At present, there are three problems in preparing polyorganosiloxane starting from organochlorosilane: 1 chlorine does not enter the polysiloxane structure, and it is impossible to enter the main chain structure, which does not contribute to the improvement of product performance. Chlorine only serves to increase the reactivity of silicon. When organochlorosilane is made into a siloxane intermediate (such as D4 or DMC, etc.), chlorine is produced as hydrochloric acid and must be recycled for recycling. ; 2 organochlorosilane monomers, especially methyl chlorosilane monomers, the boiling point difference is too small, and the production of various types of silicone products (including silicone oil, silicone rubber and silicone resin, etc.), but the use of different functionalities and The monomer of purity is the raw material. Therefore, it is necessary to use a sufficiently high fractionation tower, stable heat source, high-sensitivity instrument, high-precision control technology and patience and careful operation to obtain satisfactory fractionation results, which will inevitably lead to methylation. The proportion of chlorosilane fractionation process is too large; 3Si-Cl bond is easy to hydrolyze by-produced HCl, which is corrosive to human body and buildings, and it is easy to make the glass window fog and become opaque. This is the reality of the current domestic and international silicone production plants.
If it can be directly reacted with Si powder and ROR` (R=Me, Et, Ph, Vi, etc., R=Me, Et, etc.) to obtain RnSi(OR`)4-n; For the silicone products, the above three major problems will no longer exist, but it takes a lot of effort to lay the foundation, but we will take this step sooner or later.