37.0%and 30.5%compared with untreated fiber reinforced composites.