Synthesis And Studies Of Novel Functional Monomer Acryloyloxyethyltrimethylammonium Chloride

N,N-Dimethylaminoethyl acrylate (DA) and its quaternary salts(acryloyloxyethyltrimethylammonium chloride, DAC) are the most widely usedamino-containing acrylic monomers, which have nontoxicity and high reactivity forpolymerization and modification;their derivatives comprise a novel class ofwater-soluble polymers, which have potential applications in wastewater treatmentand sludge dewatering, in oil extraction, and in paper production. Water-solublecationic polyelectrolytes based on aminoalkyl esters of acrylic acid and theirderivatives, tertiary and quaternary salts, attract considerable interest, which is due, onthe one hand, to the possibility of widely varying their chemical nature andphysicochemical characteristics and, on the other hand, to their wide use in variousbranches of national economy, industry, technology, and medicine. The synthesis of DAC is a two-step process. The first step is the transesterificationto methyl acrylate (MA) into DA and the second step is the quaternization process toDA into DAC. This transesterification method has become an extensive study for thepresent. But these literatures and patents are almost the studies of process flows andcatalysts, only a few studies of technological conditions and reaction mechanism. We studied the transesterification and the quaternization. The technologicalconditions were mainly studied with Lewis acid and base catalysts, titanate catalysts,and organotin catalysts, respectively. At the same time, the technological conditions ofthe quaternization reaction were studied. So some conclusions could be got as follow:(1) Effect on DMAE conversions of not distilling out methanol and distilling outmethanol in time was studied with Ti(OBu)4 catalysts, and (n-Octyl)2SnO catalysts,respectively. The results showed that distilling out in time was one of the importantconditions increasing the conversions of DMAE.(2) The transesterification of MA and DMAE was investigated with Lewis acid andbase catalysts. OF the several catalysts tested, ZnCl2 has the highest activity for thereaction. Proportion of materials, amount of catalyst, reaction temperature andreaction time were also investigated based on ZnCl2. According to the experiments,when the reaction was carried out for 10h at n(DMAE):n(MA):n[ZnCl2]=1:3.5:0.088(molar ratio) and temperature 175℃, the transesterification basically reached thebalanced state, the conversion of DMAE was 93.04%, the selectivity for DA was93.52% and the total yield for DA was 85.52% when methanol was separated in situ.(3) The transesterification of MA and DMAE was investigated with four kinds oftitanate catalysts. Thermodynamics, proportion of materials, amount of catalyst,reaction temperature and reaction time were also investigated based on Ti(OBu)4.According to the experiments, when the reaction was carried out for 8h atn(DMAE):n(MA):n[Ti(OBu)4]=1:3:0.06 (molar ratio) and temperature 160℃, thetransesterification basically reached the balanced state, the conversion of DMAE was95.24%, the selectivity for DA was 93.08% and the total yield for DA was 87.94%when methanol was separated in situ.(4)The transesterification of MA and DMAE with organotin catalysts wasinvestigated. (n-Octyl)2SnO was found to have a very high activity for thistransesterification. Thermodynamics, proportion of materials, amount of catalyst,reaction temperature and reaction time were also investigated based on (n-Octyl)2SnO.When the reaction was carried out for 6h atn(DMAE):n(MA):n[(n-Octyl)2SnO]=1:2.5:0.038 and temperature 160℃, DMAEconversion was 98.26%, the selectivity for DA was 96.98%, and the total yield for DAwas 94.65%, beyond 6h DMAE conversion increased very slowly. Removing themethanol produced in the reaction could improve DMAE conversions.(5)The reaction mechanisms of the transesterification of MA and DMAE wasdiscussed with Lewis acid and base catalysts, titanates catalysts and organotincatalysts, respectively.(6) The main technological conditions of the quaternization reaction were studied:proportion of materials[n(H2O):n(DA), molar ratio], reaction temperature, additionmethod and flow rate of water, and different inhibitors.