Papers by Author: Yan Bo Li

Abstract: The magnesium oxysulfate whiskers/PE composites were prepared by melt-extrusion using whiskers as filler. The mechanical performances, including the tensile strength, elongation at break and elastic modulus, were tested by electronic universal testing machine. The results show that as the content of whiskers increases, the modulus of elasticity increases while the elongation decreases. However, the elastic modulus will improve and the tensile strength will be maximized when it is 15%. Hydrogen bond was formed between whisker and modifier after modification and was characterized by IR. The morphology of fracture was analyzed by SEM. It draws the conclusion that hydrogen bond is capable to enhance the mechanical performances of composites.

Abstract: The magnesium oxysulfate whisker/ABS composites were prepared by making the magnesium oxysulfate whisker as dispersed phase.Scaning electron microscope(SEM) was used to test the distribution of whiskers in ABS matrix.Effect of the surface modification and the amount of whiskers to the mechanical properties of composites were studied.The results show that,the surface modification can improve effectively dispersity both itself and in ABS matrix,interface acting force between ABS matrix and whiskers, and mechanical properties of composites ,remarkably.When the mass ratio of whisker to ABS is 40/100,the composite owns the optimum mechanical properties(Tensile strength,elastic modulus,and elongation at break are 67.5Mpa, 7.50Mpa,4.70%,respectively), whiskers distribute uniformly in matrix and improve the dimensioned stability of composites.The reinforcement mechanism of whiskers in ABS was also studied to explain the experimental results.

Abstract: Taking alkaline magnesium sulfate whiskers and sodium hydroxide as raw materials, the proper process parameters were experimentally investigated for magnesium hydroxide whiskers preparation by hydro-thermal synthesis. The experimental results show that satisfactory product of magnesium hydroxide whiskers can be obtained under the proper synthesis conditions. The whiskers are characterized with smooth surface, straight morphology, and small diameter. The whisker product of magnesium hydroxide is of less than 0.5μm in diameter, around 100 in slenderness ratio, and 99.69% in purity under the condition of 4.0% initial concentration of alkaline magnesium sulfate whisker, stirring intensity of 100rpm, reaction temperature at 180°C, and reaction time of 4h. The synthetic mechanism of the whiskers was analyzed by the theories of anion coordination polyhedron nucleation and screw dislocation growth of the crystal.