The main steps include the synthesis of liquid polycarbosilane, the pre-removal fraction, the synthesis reaction and the distillation purification.
- Pyrolysis to synthesize liquid cyclosilane: a certain amount of polydimethylsilane is heated to about 450 degrees under the protection of an inert gas, and liquid cyclosilane is obtained by reaction.
- Remove the front fraction: put a certain amount of cyclosilane in the reactor, vacuum to replace nitrogen, under the protection of inert gas, the synthesis temperature is heated according to the program, and remove the front fraction when the temperature reaches about 150 degrees.
- Synthetic reaction: First, the pyrolysis column is heated up, and the internal temperature is controlled by adjusting the reflux rate. The maximum temperature of the synthetic reaction is about 400 degrees, and the control reaction time is based on the melting point of the coarse material; The whole synthetic system is under positive pressure, with the pressure in the range of 0.01-0.05 mpa.
- Distillation and purification: when the material temperature is below 190 degrees, add solvent to dissolve, when the material is brought to room temperature, filter, then distillation, cooling, and then obtain solid polycarbosilane.
