Research On Preparation And Characterization Of Calcium Sulfate Whisker

At present,it is a new developing tendency for Materials Science to add whisker into resin, metal and ceramic matrix to prepare high-performance composite materials . As an inorganic whisker, the calcium sulfate whisker has the merit of high temperature resistance, chemical corrosion resistance, Toughness, High strength, easiness for surface treatment, good compatibility and smoothness and so on . Because of its high performance price ratio and the tremendous application prospect in Composite materials,so it becomes the focus of research in the area of materials.Presently, the main preparation method of calcium sulfate whisker is hydrothermal method, Plaster as raw materials. However hydrothermal method requires high temperature and pressure, this leads to high energy consumption,high equipment Requirements. It is difficult for this method to be used in industry because of the low length-diameter ratio,low dispersion of whiskers obtained.In the paper, according to this problem, use of industrial products, Calcium chloride and natrium sulfate as raw material, propose two new techniques of preparing calcium sulfate whisker. (1)Liquid Phase Synthesis of new Technology, use the organic liquid catalyst ML-1 which Developed by myself, at room temperature, the length of whisker is between 70 and 80, diameter is between 0.5 and 1.0, length-diameter ratio is about 80 of dehydrate calcium sulfate whisker are prepared. The obtained Whiskers have a good dispersion;(2) Low Temperature (0~100℃) Hydrothermal method , the length of whisker is between 80 and 90, diameter is between 0.5 and 1.0, length-diameter ratio is about 85 of dehydrate calcium sulfate whiskers are prepared, the process greatly enhanced the response of raw materials concentration. The results show that: the liquid phase catalytic synthesis of optimal conditions: the reaction concentration is 0.5mol/L, organic liquid catalyst ML-1 dosage of 50ml, pH value is controlled at 3, ultrasonic time is about 30min, reaction time is 30min. Low temperature(0~100℃)hydrothermal method of optimal conditions: raw material concentration 1.0mol/L, reaction temperature is controlled at 80℃, reaction time is 30min, stirring speed is 120r/min.The paper Also explores the study of dihydrate calcium sulfate whisker be converted to hemihydrate calcium sulfate whisker and anhydrous calcium sulfate whisker at a certain temperature, get the great length-diameter ratio of hemihydrate or anhydrous calcium sulfate whisker.