氧化镍掺杂酚醛树脂热解炭的结构及抗氧化性研究

在酚醛树脂中直接掺杂三氧化镍粉末,研究氧化镍掺杂量、炭化温度对氧化镍改性树脂热解炭结构和氧化温度的影响。用X射线衍射、拉曼光谱、扫描电镜和综合热分析等手段对氧化镍改性树脂热解炭的石墨化度、显微结构及氧化温度进行表征。结果表明,埋炭条件下掺杂三氧化二镍,450～750℃温度下被逐级还原成一氧化镍和单质镍,其催化热解炭形成晶须、片状或块状结构;氧化镍改性树脂热解炭石墨化度随炭化温度升高和氧化镍掺杂量增加而增高,其氧化温度高于酚醛树脂氧化温度;氧化镍的最佳掺杂量为3%～5%。

Structure and oxidation resistance of pyrolytic carbon from phenol resin-doped Ni_2O_3 powder

Ni2O3 was directly doped into phenol resin as a catalyzer for conversion of amorphous carbon into graphite structure in pyrolytic process.The effect of the amount of Ni2O3 powders and coking temperature on pyrolytic reaction of phenol resin,structure and oxidation of pyrolytic carbon was investigated by means of XRD,SEM,Raman spectrum and DSC-TG.It was suggested that Ni2O3 will be reduced gradually into NiO and metal Ni in the range of 450～750 ℃ in coke powder bed,and then decomposed carbon atoms absorbed at the Ni particles precipitate in forms of whisker,plate like carbons at higher temperatures.The graphitization content of pyrolytic carbon depends on coking temperatures and doping amount of Ni2O3 powder.At higher than 1 050 ℃ the graphite carbon appears remarkably in the pyrolytic product and its content increases with the doping amount in phenol resin.The pyrolytic carbon of doped resin has better oxidation resistance than that of resin without Ni2O3 dopant.The optimum amount is 3%～5% Ni2O3 into phenol resin for good oxidation resistance of pyrolytic carbon.