Abstract:

With the goal of developing high-performance ablative polymer materials， the first step was to synthesize amino-containing bisphenol monomers. The amino-containing bisphenol monomers were then subjected to S_N2 nucleophilic condensation with 2，7-dihydroxy-9-fluorenone （BHF） and 4，4'-difluorobenzophenone， resulting in a novel side amino-containing crosslinkable poly（aryl ether ketone）. Further， high-performance thermosetting poly（aryl ether ketone） resin （PEK-BAD-G） was prepared through high-temperature self-crosslinking using thermal crosslinking. The thermal stability， thermal mechanical properties， and ablative performance of the material were investigated through the use of thermogravimetric analysis （TGA）， differential scanning calorimetry （DSC）， dynamic mechanical analysis （DMA）， and an oxygen-acetylene ablation tester. The polymer properties were regulated by adjusting the copolymer monomer ratio. It was observed that the addition of BHF could enhance the overall performance of the thermosetting resin. However， when the content of BHF exceeded 50%， it precipitated during the reaction， making it challenging to obtain high relative molecular mass polymers. The results indicate that when the BHF content is 50%， the ablative resistance， thermal oxidation stability， and high-temperature mechanical properties of the thermosetting poly（aryl ether ketone） reach their optimum levels. In the nitrogen environment， the thermal decomposition temperation reached 548 ℃， the char yield were as high as 87.5% and 77.7% at 600 ℃ and 800 ℃， respectively. In addition， even under air environment， the char yield was still 85.4% even at 600 ℃. The DMA results showed that the storage modulus remained above 1.9 GPa at 400 ℃， indicating the outstanding thermomechanical properties. This study offers a new choice for ablative resin matrices. It expands the application range of poly（aryl ether ketone） materials.

Key words: High carbon residue, Poly（aryl ether ketone）, Thermosetting resin, Ablation resistance