Synthesis And Property Investigation Of Novel Selenide-containing Vinyl Polymer Applied In High Refractive Index Material

Nowadays,optical materials are widely used in many fields,such as medicine,architecture,electronic devices,and so on.Refractive index(RI)is one of the most vital and basic parameters of optical materials,and it is also an important index to measure the practical application value of materials.High refractive index(HRI)optical materials are widely used in many modern optical fields.Compared to traditional inorganic glass,HRI polymeric material owns the advantages of light weight,impact resistance,low cost,and easy processing,has been widely used in optical and optoelectronic fields with products such as optical lens,light emitting diode(LED),camera,sensor,and so on.However,some common optical polymer materials,such as poly(methyl methacrylate)(PMMA),polystyrene and polycarbonate,only show refractive index around 1.50,which greatly limits their application in optoelectronic applications.Therefore,it is of great significance to study and develop new kind of HIR material.It can be seen from the Lorentz-Lorenz equation that the RI of a material is directly proportional to the molar RI,and inversely proportional to the molar volume of the building block structure.Normally,the larger the molecular volume of the atom or group,the higher RI of the polymer would be obtained.It was known that benzene,naphthalene,halogen atoms(except fluorine)and sulfur atoms showed large value of molar RI.Thus,the refractive index of polymers could be improved after the introduction of these atoms or groups in polymer structures;on the contrary,the introduction of those groups with smaller RI,such as methyl or unsaturated carbon bonds will cause a decrease in refractive index of the materials.Therefore,one of the most effective methods to improve the RI and other optical properties of materials could be realized by introducing such groups,especially sulfur atoms or sulfur groups with HRI and low dispersion coefficient.Selenium and sulfur are located in the same period of the periodic table.They have similar physical and chemical properties.Although the molar RI([R]=11.17)of the selenium atom is much higher than that of the sulfur atom([R]=7.69),few studies have been conducted on the HRI materials based on selenium.In our previous study,it was found that the RI of the polymer can be improved by the introduction of selenium containing structures.Hence,we believe that it is beneficial to further exploration of preparing HRI polymer based on the utilizing of selenium.Here in,we design a series of selenium containing polymers with HRI as well as many other excellent properties by using two different methods.The main contents include the following two aspects:[1]In the first part,we demonstrated the construction of selenium-containing HRI polymers by using the well-established post-modification route.Firstly,poly(glycidyl methacrylate)(PGMA)was synthesized through Fe(0)-mediated living radical polymerization.Then,post-modification was performed by the reaction between pendent epoxy group and selenium-functional agent,namely PhSeZnCl.The results showed that the polymers showed higher RI than PGMA.Moreover,the present route enabled to control the molecular weight of the polymer and concentration of selenium-containing structures,which in turn enabled the characteristic ability of adjustable RI and Abbe's number of final polymers.[2]In the second part,in order to further increase the refractive index of containing-selenium optical resin and expand the types of containing-selenium polymer,we designed and synthesized different kinds of selenium-containing monomers.The polymers were obtained by traditional free radical polymerization.The selenium-containing monomers synthesized in this part including:phenyl-selenides,naphthyl-selenides,cyclohexane-selenides,pyridyl-selenides,styrene-selenides and acrylate-selenides.Narrow distribution of uncrossking-polymers with phenyl-selenides,naphthyl-selenides mononers were obtained successfully by adjusting the solution concentration.Results showed that the RI of containing-selenium polymers were improved significantly.The containing-selenium polymers showed good thermal stability and excellent transparency in the visible region which accorded with the requirement of optical materials.