热机械分析确定沥青软化点的试验设计与研究

Experimental design and study of thermomechanical analysis for determining the softening point of pitch

针对现有沥青软化点测试方法误差大、可测范围窄等问题,研究了基于热机械分析(TMA)确定沥青软化点的试验和方法,探究了旋转薄膜蒸发温度、煅烧温度和沥青平均粒径对软化点测试结果的影响,TMA测试沥青软化点试验的不确定度评定以及沥青分子组成和结构与软化点之间的内在关系。研究结果表明:旋转薄膜蒸发处理温度对沥青软化点的影响最为明显,处理温度越高,沥青软化点越高;TMA测试沥青软化点试验的合成标准不确定度为0.02936,相较于其他方法具有更小的不确定度;MALDI TOF-MS和~(13)C-NMR结果展现了平均分子量越大,分子中重组分越多,沥青的软化点越高,并且沥青芳香族组分含量越高,缩聚程度越高,芳香度越大,其软化点越高。

The method for determining the softening point of pitch based on thermomechanical analysis(TMA)were investigated to im-prove the accuracy and feasibility of softening point test.The effects of thin-layer evaporation temperature,annealing temperature,and average particle size of pitch on the softening point test results were studied.In addition,the uncertainty assessment of the designed ex-periment and the relationship between molecular composition and structure and softening point were investigated.The results show that the temperature of thin-layer evaporation treatment has the most significant effect on the final softening point of pitch,and softening point of pitch increases as the treatment temperature rises.The synthetic standard uncertainty of the designed experiment is 0.02936,which has a lower uncertainty than other methods.The spectra of MALDI TOF-MS and I3C-NMR show that the sofening point of pitch is positively related to the average molecular weight and heavy component amount,and the higher aromaticity also determines a higher softening point of pitch.