Research On The Design And Synthesis Of Hindered Amine Ether Containing Multifuncational Groups

In order to protect the macromolecule materials from the damage of photo-oxidation,various kinds of light stabilizers were developed.The hindered amine was a famous kind of light stabilizer for its eximious performance.The hindered amine ether was the alkoxylation product of piperidine NH group of the common hinered amine.Because of its low basicity,the hindered amine ethercompounds were moreeffective and stable inacid environment.The synthesis process of hindered amine ether 1-alkoxy-4-hydroxy-2,2,6,6-tetramethy--lpiperidine from 1-alkoxy-4-hydroxy-2,2,6,6-tetramethylpiperidine,a sterically hindered aminoxyl radical,were researched in this thesis.By means of reaction between the hindered aminoxyl radical and alkyl radical that provided from the fragmentation reaction of aldehydeor ketone oralkane inthepresence of catalyst and peroxides.In the preparation of 1-propoxy-2,2,6,6-tetramethylpiperidin-4-ol,using 4-hydroxy-2,2,6,6-tetramethyl-piperidinooxy and batana were used as start materials in a molar ration of 1:1.8.While cuprous chloride was selected as catalyst in a dosage of 2.5%(mass ratio,based on 4-hydroxy-2,2,6,6-tetramethyl-piperidinooxy)and 30%hydrogen peroxide as oxidant in ratio of 1:4 to 4-hydroxy-2,2,6,6-tetramethyl-piperidinooxy.A mixture of butanol and water were used as solvent in this reaction.The reaction was carried under 45~oC for10 h,the goal compound was obtained ina yield over76%inpilot scale.Using 4-hydroxy-2,2,6,6-tetramethyl-piperidinooxy and acetone in a molar ration of 1:5as raw materials,the 1-methoxy-2,2,6,6-tetramethylpiperidin-4-ol was synthesized under30~oC for 15 h in ethanol also catalyzed by cuprous chloride while 30%hydrogen peroxide was used as oxidant,andthe goal compound was obtained in a yield over 70%inpilot scale.In synthesis process of 1-cyelohexyloxy-2,2,6,6-tetramethylpiperidin-4-ol the cyclohexyl racial was provided from cyclohexane.The reaction was catalyzed by ferrous sulfate heptahydrate while acetonitrile was used as solvent.The reaction conditions were optimized as follows:1:8 of molar ration of 4-hydroxy-2,2,6,6-tetramethyl-piperidinooxy and cyclohexane,5%of catalyst dosage(mass ration to 4-hydroxy-2,2,6,6-tetramethyl-piperidinooxy),70~oC of reaction temperature,8 h of reaction time.The goal compound was obtained in a yield over63%inpilot scale.A series of multi-functional stabilizer compounds that contain hindered amine ether and hindered phenol in molecular structure were designed in this paper.Through transesterification of 1-alkoxy-2,2,6,6-tetramethylpiperidin-4-ol and dimethyl malonate derivates,1-alkoxy-2,2,6,6-tetramethylpiperidyl malonates was obtained as intermediate,then react with(4-hydroxy-3,5-di-tert-butyl-benzyl)dimethylamine the series goal compounds were obtained.And the anti-photooxidation performance of these compounds were tested in a preliminary research.