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Study On The Property Of Pa6/kaolin Composite

Posted on:2011-10-28Degree:MasterType:Thesis
Country:ChinaCandidate:X Y ZouFull Text:PDF
GTID:2121360308476070Subject:Materials science
Abstract/Summary:PDF Full Text Request
Nylon 6/kaolin composite materials were prepared with three types of kaolin by melt blending. The mechanical properties, melt crystallization behavior and rheological behavior of the composite materials were studied.First of all, the three types of kaolin were analysised by infrared spectroscopy, X-ray diffraction, scanning electron microscopy and contact angle test. The results showed that kaolin A was not calcined and coupling agent modification treatment, and kaolin B, C was heat treated and the coupling agent treatment. The calcined kaolin destroyed the crystal structure of the formation of amorphous, so the reactive functional groups changed into Si-O, Al-O tetrahedron and Al-O octahedron; The morphology of kaolin A was flake and rod-like, and the morphology of kaolin B and C was flaky single but also laminated.Silane coupling agent, rare-earth coupling agent, titanate coupling agent were used respectively to modify kaolin A, The nylon 6 composite materials with modified kaolinA filled were studied on mechanical properties. The results showed that the silane coupling agent KH-550 was the best, and the best content was 1.0wt%. By compared with the results of unmodified kaolinA, the tensile strength was raised 16.9%, bending strength increased 10.4%, and the notched impact strength increased 8.2%. With the amount of kaolin increased, the mechanical properties of composites showed some variations and the mechanical properties got to the best performance when the kaolin content was 40phr. The impact cross section of the composite materials was fracture toughness observed by SEM.Studied the melt crystallization behaviors of nylon 6/kaolin composites by using differential scanning calorimetry(DSC) and X-ray diffraction, and analyzed the non- isothermal crystallization kinetics using three kinds of method. The results showed that the melting peak of composites became so narrow with the addition of three kaolin,as while as the melting point, the crystallization peak and onset temperature increased, so the crystallization rate increased. The account for kaolin fillers played an important role in heterogeneous nucleation. Kaolin prompted the formationγcrystal for nylon 6. Non-isothermal crystallization kinetics analysis showed that, Jeziorny law and Mo methods were suitable for the analysis of nylon 6 and its composites non-isothermal crystallization kinetics, while the Ozawa method was not appropriate.The rheology behavior of nylon 6/kaolin composites was studied by the constant speed double capillary rheometer. The results showed that the shear viscosity increased as shear rate decreases of nylon 6 and nylon-6/kaolin composites in the three studies temperature and shear rate, and showing significant false plastic fluid. While the temperature increased or the amount of kaolin resuced, the viscosity was reduced. The non-Newtonian index of composites decreased with temperature reduced, shear rate increased, the amount of filler increased, the nonlinear material would be increased; With the shear rate increasing, the viscous flow activation energy of three types of kaolin filled nylon 6 composites decreased gradually.
Keywords/Search Tags:Nylon 6 kaolin, composites, crystallization behaviors, rheology behavior
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