【作者】 贾艳迪；

【导师】 周学飞；

【作者基本信息】 昆明理工大学 ， 制浆造纸工程， 2008， 硕士

【摘要】 我国拥有丰富的竹子资源,因地制宜的大力发展竹浆产业化,是解决我国原料供需矛盾的有效途径。传统的纸浆含氯漂白方式给环境带来了严重的污染问题,有针对性地研究开发环境友好的竹浆漂白新技术,有利于推进竹浆产业化,对实现我国造纸工业的可持续发展具有重大的意义。为了发展新型无（少）污染漂白技术,越来越多的研究者试图用微生物、微生物酶和仿酶的方法来解决纸浆漂白过程中的污染问题,从而开发出环境友好的新型的纸浆漂白技术。仿酶催化不仅兼有酶催化与化学催化两者的优点,而且是实现绿色化学的直接而有效的途径。本论文采用实验室自行合成的Co-salen配合物,与吡啶、NaOH、H₂O₂、O₂组成仿酶系统,对竹浆进行催化全无氯漂白。研究了Co-salen型仿酶系统催化漂白竹浆适宜的处理方式、催化漂白效果的各种影响因素及合理的工艺条件等。并将最优工艺条件下所得的终漂纸浆白度和粘度、终漂纸浆成纸强度、废水污染程度、后续漂剂用量等指标与空白样相比较,正确评价Co-salen仿酶预处理的优缺点。研究结果表明,竹浆Co-salen仿酶处理方式以单独预处理为宜,较适宜的预处理条件为条件为Co-salen用量0.03%,吡啶与Co-salen摩尔比1:1,NaOH用量3%,H₂O₂用量1.5%,氧压0.2MPa,浆浓5%,温度90℃,时间5h;竹浆经由OCoEpPaP流程漂白后的白度为90.5%SBD,比空白样增加了5.3%SBD,粘度为620 mL·g^-1,比空白样降低99 mL·g^-1;Co-salen仿酶预处理能在一定程度上提高TCF终漂纸浆物理性能,降低漂白废液污染负荷,并使后续过氧乙酸漂段和过氧化氢漂段漂剂用量减少40%以上。在竹浆Co-salen仿酶清洁漂白工艺的研究基础上,重点研究竹浆Co-salen仿酶脱木质素和漂白机理,即竹浆在Co-salen仿酶催化漂白中木质素结构变化、木质素降解产物形成、木质素降解途径等。利用红外光谱（FTIR）、核磁共振波谱(¹H-NMR、¹³C-NMR、³¹P-NMR、¹H-¹³C 2D-HMQC NMR)、凝胶渗透色谱（GPC）、元素分析、维伯克（Vieb（?）ck）法测甲氧基含量,气相色谱—质谱联用（GC-MS）等测试手段对仿酶处理前后的竹浆残余木素结构的变化和降解产物的类型进行分析,从而探讨竹浆木素在Co-salen仿酶催化漂白中的降解机理。研究结果表明,Co-salen仿酶处理使竹浆残余木素进一步氧化降解,降解的主要方式有脱甲基作用、醌型结构的产生和开环、烷基—芳基醚键的开裂、侧链碳—碳连接的氧化断裂等。相应的,对羟基苯基结构单元增加,愈创木基、紫丁香基结构单元减少;甲氧基含量降低;部分羟基被氧化为羰基,酚羟基、脂肪族羟基的含量均有减少,而羰基含量增加;木素的β-O-4、β-5、β-β、5-5＇等多种连接结构都发生了断裂,含量降低。从降解产物看,含羰基的化合物居多,其中以苯甲醛类化合物为主,这是Co-salen仿酶配合物选择性催化氧化的结果。一些醌式结构、共轭羰基和酚类的脱除,也使纸浆因发色基团减少而白度提高。研究竹浆Co-salen仿酶催化漂白的适宜工艺、建立Co-salen仿酶脱木素和漂白机理,合理解释Co-salen仿酶预处理在竹浆高效无污染漂白新流程中所起作用的原因和机制,为Co-salen仿酶清洁漂白技术的进一步研究、开发和应用提供较好的理论指导,为我国特别是云南省林浆纸一体化规划中的优势竹种资源在清洁漂白生产中的应用提供新的途径和理论基础。更多还原

【Abstract】 There are abundant bamboo resources in China.Developing the bamboo pulp industrialization according with the local conditions,what is an available way to solve the shortage of fiber material for papermaking.Due to conventional bleaching technology with chlorine containing agents bring severe pollution on environment,especially bleaching effluent,it is necessary to look for a new environment friendly bleaching technology for bamboo pulp,and it is beneficial to promote bamboo pulp industrialization. Furthermore,it is significant to the sustainable development of Chinese papermaking industry.For the requirement of developing low impact bleaching technology,many researchers try to use microorganisms,their enzymes and biomimetic system in pulp bleaching process to reduce the pollution.Biomimetic catalyst has characteristics of both enzymatic catalyst and chemical catalyst.Therefore,it is an efficient approach of green chemistry.In this paper,Bamboo pulp TCF bleaching with Co-salen biomimetic systems,which was composed by Co-salen complexes,pyridine,NaOH,H₂O₂ and O₂ was studied.The technology research mainly included the condign way of Co-salen biomimetic catalytic bleaching,catalytic effects of various factors and reasonable conditions.The advantages and disadvantages of Co-salen biomimetic systems were evaluated by the comparison of blank sample,the brightness,viscosity,physical properties of resultant bleached pulp, wastewater pollution and bleach dosage were included.The results showed that it was advisable for independent biomimetic pretreatment,and the optimum conditions were as follows:Co-salen 0.03%,molar ratio of Co（salen）:pyridine =1:1,NaOH 3%,H₂O₂ 1.5%, oxygen pressure 0.2MPa,pulp consistency 5%,temperature 90℃,time 5h.The brightness of resultant bleached pulp was 90.5%SBD,and its viscosity was 620 mL·g^-1through the bleaching sequence of OCoEpPaP.After biomimetic pretreatment,the physical properties of the resultant bleached pulp were impoved and the pollution load of the bleaching wastewater was reduced.The peracetic acid and hydrogen peroxide dosage were saved more than 40%through the pretreatment.On the basis of the studies about optimum technology conditions,the present studies focused on the mechanism of the delignification and bleaching in bamboo pulp biomimetic bleaching with Co-salen complexes.The mechanism research mainly included the changes of lignin structure,the formation of lignin degradation products,the pathway of lignin degradation,and so on.Mechanism of delignification during the process of biomimetic bleaching were studied by the methods of FTIR,NMR(¹H-NMR,¹³C-NMR, ³¹P-NMR,¹H-¹³C 2D-HMQC NMR),GPC,and so on.The results showed that the main ways of lignin degradation during the Co-salen biomimetic bleaching were involved with demethylation,quinone-type structure formation and opening,alkyl - aryl ether bond cleavage and carbon-carbon linkage breakage in side-chain.Accordingly,p-hydroxyphenyl was increased,and the guaiacyl and syringyl was reduced.The content of the methoxy was reduced.Some hydroxyl were oxidized to carbonyl.The content of aliphatic hydroxyl and phenolic hydroxyl group were both reduced,and carbonyl content was increased.β-O-4,β-5,β-β,5-5’ and other linkages of lignin were ruptured.The degraded products contained more carbonyl compounds,especially benzaldehyde-type compounds as result of catalytic oxidation of Co-salen biomimetic system.The brightness of pulp was improved because of the removal of some quinone-type structures,conjugated carbonyl and phenolic compounds.Thus the technology of bamboo pulp bleaching catalyzed by Co-salen complexes,and the mechanism of the delignification in the bamboo pulp biomimetic bleaching process were founded.The function of Co-salen biomimetic pretreatment in the bamboo pulp bleaching with efficient pollution-free short sequence were explained reasonably.The studies could provide better theoretical guidance and foundation for further research, development and application of the clean bleaching technology with salen complexes,and found a new pathway and theory of clean bleaching production for the bamboo resources, which was advantaged in the forest-pulp-paper integration planning of our country, especially Yunnan province.更多还原