Preparation method of organic silicon polymer

Abstract

The invention relates to a preparation method of an organic silicon polymer. The preparation method comprises the following steps: (1) hydrolyzing a raw material, i.e., butanonoximsilane, and removingdiacetylmonoxime generated by hydrolyzing; then adding high-grade alcohol and carrying out condensation reaction; treating in vacuum to remove residual small molecules, so as to obtain a condensationproduct; (2) adding dialkyl cyclosiloxane and a catalyst into the condensation product obtained by step (1); keeping the vacuum degree unchanged; stirring at constant temperature and carrying out chain extension reaction to obtain a chain extension product with the viscosity of 500 to 50000mPa.s; (3) adding a chain terminating agent into the chain extension product obtained by step (2) and carrying out chain terminating reaction; stirring at constant temperature and carrying out catalyst crushing treatment; then carrying out vacuum treatment to obtain the organic silicon polymer. The organicsilicon polymer obtained by the invention has good film coating performance and suitable viscosity and molecular weight; the organic silicon polymer is suitable for preparing a thin film material foroxygen separation, and the selective transmittance of oxygen in the air can reach 600 to 1.

Description

technical field [0001] The invention relates to the field of organic synthesis, in particular to a method for preparing an organosilicon polymer. Background technique [0002] Silicone polymer is the most researched compound except for organic polymers containing C, N, and O. Silicone rubber and its products are the most productive varieties of silicone polymers. Silicone rubber is composed of high molar mass linear polymers. After siloxane is vulcanized, it forms an elastomer with a network structure, which has excellent high and low temperature resistance, weather resistance, ozone resistance, arc resistance, electrical insulation, high air permeability and physiological inertness. Silicone rubber products have excellent With comprehensive performance and good economic benefits, it has been widely used in aviation, aerospace, electrical, electronic, electrical, chemical, instrumentation, automobile, machinery and other industries, as well as in various fields of medical ca...

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Problems solved by technology

[0003] Among them, polydimethylsiloxane (PDMS) is one of the most important organosilicon polymers. The silicon-oxygen bond on the main chain of PDMS and its easy rotation make the molecular chain of PDMS have a large free volume and are very flexible. Therefore, PDMS is often used to prepare membrane materials with elasticity and high gas permeability, such as gas separation membranes. However, the cohesive energy density between PDMS polymer chains is low, and the separation coefficient α is low, making it difficult to ultra-thin. In view of the above defects, the existing technology often modifies the main chain and side chain of PDMS to improve its film-forming performance.

[0004] A common method for modifying the molecular chain of PDMS, such as introducing long-chain alkanes as side groups, hydrogenating monoalkylsiloxane and long-chain terminal olefins under the action of a hydrogenation catalyst, introducing long chain, and then add catalyst and cyclosiloxane to carry out cationic or anionic polymerization. The hydrogenation catalyst used in the above method is mostly expensive noble metals such as platinum black. Moreover, in the subsequent polymerization step, if the reaction system uses cationic Polymerization, the polymerization reaction rate is fast, but the molecular weight is not easy to control, and the catalyst is not easy to remove. If anionic polymerization is used, although the catalyst is easy to remove, the reaction speed is slow

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