Study On The Synthesis And Properties Of Poly (Aryl Ether Nitrile Sulfone) Copolymers

As a class of important high performance polymeric materials,co-polyarylene ether has been widely used in military defense and civil high-tech fields such as aerospace,ships,electronics,machinery and chemical industry,and rail transportation due to its excellent comprehensive properties.As structural material,co-polyarylene ether has outstanding mechanical properties and heat resistance,but its processing is difficult and costly and it is mainly used in the field of high-end manufacturing now.Carrying out research on the structure and performance of this type of high-performance polymer materials,especially expanding its application range as special functional polymer materials and further enhancing its added value,has important practical significance for promoting the sustainable development of co-polyarylene ether.Polyarylene ether nitrile?PEN?and polyethersulfone?PES?are two typical polyarylether special polymers.This dissertation focuses on the relationship between the structure and performance of poly?aryl ether nitrile sulfone?copolymers?PENS?.Firstly,a series of random PENS have been synthesized to determine the copolymer polymerization conditions.Next,then amphiphilic block copolymerized poly?aryl ether nitrile sulfone??amPENS?has been further synthesized through molecular design,and the experimental method for preparing intrinsically fluorescent polymer microspheres using amPENS as raw materials has been established.Finally,cross-linked fluorescent polymer microspheres with multi-band fluorescence emission properties were obtained by coordination with rare earth ions,open the way for the application of poly?aryl ether nitrile sulfone?fluorescent polymers in biological detection and optical anti-counterfeiting.The specific research content is described as follows:?1?Using 2,6-dichlorobenzonitrile,4,4'-dichlorodiphenylsulfone and bisphenol A as raw materials,a series of poly?aryl ether nitrile sulfone?random copolymers?PENS?with different ratios of cyano and sulfone groups were synthesized by nucleophilic substitution reaction.The results of infrared spectrum and nuclear magnetic resonance spectrometry showed that PENS copolymer was successfully synthesized and PENS exhibits excellent thermal stability,with the temperature of 5%weight loss under nitrogen atmosphere is greater than 480 ^oC,and the glass transition temperature is higher than 180^oC.The PENS film was prepared by the solution casting.Experimental results have shown that increase of the cyano group content will lead to the increase of the tensile strength,tensile modulus and elongation at break of PENS.The dielectric constant and dielectric loss will also increase with the increase of cyano group content.Increasing the sulfone content increases the heat resistance of PENS,while the energy storage density of PENS is between 0.51-0.68 J/cm³.?2?In order to expand the application range of poly?arylene ether nitrile sulfone?copolymers,block copolymer of poly?arylene ether nitrile sulfone??amPENS in short?was designed and synthesized,and the self-assembly behavior of amPENS in the emulsion system was studied.Based on the results in the first part,amphiphilic block copolymerized poly?aryl ether nitrile sulfone??amPENS?was synthesized by two-step polycondensation reaction with carboxylated PEN as the hydrophilic segment and PES as the hydrophobic segment.The chemical structure of amPENS is confirmed via the FTIR and NMR spectroscopy.Then,the self-assembly of amPENS to form fluorescent nanospheres was induced by the evaporation of the emulsion solvent.The change of the pH of the emulsion system will greatly affect the stability of the emulsion droplets and the increase of the oil-water ratio will reduce the size of the microspheres,while the increase of the emulsion stirring rate can significantly change the particle size distribution of the nanospheres.The microspheres solution fluorescence test showed that the fluorescence emission spectrum of amPENS microspheres with regular and smooth morphology tended to have two distinct peaks.Finally,bio-functionalized amPENS fluorescent microspheres that can be used for protein separation experiments and fluorescent flow detection of insulin were obtained by optimizing the experimental conditions.?3?In order to further expand the fluorescence properties and application fields of poly?aryl ether nitrile sulfone?nanospheres,research work was carried out from the perspective of the molecular chain structure and cross-linking methods of amphiphilic block copolymerized poly?aryl ether nitrile sulfone?nanospheres.Firstly,sulfonic acid group was introduced into the hydrophilic segment to synthesize sulfonic acid-containing poly?aryl ether nitrile sulfone?block copolymer?CS-amPENS?with better hydrophilicity,whose chemical structure is confirmed by the FT-IR and NMR spectroscopy.Secondly,rare earth ions(Tb³⁺,Eu³⁺)were introduced into the CS-amPENS emulsion self-assembly process to prepare the metal crosslinked microspheres.Studies have shown that increasing the concentration of coordination ions will significantly increase the fluorescence intensity of the corresponding color,while the increase of the CS-amPENS content and the stirring rate generally results in the decrease in fluorescence intensity.When the synthesized CS-amPENS was coordinated with both Tb³⁺and Eu³⁺,it was found that the fluorescence color of crosslinked microspheres can be easily adjusted by changing the ratio of coordination ions,and pH has little effect on the fluorescence intensity of the nanospheres,indicating that it has high stability.Finally,the rare earth ions coordinated fluorescent microspheres prepared by emulsion self-assembly also exhibit strong fluorescence emission in the solid state,showing potential application in the optical anti-counterfeiting.In summary,as a new type of co-polyarylene ether,the synthesized poly?aryl ether nitrile sulfone?copolymers combine the advantages of PEN and PES.The introduction of nitrile groups can increase the polymerization activity of polyarylene ether sulfone,and the introduction of sulfone groups can improve the biocompatibility of polyarylene ether nitriles.By tuning the molecular structure of the copolymerized poly?aryl ether nitrile sulfone?and regulating the aggregation behavior,not only copolymer films with excellent mechanical and thermal properties can be obtained,but also polymer functional micro/nano-spheres with rich fluorescent properties can be prepared.Therefore,the synthesis strategy and material fabrication method of co-polyarylene ether established in this paper is expected to serve as important reference for expanding the application field of this kind of high-performance polymeric materials.