以2-溴异丁酸乙酯为引发剂,丙烯酰胺(AM)、甲基丙烯酸2,2,6,6-四甲基哌啶醇酯(TMPM)为单体,采用电子转移再生催化剂原子转移自由基聚合(ARGET ATRP)制备了两亲性嵌段共聚物PTMPM-PAM,进而将其氧化为含氮氧自由基的嵌段共聚物PTMA-PAM。用红外光谱(FT-IR)和电子顺磁共振光谱(ESR)对共聚物进行了表征。以NaClO为氧化剂,研究了PTMA-PAM对苯甲醇的选择性催化氧化性能。结果表明:PAM链段的引入不仅使大分子催化剂更易回收,而且有利于其催化性能的提高,苯甲醛收率可达99%。
Using ethyl 2-bromoisobutyrate as initiator and acrylamide(AM) and 2,2,6,6-tetramethylpiperidyl methacrylate(TMPM) as monomers,the amphiphilic block copolymer of PTMPM-PAM was prepared by activators regenerated by electron transfer atom transfer radical polymerization(ARGET ATRP).Followed by an oxidation process,the block copolymer of PTMA-PAM with nitroxide moieties was obtained.The block copolymer was characterized by fourier transform infrared spectroscopy(FT-IR) and electron paramagnetic resonance spectroscopy(EPR).It was used as a recoverable catalyst for selective catalytic oxidation of benzyl alcohol with NaClO as oxidant.The results showed that the block copolymer was easy to be recycled due to the introduction of PAM.Furthermore,the catalytic performance was improved and the benzaldehyde yield was up to 99%.
[1] 孙绪兵,杜京城,由耀辉.TEMPO/NaClO/NaBr表面改性甲壳素及吸附性能研究[J].化工新型材料,2017,45(8):223-226.
[2] Tanyeli C,Gümüs A.Synthesis of polymer-supported TEMPO catalysts and their application in the oxidation of various alcohols[J].Tetrahedron Letters,2003,44(8):1639-1642.
[3] Luo J,Pardin C,Lubell W D,et al.Poly(vinyl alcohol)-graft-poly(ethylene glycol) resins and their use in solid-phase synthesis and supported TEMPO catalysis[J].Chemmical Communications,2007,7(21):2136-2138.
[4] Yoshitomi T,Yamaguchi Y,Kikuchi A,et al.Creation of a blood-compatible surface:a novel strategy for suppressing blood activation and coagulation using a nitroxide radical-containing polymer with reactive oxygen species scavenging activity[J].Acta Biomaterialia,2012,8(3):1323-1329.
[5] Yu Y L,Gao B J,Li Y F.Immobilized 2,2,6,6-tetramethyl-piperidinyl-1-oxy catalyst on polymer microspheres and its catalytic oxidation of benzyl alcohol with molecular oxygen[J].Chinese Journal of Catalysis,2013,34(9):1776-1786.
[6] Ferreira P,Hayes W,Phillips E,et al.Polymer-supported nitroxyl catalysts for selective oxidation of alcohols[J].Green Chemistry,2004,6(7):310-312.
[7] Ferreira P,Phillips E,Rippon D,et al.Poly(ethylene glycol)-supported nitroxyls:branched catalysts for the selective oxidation of alcohols[J].The Journal of Organic Chemistry,2004,69(20):6851-6859.
[8] Ferreira P,Phillips E,Rippon D,et al.Catalytic oxidation of alcohols using molecular oxygen mediated by poly(ethylene glycol)-supported nitroxyl radicals[J].Applied Catalysis B:Environental,2005,61(3):206-211.
[9] Pozzi G,Cavazzini M,Quici S,et al.Poly(ethylene glycol)-supported TEMPO:an efficient,recoverable metal-free catalyst for the selective oxidation of alcohols[J].Organic Letters,2004,6(3):441-443.
[10] 余依玲.固载化TEMPO的制备及其对醇类物质催化氧化性能的研究[D].太原:中北大学,2014.
[11] 刘霖,孙真,李罗丹,等.聚苯乙烯负载TEMPO催化醇的选择性氧化[J].淮海工学院学报(自然科学版),2010,19(4):31-33.
[12] Nakahara K,Iwasa S,Satoh M,et al.Rechargeable batteries with organic radical cathodes[J].Chemical Physics Letter,2002,359(5):351-354.
[13] Hauffman G,Rolland J,Bourgeois J P,et al.Synthesis of nitroxide-containing block copolymers for the formation of organic cathodes[J].Journal of Polymer Science Part A:Polymer Chemistry,2013,51(1):101-108.
[14] Hansson S,Östmark E,Carlmark A,et al.ARGET ATRP for versatile grafting of cellulose using various monomers[J].ACS Applied Materials and Interfaces,2009,1(11):2651-2659.
[15] Jonsson M,Nyström D,Nordin O,et al.Surface modification of thermally expandable microspheres by grafting poly(glycidyl methacrylate) using ARGET ATRP[J].European Polymer Journal,2009,45(8):2374-2382.
[16] Aitchison T J,Markovic M G,Saunders M,et al.Polymer brushes on multiwalled carbon nanotubes by activators regenerated by electron transfer for atom transfer radical polymerization[J].Journal of Polymer Science Part A:Polymer Chemistry,2011,49(19):4283-4291.
[17] Cheesman B T,Willott J D,Webber G B,et al.pH-responsive brush-modified silica hybrids synthesized by surface-initiated ARGET ATRP[J].ACS Macro Letters,2012,1(10):1161-1165.
[18] Pour S N,Ghugare S V,Wiens R,et al.Controlled in situ formation of polyacrylamide hydrogel on PETsurface via SI-ARGET-ATRP for wound dressing[J].Applied Surface Science,2015,349(15):695-704.
[19] Liu S J,Hu Q Q,Zhao F Q,et al.Nitroxide polymer brushes prepared by surface-initiated ARGET ATRP and their selective oxidation performances[J].eXPRESS Polymer Letters,2014,8(11):862-868.
基金资助
国家自然科学基金(21304030)
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