Effect of Storage Temperature and Time On Rheological Properties and Spinnability of Mullite Sol

the changes in viscosity or rheological properties during the static process of mullite sol have a significant impact on its spinnability. Herein, mullite spinning sols were prepared by vacuum concentration using aluminum chloride and acidic silica sol, and polyvinyl alcohol as the spinning aid. The influence of storage temperature and time on the stability of sol were studied. And focused on the influence of temperature changes and time on the rheological properties of mullite sols, such as non Newtonian index, structural viscosity index, and viscous flow activation energy. The stretchable fiber length of the sol is used as an evaluation of its spinnability. The results showed that low temperature is beneficial for the preservation of the internal structure of the sol and for maintaining its spinnability for a long time. High temperatures can accelerate the aggregation of rubber particles to form large particles, and lose spinnability in a short time. Furthermore, the sol stored at low temperature for 14 days can continuously draw the gel fiber over 100 m, and mullite ceramic fibers with good morphology, small grains and uniform diameter distribution were obtained after calcination at 1200 ℃.