Relatively weak mechanical performance
The hardness of organic silicon coatings is generally not as good as epoxy coatings, polyurethane coatings, etc. When scratched by sharp objects or impacted by external forces, they are relatively more prone to scratches, damages, and other situations. For example, in some industrial places with frequent mechanical friction, if only organic silicon coatings are used for protection, surface damage may not last for too long, affecting their protective and decorative effects.
Its mechanical performance indicators such as tensile strength and adhesion are also slightly insufficient in some high-strength use scenarios. In some application scenarios that require close bonding between the coating and the substrate and withstand large external forces, coating peeling may occur.
High cost
The preparation cost of organic silicon materials themselves is relatively high, making the price of organic silicon coating products often much higher than ordinary acrylic coatings, alkyd coatings, etc. This limits its use in large-scale application scenarios that are sensitive to cost and do not require extremely high performance requirements such as low temperature resistance. For example, in ordinary protective scenarios such as exterior walls of civil buildings, lower cost coating products are often preferred.
The curing conditions are relatively strict
Some organic silicon coatings require specific curing conditions such as temperature and humidity to fully cure and achieve the desired performance state. For example, some silicone coatings require a relatively high temperature environment and a long time of baking to fully cure. If the curing conditions are not met, it may lead to incomplete coating curing, resulting in surface stickiness, insufficient hardness, chemical resistance and other performance issues that do not meet the standards. This requires high requirements for construction environment and process control in practical construction applications.
Limited resistance to organic solvents
Compared to some coatings with strong chemical corrosion resistance such as fluorocarbon coatings, organic silicon coatings have less than ideal resistance to certain organic solvents. When exposed to strong organic solvents such as acetone and toluene for a long time, organic silicon coatings may swell, soften, or even be corroded and damaged. Therefore, in some chemical environments where organic solvents are often present, using organic silicon coatings alone may not meet the protection requirements.

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