辣根过氧化物酶改性木质素磺酸钠的结构特征及吸附分散性能  

Structural Characterization,Adsorption and Dispersion Properties of Sodium Lignosulfonate by Horseradish Peroxidase Incubation

作　　者：周海峰[1] 杨东杰[1] 邱学青[1] 伍晓蕾[1] 

机构地区：[1]华南理工大学制浆造纸工程国家重点实验室,化学与化工学院,广州510640

出　　处：《高等学校化学学报》2014年第4期895-902,共8页Chemical Journal of Chinese Universities

基　　金：国家'九七三'计划项目(批准号:2012CB215302);国家自然科学基金(批准号:20925622;21176096);广东省部产学研结合项目专项基金(批准号:2011A090200019)资助~~

摘　　要：在室温及水溶液体系中,采用辣根过氧化物酶(HRP)对亚硫酸法制浆造纸废液的副产物木质素磺酸钠(木钠)进行改性,通过凝胶渗透色谱、电位滴定、红外光谱和核磁共振波谱等表征了HRP改性木钠的结构.结果表明,HRP可以有效聚合木钠大分子,调节HRP的用量,得到不同分子量的木钠产品,当HRP浓度为6 g/L时,可使木钠分子量增大155%.HRP可氧化木钠分子上的酚羟基变成苯氧自由基,该自由基可直接交联,也可转移到酚羟基的邻位或对位再发生聚合作用,其聚合方式主要为β-O-4'及β-β'连接.HRP改性还可使木钠磺化度增加27%.采用静电逐层自组装技术研究了HRP改性对木钠吸附特征的影响,结果表明,经HRP改性后,木钠在平板上的吸附量增大;对TiO2浆体的分散稳定性能也得到改善,这主要是因为分子量增大,空间位阻作用增强;磺化度增大,静电排斥作用增强,从而使TiO2颗粒更好地分散在水中.A novel and efficient polymerization of lignosulofonate （ by-products from sulfite pulping process ） was investigated in the present study. The ability of commercial horseradish peroxidase（ HRP） for polymerizing sodium lignosulfonate（ SL） was investigated in aqueous solution at room temperature. The gel permeation chro-matography（GPC）, potentiometric titration, infrared spectroscopy（IR）, and 1H nuclear magnetic resonance （ 1 H NMR） were used the structural characterization of SL. GPC results showed a significant increase in mo-lecular weight（ Mw ） of SL. With different dosages of HRP added, SLs with different Mw could be obtained. When 6 g/L HRP was added, the Mw of SL could increase by 155%. During the HRP incubation, phenolic groups were oxidized to phenoxyl radicals. These radicals could undergo radical-couplings directly. On the other hand, unbound electron could transfer to the para-and ortho-carbon of the phenols and β-carbon of the branch, undergoing radical-couplings. Among the radical-couplings, β-O-4’ and β-β’ were the predominant. Moreover, the sulfonic group increased by 27% after HRP incubation. The adsorption of SL by HRP incuba-tion was studied by electrostatic self-assembly technology. After HRP incubation, the adsorption amount of SL increased significantly. Further, because of the increase of Mw and sulfonic group content, resulting in the stronger steric hindrance and electronic repulsion, the dispersion ability of SL on TiO2 slurry was improved.

关 键 词：辣根过氧化物酶 木质素磺酸钠 分子量分布 结构特征 吸附分散性能 

分 类 号：O636.2[理学—高分子化学] Q554.9[理学—化学]