SO42-/ZrO2催化氢还原碱木质素的抗氧化性能

摘要

采用自制SO42-/ZrO2固体酸催化剂，在氢还原体系中对碱木质素进行活化，以化学法对活化前、后碱木质素的官能团含量进行定量分析，利用 DPP H自由基清除率、超氧阴离子自由基清除能力和还原力对碱木质素的抗氧化性能进行评价.结果表明，活化后碱木质素的总羟基和酚羟基含量分别达到9．39％和3．32％，较反应前提高55．98％和15．28％；碱木质素在浓度为0．005~0．160 mg/mL 范围内，对 DPPH 自由基有较强的清除能力，活化后碱木质素对自由基清除率可达80．56％，较反应前提高4．61％；碱木质素在浓度为0．0025~0．080 mg/mL 范围内，对超氧阴离子清除能力较弱；碱木质素在浓度0．002~0．060 mg/mL范围内，活化后碱木质素的还原力较活化前有所提高；碱木质素可以作为天然高分子抗氧化剂进行开发.%In this study,laboratory-prepared SO4 2-/ZrO2 catalysts were used for the reduction of alkali lignin by hydrogen in order to increase alkali lignin activity,and the active functional groups of alkali lignin were analyzed by chemical method,the antioxidation abilities of alkali lignin was evaluated on DPPH radicals scavenging,su-peroxide anion radicals scavenging and reducing power.Results showed that the contents of total hydroxyl and phenolic hydroxyl of alkali lignin after reaction were 9.39% and 3.32%,with an increase of 55.98% and 15.28%respectively compared with the original alkali lignin,both alkali lignin and its reduced products had strong radi-cal scavenging activity against DPPH at a concentration ranging from 0.005 to 0.160 mg/mL in reaction system, the maximum DPPH free radical scavenging rates of activated alkali lignin were 80.91%,with an increase of 4.61% compared with the original alkali lignin,alkali lignin had low radical scavenging activity against superox-ide anion at a concentration ranging from 0.0025 to 0.080 mg/mL in reaction system,the reducing power of al-kali lignin after reaction was enhanced at a concentration ranging from 0.002 to 0.060 mg/mL in reaction sys-tem.Alkali lignin could be used as natural antioxidant.