中低温煤焦油沥青催化聚合制备改质沥青

以中低温煤焦油沥青为原料,采用催化聚合法制备改质沥青,并在中低温煤焦油沥青中加入乙烯焦油和蒽油进行调和来提高改质沥青的流变性能,分别考察反应时间、反应温度及催化剂和交联剂的加入量对改质沥青的软化点、结焦值、甲苯不溶物含量和喹啉不溶物含量的影响。结果表明:加入乙烯焦油和蒽油调和可以有效提高改质沥青的流变性能,催化剂和交联剂按照1∶1的质量比加入,可以有效降低改质沥青的软化点,这是因为酸性催化剂和交联剂之间形成相对均相的反应体系,解决了改质沥青软化点高的问题。采用调和中低温煤焦油沥青制备改质沥青,筛选出的最佳工艺条件为:反应温度370℃,反应时间7h,催化剂和交联剂的加入量2.5%,该条件下制备的改质沥青的性质符合工业标准YB/T 5194-2015的要求,改质沥青的软化点为120℃,结焦值为56.28%,甲苯不溶物含量为30.52%,喹啉不溶物含量为8.21%,β树脂含量为22.31%。采用傅立叶变换红外光谱仪和偏光显微镜对制备出的改质沥青和中低温煤焦油沥青进行分析,初步推断出改质沥青中化合物芳环上的取代基明显增加且烷基取代的化合物大多数为芳烃分子,且在偏光显微镜下改质沥青中出现小球体,表明中低温煤焦油沥青在制备成改质沥青的这一过程中其相对分子质量变大,稠环芳烃含量增多。

Preparation of Modified Asphalt by Catalytic Polymerization of Medium-low-temperature Coal Tar Asphalt

The modified asphalt was prepared from medium-low-temperature coal tar asphalt by applying catalytic polymerization method.Both ethylene tar and anthracene oil were added to the medium-low-temperature coal tar asphalt for improving the rheological properties of the modified asphalt.The effects of reaction time,reaction temperature and amount of catalyst&cross-linking agents on several properties of the modified asphalt were investigated respectively,involving softening point,coking value,the content of toluene insoluble,and the content of quinoline insoluble.The results show that the addition of ethylene tar and anthracene oil can effectively improve the rheological properties of the modified asphalt.Moreover,if the catalyst and cross-linking agents added in mass ratio of 1∶1,the softening point of the modified asphalt can be effectively reduced.It is because that a relatively homogeneous reaction system is formed between the acidic catalysts and cross-linking agents,which solves the problem of high softening point of the modified asphalt.In terms of the modified asphalt preparation method using blending medium-low-temperature coal tar asphalt,the optimum processing conditions are concluded as follows:the modified asphalt can be prepared under the conditions that the reaction temperature is 370℃,the reaction time is 7h,and the addition of catalyst&cross-linking agents is 2.5%.The properties of the modified asphalt were proved to meet the requirements of the industrial standard YB/T 5194-2015.Specifically,the softening point is 120℃,the coking value is 56.28%,the content of toluene insoluble is 30.52%,the content of quinoline insoluble is 8.21%,and the content ofβ-resin is 22.31%.Fourier transform infrared spectroscopy and polarizing microscope were used to analyze the prepared modified asphalt and the medium-lowtemperature coal tar asphalt.It can be inferred that the substituents on the aromatic rings of the compounds in the modified asphalt increase significantly and most of the alkyl substituted compounds are aromatic molecules.In addition,the modified asphalt presents small spheres under the polarized light microscope,which indicates that the processing of medium-low-temperature coal tar asphalt increases the molecular mass as well as the content of condensed aromatic hydrocarbons.