Preparation of Palygorskite hybrid iron oxide red pigment and its application in waterborne polyurethane composite coatings and ceramics

Abstract

Palygorskite (Pal) is a kind of magnesium aluminum silicate clay mineral with a one-dimensional rod and layer chain structure. Herein, Pal hybrid iron oxide red pigment (Pal/α-Fe2O3) was prepared by the grinding method. Pal acted as a matrix to fix α-Fe2O3 particles and influenced the performances of composite pigments by changing the particle size and distribution of α-Fe2O3. The color difference analysis showed that the color performances of composite pigments were closely related to the ratio of Pal to α-Fe2O3. Compared with the original red iron oxide pigment, the tinting strength of the composite pigment was increased by about 15%. When Pal/α-Fe2O3 was used as the red pigment for coating, it had good storage stability for waterborne coating and improved its adhesion and corrosion resistance. Pal/α-Fe2O3 composite pigments had excellent high-temperature resistance, which could increase the calcination temperature of ceramic pigments and would be beneficial for the ceramic industry. The synthetic method of Pal/α-Fe2O3 composite pigment was simple, low-cost, and environmentally friendly, and could be applied to large-scale industrial production.