A kind of anhydrous calcium sulfate whisker surface modification method

Abstract

The invention provides a surface modification method of anhydrous calcium sulfate crystal whiskers. The surface modification method is characterized by comprising the following steps: mixing the anhydrous calcium sulfate crystal whiskers and an inorganic salt solution at a mass ratio of 1:(20 to 50) and stirring; carrying out solid-liquid separation to obtain a first filtrate and a first filtering cake, wherein the substance amount concentration of the inorganic salt solution is 0.015mol / L to 0.1mol / L; adding stearic acid and absolute ethyl alcohol into the first filtering cake; after mixing, heating to 20 DEG C to 90 DEG C to prepare paste, wherein the use amount of the stearic acid is 6 percent to 15 percent of the mass of the anhydrous calcium sulfate crystal whiskers; adding the paste and mixing and stirring for at least 5min; carrying out the solid-liquid separation to obtain a second filtrate and a second filtering cake; washing and drying the second filtrate to obtain modified anhydrous calcium sulfate crystal whiskers. According to the surface modification method of the anhydrous calcium sulfate crystal whiskers, the surface activity of the crystal whiskers is increased; the anhydrous calcium sulfate crystal whiskers can be easily reacted with fatty acid organic surfactants including the stearic acid and the like, and expanded production can be easily realized.

Description

technical field [0001] The invention relates to the technical field of crystal preparation, in particular to a method for surface modification of the anhydrous calcium sulfate whisker. Background technique [0002] Since the surface of anhydrous insoluble calcium sulfate whiskers is polar, hydrophilic and oleophobic, it is poorly compatible with organic materials as a filler, so surface modification is required to add anhydrous insoluble calcium sulfate whiskers to rubber, plastics, etc. It has better compatibility and better dispersion in the organic matrix, which can effectively improve the mechanical properties of the composite material. [0003] Anhydrous insoluble calcium sulfate is an orthorhombic crystal structure, the crystal structure is closely arranged, the surface is smooth, and there is no hydroxyl group or Ca on the surface. 2+ The activity is small, and the surface modification is directly carried out with organic surface modifiers, and the modification effec...

AI Technical Summary

Problems solved by technology

For anhydrous and insoluble calcium sulfate whiskers, there is no hydroxyl group on the surface, the crystal lattice is dense, and the surface activity of the whiskers is small, so it is difficult to directly interact with organic modifiers

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