Synthese And Properties Of Poly (Arylene Ether Nitrile) End-capped With Phthalonitrile

Poly (arylene ether nitrile)(PEN) is a type of engineering thermoplastic resinwhich have been identified as excellent matrix resins in microelectronic industry,aerospace, electrical insulation, and semiconductor industries due to their heat resistance,mechanical s trength, solvent resistance and flame retardancy properties. The aromaticportion of the poly(arylene ether) is believed to contribute to thermal stability and goodmechanical properties of the polymer and the ether linkages are considered to facilitatepolymer processing while maintaining oxidative and thermal stability. The presence ofnitriles in PEN endows the polymers with strong polarizability, which promotes theadhesion of the polymers to many substrates. Moreover, the nitriles also serve aspotential sites for the crosslinking reaction of PEN because the groups are likely to formthermally stable phthalocyanine rings. The high molecular weight linkable PEN canadapt to the rapid development in the future demand of the high-tech field of materials.In this paper, a novel linkable PEN end-capped with4-nitrophthalonitrile wassynthesized. biphenyl (BP), hydroquinone (HQ),2,6-dihalobenzonnitriles (DCBN) andmethylbenzene and N-Methyl-2-pyrrolidone (NMP) were added into a flask. During thecourse of the reaction, the K2CO3were added in several portions. Then,4-nitrophthalonitrile and NMP were add into three-necked flask after reaction for4h.The mixture was heated at80oC for4h. The structure of PEN was characterized byinfrared spectroscopy and nuclear magnetic resonance spectroscopy. The thermalproperties, dynamic mechanical properties, mechanical properties and dielectricproperties of PEN were investigated, which have not much change.The as-prepared flexible PEN (after elevated temperature treatment) wascharacterized by infrared spectroscopy, nuclear magnetic resonance, gel permeationchromatography and rheological measurements. In addition, the effects of curingbehaviors on properties of PEN films were studied by thermal, dielectric andmechanical measurements. Differential scanning calorimetry analysis showed that glasstransition temperature of PEN was improved as the curing temperature and time increased. Mechanical properties showed that tensile strength of PEN increased. Theproperties of cured PEN were improved.In this paper, crosslinkable poly (arylene ether nitrile) composites were preparedby solution mixing and thermalcompression method and the fracture morphologies ofPEN composites were analyzed by SEM. The relationship with dielectric properties andthe fracture morphologies of PEN/HGM composites and PEN/GF composites werestudied. These results can prove that cross-linked network enhanced dispersion andinterfacial interaction of PEN composites are in accordance with the analysis of thermal,mechanical and dielectric properties of PEN composites.This paper revealed that crosslinkable PEN and composites can possess theproperties of the thermosetting engineering materials via thermoplastic engineeringmaterials processing method.