Preperation of Polystyrene with 8-hydroxyquinoline Side Chain
|School||University of North|
|Keywords||8-Hydroxyquinoline Polymerization Gabriel reaction Chloromethyleted polystyrene Phase-transfer catalysis Micellar catalysis|
In this work, it was realized to transfer chloromethylated polystyrene(CMPS) into aminomethylated polystyrene by Gabriel reaction and use potassium salt of phthalic imidine as the reagent of nucleophilic substitution. In this paper, the reaction process to prepare the precursor of aminomethyl polystyrene with phase-transfer catalysis system was primarily studied,effects of various factors on the phase-transfer catalysis reaction were examined, and the phase-transfer catalysis mechanism was explored. The experiment results show that the functional transformation reaction of polymers can be conducted via phase-transfer catalysis successfully. In this study system, the phase-transfer catalysts transfer the anions of phthalic imidine from water phase into organic phase, make the nucleophilic substitution reaction between chloromethylated polystyrene and the anions of phthalic imidine carried out, and the chloromethyl groups on the macromolecular chains of chloromethylated polystyrene were easily transformed into phthalimido groups, and phthalimido-methylated polystyrene(PIPS) received. There are some factors which effect on the phase-transfer catalysis reaction, such as the species and used amount of the catalysts, the polarity of the solvents, the ratio of oil phase to water phase and the reaction temperature. For this reaction system, cetyl trimethyl ammonium bromide is the suited catalyst, and the conversion of chloromethyl groups can get up to 87% when used toluene as solvent and at the temperature of 50℃for 8 h.On the basis of receiving phthalimido-methylated polystyrene by phase-transfer catalysis reaction, the hydrolization reaction of PIPS was performed under acidic condition and via micellar catalysis system, and phthalimido-methylated polystyrene was successfully transformed into aminomethyl polystyrene(AMPS). The mechanism of such hydrolization process on the micellar catalysis was investigated, in which the effects of cationic, anionic and non-ionic surfactants on the reaction were compared. The results show that the micellar catalysis effectively catalyzed the hydrolization reaction of phthalimido-methylated polystyrene, and the cationic surfactant showed the most effectiveness. The longer the hydrocarbon chain of the surfactant is, the better the catalysis effect is, and the addition of electrolyte can greatly accelerate the catalysis effect.Finally,using N,N-dimethylformamide as the solvent ,the reaction between aminomethyl polystyrene and 5-chloromethyl-8-hydroxyquinoline which was firstly obtained via chloromethylation of 8-hydroxyquinoline(8HQ) was performed in a homogeneous system. Polystyrene with 8-hydroxyquinoline side chain (PS8q) was obtained. The conversion of AMPS was up to 78%. The reaction realized polymerization of 8HQ triumphantly.