High temperature resistance range
Organic silicone resin can generally be used stably for a long time in the temperature range of 200 ℃ -300 ℃. Within this temperature range, its chemical structure is relatively stable and will not easily undergo significant changes such as decomposition or carbonization that could affect its performance. It can continue to perform its intended protective and insulating functions. However, some silicone resins that have been specially modified or formulated with high-performance formulas can even withstand short-term temperatures up to around 500 ℃, but their performance will gradually decline when exposed to such high temperatures for a long time.
High temperature resistance principle
Stable silicon oxygen bond structure: The main chain of silicone resin is composed of silicon oxygen bonds (- Si-O -), with a high bond energy of approximately 452 kJ/mol. Compared to many common organic compounds such as carbon carbon bonds (bond energy of approximately 348 kJ/mol), silicon oxygen bonds are less likely to be destroyed, thus maintaining the basic stability of molecular structure in high temperature environments, making the silicone resin exhibit good high-temperature resistance as a whole.
The influence of side chain groups: Side chain groups (such as methyl, phenyl, etc.) in organic silicon resin molecules also have an impact on their high temperature resistance. For example, the introduction of phenyl groups can improve the thermal stability of silicone resins, as phenyl groups can increase the rigidity of molecular chains, making them less likely to move or deform at high temperatures, further enhancing the resin's resistance to high temperatures.
Comparison with other materials
Compared to ordinary organic materials such as common thermoplastics like polyethylene and polypropylene, which may soften and deform at temperatures ranging from tens of degrees Celsius to over a hundred degrees Celsius, organic silicone resins can still maintain good shape and performance above 200 degrees Celsius, demonstrating significant advantages. For example, in terms of insulation protection for outdoor wires and cables, insulation layers made of ordinary organic materials may experience aging, cracking, and other problems in high temperature environments in summer, while silicone resin insulation layers can better withstand high temperatures and ensure the normal use of cables.
Compared to some inorganic high-temperature resistant materials, although ceramic inorganic materials such as alumina and zirconia have extremely high melting points and excellent high-temperature resistance, organic silicon resins have better flexibility, processability, and adhesion to the substrate. For example, when coating high-temperature resistant coatings on the surfaces of some electronic components with complex shapes, silicone resin can be more easily uniformly covered by spraying, brushing, and other methods, while ceramic materials are relatively complex in molding processes and difficult to apply to coating scenarios with such complex shapes.
Performance changes under high temperature environment
In terms of physical properties, as the temperature gradually approaches its tolerance limit, the hardness and elastic modulus of silicone resin may undergo certain changes, such as a decrease in hardness and an increase in elasticity, making the material relatively softer and more prone to deformation. However, within a reasonable temperature range, this change will not cause serious obstacles to its use and can still maintain a certain physical protection capability.
In terms of chemical properties: When the temperature is too high, organic silicon resin may begin to undergo chemical changes such as oxidation and decomposition, resulting in a decrease in its original electrical insulation, corrosion resistance, and other chemical properties. For example, if exposed to ultra-high temperatures for a long time, some organic groups in the resin may be oxidized and detached, thereby affecting its overall performance and rendering it ineffective in protecting the matrix from external factors.

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