There are significant differences in the preparation methods between polysilazane and silicone resin, which will be introduced below:
Preparation method of polysilazane
Synthesis pathway using chlorosilane as raw material:
Reaction principle: Chlorine containing silane compounds (such as methylchlorosilane, phenylchlorosilane, etc.) are usually used as starting materials and reacted with ammonia or amine compounds. During the reaction process, chlorine atoms are gradually replaced by amino (- NH ₂) or imino (- NH -) groups, and undergo a series of condensation reactions to ultimately form polysilazane. For example, under suitable reaction conditions (such as specific temperature, pressure, and solvent environment), methylchlorosilane and ammonia gradually generate polysilazane molecular chains containing silicon nitrogen bonds (- Si-N -) as the main chain structure, and as the reaction progresses, the molecular chains continue to grow and the degree of polymerization increases.
Specific operation example: Slowly introduce methylchlorosilane into a reaction kettle filled with ammonia gas. The appropriate temperature is pre-set in the reaction kettle (usually in the range of low temperature to room temperature to control the reaction rate and avoid excessive side reactions), and an appropriate amount of organic solvent (such as toluene, etc., to facilitate the dispersion of reactants and the smooth progress of the reaction) is added. Under continuous stirring, the reaction takes several hours to tens of hours, during which attention should be paid to controlling the gas inlet rate, reaction temperature and other parameters. After the reaction is completed, relatively pure polysilazane products are obtained through separation and purification methods such as distillation and filtration.
Open loop polymerization pathway:
Reaction principle: Use some compounds containing silicon nitrogen ring structures, such as cyclic silazane, to undergo ring opening polymerization under the action of initiators to prepare polysilazane. Initiators can provide active centers, causing the silicon nitrogen ring of the cyclic silazane to open, and the newly generated active end continuously reacts with other cyclic silazane molecules, causing the molecular chain to continuously grow and ultimately forming a polymeric silazane macromolecule. Different types of cyclic silazanes (such as ternary cyclic silazanes, quaternary cyclic silazanes, etc.) and different initiators (such as organic bases, metal organic compounds, etc.) can affect the rate and degree of polymerization of the polymerization reaction, as well as the structure and properties of the product.
Specific operation example: Taking a ternary silazane as an example, dissolve it in an anhydrous organic solvent (such as tetrahydrofuran, etc.), add an appropriate amount of organic base (such as n-butyl lithium, etc.) as an initiator, and maintain a certain low temperature environment (such as -78 ℃ to control the reaction and reduce side reactions) under the protection of an inert gas (such as argon). After a period of reaction, slowly raise the temperature to room temperature to allow the reaction to fully proceed, and finally obtain the target silazane product through conventional separation and purification methods.
Preparation method of silicone resin
Hydrolysis condensation method:
Reaction principle: Organic chlorosilanes (such as methylchlorosilane, phenylchlorosilane, etc.) or alkoxysilanes (such as methyltrimethoxysilane, phenyltriethoxysilane, etc.) are used as the main raw materials and added to a reaction system containing water, organic solvents (such as ethanol, toluene, etc.), and catalysts (such as hydrochloric acid, ammonia, etc.). Firstly, the hydrolyzable groups in silane (such as chlorine atoms, alkoxy groups, etc.) undergo hydrolysis reactions under the action of water, generating corresponding silanol (- Si-OH) compounds. Then, these silanol compounds undergo further condensation reactions, and the molecular chains continue to grow and crosslink through the formation of silicon oxygen bonds (- Si-O -), ultimately forming silicone resin. For example, methyltrimethoxysilane hydrolyzes in the presence of water and acidic catalyst to form an intermediate containing silanol groups, and then gradually constructs the molecular network structure of silicone resin through condensation reaction.
Specific operation example: Slowly add methyltrimethoxysilane dropwise into a reaction vessel containing a mixed solution of water, ethanol, and a small amount of hydrochloric acid. The reaction vessel is equipped with a stirring device and a condensation reflux device, and the reaction is carried out at a suitable temperature (usually between room temperature and the heating reflux temperature range, depending on the requirements of the raw materials and products). During the dropwise addition process, the speed should be controlled to prevent the reaction from being too intense. After the reaction is completed, it undergoes separation and purification steps such as water washing and distillation to remove unreacted raw materials, by-products, solvents, etc., and obtain the finished silicone resin product.
Co hydrolysis condensation method:
Reaction principle: When preparing silicone resins containing different organic groups (such as both methyl and phenyl groups) or with specific properties, multiple different organic silane raw materials (such as methylchlorosilane and phenylchlorosilane) are used simultaneously for hydrolysis and condensation reactions. The silanol generated by the hydrolysis of these different silane raw materials interacts with each other during the condensation process, making the final molecular structure of the formed silicone resin more complex and diverse. This allows for the regulation of the properties of the silicone resin, such as heat resistance, flexibility, and other performance indicators. By reasonably matching the proportions of different raw materials, different performance requirements can be achieved.
Specific operation example: Mix methylchlorosilane and phenylchlorosilane in a certain molar ratio, add them to a reaction system containing water, organic solvents (such as toluene), and suitable catalysts (such as ammonia water), and carry out the reaction under conditions such as stirring and appropriate temperature (similar to the temperature range of hydrolysis condensation method). Subsequently, after separation and purification operations, obtain a silicone resin product with specific properties of mixed organic groups.
In summary, polysilazane is mainly prepared by reacting chlorosilanes with nitrogen-containing compounds or ring opening polymerization of cyclosilazane, while silicone resins are often synthesized by hydrolysis condensation or co hydrolysis condensation. The two have significant differences in raw material selection, reaction principles, and specific operations.

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