The main factors affecting the solidification of polysilazane are as follows:
1. Chemical structural factors
Types and quantities of functional groups:
The functional groups contained in polysilazane molecules play a crucial role in the curing reaction. For example, polysilazanes containing more active silicon nitrogen bonds (Si-N) tend to have stronger reactivity and are more prone to cross-linking and curing reactions. If there are other active functional groups such as amino (- NH ₂) and vinyl (- CH=CH ₂) in the molecule, it will further affect the rate and mode of curing. They can participate in crosslinking reactions related to silicon nitrogen bonds or react with each other to promote curing.
Molecular chain length and degree of branching:
Polysilazane with shorter molecular chains and smaller relative molecular weights has relatively stronger molecular activity, making it easier for functional groups to come into contact and collide with each other. The curing reaction is relatively easy to initiate, and the curing rate may be faster. Polysilazane with high branching degree, due to its numerous branching structures on the molecular chain, can provide more cross-linking sites during curing, which accelerates the curing process and ultimately forms a denser network structure of the cured product, which also has a significant impact on its performance.
2. External environmental factors
Temperature:
The temperature has a significant impact on the curing of polysilazane. For high-temperature curing type polysilazane, increasing the temperature can greatly accelerate the curing reaction rate, allowing the cross-linking reaction of molecular chains to proceed rapidly. This is because the temperature increase provides more energy to the molecules, overcomes the activation energy barrier, and promotes chemical reactions between functional groups. For room temperature cured polysilazane, although it can be cured at room temperature, increasing the ambient temperature appropriately can also accelerate the curing speed and shorten the curing cycle to a certain extent.
Humidity:
Humidity mainly affects the types of polysilazanes that can react with water. For example, the silicon nitrogen bonds in some polysilazane molecules can undergo hydrolysis reactions with moisture in the air, leading to subsequent crosslinking reactions such as condensation and solidification. Under suitable humidity conditions, this hydrolysis crosslinking reaction can proceed smoothly. If the environment is too dry and lacks sufficient moisture to participate in the reaction, the curing process will be hindered; However, excessive humidity may lead to rapid or uneven reactions, affecting the quality of curing.
Oxygen content:
In some aerobic curing reaction systems, the presence and content of oxygen can affect the curing process. For example, some polysilazanes containing unsaturated functional groups may undergo oxidative crosslinking reactions under the action of oxygen. When the oxygen content is sufficient, the reaction will continue according to the corresponding oxidative crosslinking mechanism. If they are in a low oxygen or anaerobic environment, the curing reaction of this pathway cannot proceed normally and requires other reaction mechanisms to achieve curing.
3. Catalyst factors
Catalyst type:
The catalytic effect of different types of catalysts on the solidification of polysilazane varies greatly. For example, organometallic catalysts (such as organotin compounds) are commonly used to catalyze polymerization reactions containing silicon functional groups. They can effectively reduce the activation energy of the reaction, allowing the curing reaction of polysilazane to proceed faster at lower temperatures; And some inorganic acids (such as hydrochloric acid, etc.) can also catalyze the hydrolysis and condensation reaction of some polysilazane to achieve solidification, but the reaction conditions and characteristics of catalysis are different from those of organic metal catalysts.
Catalyst dosage:
An appropriate amount of catalyst can accelerate the curing speed and improve the curing efficiency. When the amount of catalyst used is too small, the catalytic effect may not be fully utilized, and the curing reaction may be slow; If too much catalyst is used, on the one hand, it may cause the curing reaction rate to be too fast, difficult to control, and even lead to abnormal situations such as polymerization. On the other hand, it may also affect the performance of the cured product, such as reducing its flexibility and abnormally increasing its hardness.
4. Impurity factors
Impurity type:
The presence of impurities may interfere with the curing reaction of polysilazane. For example, trace amounts of metal ion impurities (such as iron ions, copper ions, etc.) may undergo coordination reactions with functional groups in polysilazane, changing the original reaction pathway and affecting the normal curing reaction; If some organic impurities (such as residual organic solvents that have not been completely removed) interact with polysilazane, they may hinder the contact between functional groups, thereby delaying the curing process.
Impurity content:
The higher the impurity content, the more severe the interference on the curing reaction. Even small amounts of impurities can lead to incomplete curing and decreased performance of cured products in some highly demanding polysilazane systems. Therefore, in the production and use of polysilazane, it is necessary to strictly control the impurity content to ensure the smooth progress of curing reaction and the quality of cured products.

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