甘氨酸接枝酶解木质素的制备及表征

Preparation and Characterization of Graft Copolymers from Enzymatic Hydrolysis Lignin and Glycine

以酶解木质素(EHL)、甘氨酸(Gly)和甲醛为原料,采用Mannich反应制备了甘氨酸接枝酶解木质素(EHL-g-Gly)。研究了反应温度与时间,甲醛/甘氨酸物质的量比对接枝产物的产率和接枝率的影响。结果表明,在反应温度为90℃、反应时间3h、甘氨酸/EHL质量比为1∶1、甲醛/甘氨酸物质的量比为2∶1时接枝率可达25.6%;EHL-g-Gly的残炭量比未改性的EHL有明显提高(增加7.0%)。元素分析表明,EHL-g-Gly的氮含量分别达到2.16%,较未改性EHL(0.81%)有较大幅度的提高。

Enzymatic hydrolysis lignin grafted glycine（EHL-g-Gly） copolymers were prepared by Mannich reaction with enzymatic hydrolysis lignin,glycine and formaldehyde as raw materials.The effects of reaction temperature and time,the dosage of formaldehyde on yield and graft rate were investigated.The EHL-g-Gly grafted copolymers were characterizated by FT-IR,TGA,and elemental analysis.The results show that the reaction temperature and time,dosage of formaldehyde have great influences on the yield and grafting rate.The most high graft ratio of 25.6% is achieved at the reaction temperature of 90 ℃ for 3 h with the mass ratio of glycine to EHL of 1∶1,the molar ratio of formaldehyde to glycine of 2∶1.The TGA results show that the carbon residue of EHL-g-Gly significantly increases（7.0%） than unmodified EHL.The nitrogen content of resultant EHL-g-Gly has obvious increase confirmed by elemental analysis.