By comparing parameters such as functional groups,morphology,thermal stability,and hydrophilicity,suitable lignin for bitumen modification was selected.The lignin was modified by citric acid hydrophobic treatment and then characterized to explore the changes in bitumen performance of lignin before and after modification.The results showed that organosolv lignin contains abundant hydroxyl groups,a rough surface,good thermal stability,and hydrophobic properties.The optimal temperature for hydrophobic modification was 130 ℃,and the optimal mass ratio of citric acid to lignin was 7∶1.At this condition,the yield was 28.70％.After modification,the hydroxyl content of organosolv lignin decreased,the surface was still relatively rough,the thermal stability was good,and the hydrophobic performance was enhanced.The complex modulus of modification organosolv lignin based bitumen increased,the phase angle decreased and the anti rutting performance improved.
维普
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