Ni(NO_3)_2催化酚醛树脂的炭化结构特性及其力学性能（英文）

Microstructures and mechanical properties of pyrocarbons produced from phenolic resin with added Ni(NO_3)_2

在酚醛树脂中添加Ni(NO_3)_2,逐步固化、高温炭化后,用X射线衍射、扫描电镜和透射电镜观察表征树脂高温炭化显微结构,并测试树脂炭的抗折强度、弹性模量和断裂能来分析其力学性能。显微结构观察表明:添加质量分数5%的Ni(NO_3)_2会在酚醛树脂炭化结构中生成体积分数约2%的纳米炭纤维,纳米炭纤维交错排布;由于酚醛树脂热解产生的含碳小分子气体成分复杂,在树脂玻璃炭出现了炭纳米纤维与碳纳米管接替生长的现象。力学性能测试结果表明:树脂玻璃炭中原位生成的纳米炭纤维与树脂炭基体有一定的结合强度,能提高树脂玻璃炭的抗折强度、弹性模量;可显著提高树脂炭的断裂能,增强其抗拉强度和断裂韧性。

A refractory containing graphite is commonly used in the metallurgical industry in locations subject to severe thermal shock because of the high thermal conductivity and good thermal shock resistance of graphite. However,a refractory that uses phenolic resin as the carbon precursor is brittle,and to improve its strength and toughness,Ni（NO3）2is added to the resin to catalyze the in-situ formation of carbon nanofibers/nanotubes. The microstructure and mechanical properties of the Ni（NO3）2-modified phenolic resin carbons were characterized by XRD,SEM,TEMand mechanical tests. Results indicate that carbon nanofibers/nanotubes（ 2% by volume） were formed within the pyrocarbons as a result of the nickel catalyst and these are interconnected to form a network structure. The nanocarbon fibers/tubes significantly improve the bend strength,elastic modulus,tensile strength and fracture toughness of the pyrocarbons and their fracture energies are increased accordingly.