论文部分内容阅读
本文用在位红外光谱考察了A-240石油沥青在空气和氮气气氛下的热解反应机理。发现该试样在空气下加热时发生了激烈的氧化作用:随着反应温度升高氧化反应依次生成烷芳酮的羰基、羧基、芳香醚及脂肪醚,进一步的氧化生成小量酚羟基。此外,还发生脱氢、缩聚和交联反应。在氮气气氛下仅发生脱烷基、环烷脱氢、芳环脱氢、缩聚反应,且脱氢速率低于空气条件下的脱氢速率。在空气条件下芳香分子缩聚反应之剧烈进行归因于氧的诱导作用。根据芳香族和脂肪族C—H 键的吸收强度和氢的总含量,近似地计算了芳香族氢和脂肪族氢二者含量之比,进一步表征出石油沥青在热处理过程中芳香度的改变。
In this paper, infrared spectroscopy was used to investigate the pyrolysis reaction mechanism of A-240 petroleum pitch under air and nitrogen atmosphere. It was found that the sample was heated under air intense oxidation occurred: As the reaction temperature increases the oxidation reaction in turn generate alkyl aryl ketone carbonyl, carboxyl, aromatic ethers and aliphatic ethers, and further oxidation to generate a small amount of phenolic hydroxyl. In addition, dehydrogenation, polycondensation and cross-linking reactions also take place. Under nitrogen atmosphere only dealkylation, naphthene dehydrogenation, aromatic ring dehydrogenation, polycondensation reactions occur and the dehydrogenation rate is lower than the dehydrogenation rate under air. The intense reaction of aromatic molecule polycondensation under air conditions is attributed to the induction of oxygen. According to the absorption intensity of aromatic and aliphatic C-H bonds and the total content of hydrogen, the ratio of the contents of aromatic and aliphatic hydrogen was calculated and the aromaticity of petroleum pitch during heat treatment was further characterized.