The Design,Synthesis And Characterization Of Novel Bifunctional Hindered Amine Light Stabilizer

Hindered amine light stabilizers(HALS)are the most popular light stabilizers and are used widely all over the world.Chimassorb 119 is a kind of monomeric HALS which is mainly used in polymeric materials like polyethylene and polypropylene for its excellent extraction resistance and migration resistance.However,other countries always have a monopoly on the synthetic technology of Chimassorb 119.In order to provide a research foundation of the synthesis of Chimassorb 119,the synthetic route of N,N,N',N',N”-Pentamethyldipropylenetriamine(PMDPTA)was studied as a model reaction.With methylamine,acrylonitrile and formaldehyde as the main materials,PMDPTA was prepared via a Michael addition,catalytic hydrogenation and methylation in 52.0% overall yield.Moreover,Methanol was employed as the only solvent in all of the three steps,resulting in the convenient recovery of methanol.This green and efficient route is thus suitable for industrial production and the synthetic process was optimized as well.Chimassorb 119 was synthesized with ethylenediamine,acrylonitrile,cyanuric chloride,2,2,6,6-tetramethylpiperidine-4-butylamine,formaldehyde via Michael addition,catalytic hydrogenation,nucleophilic substitution and methylation based on the study on the synthesis of PMDPTA in 53.5% overall yield.According to the development trend of HALS,three bifunctional hindered amine light stabilizer were synthesized and characterized by 1H NMR,13 C NMR and FT-IR based on the study on the synergistic effect between HALS and UV absorbers.4-benzoyl-3-hydroxyphenyl-2-((2,2,6,6-tetramethylpiperidin-4-yl)amino)acetate(TM1)was prepared with 2,4-dihydroxybenzophenone,chloroacetyl chloride and 2,2,6,6-tetramethylpiperidine-4-amine through nucleophilic substitutions.Bis(4-benzoyl-3-hydroxyphenyl)-3,3'-(hexane-1,6-diylbis((2,2,6,6-tetramethylpiperidin-4-yl)azanediyl))dipropanoate(TM2)was prepared with acryloyl chloride,2,4-dihydroxybenzophenone,N,N'-bis(2,2,6,6-tetramethylpiperidin-4-yl)hexane-1,6-diamine via nucleophilic substitutions and Michael addition.2-(4-benzoyl-3-hydroxyphenoxy)ethyl 3-((2,2,6,6-tetramethylpiperidin-4-yl)amino)propanoate(TM3)was synthesized with 1,3-dioxolan-2-one,2,4-dihydroxybenzophenone,methyl acrylate and 2,2,6,6-tetramethylpiperidine-4-amine through Michael addition and transesterification.The reaction conditions of transesterification were also optimized.Furthermore,the thermal stability and photo-stability of TM1 were studied.The results indicate that compound TM1 is potential as a hindered-amine light stabilizer or an ultraviolet light absorber for inhibiting the degradation of polyethylene materials.