Synthesis method of 1,4-butylene glycol dimethacrylate

Abstract

The invention discloses a synthesis method of 1,4-butylene glycol dimethacrylate, and belongs to the field of organic chemical industry. The synthesis method includes the steps that when reaction rawmaterials: 1,4-butanediol, methacrylic acid, a polymerization inhibitor and a water-carrying agent are heated to 80-90 DEG C, an HZSM-5 molecule sieve is added to serve as a catalyst, the temperatureis increased and kept to be 100-130 DEG C, the 1,4-butanediol and the methacrylic acid are subjected to an esterification reaction to generate 1,4-butylene glycol dimethyl alkenyl benzoate; after thereaction is completed, cooling is conducted to the room temperature, the catalyst is filtered and separated, still standing for layering is conducted in a separating funnel, and an upper layer organicphase is taken; the organic phase is washed with distilled water for 2-3 times; and then vacuum distillation is conducted to remove an organic solvent, and after cooling, a target product, namely the1,4-butylene glycol dimethacrylate is obtained. The catalyst has high activity, good selectivity, the mild reaction condition, easy and convenient post-treatment and no corrosivity, and is easy to separate and capable of being reused, and thus the synthesis method is high in production safety, low in energy consumption and high in yield.

Description

technical field [0001] The invention relates to a method for synthesizing 1,4-butanediol dimethacrylate, specifically using 1,4-butanediol and methacrylic acid to synthesize 1,4-butanediol dimethacrylate through esterification . It belongs to the field of organic chemical industry. Background technique [0002] 1,4-Butanediol dimethacrylate is an important unsaturated organic ester in industrial production. Its chemical structure contains unsaturated carbon-carbon double bonds and carboxyl or carboxyl-derived characteristic functional groups. It has excellent weather resistance and UV resistance. Light, water resistance, heat resistance and other properties, it is widely used in coatings, adhesives, leather, chemical fibers, papermaking, printing and dyeing, auxiliary agents, etc. [0003] At present, the synthesis methods of 1,4-butanediol dimethacrylate mainly include alkyd direct esterification and transesterification. Alkyd direct esterification method: catalyzed este...

AI Technical Summary

Problems solved by technology

In the reaction, concentrated sulfuric acid is used as a catalyst, which has high reactivity and is cheap. However, using it as a catalyst to synthesize esters has the following disadvantages: under the conditions of esterification, concentrated sulfuric acid has both esterification and dehydration And oxidation, leading to a series of side reactions, so that the reaction mixture contains a small amount of ether, sulfuric acid ester, unsaturated compounds and carbonyl compounds, etc.

It brings difficulties to the refinement and recovery of products; the concentrated sulfuric acid used as a catalyst has to be removed by alkali neutralization and water washing, the process is complicated, the loss of products and unreacted raw materials is large, and a large amount of high-salt waste liquid is produced, and the equipment is severely corroded. After the reaction, it is difficult to separate the catalyst and the product, the post-treatment process is complicated, the environmental pollution is serious, and the catalyst is difficult to reuse, etc.