Study On The Interfacial Adhesion And Dispersion In Nylon-6/glass Fiber Composites

In our work, three modified agent are added into the composites. They are N-butyl-p-toluenesulfonamide(BTSA), N-cyclohexyl-p-toluene-sulfonamide(CTSA), m-phthalic-5-sulfonic acid sodium(5-SSIPA). We hope the addition of these agents can improve the level of interfacial adhesion and the dispersion of glass fiber in matrix simultaneously.BTSA, CTSA, 5-SSIPA was blended with PA6 respectively. The materials were prepared in a twin-screw-extrusion machine. The relation of the structural character and dosage of agents to the improvement is confirmed by means of mechanical properties testing. The interaction between 5-SSIPA and amide group in PA6 molecules is studied by means of Fourier Transform Infrared Spectroscopy(FT-IR) and Differential Scanning Calorimetry(DSC) and the change of crystalline properties is also viewed.The mixtures A(5-SSIPA:BTSA=3:3), B(5-SSIPA:CTSA=3:3)were added into PA6/E-SGF composites. The changes of static and dynamic mechanical properties were tested. Scanning Electron Microscopy (SEM) was carried out to study the fracture surface of tensile failing specimen.The glass translation temperature (Tg), melting temperature (Tm), vicat softening temperature of modified and unmodified composites were all tested. The thermal degradation of composites was also investigated through thermogravimetric analysis. The diffusion of water in composites was studied at different temperature by use of Fick theory and Arrhenius equation.The results of mechanical testing show that 5-SSIPA is confirmed to be the best reagent for PA6. When 3% of 5-SSIPA is incorporated to PA6, the mechanical properties of the blend increases significantly.The FITR spectrogram indicates that there is a kind of hydrogen bonding between the polar group in 5-SSIPA and amide group in PA6 chains. As the temperature raise, the hydrogen bonding in PA6/5-SSIPA exhibits a higher thermal stability than that in PA6.When 3% of 5-SSIPA is incorporated to PA6, the crystalline degree of PA6/5-SSIPA is improved from 27.2% to 35.5%., and the crystalline temperature is improved from164.1℃to 179.4℃.From the SEM figures, we can find that in PA6/GF/A the matrix becomes much tight and the dispersion of fibers is improved markedly. The fracture surface contains lines or ridges that radiate from the interface around the fibers. The results of static mechanical testing...