Polysilazane has excellent properties, small Angle between silicon and nitrogen bonds, large molecular bond tension, so the molecular chain is not easy to form a ring, not easy to bite back, rearrangement and other side reactions in the process of molecular polymerization, and good thermal stability. Polysilazanes with specific properties can be designed by changing the silicon or nitrogen substituents. At present, polysilazanes materials are not widely used, the main reasons are: most of the polysilazanes are relatively active, have high reactivity, easy to react with water, polar compounds and oxygen, so it is difficult to preserve and transport; The synthetic method of polysilazane is not mature yet, the molecular structure of the reaction product is complex, and the molecular weight of the polymer is generally low. Polysilazanes mostly exist in the form of binary ring, quaternary ring structure or linear oligomer, and their heat resistance is generally poor.
Polysilazane materials are mainly used in ceramic precursor preparation, coating material synthesis and medical surgery and other fields. Polysilazane is widely used in the preparation of foamed ceramic materials because of its good fluidity, design of components, good heat resistance and uniform product composition.


With the continuous development of modern science and technology, the research on the molecular structure design, product synthesis and application of polysilazanes has made extraordinary rapid progress, and the related research achievements on the construction of polysilazanes with clear molecular structure have been reported. In recent years, the research on the spinning ability of polysilazane ceramics and the application of material coating are more extensive at home and abroad, but the research on the heat resistance of polysilazane needs to be further studied. In this paper, the present synthesis methods and reaction principles of polysilazanes are reviewed, the special chemical properties can be designed by using the molecular structure of polysilazanes, the research ideas for the synthesis of heat-resistant high molecular weight polysilazanes are put forward, and the development prospect and research direction of polysilazanes are prospected.