乙烯渣油沥青的改性及表征

Modification and characterization of ethylene tar pitch

以乙烯渣油沥青为原料,通过常压空气氧化聚合处理对其进行改性,利用单因素方法考察了反应条件(反应温度、反应时间、空气流量)对改性沥青性质(软化点、喹啉不溶物、结焦值、甲苯不溶物、收率)的影响。结果表明,在反应温度370℃,反应时间5 h,空气流量24 L/h的条件下,可以获得软化点(SP)为233℃、喹啉不溶物(QI)为1.21%、结焦值(CV)为75.45%、甲苯不溶物(TI)为43.42%的改性沥青,其收率(Y)可达51.67%。通过元素分析、FTIR等手段对乙烯渣油沥青和改性沥青的芳香性指数(Iar)、支链化指数(CH3/CH2)进行计算,并利用TGA方法观察改性前后沥青的热稳定性变化。结果表明,乙烯渣油沥青和改性沥青的Iar分别为0.39,0.53,CH3/CH2分别为0.88,1.08,说明改性过程中乙烯渣油沥青支链不断减少,芳香缩合度和热稳定性均有所提高。

Ethylene tar pitch was modified by the method of atmospheric pressure air oxidation polymerization.And the factors of reaction(reaction temperature,reaction time,air flow)on pitch properties(softening point,quinoline insoluble matter,coking value,toluene insoluble,yield)were investigated by single factor method.The results shown that the modified pitch with the softening point(SP)of 233℃,quinoline insoluble(QI)of 1.21%,coking value(CV)of 75.45%,toluene insoluble(TI)of 43.42%,and yield(Y)of 51.67%have been obtained under the reaction temperature of 370℃,reaction time of 5 h,and the air flow rate of 24 L/h.The aromatic index(I ar)and branching index(CH3/CH2)of ethylene tar pitch and modified pitch have been calculated by elemental analysis and FTIR.What’more,the thermal stability of pitch before and after modification was observed by TGA method.The results show that,the I ar of the ethylene tar pitch and the modified pitches were 0.39 and 0.53,the CH3/CH2 was 0.88 and 1.08,respectively.In other words,the ethylene tar pitch is continuously reduced during the modification process,but the aromatic condensation degree and thermal stability were improved.