Study On Synthesis Technics Of Methylacrylic Acid (Poly) Ethylene Glycol Ether Monoester

Methylacrylic acid (polyethylene) glycol ether monoester has unsaturated double bond,it is widely used in high efficiency water reducing agent,super absorbent polymer,dispersant of coal-water slurry, curable coating and other fields.Synthesized MEMA from MAA and EM as the raw material. Toluene was the water entrainer,the optimal technology condition were confirmed by orthogonal experiments: n(EM):n(MAA)=1.4,PTSA catalyst mass fraction in the total reactants 1.5%,phenothiazine mass fraction in the total reactants 0.15%,reaction time was 7h. Under vacuum degree of-0.098MPa, the crude MEMA were rectified by vacuum operation, kettle temperature was less than 96℃,distillate of 80～82℃was collected which content was 99.8%.The methylacrylic acid polyethylene glycol single methy ether ester were prepared by MAA and the polyethylene glycol single methyl ether (MPEG-400、MPEG-800、MPEG-1200). The suitable technical condition were:n(MAA):n(MPEG-400,800)=1.13,n(MAA): n(MPEG-1200)=1.2,H2SO4 catalyst mass fraction in the total reactants 2.0%,reaction temperat-ure was 122℃,reaction time was 6h,phenothiazine mass fraction in the total reactants 0.15%, water entraine toluene-cyclohexane dosage were 54%(mass ratio12.5:1).Under this condition the yield of esterificatin of MPEG-400,MPEG-800,MPEG-1200 were 96.9%,89.6%,82.1%。Preparation of methylacrylic acid polyethylene glycol monoester by addition reaction of HEMA and EO,the catalyst of BF3-O(C2H5)2 with much byproducts,it got a better result when the EO adduct number was less than 10mol.the catalyst of KOH has fewer side reaction, the maximal EO adduct number was 14mol.Synthesized different molecular weight of MPEG by polyglycol monomethyl ether and EO as the raw material,the molecular weight distribution of MPEG-1200 were characterized using gel permeation chromatography (GPC).the molecular weight distribution of MPEG-1200 was less than 1.1,the range was narrow.Research on the condition of preparation of SO42-/TiO2 solid superacid catalyst and the reaction condition of catalytic synthesis of MEMA.The ESR signal show that, the catalyst has the best activity when calcination temperature was 450℃.The catalyst is used repeately for 3 times with obvious loss of activity,the results of ESR proved that may because the catalyst surface was recovered by carbonaceous.The anatase structure of solid superacid catalyst were confirmed by XRD. Lei Haiqin (Chemical Technology) Supervised by Zhu Xinbao...