A Novel Of Synthesis Poly(ester-alt-selenide)s By Ring-Opening Copolymerization And Study Of Dynamic Seleniranium Ion Bond

Selenide-containing polymers are widely used in the field of biomedicine and optoelectronic materials.At present,the methods for preparation of selenide-containing polymers are the living radical polymerization,step-growth polymerization and ring-opening polymerization.Selenium possesses distinct chemical features,researchers not only pay attention to the establishment of the polymerization method,and also develop the applications of selenium-containing polymers in the field of intelligent materials,including self-healing materials and shape memory materials.Therefore,explore dynamic selenium-containing covalent bond system plays an important role in the application of selenium-containing polymers in the field of materials.Based on the above research status,this thesis has carried out relevant research from the provide polymerization method to demonstrated the a dynamic covalent bond system.The specific research contents of this thesis are as following:1.A Novel Synthesis of Poly(ester-alt-selenide)s by Ring-Opening Copolymerization of y-Selenobutyrolactone and Epoxy Monomer.Ring-opening copolymerization(ROCOP)is an effective means to prepare functionalized polyester.In this work,a type of selenide-containing polyesters with controllable structure,molecular weight,and molecular weight distribution was successfully prepared by ROCOP of y-selenobutyrolactone and epoxy compounds.The influence of the catalyst,solvent,and reaction temperature on the reaction efficiency was examined.Then,kinetic study was investigated under an optimized condition.The structure of the copolymers was carefully characterized by nuclear magnetic resonance(NMR),1H NMR,13C NMR,and 77Se NMR,Matrix-assisted laser-desorption-ionization time-of-flight mass spectrometry(MALDI-TOF-MS),and gel permeation chromatography(GPC).The resulting polymers showed a linear structure with a sequence regulated backbone repeating unit of ester-selenide.On this basis,some typical epoxides were investigated to verify the scope of the polymerization system.Due to the "living"/controlled characteristics of this ROCOP,multiblock,amphiphilic,and stereotactic copolymers could be prepared with a pre-designed structure.As expected,the selenide-containing amphiphilic copolymer could self-assemble to micelles and showed an oxidative response.2.Ring-opening copolymerization behavior of episulfides and γ-selenobutyrolactone(SBL).Homopolymerization and copolymerization behavior of 2-(phenoxymethyl)thiirane(POMT)and SBL were studied,the structure of polymer was determined by 1H NMR and GPC,the results showed that SBL cannot be homopolymerized and POMT can be homopolymerized and copolymerized with SBL.Secondly,the degradation and optical properties of polymer were studied,the optical properties of the polymer were tested by spectroscopic ellipsometer,the results showed that the polymer not only had excellent optical properties,but also can degrade under the different oxidants.It provides a basis for the preparation of multifunctional and degradable selenium-containing polymer,and further widens the scope of application of degradable selenium-containing polymer in optical field.3.Study on dynamic exchange behavior and performance of dynamic seleniranium ion bond.Sulfuryl chloride reacted with diethyl γ,γ’-diselenodibutyrate(DSDEB)to give selenyl chloride,followed by the addition to 1-hexene as the model reaction.The effects of different olefins such as terminal alkenes and cycloalkenes on the dynamic exchange of seleniranium ion bond were studied and the effects of selenium chloride reagents with different structures such as aryl selenium chloride on the dynamic exchange of seleniranium ion bond were further studied,the dynamic exchange process was characterized by 1H NMR.The results show that the exchange degree of selenium ion dynamic bond can be effectively regulated by changing the structure of alkene and selenium chloride reagent.Secondly,the seleniranium ion bond was introduced into the polyesters and the dynamic exchange between polymers and small molecules was studied,the results of dynamic exchange can be characterized by GPC.The results show that the dynamic exchange of seleniranium ion in polymer is realized.Finally,the introduction of dynamic bond into the crosslinked polymer was studied,which provided the basis for the application of seleniranium ion bond in functional polymer materials.