Preparation And Properties Of Photoluminescent Polymer Materials From Biobased Small Molecules

With the development of research,polymer materials are developing and becoming more and more functional.In order to meet the various needs of practical applications,a variety of functional polymer materials with good performance have been developed,such as various adsorption materials,filtering materials,medical materials,photoelectric materials and so on.The use of renewable resources can effectively reduce the use and dependence on non-renewable resources and alleviate various environmental problems.As an excellent renewable resource,biobased materials have the advantages of wide source,price moderate.Biobased materials can be divided into natural biobased macromolecules and biobased small molecular according to different structures.Although natural biobased macromolecules are rich,their structure is complex,which is not conducive to practical application.Compared with natural biobased macromolecules,biobased small molecular have many advantages,such as a wealth of sources and categories,clear chemical structures and stable performance.In the present study,it is one of the hot topics to prepare biobased functional materials from biobased small molecules.In addition,photoluminescent polymer materials are widely used in daily life due to their excellent optical properties.However,the current photoluminescent materials are most conventional fluorescent materials.By contrast,there are few studies on the nonconventional fluorescent materials,and there are few reports on the studies using biobased monomers as raw materials.Therefore,the photoluminescence materials related to biobased materials will be more meaningful.The purpose of this study is to design and prepare a series of biobased photoluminescent functional polymer materials by utilizing biobased small molecules reasonably,and to study the potential applications of these materials.We prepare the biobased functional polymer materials with specific morphologies through appropriate polymerization methods,and develop the interdisciplinary field of biobased functional polymer materials from the perspectives of science and practical application.The main research contents are as follows:1.Three kinds of biobasedβ-methylstyrene derivatives,trans-anethole,Methyl isoeugenol（Me IE）and acetyl isoeugenol（Ac IEu）,were separately used as comonomer to copolymerize with maleic anhydride（MAH）via free radical copolymerization to prepare a series of biobased copolymers.The obtained biobased copolymers carried no conventional fluorescent units,but exhibited blue fluorescence under 365 nm UV light.In addition,such fluorescent properties were deeply influenced by the type ofβ-methylstyrene derivative and the hydrolytic process of anhydride group.For the copolymer PMM（constructed by Me IE and MAH）,it could be easily hydrolyzed in Na OH aqueous solution,and the resulting hydrolyzed copolymer（named as h-PMM-Na）could emit enhanced blue emission.Furthermore,water-soluble h-PMM-Na also exhibits concentration-enhanced emission and excitation-dependent fluorescence characteristics,and can be further used as dual-channel chemosensor for detecting Fe²⁺.In particular interestingly,h-PMM-Na powders exhibit persistent room temperature phosphorescence（RTP,up to 400 ms）under air conditions,with reversible emission performance switched via uptake and removal of water.The as-obtained polymers demonstrate promising potential as anti-counterfeiting materials.2.Based on the characteristics of the best fluorescence performance of PMM in the previous chapter,the biobased monomer Me IE was further used to copolymerize with MAH,and the biobased copolymerization microspheres were prepared by free radical precipitation polymerization.Under the proper ratio of good solvent/poor solvent and comonomer concentration,the regular morphology of biobased microspheres was prepared.A core/shell microsphere was successfully prepared by using biobased microspheres as the core,and by means of chemical bonding,chiral helical substituted polyacetylenes were grafted onto the outer layer.Circular dichroism（CD）and UV-vis absorption spectra showed that the core/shell microspheres had significant optical activity.Fluorescenct spectra show that core/shell microspheres have wavelength excitation dependence and AIE effect,which belongs to the category of nonconventional fluorescence.CPL signals at 500 nm were further observed,and the values of g_lum is between-5×10^-3 and 5×10^-3.This chapter establishes a new method for preparing CPL materials,which not only is conducive to the AIE effect of nonconventional fluorescence,but also enables the successful application of nonconventional fluorescence to CPL materials.