The generation and removal methods of methyl silicone oil odor
Silicone oil has a wide range of applications and powerful functions, and is used in the textile industry and daily chemical products. Many people may not be familiar with silicone oil, or their understanding of silicone oil is limited to whether shampoo contains silicone oil.
Methyl silicone oil is one of the earliest commercialized, most widely used, and commonly used organic silicon polymers. The production methods of methyl silicone oil mainly include acid equilibrium method and alkali equilibrium method. The acid balance method is suitable for producing low viscosity silicone oil with a viscosity of less than 500mm2/s. This method generally uses concentrated sulfuric acid as a catalyst, reacts at 50-60 ℃, and then washes with water to remove acid, remove low boiling point substances, add activated carbon for decolorization, and transition to obtain the finished product; The alkaline equilibrium method is suitable for producing medium and high viscosity silicone oils with a viscosity of over 100mm2/s.
When producing methyl silicone oil, each component in the raw material DMC (dimethyl mixed ring) is activated at different temperatures to achieve the optimal state, and ring opening polymerization is carried out separately, which improves the conversion rate and greatly enhances production efficiency.
After the ring opening polymerization reaction is completed, it is difficult for the catalyst (CH3) 4NOH to fully decompose during the medium breaking process; And the decomposed ammonia also has a small amount of miscibility in the system, causing the silicone oil to have an odor. Adopting the method of cooling down the system to below 140 ℃ and introducing dry air for bubbling, the gas phase pressure of the system is increased to achieve the purpose of eliminating irritating odors.
By using programmed temperature control method between 90-120 ℃ and cooling to 140 ° C after dehydration, dry air can be introduced for bubbling to obtain colorless, odorless, and qualified methyl silicone oil. The average conversion rate has increased from 65% to over 80%. This type of silicone oil with qualified indicators is suitable for use. Of course, colorless and odorless is also a reference standard for everyone to judge whether silicone oil is qualified.