Method for synthesizing low molecular weight hydroxy-terminated fluorine silicon oil

Abstract

The invention relates to a method for synthesizing low molecular weight hydroxy-terminated fluorine silicon oil, which is characterized by comprising the following steps of: adding a certain amount of 3,3,3-trifluoropropylmethyl ring trisiloxane into three flasks, starting stirring, and then adding a certain amount of polar solvent, capping agent and catalyst into the flasks; slowly heating the mixture to between 50 and 80 DEG C till reflux appears, and maintaining the reaction till the reaction is complete; then cooling the mixture to room temperature, adding a certain amount of magnesium oxide and kieselguhr for filtration, and washing the filter cakes by using the same part of solvent; and transferring the filtrate to the three flasks, adjusting the temperature and pressure to evaporate the solvent, and then removing low-boiling substances to obtain a required product. The method has the advantages of simple and quick operation, economy, applicability, high yield, clarity, transparency and low viscosity of the obtained product and the like.

Description

technical field [0001] The invention relates to the preparation of low molecular weight hydroxyl-terminated fluorosilicone oil, especially the preparation of 1,3,5-tris(trifluoropropyl)-1,3,5-trimethylcyclotrisiloxane with heteropolyacid as catalyst alkane (D 3 F ) is dissolved in a polar solvent, and distilled water is used as an end-capping agent for reflux reaction to carry out a synthesis method of low-molecular-weight hydroxyl-terminated fluorosilicone oil. Background technique [0002] Low-molecular-weight hydroxyl-terminated fluorosilicone oil is a special synthetic material whose main chain contains silicon-oxygen structures, side chains contain oxygen-containing structures, and both ends are hydroxyl groups. The special chemical structure of this material not only has the characteristics of high and low temperature resistance and fuel resistance of general fluorosilicone polymers, but also has great chemical activity due to the existence of a large amount of silan...

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Problems solved by technology

However, the surface of silica contains active Si-OH groups, and its active Si-OH groups will react with Si-OH groups or terminal Si-OH groups of silicone rubber molecules to form hydrogen bonds, resulting in physical adsorption and chemical bonding, which makes Silica is difficult to disperse evenly in the silicone rubber compound, and the mixed compound will gradually harden during storage, reduce plasticity, and gradually lose back-milling and processing performance

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