Studies On Synthesis Of4-chloromethylstyrene And Its Homopolymer

1-(Chloromethyl)-4-ethenylbenzene (p-CMS) is a kind of very important organicintermediate, it is very important in the synthesis of many organic compounds.Inmany areas of chemical synthesis,4-Chloromethylstylene also has an indispensablerole.In this paper,the synthesis methods of4-Chloromethylstylene and its polymersis:with phenethyl alcohol as the starting material, after substitution reaction,chloromethylation reaction, elimination reaction, by this way to synthesize4-Chloromethylstylene, and by the free radical polymerization reaction to synthesizepolychloromethylstyrene.The first step is the substitution reaction,in the function ofconcentrated sulfuric acid, phenethyl alcohol reacted with hydrobromic acid synthesisreaction of1-bromo-2-phenylethane.In the second step of chloromethylationreaction,with carbondisulfide as a solvent,with Lewis acid zincchloride ascatalyst,and paraformaldehyde and hydrochloric acid as the chloromethylation reagent,synthesis of2-chlorine methyl phenyl-bromoethane.In the third step,theelimination reaction,with2-chlorine methyl phenyl-bromoethane as rawmaterials,in the alcohol solution of potassium tert-butoxide removal reaction,synthesis of4-Chloromethylstylene.In the fourth step of the free radicalpolymerization,With4-Chloromethylstylene as monomer, azodiisobutyronitrile asinitiator,occurrence of the homopolymerization reaction,synthesis ofpolychloromethylstyrene.In the first step, studying the effect of sulfuric acid amount, reaction time,reaction temperature and stirring rate on experimental results.And the optimumreaction conditions were determined: the reaction temperature is115℃, the reactiontime is150min, the stirring speed is10r/min, the amount of sulfuric acid is16mL+13mL.In the second step reaction,studying reaction time, the dosage of catalyst, thedosage of paraformaldehyde, stirring rate and the amount of hydrogen chloride gasinfluence on the experiment. And the optimum reaction conditions were determined:reaction temperature is35~45℃, reaction time is25h, the dosage of1-bromo-2-phenylethane is22.0g,the dosage of catalyst is7.0g, the dosage of solventis12mL, the dosage of paraformaldehyde is6.0g, the stirring rate is17r/min,in the reaction process shall ensure that the dosage of hydrogen chloride gas is excess.In thethird step, the optimum reaction conditions were determined: the dosage of tert-butylalcohol is40mL, the dosage of potassium tert-butoxide is5.6g,the dosage of2-chlorine methyl phenyl-bromoethane is4.1g,the reaction temperature is35℃, thereaction time is160min, stirring rate is12r/min.In the fourth step reaction, theoptimum reaction conditions were determined: the amount of azodiisobutyronitrile is0.1g, the reaction temperature is70℃, the reaction time is13h, stirring rate is17r/min.