III. Synthesis of new polysilazanes
 Polysilazane polymers generally have low molecular weight and poor thermal stability. Polysilazane polymers with a certain proportion of methyl groups will show good ductility and thermal stability, which can effectively improve the heat resistance of polysilazane.
The research on polysilazanes is mainly concentrated in the fields of ceramic precursors and ceramic fibers, but the research on improving the heat resistance of polysilazanes is seldom reported. The author has designed the molecular structure of polysilazanes with good heat-resistant properties through the ring-opening polymerization of octamethylcyclotetrasilazane and the introduction of methyl groups to provide certain design ideas and theoretical bases for the later architecture of polysilazane molecular structures with specific performance, and the specific research ideas are as follows: octamethylcyclotetrasilazane as the ring-opening monomer, hexamethyldisilazane as the capping agent, toluene as the reaction solvent, and toluene as the reaction solvent. Under the protection of dry nitrogen, the ring-opening polymerization was catalyzed by ruthenium catalyst as initiator.
Application Analysis of Polysilazane
In terms of material coating, polysilazane can be converted into silica under certain conditions, which is a good coating material with good solubility, excellent adhesion, simple curing, corrosion resistance, oxidation resistance, long-term weathering, resistance to high and low temperatures, transparency and scratch resistance, etc. It is widely used in semiconductor and electronic devices, metal protection, plastic packaging and printing industry, and at the same time, it has a certain function of anti-scrawl, which is widely used on the surface of buildings and public transportation. It is also widely used in building surfaces and public transportation.
In terms of ceramic materials, the ceramic precursor prepared by cracking of polysilazane combines the characteristics of polymer easy processing and high and low temperature resistance, and is a new organic material that can be used as a reinforcing material in aerospace device development, and is also widely used in the preparation of high and low temperature resistant coatings, foams, and coating of structurally complex components.
In the field of medical surgery, by means of radio frequency glow discharge, surgical elastic sutures will form polyester coating in hexamethyldisilazane vapor, which can effectively eliminate tender and weak tissue damage due to suture vibration or disintegration, and at the same time, it has the characteristics of good hydrophobicity and antioxidant properties. In addition, polysilazane products are widely used in the preparation of capillary tubes with high thermal stability, high adsorption and no catalytic activity.
V. Prospects for the development of polysilazanes
 (1) Polysilazanes mostly exist in the form of cyclic monomers or oligomers, and there is a lack of mature synthesis methods for structurally defined high molecular weight polysilazanes, so exploring mature synthesis methods for high molecular weight polysilazanes has become a hotspot for future research.
(2)N-methyl polysilazane is a semi-crystalline thermoplastic polymer with high force resistance and surface energy, which has become a hotspot for attention in the reinforcement of silicone elastomers.
(3) Strengthen the research on the heat resistance and thermodynamic properties of polysilazanes. Synthesize polysilazanes with specific structures, improve the heat resistance and thermodynamic properties of polysilazanes, and provide certain design ideas and theoretical basis for the architecture of polysilazane molecular structure with specific chemical properties.

Room termperature curing polysilazane, pls check IOTA 9150, IOTA 9150A. 
High termperature curing polysilazane, pls check IOTA 9108, IOTA 9118.