Papers by Author: Yu Zhi Jiang

Abstract: White carbon black (WCB) has important applications in many fields such as rubber production and bioengineering and it has become one of the most promising functional materials currently available on the market. This paper summarizes the preparation of domestic and overseas WCB and it introduces the application progress of WCB. The main problems regarding to the development and application of WCB and its future in China are also discussed.

Abstract: The modified and unmodified magnesium hydroxide whiskers (MH) were mixed with PE, PP, ABS matrix respectively. The mechanics performance of MH/polymer composites was tested by the universal testing machine. The effect of modified and unmodified MH whiskers addition on the performance of composite material mechanics was studied. The results show that the whiskers modified by sodium stearate had a significant mechanical improvement to the MH/PE, MH / PP and MH/ABS composites than unmodified whiskers. The content of modified MH whiskers added to PE, PP, ABS matrix materials are different when the best comprehensive mechanical properties are obtained, which are 20%20% and 40% respectively. Overall, the modified MH whiskers had a significant enhancement effect on the general plastics and engineering plastics.

Abstract: The magnesium oxysulfate whiskers/PP composites were prepared by melt-extrusion with modified whiskers as fillers. The mechanical performances including the tensile strength, elongation at break and elastic modulus were tested by electronic universal testing machine.The effect of surface modifier on the mechanical properties of the composites was studied. In general, the mechanical properties of the composites of the zinc stearate modified whiskers/PP were better than it modified by coupling agent KH550. when the contents of the whiskers modified were 20%, the mechanical properties of the composites got the best. There occurred different organic molecule membranes on the surface of the modified whiskers, which lowered the interfacial energy of whiskers. So modified whiskers had different strengthening with PP matrix.

Abstract: The magnesium hydroxide (MH) whisker/PE composites were prepared by melt-extrusion with modified whiskers and unmodified whiskers as fillers respectively. The flame retardant property of composites was tested by the oxygen index machine. The magnesium hydroxide whiskers could improve the flame retardant property of the composites. When the contents of the modified and unmodified whiskers increased from 10% to 60%, the oxygen index of the composites increased from 24.4% to 43.4%, 23.2% to 40.2% respectively. The flame retardant of the modified whiskers/PE composites was better than the unmodified. The morphology of fracture was analyzed by SEM: the modified whisker could be more evenly divided into PE matrix with better dispersibility and compatibility, for that there occurred organic molecule membranes on the surface of the crystal whiskers after being modified, which lowered the interfacial energy of whiskers.

Abstract: The diatomite-cellulose composite fiber (DCCF) was used to modify the asphalt for pavement, and then the DCCF-modified asphalt was researched by DSC from the point of congeries state and energy change, the temperature and heat absorption of the phase transition as index, combined with the macro-road performance of asphalt. The results showed that the high/low-temperature performance and temperature susceptibility of the DCCF-modified asphalt were all improved obviously and would be the best if the modifier dosage was 0.5%. DSC could effectively explain the influence of DCCF on the properties of asphalt from the view point of congeries state and energy change, and the variation were consistent with the Macro-mechanical properties test results of the modified asphalt.

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.