本文選題：電解 + 木質(zhì)素　； 參考：《廣西大學(xué)》2017年碩士論文

【摘要】：木質(zhì)素廣泛存在于自然界中是植物的三大組份之一。如何有效利用木質(zhì)素是生物質(zhì)材料和生物質(zhì)能源這兩個領(lǐng)域的研究熱點。本文從制漿黑液中提取純化木質(zhì)素,繼而利用電場誘導(dǎo)水溶液產(chǎn)生自由基的方法來改性木質(zhì)素;其原理是通過氫自由基與木質(zhì)素的自由基反應(yīng),和陰極反應(yīng)來實現(xiàn)加氫效果;通過電場誘導(dǎo)和電極反應(yīng)產(chǎn)生的羥基自由基破壞木質(zhì)素分子之間的醚鍵等連接鍵,也可以與木質(zhì)素發(fā)生氧化反應(yīng),使部分基團羧基化,從而達到改性的目的。研究結(jié)果如下:(1)經(jīng)過EA分析,電解改性木質(zhì)素的C、H元素含量增加,O元素含量減少,且XPS分析表明,木質(zhì)素在電解改性后O/C值由28.22%變?yōu)?7.63%,碳原子的電子結(jié)合能(eV)的峰位值從282.100 eV下降到281.9.00 eV(校正前),說明木質(zhì)素電解后元素組成和比例發(fā)生了變化。(2)GPC分析表明,經(jīng)過電解改性的木質(zhì)素平均分子量呈現(xiàn)下降的趨勢;利用STA得到電解改性木質(zhì)素前后的TG和DSC曲線,發(fā)現(xiàn)電解改性的木質(zhì)素玻璃態(tài)轉(zhuǎn)化溫度下降;NMR圖譜顯示電解改性木質(zhì)素的β-0-4、甲氧基等結(jié)構(gòu)醚鍵被大規(guī)模破壞,羧基等基團含量卻增加,說明木質(zhì)素電解后分子結(jié)構(gòu)發(fā)生了變化。(3)通過GC-MS分析電解改性木質(zhì)素產(chǎn)物中存在2,4-已二烯醇、十二烷、十三烷、正十五烷、2,6-二甲氧基苯酚、3-甲氧基-4-羥基苯甲醛4-羥基-3-甲氧基苯乙酮、丁香醛、3',5'-二甲氧基-4'-羥基苯乙酮、鄰苯二甲酸正丁異辛酯、鄰苯二甲酸單(2-乙基己基)酯等物質(zhì),通過氧彈熱值儀測試電解前后的木質(zhì)素的熱值分別為20348 kJ·kg-1和20498 kJ·kg-1,說明木質(zhì)素電解后組份物質(zhì)發(fā)生了變化。(4)通過單因素實驗,得到了電解法對木質(zhì)素改性的最佳條件是:反應(yīng)時間96 h,反應(yīng)溫度80℃,反應(yīng)電壓8 V,底物濃度2.5 g·L-1。
[Abstract]:Lignin is one of the three major components of plants in nature. How to utilize lignin effectively is the research hotspot in biomass material and biomass energy. In this paper, lignin was extracted and purified from the black liquor of pulping, and then the lignin was modified by the method of producing free radical in aqueous solution induced by electric field, which is based on the reaction of free radical of hydrogen with lignin and cathodic reaction to realize the hydrogenation effect. The hydroxyl radical produced by electric field induction and electrode reaction can destroy the bond such as the ether bond between lignin molecules, and it can also oxidize lignin and make some groups carboxylated, thus achieving the purpose of modification. The results are as follows: (1) after EA analysis, the content of Con H in electrolytic modified lignin increased and decreased, and XPS analysis showed that, After electrolysis modification, the O / C value of lignin changed from 28.22% to 27.63%, and the peak value of electron binding energy of carbon atom decreased from 282.100 EV to 281.9.00 EV. The TG and DSC curves before and after electrolytic modification of lignin were obtained by STA. It was found that the glass state transition temperature of electrolytic modified lignin was decreased by NMR, and the 尾 -0-4 of electrolytic modified lignin was found to be 尾 -0-4. The structure ether bond such as methoxy was destroyed on a large scale, but the content of carboxyl group was increased. The results showed that the molecular structure of lignin was changed after electrolysis. (3) by GC-MS analysis, there were 2k4- hexadienol, dodecane, tridecane in the products of lignin modified by electrolysis. N-pentadecane 6-dimethoxy phenol 3-methoxy-4-hydroxybenzaldehyde 4-hydroxy-3-methoxy acetophenone, eugenaldehyde 3- (5) -dimethoxy -4- (4) -hydroxyacetophenone, n-butyl phthalate (n-butyl) -isooctyl phthalate, mono-2-ethylhexyl phthalate, etc. The calorific values of lignin measured by oxygen bomb calorimeter were 20348 kJ kg-1 and 20498 kJ kg-1, respectively, which indicated that the composition of lignin electrolysis changed. The optimum conditions for the modification of lignin by electrolysis were obtained as follows: reaction time 96 h, reaction temperature 80 鈩，

本文編號：2002542