基于苯甲醛交联剂的煤直接液化残渣改性石油沥青

摘要

以苯甲醛为交联剂，采用煤直接液化残渣的四氢呋喃萃取物( THFS)对石油沥青进行了改性。考察了THFS、交联剂的掺杂量以及掺混温度对改性沥青性能的影响。研究表明，当THFS的掺杂量为4％，掺混温度为170℃时改性效果最佳，而且苯甲醛作为交联剂加入可使沥青改性效果更佳。利用热重-傅里叶红外光谱联用仪( TG-FTIR)、傅里叶变换红外光谱仪( FT-IR)和荧光显微镜对改性沥青进行了表征，结果表明，添加了苯甲醛的改性沥青的失重残余率较其他沥青略有提高；苯甲醛交联的改性沥青在热解过程中释放的CH4含量减少且释放温度有所提高；改性沥青在2924 cm-1和2854 cm-1处的脂肪族-CH2-的伸缩振动和表征苯环位取代872、810和746 cm-1处吸收峰的透射率均有较大幅度的提高，并在1060 cm-1处出现C-O-C伸缩振动峰，以及荧光显微镜图像中出现新的改性粒子，表明交联剂的添加使THFS和基质沥青发生了缩合反应。%The modified asphalt was prepared via adding tetrahydrofuran soluble fraction of direct coal liquefaction residue ( THFS) as modifier and benzaldehyde as crosslinking agent. Modification conditions such as mixing temperature, ratio of THFS and crosslinking agent to asphalt were studied. The optimal conditions are mixing temperature of 170 ℃, and THFS to asphalt ratio of 4%. The modified asphalt can get the better properties by using crosslinking agent. Characterizations of modified asphalt were analyzed by TG-FTIR, FT-IR and fluorescence microscope. Comparing with other asphalt the weight loss of modified asphalt which added benzaldehyde as crosslinking agent is lower. The modified asphalt with benzaldehyde as crosslinking agent has less CH4 release than other samples and CH4 was released at higher temperature. The involvement of benzaldehyde significantly enhances the stretching vibration of aliphatics (-CH2-) of modified asphalt at 2 924 and 2 854 cm-1 as well as the transmittance of the absorption peaks at 872 , 810 and 746 cm-1 representing benzene substituent, and a new absorption peak at 1 060 cm-1 assigned to C-O-C stretching vibration. Moreover the new modified particle in the fluorescence microscope images indicates that the involvement of cross-linking agent may cause polycondensation of THFS and the matrix asphalt.