Construction of an In Situ-Generated Nanoscale Organic-Inorganic Hybrid System Using Hydrogen Bonding Interaction To
Yuhang Wang1,2, Jingyi Wang1,2, Zichun Ding1,2
1State Key Laboratory of Fine Chemicals and Department of Polymer Science and Engineering, Dalian University of Technology, Dalian 116024, China.
Abstract:
With the rapid development of science and technology, high-temperature-resistant resin systems are facing more severe challenges in extreme applications. To further improve the comprehensive thermal properties of phthalonitrile resins, an in situ generation of a high-temperature-resistant phthalonitrile resin achieving an organic-inorganic hybridization network is reported. A 3-aminophenol phthalonitrile containing -NH2 is used as a material to hybridize with prepared calcium phosphate nano-oligomers (CPOs), and the hybrid precursor is named as CAPN. Notably, the hydrogen bonding plays a crucial role in the hybrid, as nanosize control of CPOs, and in the synthesis of CAPN. The presence of hydrogen bonding interaction is proved by Fourier transform infrared, Raman, 31P solid-state nuclear magnetic resonance spectra, isothermal differential scanning calorimetric testing, and calculation of apparent activation energy (Ea). Based on organic-inorganic hybrid cross-linked networks formed by resins during the curing process, 50CAPN (the hybrid containing 50 wt % CPOs) has superior thermo-mechanical properties [glass transition temperature (Tg) > 580 °C] and thermal stability [5% pyrolysis temperature (Td5%(N2) = 574 °C, Td5%(air) = 543 °C)] than the blending system 50HAPN [the mixture with 50 wt % nanohydroxyapatite (HAP)]. Additionally, under extreme high temperature and combustion conditions, it demonstrates that 50CAPN has more stable thermo-oxidative aging resistance and flame retardancy than 50HAPN. We believe that this organic-inorganic hybrid system of phthalonitrile formed based on hydrogen bonding will elevate the introduction of the inorganic phase into the organic phase for the preparation of high-temperature-resistant resin systems to a certain level.
