Phenylselenide Polymers And Its Oxidative Response Behavior

Selenium is an important trace element in life.The element is now known to play important role in biology as an enzymatic antioxidant.Mimicking this reaction,chemists have synthesized several selenium-contained polymers that undergo redox transformations.These compounds are important in the future of both medicinal and material chemistry.Based on the oxidative property of selenium containing group,this thesis focused on the developing of oxidative response phenylselenide polymers which showed different electronic structures and hydrophilic properties before and after oxidization.The detailed studies were summarized as the following:(1).Polymerizations of styrene and PEGMA were carried out under high pressure mercury lamp using diselenide containing fluorescence agents regulator.The structures of these selenium-containing polymers were characterized using GPC,1H NMR.The oxidative response behavior of these polymers was investigated by monitoring the fluorescence emission behavior.(2).Selenium-containing monomer monophenyl maleimide selenide(MSM)was synthesized and copolymerized with styrene(St)using reversible addition-fragmentation chain transfer(RAFT)polymerization.Copolymers with controlled molecular weight and narrow molecular weight distribution were obtained.The structure of the copolymer was characterized by nuclear magnetic resonance,MALDI-TOF MS spectrum,FT-IR and UV-vis spectroscopy.The copolymer can be oxidized by H2O2 to form carbon-carbon double bonds within main chain due to the unique sensitivity of selenide groups in the presence of oxidants.Such structure changing resulted with interesting concentration related photoluminescence emission enhancement.(3).Selenium-containing monomer phenyl vinyl selenide(PVSe)was copolymerized with N-isopropylacrylamide(NIPAM)using reversible addition-fragmentation chain transfer(RAFT)polymerization.The structure of the copolymer was characterized by nuclear magnetic resonance,GPC and UV-vis spectroscopy.Copolymers with different lower critical solution temperature(LCST)were obtained by changing monomer ratios(NIPAM/PVSe).The LCST of such copolymer could be changed under different oxidative conditions due to integral of responsive selenide moiety inside copolymers.