Synthesis And Nonlinear Optical Properties Of Azobenzene-containing Poly(arylene Ether)s With Metallophthalocyanine Pendant

Since the coming out of the laser,new laser technology for civilian and military applicationg has received considerable attention.Aside from the civilian applications of laser source,the lasers have evolved into weapons,which are designed to disable humans by blinding or destroy optical sensors.Based on the theory of nonlinearoptics,optical limiting materials which could protect optical sensors and human eyes from exposure to laser,have been extensively investigated.In the past decades,significant research has been invested into optical limiting materials.Many functional materials e.g.carbon nanotubes,azo-polymer,porphyrins,phthalocyanines,polyimides,and mixed metal complexes have been studied.Up to date,research and development of optical limiting materials still presents a considerable challenge.In general,an ideal optical limit material required fast response time,broad-band spectral response range,large nonlinearities,low limiting threshold,and high linear transmittance in the absence of intense light.Furthermore,good mechanical strength and thermal stabilities are also necessary.The aromatic azobenzol compounds with electron withdrawing groups(such as cyano)are well known to exhibit excellent nonlinear optical properties for containing conjugate ?-electron systems and good fluidity of ? electrons in their molecules.Azo-polymers have been considered as promising materials because of their large third-order susceptibilities and fast response time.Phthalocyanines(Pcs)have been applied in various fields because of their special 18-electrons conjugated macrocycle structure.In recent years,Pcs have become one of the most promising third-order nonlinear optical materials because of their large nonlinear susceptibility and fast response time.Poly(aryl ether)s are a family of high-performance engineering thermoplastics with excellent thermal and mechanical properties.Functionalized poly(arylene ether)s have received considerable attention due to their potential applications in nonlinear optical materials,fluorescent material and proton-exchange membranes? In this paper,we prepared a novel poly(arylene ether)containing azobenzene groups and metallophthalocyanine groups in side chains was prepared.The thermal property and third-order NLO effect of the polymer are investigated.First of all,we designed a new bisfluoro monomer containing azobenzene chromophores,4-((3,4-dicyanophenyl)diazenyl)phenyl 2,6-difluorobenzoate.And a novel polymer,PAE-azo-DCN,was synthesized by a typical nucleophilic substitution polycondensation reaction from the novel bisfluoro monomer and 4,4'-(hexafluoroisopropylidene)diphenol.The chemical structure of PAE-azo-DCN was confirmed by 1H-NMR,IR and UV-Vis and XRD.The thermal propery of the polymer was investigated by TGA and DSC,indicating the polymes had high glass transition temperatures and good thermal stability.Secondly,we synthesized azobenzene-containing poly(arylene ether)s with metallophthalocyanine pendant(PAE-azo-CoPc).The PAE-azo-CoPc was prepared by PAE-azo-DCN,1,2-benzodinitrile and Cobaltous chloride anhydrous.The chemical structure of PAE-azo-CoPc was confirmed by 1H-NMR,IR,Uv-Vis and XRD.The polymer exhibited higher glass transition temperature and better thermal stability than PAE-azo-DCN because of the introduction of metallophthalocyanine pendant.The third-order nonlinear coefficient was measured by Z-scan technique.The results showed the PAE-azo-CoPc has large third-order nonlinear susceptibility.Such a novel azobenzene-functionized poly(arylene ether)containing metallophthalocyanine is expected to be a potential candidate for optical limiting,optical switching and other fast photonic applications.