Study On Characteristics Of Several Inorganic Whiskers Used As Novel Papermaking Fillers

The inorganic whiskers as new reinforcing materials have many specific advantage and function, such as high strength, heating-resisting, anti-corrosion, conduction, insulate and flame retardant etc. The whiskers have the transition state between fibres and particles, and the shape is similar to brief fibers. The whiskers as fillers can combine the characteristic of fibers and particles, and improve the additions greatly, while have no effect on strength. In addition, a few whiskers as fillers can give the certain special function to paper.The disperse effect of different dispersants on inorganic whisker fillers was discussed. Dispersants were used in the experiment, respectively, sodium dodecyl benzene sulfonate (SDBS), sodium dodecyl sulfate (SDS), alkylphenol ethoxylates (OP-10), sodium hexametaphosphate (SHMP). The results showed that the disperse effect using the OP-10 as a dispersant was better than the others.The application of different kinds of inorganic whiskers as paper fillers was researched to improve the properties of paper and give the new functions through comparing with the traditional fillers. The application of tetrapod-like calcium carbonate whisker (CCW), zinc oxide whiskers (T-ZnOw) and basic magnesium sulfate whiskers was discussed through comparing with conventional powder-like calcium carbonate, powder-like zinc oxide particles (ZnO) and natural brucite respectively. The results showed that it seemed to be feasible for using CCW as papermaking fillers. Compared with conventional precipitated calcium carbonate (PCC), CCW had higher retention. The use of CCW was also favorable to improve the strength properties of paper sheets. A model was proposed to suggest the mechanism of paper strength improvement, based on the scanning electron microscope (SEM), scanning electron microscope/energy-dispersive x-ray analysis (SEM-EDAX) and the zero/short span tensile strength data.The results showed that filling a certain amount of T-ZnOw had little effect on the strength properties of paper. A higher retention of T-ZnOw could be obtained even without any retention aid. The T-ZnOw filling was beneficial to the improvement of the brightness and opacity of paper. The antibacterial paper filled T-ZnOw showed a broad-spectrum antibacterial property, and its inhibitory efficiency was high than that of the antibacterial paper filled ZnO. Meanwhile, the results showed that basic magnesium sulfate whiskers gave better flammability characteristics, compared with natural brucite. When the adding amount of basic magnesium sulfate whiskers was 25%, the oxygen index was more than 25%, and met flame-retardant demand. The negative effect on paper strength was obvious when the adding amount of basic magnesium sulfate whiskers was more than 25%. The solubilities of basic magnesium sulfate whiskers in water with different pH values and temperatures were measured. The morphology, distribution in paper and flame-retardant mechanism of basic magnesium sulfate whiskers were revealed by SEM, SEM-EDAX and thermal gravimetric analysis (TGA).