Method for synthesizing short-chain hydroxyl silicone oil

Abstract

The invention relates to a synthetic method for short-chain hydroxyl silicone oil. Firstly, the materials are proportionally measured according to raw materials components, then adding acid clay, water, and cyclotetrasiloxanes to a three-mouth flask with a reflux device, adding concentrated sulfuric acid in agitation condition, and reacting by controlling the reaction temperature, when the reaction is completed, adding magnesia and agitating about 10 minutes, then processing pumping filtration, distilling and recovering acetone using a rotary evaporimeter used for filtrating under the temperature of 45 DEG C, then adding sodium carbonate solution for neutralization under controllable temperature for stratification; then watering and washing the organic layer on the upper layer once or twice, then discharging water through stratification, and then feeding the organic layer into the rotary evaporimeter for warming up to 95 DEG C, depressing and detracting low-boiling residues, obtaining micromolecule hydroxyl silicone oil. The synthetic method for short-chain hydroxyl silicone oil has the advantages of simple technological process, easy controllable reaction condition, low cost and easily available raw materials, fast reaction generating speed, good product quality and high reactivity, and wide application range.

Description

Technical field: [0001] The invention relates to a method for synthesizing short-chain hydroxy silicone oil, in particular to a method for synthesizing side groups using acid clay and concentrated sulfuric acid as dual catalysts, which are hydrogen, C 1 -C 7 The method of small molecule hydroxy silicone oil of alkyl chain or vinyl, nitrile ethyl. Background technique: [0002] Short-chain hydroxy silicone oil is a structure control agent for high-temperature vulcanized silicone rubber, and can also be used for the synthesis of silicone resins or organic compounds. At present, its main synthesis methods are as follows: (1) U.S. Patent Publication No. USP3853932, published on In October 1974, a patent for the production of low-molecular-weight silanol-terminated polymers disclosed a method for catalyzing hexamethylcyclotrisiloxane (D 3 ) method for synthesizing low molecular weight hydroxysilicone oil; (2) Chinese Patent Authorization Announcement No. CN 1025861C, the author...

AI Technical Summary

Problems solved by technology

Among them, in method (1) D 3 The output is less, the price is high, and the low-cost octamethylcyclotetrasiloxane (D 4 ), ordinary acid clay can not be effectively catalyzed; the viscosity of the synthetic hydroxy silicone oil of method (2) is at 350-3500CS / 25°C, the viscosity is too high, and the hydroxyl content is too low, which is not suitable for the needs of organic synthesis; in method (3) To use a large amount of sodium hydroxide to catalyze and neutralize with a large amount of sulfuric acid, the cost is higher; method (4) needs to use acetic anhydride as end-capping agent, except that the price is high, adopting this method has poor process stability and is difficult to control

In method (5), the hydrolysis reaction of chlorosilane is too violent, the process is difficult to control, and a large amount of waste acid is produced, which requires post-processing, and the cost is relatively high

In addition, the above five methods synthesized are all short hydroxyl silicone oils with methyl side groups, and do not contain hydrogen, C 2 -C 7 Alkyl chains, vinyl and nitrile ethyl and other functional side chains with rich functions cannot meet the needs of special industries