Method for synthesizing polyethylene glycol monomethacrylate from solid superacid by catalytic esterification

Abstract

The invention discloses a method for synthesizing polyethylene glycol monomethacrylate from solid superacid by catalytic esterification. The method takes polyethylene glycol and methacrylic acid as reactants, uses a solid superacid SO4<2-> / ZrO2 as a catalyst, and comprises the steps of adding a polymerization inhibitor, heating and carrying out a reflux reaction, adding a water-carrying agent toluene to continuously remove water generated in the reaction, filtering, recovering the solid superacid SO4<2-> / ZrO2 after the reaction, and purifying the product under the condition of reduced pressure distillation to directly obtain the polyethylene glycol monomethacrylate, i.e. a macromonomer polyethylene glycol monomethacrylate for synthesizing a polycarboxylic acid water reducer. The conversion rate based on the polyethylene glycol is above 98.1%, and the yield of ester is above 98%. The recovered water-carrying agent and the recovered solid superacid SO4<2-> / ZrO2 can be recycled.

Description

technical field [0001] The invention relates to the field of fine chemicals, in particular to a method for synthesizing polyethylene glycol monomethacrylate (PEGMA). The synthesized macromonomer is used in the synthesis of polycarboxylate water reducer. Background technique [0002] At present, esters of synthetic polyethylene glycol systems are widely used in the surfactant industry. Chen Jianqin and Lin Zhiyong used solid super acid SO 4 2- / ZrO 2 Catalytic esterification of industrial oleic acid and polyethylene glycol to synthesize polyethylene glycol oleate for leather products; Qilu Petrochemical Company's patent CN 1208032A uses activated carbon, silica to absorb sulfuric acid, p-toluenesulfonic acid, etc. as solid acids to prepare formazan Higher esters of acrylic acid; Li Jinbiao and other published patents CN 101544729A utilize allyl polyethylene glycol and acrylic acid to prepare allyl polyethylene glycol acrylate, and are used to prepare monomers for water red...

AI Technical Summary

Problems solved by technology

[0002] At present, esters of synthetic polyethylene glycol systems are widely used in the surfactant industry. Chen Jianqin and Lin Zhiyong used solid super acid SO 4 2- / ZrO 2 Catalytic esterification of industrial oleic acid and polyethylene glycol to synthesize polyethylene glycol oleate for leather products; Qilu Petrochemical Company's patent CN 1208032A uses activated carbon, silica to absorb sulfuric acid, p-toluenesulfonic acid, etc. as solid acids to prepare formazan Higher esters of acrylic acid; Li Jinbiao and other published patents CN 101544729A utilize allyl polyethylene glycol and acrylic acid to prepare allyl polyethylene glycol acrylate, and are used to prepare monomers for water reducers; patent CN1636921 introduces that the degree of polymerization is 5 ~40 polyethylene glycol and acrylic acid are the main raw materials, p-toluenesulfonic acid is used as catalyst, hydroquinone is used as polymerization inhibitor, cyclohexane is used as water-carrying agent, and the reaction is carried out at 80~90℃ for 8±0.5 hours to form Polyethylene glycol monoacrylate is used as a macromonomer for the synthesis of polycarboxylate water reducers; Sun Risheng of Nanchang University used polyethylene glycol and methacrylic acid in a molar ratio of 1: 2. Polyethylene glycol monomethacrylate is synthesized, but it is not indicated in the text whether it is a diester or a monoester. At the same time, there is a large excess of methacrylic acid, which is easy to cause waste and difficult to recycle.

And using solid superacid SO 4 2- / ZrO 2 Esterification of polyethylene glycol monomethacrylate as a macromonomer for the synthesis of polycarboxylate superplasticizers has not been reported at home and abroad