Study Of Synthesis And Application Of Polyol Dimethacrylate

Polyethylene glycol dimethacrylate, one of the fine chemical intermediates is the main ingredient of anaerobe. With the development of adhesives, the domestic production of polyethylene dimethacrylate has been challenged from many aspects, therefore, to improve the production technics and yields has been the key problem to resolve at present. This paper focused on the synthesis of polyethylene dimethacrylate by interesterification.Firstly, the catalyst R used in the course of interesterification was prepared; when the molar ratio of acetylacetonate and C salts is 4.3:1, reaction time is 3 h and pH is 7, the yield of R gets to about 99 % under the condition of room temperature and and water solution.Secondly, at the best condition that the molar ratio of MMA and TEG is 6:1, reaction time is 4 h, and the weight percent of catalyst and inhibitor are 1.5 % and 0.15 %,TEGDMA has been synthesized by interesterification. The yield of TEGDMA reaches 95.77 % analyzed by HPLC, and the conversion of TEG gets to 97.25 % analyzed by GC. The concentration of metal ion C in the TEGDMA analyzed quantity by the color reagent MONPF is lower than 10ppm when the weight ratio of C and 10% phosphate is 0.076. According to the dissolution difference of MMA and methanol in the water, MMA and methanol have been separated when the volume ratio of constant boiling mixture and water is 10:20, and the result is good. According to the interesterification reaction mechanism, kinetics model has been founded, and the results show that the interesterification between MMA and TEG obeys the sencond order reaction kinetics and the apparent rate constant K at constant temperature was 4.85×10~2. The results of the performance test on anaerobes accord with corresponding requires. DEGDMA ,TTEGDMA, PEG(200)DMA and PEG(400)DMA have been synthesized at the best synthesis condition of TEGDMA and the yield of each of them is above 80 % analyzed by HPLC.Finally, the esterification reaction with the prepared solid superacid was studied, but the result is not good. However, the esterification rate and yield reach 94 % and 89 % with the oil of vitriol as catalyst, and the best reaction conditions are that the weight ratio of catalyst and inhibitor are 2.5 % and 0.6 %, the volume of toluene is 60 mL, the molar ratio of MAA and TEG is 2.2:1 and reaction time is 3 h, and the content of TEGDMA is 88 % analyzed by GC. Comparing interesterification with esterification from five aspects, the former is prior to the latter.