Study On The Structure And Properties Of And Fibers-reinforced Polyamide6Composite

The properties of fibers-reinforcing composite are not only associated with theperformance of matrix resin, but also related largely with the fiber types andcharacteristics. This thesis was based on inorganic glass fiber (GF) and organic PETfiber (PET-F) as research object, the EAA was selected as impact modifier for thefiber reinforced composites; and then respectively incorporated with matrix resin toprepare the fibers-reinforced polyamide6composites through melt blending. Focuson the effect of organic PET fiber morphology distribution and the fiber types on theproperties of composites. The properties of composites were studied andcharacterized through cupping machine, simple beam impact testing machine,differential scanning calorimeter (DSC), scanning electron microscope (SEM),advanced Rheometer (ARES).The study on the mechanical properties of the composites indicated that withthe addition of glass fiber, PET fiber, PET fiber/glass fiber, the tensile and flexuralstrength, tensile and flexural modouls of composities were increased at differentdegree, the PET fiber/glass fiber showed obvious enhancement, when the (PETfiber/glass fiber) ratio was10/30and comparing with pure PA6, the tensile andflexural strength, tensile and flexural modulus of PET fiber/glass fiber-reinforcedcomposites increased47%,82%,95%,169%respectively, and its notched impactstrength remains at round8kJ/m2, possessed integrated mechanical properties. ForPA6/PET-F composites, The tensile and flexural strength of the were much higherwhen PET-F scattered in PA6matrix as fibrous compared with those as apheres,however, and its notch impact strength showed opposite tendency.The observation of the morphology structure of the composites showed that: inthe samples of PET fiber-reinforced PA6composite that prepared under theprocessing technology of235℃, PET fiber distributed as fibrous in matrix resin. Inthe samples of glass fiber-reinforced PA6composite and PET fiber/glassfiber-reinforced PA6composite, the glass fiber distributed uniformly and had acertain degree of orientation in the matrix resin, also had a good bonding effect onthe matrix resin interface, in the samples of PA6/PET fiber composites, the PET fiberdistributed as shape of thiny particles in the matrix resin.Investigation of the melting and crystallization process of the compositesdemonstrated that glass fiber as a role of heterogeneous nucleation in crystallization of composites, whereas, under the processing technology of235℃, PET fiber’sinhibition on crystallization of composite is more obvious. The degree ofcrystallinity of glass fiber-reinforced PA6composite is higher than that of pure PA6,while the degree of crystallinity of the PET fiber-reinforced PA6and PET fiber/glassfiber-reinforced PA6is lower than pure PA6.The research of dynamic rheological behavior of composites evinced that thecomplex viscosity of composites increased by the increase of fiber content,decreased by the increase of frequency, and they all had shear thinning behavior; theshear thinning behavior of glass fiber-reinforced PA6composite and PET fiber/glassfiber-reinforced PA6composite were more evident. The storage modulus and theloss modulus of composites increased by the increase of the fiber content, thedependency of the fiber content in the low frequency region is above that of the highfrequency area, when fiber content of composites reached to a certain value, thesecond modulus of platform would emerge, appearing pseudo solid-like behavior.