Synthesis Of High Performance Poly(arylether Nitrile) And Study On The Properties Of Its Modified Cyanate Este

The cyanate ester（CE）resin is a high-performance thermosetting material that exhibits exceptional temperature resistance,dielectric properties,and dimensional stability.The CE resin exhibits tremendous potential for applications in areas such as advanced composite materials,adhesives,and so on.However,due to the high crosslinking density and high crystallinity of the triazine ring structure,the cured CE resin has a relatively high level of brittleness.When used as the adhesives,CE can not meet the required level of toughness and thus necessitated modification to enhance its toughness.Incorporating engineering plastics into the cross-linking network of CE resins is an effective strategy for improving their toughness.PEN（polyaryl ether nitrile）is a novel type of specialized engineering plastic that exhibited remarkable thermal properties,mechanical properties and dielectricc properties,which have great application prospects in the modification of high-performance composites.In this article,a series of novel fluorinated poly（aryl ether nitrile）（FP-PEN）was successfully synthesized by copolymerizing phenolphthalein and bisphenol-AF with2,6-dichlorobenzonitrile,which successfully introduced both phenolphthalein structure and-CF₃ groups into the main chain of PEN.The FP-PEN polymers exhibited high T_g,excellent heat resistance and solubility,outstanding mechanical properties and dielectric properties.Then,the modified resin systems of FP-PEN/ACE were successfully prepared through using synthesized FP-PEN to modify ACE resin and the performance changes of the FP-PEN/ACE resins were systematically analyzed by means of comparative analysis.Finally,the comprehensive performances of FP-PEN/ACE resins were further enhanced through the utilization co-modification of EP and FP-PEN.Additionally,a detailed discussion was conducted on its curing kinetics and mechanism.The main content of this article was shown as follows:A series of the novel fluorinated poly（aryl ether nitrile）（FP-PEN）were synthesized as a nucleophilic substitution reaction of phenolphthalein,bisphenol AF and 2,6-dichlorobenzonitrile.The solubility,thermal,mechanical,and dielectric properties of FP-PEN were investigated systemically.Furthermore,a detailed discussion was conducted on how changes in molecular structure affected the macroscopic properties of the polymer.The results demonstrated that FP-PEN exhibited exceptional thermal performance and dielectric performance,as evidenced by the T_g exceeding 200℃and T_5%surpassing470℃.When the molar ratio of bisphenol AF to phenolphthalein was 0.3,FP-PEN films showed excellent mechanical properties with a tensile strength and elongation at break of82.8 MPa and 3.47%,respectively.A series of synthesized FP-PEN were utilized to enhance the toughness of biscyanatophenylpropane（ACE）.The type and amount of FP-PEN in modified ACE resins were ultimately determined by comparative research on their thermal properties,dielectric properties,mechanical properties,and adhesive properties.It was discovered that when the molar ratio of bisphenol AF reached 30%in F₃P-PEN,it had a significant modifying effect on ACE resin.When the addition amount of F₃P-PEN was 20 phr,the mechanical properties and adhesive properties of the modified ACE resins were significantly improved,which its tensile strength and impact strength increased to 66.2MPa and 15.17 k J/m²,respectively,while its shear strength and peel strength at room temperature reached 26.9 MPa and 2.27 k N/m.The overall performance of F₃P-PEN/ACE resin systems was further enhanced by incorporating different EP resins and F₃P-PEN.Through DSC,FT-IR,TGA tests and so on,the effects of different EP types on the enthalpy,activation energy,thermal properties and adhesive properties of the modified system were investigated.The research findings suggested that the incorporation of E20 epoxy resins could effectively enhance the mechanical properties and adhesive properties of F₃P-PEN/ACE resins,which the tensile strength and impact strength could be increased to 74.6 MPa and 19.35 k J/m²,as well as the shear strength and peel strength at room temperature can reach 32.6 MPa and 2.74k N/m,respectively.However,the shear strength at high-temperature of the modified resin would decrease to a certain extent.