As a kind of low-cost and readily available industrial byproduct, ethylene tar （ET） was for the first time utilized for the preparation of heat-resistant condensed polynuclear aromatic resin （COPNAR）. The basic pr...As a kind of low-cost and readily available industrial byproduct, ethylene tar （ET） was for the first time utilized for the preparation of heat-resistant condensed polynuclear aromatic resin （COPNAR）. The basic properties of ET and the resulted COPNAR were characterized by FT-IR, IH-NMR, TGA and elemental analysis. The test results showed that ET with high aromatic content （〉50%） was suitable for the synthesis of COPNAR with superior heat resistance. The average molecular structure of ET was obtained by means of the improved Brown-Ladner method, and the reaction mechanism was considered as an acid-catalyzed positive ion-typed polymerization. Our findings have provided a new route to develop ET into technology-added heat-resistant resins.展开更多
In order to improve the thermal stability of condensed polynuclear aromatic(COPNA) resin synthesized from vacuum residue, 1,4-benzenedimethanol was added to cure COPNA resin. The curing mechanism was investigated by p...In order to improve the thermal stability of condensed polynuclear aromatic(COPNA) resin synthesized from vacuum residue, 1,4-benzenedimethanol was added to cure COPNA resin. The curing mechanism was investigated by proton nuclear magnetic resonance spectrometry, solid carbon-13 nuclear magnetic resonance spectrometry and Fourier transform infrared spectroscopy. Microstructures of the uncured and the cured COPNA resins were studied by scanning electron microscopy and X-ray diffractometry. The thermal stability of COPNA resins before and after curing was tested by thermogravimetric analysis. The element composition of the cured COPNA resin heated at different temperatures was analyzed by an element analyzer. The results showed that the uncured COPNA resin reacted with the cross-linking agent during the curing process, and the curing mechanism was confirmed to be the electrophilic substitution reaction. Compared with the uncured COPNA resin, the cured COPNA resin had a smooth surface, well-ordered and streamlined sheet structure with more crystalline solids, better molecular arrangement and orientation. The weight loss process of the uncured and cured COPNA resins was divided into three stages. Carbon residue of the cured COPNA resin was 41.65% at 600 ℃, which was much higher than 25.02% of the uncured COPNA resin, which indicated that the cured COPNA resin had higher thermal stability.展开更多
基金supported by the Program for New Century Excellent Talents in University, China Ministry of Education, 2009 (No. NCET-10-0768)the National Natural Science Foundation of China (Nos. 20876176 and 51172285)the Natural Science Foundation of Shandong Province (ZR2011EL031, ZR2011EL030)
文摘As a kind of low-cost and readily available industrial byproduct, ethylene tar （ET） was for the first time utilized for the preparation of heat-resistant condensed polynuclear aromatic resin （COPNAR）. The basic properties of ET and the resulted COPNAR were characterized by FT-IR, IH-NMR, TGA and elemental analysis. The test results showed that ET with high aromatic content （〉50%） was suitable for the synthesis of COPNAR with superior heat resistance. The average molecular structure of ET was obtained by means of the improved Brown-Ladner method, and the reaction mechanism was considered as an acid-catalyzed positive ion-typed polymerization. Our findings have provided a new route to develop ET into technology-added heat-resistant resins.
基金supported by the National Natural Science Foundation of China(51172285 and 51372277)the Fundamental Research Funds for the Central Universities(14CX02060A,15CX02084A)the Natural Science Foundation of Shandong Province(ZR2011EL030)
文摘In order to improve the thermal stability of condensed polynuclear aromatic(COPNA) resin synthesized from vacuum residue, 1,4-benzenedimethanol was added to cure COPNA resin. The curing mechanism was investigated by proton nuclear magnetic resonance spectrometry, solid carbon-13 nuclear magnetic resonance spectrometry and Fourier transform infrared spectroscopy. Microstructures of the uncured and the cured COPNA resins were studied by scanning electron microscopy and X-ray diffractometry. The thermal stability of COPNA resins before and after curing was tested by thermogravimetric analysis. The element composition of the cured COPNA resin heated at different temperatures was analyzed by an element analyzer. The results showed that the uncured COPNA resin reacted with the cross-linking agent during the curing process, and the curing mechanism was confirmed to be the electrophilic substitution reaction. Compared with the uncured COPNA resin, the cured COPNA resin had a smooth surface, well-ordered and streamlined sheet structure with more crystalline solids, better molecular arrangement and orientation. The weight loss process of the uncured and cured COPNA resins was divided into three stages. Carbon residue of the cured COPNA resin was 41.65% at 600 ℃, which was much higher than 25.02% of the uncured COPNA resin, which indicated that the cured COPNA resin had higher thermal stability.
