- Benzoxazole ionic compound, PBO fiber emulsion sizing agent containing benzoxazole ionic compound and preparation method of PBO fiber emulsion sizing agent
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The invention discloses a benzoxazole ionic compound shown as a formula X, a sizing agent containing the compound, and a preparation method and application of the sizing agent. The benzoxazole ionic compound shown in the formula X is similar to the PBO fiber in chemical structure, the compatibility of the sizing agent and the PBO fiber can be improved, and the preparation process is simple and easy to operate. According to the sizing agent, the problems that an existing sizing agent is poor in compatibility with the PBO fiber, a large number of flammable and combustible organic solvents need to be used in the sizing agent, and nano reinforcements in the sizing agent are difficult to effectively cover the surfaces of the fibers are solved. The sizing agent takes water as a solvent, is greenand efficient, is simple and environment-friendly to prepare, and not only can keep the original tensile strength of PBO fibers, but also can remarkably improve the IFSS of the composite material.
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Paragraph 0132-0133
(2020/11/05)
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- Preparation method of diamido nitrogen-containing aromatic heterocycle compound
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The invention relates to the technical field of synthesis of compounds, in particular to a preparation method of diamido nitrogen-containing aromatic heterocycle compound. The preparation method includes mixing a compound having the structure as shown as the formula (I) with inorganic acid, reacting to obtain water-soluble organism, performing reduction reaction with a reducing agent sulfide to effectively reduce nitro-organism into amino-compounds, performing neutral reaction with alkali liquor so as to obtain the diamido nitrogen-containing aromatic heterocycle compound having the structureas shown as the formula (II) and having high yield and purity. The preparation method is simple and environmental friendly, is low in cost, needs mild reaction conditions, and is suitable to be popularized and applied in scale. According to tests, the yield of the diamido nitrogen-containing aromatic heterocycle compound prepared by the method is not lower than 90%, and even can reach 96%, and itspurity can reach 99.9%.
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Paragraph 0088; 0089; 0090
(2018/10/19)
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- Effect of multiple H-bonding on the properties of polyimides containing the rigid rod groups
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To investigate the influence of hydrogen bonding on the properties of polyimides (PIs) containing rigid rod-like groups, five symmetrical diamines containing benzimidazole, benzoxazole, and hydroxy group were synthesized, and then a series of PIs were prepared. Results showed that hydroxyl-containing poly(benzoxazole imide)s possess higher glass transition temperature (Tg) and dimensional stabilities than their corresponding poly(benzoxazole imide)s. Moreover, the corresponding poly(benzimidazole imide)s presented the best performances, such as the highest Tg, the highest char yield and the highest dimensional stabilities. The influence of hydrogen bonding of benzimidazole on the properties of PIs was stronger than that of hydroxyl groups. Hydroxyl-containing poly(benzoxazole imide)s were formed in crosslinking structures after heat treatment at 400 °C.
- Ma, Xiaoye,Kang, Chuanqing,Chen, Wenhui,Jin, Rizhe,Guo, Haiquan,Qiu, Xuepeng,Gao, Lianxun
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p. 570 - 581
(2016/03/22)
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