Synthesis And Characterization Of Polybenzoxazine And Polybenzoxazole Materials

Since the 21st century,the rapid development of 5G has put forward higher requirements for low dielectric materials and trapezoidal polymers with the advantages of high elastic modulus,high tensile strength,good thermal stability and low dielectric have become the focus of research.In order to prepare polymer films with low dielectric,high strength and high selective permeability,the following studies were carried out around semi trapezoidal polybenzoxazole and trapezoidal polybenzoxazine.（1）Synthesis and characterization of semi trapezoidal polybenzoxazole（PBO）materials.Nine kinds of PBO thin film materials（PBO 1-9）were synthesized by improving the traditional polymerization process,the structure of PBO thin film materials was characterized by ATR,XRD and SEM.The related properties were tested by microcomputer controlled electronic testing machine,thermogravimetric analyzer,gas permeability meter and high frequency dielectric tester.It was found that among the nine film materials,PBO-1 was synthesized with 2,2-bis（3-amino-4-hydroxyphenyl）hexafluoropropane（6FAP）as monomer A and p-benzoyl chloride（TPC）as monomer B;PBO-2 synthesized with 2,2-bis（3-amino-4-hydroxyphenyl）hexafluoropropane（6FAP）as monomer A,p-benzoyl chloride（TPC）and m-benzoyl chloride（IPC）as monomer B showed relatively balanced properties.The related properties were tested by microcomputer controlled electronic prototype,thermogravimetric analyzer,gas penetrameter and high frequency dielectric tester.The tensile strength of PBO-1 film is slightly reduced to 146.821MPa,the elongation at break is 4.444%,and the elastic modulus is 5.330 GPa.The tensile strength of PBO-2 film is slightly reduced to 118.264 MPa,the elongation at break is9.741%,and the elastic modulus is 1.890 GPa.The glass transition temperature of PBO-1 is351.80℃and the thermogravimetric temperature is 531.80℃;the glass transition temperature of PBO-2 is 354.00℃and the thermogravimetric temperature is 520.85℃.The dielectric constant of PBO-1 at 1 GHz is 2.847 and the dielectric loss is 3.670×10^-3,at 10GHz,the dielectric constant is as low as 2.749 and the dielectric loss is 4.920×10^-3;the dielectric constant of PBO-2 at 1 GHz is 2.942 and the dielectric loss is 3.830×10^-3,at 10GHz,the dielectric constant is 2.980 and the dielectric loss increases to 1.127×10^-2.The gas permeation study found that PBO-1 had good selective permeability for methane and carbon dioxide.The preliminary study showed that PBO-1 could be used as hollow fiber membrane material for biogas separation.It can also be used for 5G radome material and5G terminal antenna material.（2）Synthesis and characterization of trapezoidal polybenzoxazine（CLP）polymer.Four benzoxazinyl conjugated trapezoidal polymers（CLP 1-4）were synthesized with diamino hydroquinone molecules as monomer A and benzoquinone compounds as monomer B.Their structures were characterized by FITR and XRD.CLP-1 polymer with the most balanced performance is selected for hydrothermal reaction with transition metals to realize metal doping,so as to improve its gas detection performance.Prepare the gas sensor,test its hydrogen sulfide gas detection performance by using electrochemical workstation and gas detector,and preliminarily explore its application as the core sensing material for hydrogen sulfide gas detection.