Control reaction conditions
Adjusting reaction temperature: Appropriately increasing the temperature of hydrolysis condensation reaction can usually accelerate the reaction rate, promote more silanol intermediates to undergo condensation reaction, and thus continuously increase the molecular chain, which is beneficial for improving the molecular weight of the product. However, the temperature should not be too high, otherwise it may lead to an increase in side reactions, such as monomer decomposition, excessive cross-linking, etc., which will affect the reasonable growth of product quality and molecular weight. Generally speaking, it is possible to gradually increase the temperature within a certain range to find the most suitable range, such as gradually increasing from room temperature to around 50 ℃ -80 ℃ (which may vary depending on the type of monomer and reaction system), and observe the changes in the molecular weight of the product.
Extend reaction time: Give sufficient reaction time to allow the hydrolysis condensation reaction to proceed fully, giving more opportunities for silanol molecules to undergo condensation dehydration and form longer molecular chains, thereby increasing the molecular weight of the product. As the reaction time prolongs, the molecular weight will gradually increase, but the growth rate may slow down in the later stage. It is necessary to comprehensively consider factors such as production efficiency to determine the appropriate reaction time.
Optimize raw material factors
Choosing the appropriate organic silicon monomer: Organic silicon monomers with different structures have a significant impact on the molecular weight of the product. For example, selecting monomers containing multiple hydrolyzable groups (such as chlorine atoms, alkoxy groups, etc.), such as methyltrichlorosilane, phenyltrimethoxysilane, etc., can provide more active sites (hydroxyl groups) for condensation reactions after hydrolysis, making it easier to form high molecular weight products. At the same time, by combining monomers with different functionalities in a certain proportion, such as combining bifunctional monomers with trifunctional monomers, silicone resin structures with different degrees of crosslinking and molecular weights can be constructed. Reasonable blending can help improve the molecular weight of the product.
Control the purity of raw materials: Ensure that the purity of raw materials is high and the impurity content is low. Impurities may interfere with the normal progress of hydrolysis and condensation reactions, for example, some metal ion impurities may catalyze side reactions, hinder the normal growth of molecular chains, and make it difficult to increase the molecular weight of the product. So strict purification and quality testing of the raw materials are necessary to ensure that the reaction can efficiently proceed towards the generation of high molecular weight products.
Reasonable use of catalysts
Choosing the appropriate catalyst type: Catalysts play a crucial role in hydrolysis condensation reactions, and different catalysts have varying effects on the molecular weight of the products. For example, acid catalysts (such as hydrochloric acid, sulfuric acid, etc.) are beneficial to the formation of linear structures in silicone resins. As the reaction progresses, the linear molecular chains continue to grow, which can increase the molecular weight; And alkaline catalysts (such as sodium hydroxide, etc.) are relatively more likely to promote the formation of highly cross-linked bulk structures. With controlled reaction degree, they also help to construct high molecular weight silicone resin network structures. Select the appropriate catalyst based on the structural characteristics and molecular weight requirements of the target product.

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