Surface Modification Methods of Inorganic Whiskers

The ideal conditions of whisker-reinforced resin are as follows whiskers are dispersed evenly in a matrix, separated from each other, and are well wetted by matrix resin. Surface modification of whiskers is needed to improve the dispersion 

The surface modification methods of inorganic whiskers mainly include the wet method, dry method, in situ polymerization, sol-gel method, surface coating and coupling agent modification, self-assembly method, and so on. 

Han et al. modified basic magnesium sulfate whiskers using sodium stearate. The method is as follows. First, measure 50 g of basic magnesium sulfate whiskers and prepare a 5% (mass fraction) mixture of whiskers and water. Second, blend the mixture evenly and then keep it at constant temperature at 80°C in a water bath. Third, add sodium stearate to the mixture and stir for 30 minutes. Products are obtained after filtration and low-temperature drying. Finally, strong chemical adsorption between whiskers and sodium stearate develops after modification. 

Coupling Agent pH Solvent Hydrolysis Temperature rc) Dispersion Time (min) 

The treatment process of calcium carbonate whiskers using the dry method is as follows. Measured materials are mixed in a high-speed mixer at slow speed for 1 minute and at high speed for 1 minute. Wang et al. added calcium sulfate whiskers into a high-speed mixer, then heated and stirred. They then added surface treatment agent diluted with liquid paraffin at 100°C, stirred for 6 minutes, and obtained modified calcium sulfate whiskers. 

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