木质素亲水改性研究

Study on Hydrophilic Modification of Lignin

为提高木质素的功能性,利用2-溴代异丁酰溴改性木质素制备木质素基引发剂,然后采用原子转移自由基聚合(ATRP)法将亲水单体甲基丙烯酸羟乙酯(HEMA)、乙酸乙烯酯(VAC)和丙烯酸(AA)分别接枝到木质素上,合成亲水性木质素基接枝共聚物。对接枝聚合物进行接触角测试和红外光谱分析,结果表明:接枝单体甲基丙烯酸羟乙酯时,木质素接枝聚合物亲水效果最佳;木质素接枝前后接触角分别为45°、21.6°,接枝后木质素亲水性能提高。红外光谱分析显示,木质素接枝甲基丙烯酸羟乙酯(Lignin-g-PHEMA)共聚物中具有HEMA的特征峰,表明单体甲基丙烯酸羟乙酯成功接枝到木质素分子上。

To improve the functionality of Lignin,Lignin-based macromolecular initiator was prepared by 2-bromoisobutyryl bromide modified Lignin.The hydrophilic monomers 2-hydroxyethyl methacrylate(HEMA),vinyl acetate(VAC)and acrylic acid(AA)were grafted to Lignin by ATRP method and then the polybranched Lignin-based graft copolymers were synthesized.Then contact angle test and FTIR characterization were conducted for the copolymers.The results showed that the contact angle of Lignin-g-PHEMA was the smallest,which changed from 45°to 21.6°,indicating that the Lignin with hydrophilic monomers ethyl methacrylate could be improved.The FTIR results showed that the characteristic peak of HEMA was found in Lignin-g-PHEMA,indicating that hydrophilic monomers ethyl methacrylate was successfully grafted onto Lignin molecule.