Condensation Reaction of Epoxy Resin
May 15, 2023
Oxidation reaction using unsaturated double bonds of peracetic acid and vinyl silicone resin
Condensation reaction between bisphenol A type epoxy resin and low molecular weight polysiloxane containing Si -- OR and Si -- OH
The condensation reaction is carried out in three ways:
1.The light group in polysiloxane reacts with the secondary tibial group in epoxy resin to generate a pressure of 0 and form a stable silicon oxygen bond:
The epoxy group of epoxy resin is not affected between the shin group on silicone resin and the light group on epoxy resin, but can play a role in future crosslinking and curing reactions.
2.CD containing oxylated polysiloxane reacts with the secondary tibial group in epoxy resin to generate ROH and form stable silicon oxygen burn bonds:
Practice has shown that when organic silicon oligomers containing burning oxygen groups react with epoxy resin, only the tibial group in the epoxy resin participates in the reaction, and the number of epoxy groups in the epoxy resin does not change.
3.The light group in polysiloxane reacts with the epoxy group in epoxy resin to form a silicon oxygen burnt bond. The formed tibial base can still continue to react:
The reaction mechanism is that the terminated groups in an alkaline environment can form silicon oxide anions, and then react through two pathways. One is to react with the light groups in the epoxy resin to form Si-0-C bonds:
Another method is to initiate ring opening reaction with the epoxy group in the epoxy resin to form Si-0-C bonds, and the formed light groups can still continue to react:
In industrial production, this method is mainly used, which involves selecting suitable commercial epoxy resins containing C-OH linear epoxy resins according to requirements, and starting from RO (or OH) containing silicone resin intermediates to obtain epoxy modified silicone resins connected by SiOC bonds through condensation reactions. Easy to obtain with raw materials, and the method is simple. It has good electrical insulation performance and mechanical strength, low water absorption, and can be used as coatings and molding materials. Epoxy resin can modify silicone resin to produce new practical resins with properties such as weather resistance, solvent resistance, corrosion resistance, and high temperature resistance. The polymer prepared by this method has S! - The 0 bond is unstable and prone to fracture in the presence of water.
[Example 1] A new type of modified resin with good heat resistance and mechanical properties. Place epoxy resin CE44 and triphenyl phosphorus/butyrate catalyst into a three necked flask equipped with a stirrer, reflux condenser tube, and drip funnel. Heat and raise to a certain temperature before stirring. Slowly add 26018 organic silicon dimethyl benzene solution at a mass ratio of 5:10 to 26018: E44,
React at 200 ° C for 5 hours, and continuously separate small molecule compounds such as alcohols and water generated by the reaction through reflux condensation. After the viscosity is determined to be qualified by the wire drawing method, the material can be discharged, resulting in a brownish red semi transparent viscous organosilicon modified epoxy resin.
The modified resin has uniform color, good stability and compatibility, and does not delaminate after prolonged use, resulting in the best overall performance.
SILIBASE SILICONE is focused on producing and selling all kinds of SILICONE-BASED new materials.Our main products are Silicone Resin Adhesive，Silicone Resin of mica plate，Silicone Resin Emulsion，Silicone Resin Intermediate，Silicone Resin for Coating，silicone coating resin，Silicone Resin Paint，Silicone Modified Acrylic Resin.
