为了提高酚醛树脂的残炭率并优化热解炭的结构和性能,将Ni(NO3)2·6H2O按1:100的质量比掺入热固性酚醛树脂中制备Ni掺杂酚醛树脂,经200℃固化后,分别在不同气氛(埋炭和Ar气氛)和不同温度(600、800、1000和l200℃)下保温3h炭化,然后检测其残炭率,并借助差示扫描量热仪、X射线衍射仪、能谱仪、扫描电镜、透射电镜表征其热分解特征及其热解发的抗氧化性、物柏组成和显微结构。结果表明:1)Ni掺杂酚醛树脂在800和1000℃的残炭率均比未掺杂酚醛树脂的提高较多;2)随炭化温度的升高,M掺杂酚醛树脂热解发逐渐向石墨化碳结构方向演化;3)Ni掺杂酚醛树脂经1000℃炭化形成的热解炭中有大量直径50~100nm、长度可达几十微米的多壁碳纳米管;4)在血气氛中炭化更有利于碳纳米管的生成,并且热解发具有更高的残炭率和结晶度;5)1200℃炭化形成的热解炭的抗氧化性显著提高,氧化峰值温度比未掺杂酚醛树脂的提高约84℃。
Ni-doped phenol resin was prepared with 1:100 mass ratio of Ni( NO3)2 · 6H20 to thermosetting phenol resin to optimize the structure and properties of pyrolytic carbon derived from phenol resin and in- crease its carbon yield. The specimens were cured at 200 ℃ and coked under different atmospheres (car- bon-embedded atmosphere and Ar atmosphere) and at different temperatures (600,800,1 000 and 1 200 ℃) for 3 h, respectively. The carbon yield was measured. Thermal decomposition characteristics of Ni- doped phenol resin, and the oxidation resistance, phase composition and microstructure of pyrolytic carbon were characterized by differential scanning calorimetry,X-ray diffraction, energy dispersive spectroscopy, scanning electron microscopy and transmission electron microscopy. The results show that the carbon yield of Ni-doped phenol resin coked at 800 or 1 000 ℃ is increased significantly, compared with that without any dopants. The graphitization degree of pyrolytic carbon structure derived from Ni-doped phenol resin increa- ses with the increase of carbonization temperature. The massive multi-wall carbon nanotubes of 50 - 100 nm in diameter and of micrometre scale in length are generated at 1 000 ℃. Compared with the carbon-em- bedded atmosphere,carbon nanotubes can be more easily generated under Ar atmosphere, resulting in higher carbon yield and degree of crystallinity of the pyrolytic carbon derived from Ni-doped phenol resin. The oxidation resistance of the pyrolytic carbon derived from Ni-doped phenol resin at 1 200 ℃ is improved significantly and its highest oxidation temperature is increased by about 84 ℃,compared with that from Ni free phenol resin.