Modification of Kraft Lignin to Expose Diazobenzene Groups: Toward pH- and Light-Responsive Biobased Polymers
Modification of Kraft Lignin to Expose Diazobenzene Groups: Toward pH- and Light-Responsive Biobased Polymers
复制标题
DOI：
10.1021/acs.biomac.5b00882
复制
发表时间：
2015-09-01
影响因子：
6.2
通讯作者：
Crestini, Claudia
中科院分区：
文献类型：
--
作者：
Duval, Antoine;Lange, Heiko;Crestini, Claudia
以软木硫酸盐木质素为原料，采用两步法合成了一种pH和光响应聚合物，目的是结合重氮苯基团。最初，氧化苯乙烯与木质素中的酚羟基反应，提供苯环的附着，从而为进一步修饰创造畅通的反应位点。利用先进的光谱技术（H-1和P-31核磁共振，紫外和红外光谱）证明了该反应对酚羟基是定量和选择性的。在第二步中，新加入的苯环与重氮离子反应形成目标重氮苯基序，其形成再次得到彻底验证。正如预期的那样，含重氮苯的硫酸盐木质素衍生物在溶液中表现出ph依赖的颜色变化和由于重氮苯基团的顺反光异构化而产生的光响应特性。
A pH- and light-responsive polymer has been synthesized from softwood kraft lignin by a two-step strategy that aimed to incorporate diazobenzene groups. Initially, styrene oxide was reacted with the phenolic hydroxyl groups in lignin, to offer the attachment of benzene rings, thus creating unhindered reactive sites for further modifications. The use of advanced spectroscopic techniques H-1 and P-31 NMR, UV and FTIR) demonstrated that the reaction was quantitative and selective toward the phenolic hydroxyl groups. In a second step, the newly incorporated benzene rings were reacted with a diazonium cation to form the target diazobenzene motif, whose formation was again thoroughly verified. As anticipated, the diazobenzene-containing kraft lignin derivatives showed a pH-dependent color change in solution and light-responsive properties resulting from the cis-trans photoisomerization of the diazobenzene group.