Application Study Of Catalytic Performance Of Calcium Sulfate Whisker

The calcium sulfate whisker is calcium sulfate fibrous crystals which is growth with gypsum as raw material under artificial control conditions. It has single crystal structure. Whiskers are widely used in modified composite materials, coatings and paint, environmental engineering, could replace the traditional friction material due to its complete crystal structure, uniform cross section and small size. The calcium sulfate whisker is a kind of green environmental protection material with high activity, excellent performance, low prices, excellent cost-effective, and non-toxic in itself, which belongs to environment-friendly material. This paper is mainly talks about two different kinds of calcium sulfate whisker, research its other properties except reinforced composite--catalytic performance.At present, most of the ester exchange reaction needs the addition of a catalyst, the traditional strong acid and alkali catalyst has good catalytic effect and low price. But the large amount of waste liquid become nonnegligible environmental problems, it has strong corrosion to the equipment and against sustainable development. In this paper uses calcium sulfate whisker the model of whisker material as the research object, applies it into the transesterification reaction. This catalyst has non-corrosion to equipment and non-pollution to the environment.This paper investigates the catalytic properties of calcium sulfate whisker with the synthesis of n-butyl acetate. We select methyl acetate and n-butyl alcohol as reactants, two different kinds of calcium sulfate whisker as catalyst, got the best reaction conditions through the experiment:(1) select modified calcium sulfate whisker as catalyst, molar ratio of ester and alcohol is3, the addition of calcium sulfate whisker is2%, ultrasonic frequency is25kHz, reaction temperature110℃and reaction time is6h, the esterification yield can reach73%or more.(2) select non-modified calcium sulfate whisker as catalyst, molar ratio of ester and alcohol is3, the addition of calcium sulfate whisker is2%, ultrasonic frequency is20kHz, reaction temperature110℃and reaction time is6h, the esterification yield can reach59%or more. In addition, we can see the different crystal properties of two kinds of whisker through the n-butyl acetate yield. Modified calcium sulfate whisker shows better catalytic effect than non-modified one. Finally, research the esterification kinetics of methyl acetate and n-butyl alcohol catalyzed by calcium sulfate whisker. Get the apparent activation energy of Ea=5.243KJ/mol, and Arrhenius equation k=3.8496×103exp(-5243/RT) through the experiment, finally establish the model kinetics of the ester exchange reaction r=3.8496×103exp(-5243/RT)cACB.