褐煤腐植酸磺化改性工艺及表征

为提高腐植酸的亲水性能,对褐煤腐植酸进行磺化改性。以Na2SO3为磺化剂,以磺化度为考察指标,通过单因素实验和正交实验研究了磺化温度、磺化剂固液比、磺化时间对褐煤磺化腐植酸磺化度的影响,得到褐煤磺化腐植酸最佳制备条件,并通过红外光谱分析和热重分析对褐煤磺化腐植酸性能进行表征。结果表明:磺化温度对褐煤磺化腐植酸磺化度的影响最大,其次为磺化时间,磺化剂固液比影响较小。在磺化温度50℃,磺化剂固液比2∶20,磺化时间90 min条件下制备的褐煤磺化腐植酸磺化度为17.72%。红外光谱表明:褐煤磺化腐植酸含有苯环、羧基、羟基、酚羟基,磺酸基团明显增多,褐煤腐植酸磺化改性成功。热重分析表明:褐煤磺化腐植酸低于200℃时稳定,大于200℃时发生裂解反应;小于330℃裂解反应为吸热过程,大于330℃为放热过程。

Sulfonation and characterization of lignite humic acid

In order to improve the hydrophilicity of humic acid,the lignite humic acid was modified by sulfonated method.Taking Na2 SO3 as sulfonatingagent,sulfonation degree as index,the influence of humic acid-sulfonating agent ratio,reaction time,temperature on acid sulfon-ation degree was studied through the single factor experiment and orthogonal design method.The authors got the optimum preparation condi-tion,meanwhile,characterized the humic acid through infrared spectrum analysis and thermogravimetric analysis （ TGA）. The results showed that,the reaction temperature was the main influencing factor,followed by reaction time,humic acid- sulfonating agent ratio.When the sulfonating agent-humic acid ratio was 2 to 20,the sulfonation temperature was 50 ℃ ,the reaction time was 90 minutes,the sulfonation degree was 17.72%.The IR spectra showed that the modified humic acid contained benzene ring,carboxyl,hydroxyl,phenolic hydroxyl group.Its sulfo groups increased significantly.The TGA showed that,the sulfonatedhumic acid was stable when the temperature was lower than 200 ℃ ,while the temperature was higher than 200 ℃ ,the sulfonatedhumic acid began to deposit.When the temperature was lower than 330 ℃ ,the deposition was endothermic reaction,otherwise,the deposition was exothermic reaction.