蔗渣氧碱木质素基环氧树脂的合成研究

【作者】 王海洋；

【导师】 陈克利；

【作者基本信息】 昆明理工大学 ， 应用化学， 2004， 硕士

【摘要】 木质素是植物通过光合作用合成的储量丰富的、可降解的天然酚类高分子化合物，是化工原料重要的潜在资源，能在高分子材料中获得大量应用。通过对蔗渣氧碱木质素合成环氧树脂的研究，不仅有利于帮助制浆造纸工业废水对环境污染的消除，还可为木质素高附加值的利用开辟新的途径。 本论文的主要内容是蔗渣氧碱木质素的分离提取以及以蔗渣氧碱木质素和氢解麦草木质素作为原料来合成木质素基环氧树脂的研究。论文主体内容分为三部分： (一) 蔗渣原料的化学成分分析及氧脱蔗渣木质素(OLG)的分离提取。通过实验，分析了蔗渣原料的化学成分，所得的数据见表2—1原料试样化学成分分析结果。研究采用本论文介绍了一种新型的脱木质素的制浆方法——氧碱制浆法。采用单因素三水平的试验方法，发现在氧压为0.6 MPa，温度为130℃，用碱量为14％时，测得浆的卡伯值为18.9，已经达到氧脱木质素的基本目的。因此，在此反应条件下进行了蔗渣的氧碱制浆反应，对制浆废液中的溶解木质素用酸析法进行沉淀与分离，获取蔗渣的氧碱木质素。 (二) 木质素的红外光谱与核磁共振谱图分折。对氧脱蔗渣木质素(OLG)和氢解麦草氧碱木质素(HLG)进行了红外光谱(FTIR)和核磁共振氢谱(~1H-NMR)的分析比较，发现氢解麦草氧碱木质素的总羟基比蔗渣氧碱木质素的总羟基含量要大，氢解麦草氧碱木质素的醇羟基和酚羟基也相应的提高。由于醇羟基和酚羟基是反应的活性基团，有利于提高木质素的反应活性，从而更有利于包括环氧树脂在内的高分子材料的合成与利用。 (三) 木质素基环氧树脂的合成工艺探索及分析。本论文采用的合成环氧树脂的方法是先对木质素进行改性，然后再与环氧氯丙烷合成环氧树脂。 a：苯酚改性木质素基环氧树脂的合成。改性反应条件是：原料配比，木质素：苯酚=4：6(木质素5 g，苯酚7.5 g)、反应时间为3 h、反应温度95℃、催化剂用量为2 mol／L的硫酸20 ml。环氧树脂合成反应条件：催化剂，20％氢氧化钠溶液50 ml、环氧氯丙烷20 ml、反应温度80℃；保温时间3 h。利用红外光谱和核磁共振氢谱分析方法初步探讨了其合成机理，见反应方程式1。 b：双酚A改性木质素基环氧树脂的合成。改性反应条件是：原料配比，木质素：双酚A=5：5(木质素5 g，双酚A 5 g)；反应时间为1.5 h；反应温度90℃；催化剂用量为20％的氢氧化钠10 ml。环氧树脂合成反应条件：环氧氯丙烷10 ml：催化剂，20％(质量分数)氢氧化钠20 ml；反应温度75℃：保温时间1.5昆明理工大学硕士研究生论文h。利用红外光谱和核磁共振氢谱分析方法初步探讨了其合成机理，见反应方程式2。 c:双酚A改性氢解氧碱木质素基环氧树脂的合成。合成方法与双酚A改性木质素基环氧树脂的合成方法一样。对其合成机理的探索也如反应方程式2。 通过研究证明，蔗渣的氧碱木质素完全适合于进行高分子材料的合成。用苯酚以及用双酚A对蔗渣的氧碱木质素进行改性处理后，所合成出来的环氧树脂其性能指标达到或超过市售环氧树脂的性能指标，氧碱木质素对环氧树脂合成基质—苯酚或双酚A的取代率达到了40%。对氧碱木质素进行氢解后，经基比例明显提高，更有利于提高合成高分子材料的反应活性。更多还原

【Abstract】 The lignin rich in plant is a natural degradable hydroxybenzene macroraolecule. It can be used in the synthesis of raacroraolecule material, in order to promote the high-valued utilization of lignin in industry. By the means of the research of synthesis of lignin based epoxy resins, we can not only help to reduce the natural pollution from pulping industry, but also find a new way of utilizing lignin .This paper is to discuss the isolation and extraction of bagasse lignin from alkali-oxygen pulping waste liquor and the method of synthesis of lignin based epoxy resins. Meanwhile the lignin based epoxy resins are analyzed by means of FTIR and 1H-NMR .The experiments were constituted of three main parts as followed.1. The isolation and extraction of bagasse alkali-oxygen lignin (OLG). The content of bagasse material were analyzed and the data of result- are shown in table 2-1. The new clean pulping method, alkali-oxygen pulping, is used for the pulping of bagasse. By the method of single-factor-three-level, the optimal conditions are the initial Oz pressure 0. 6 MPa, the temperature 130"C and the amount of NaOH 14% (by o. d. soaked material), when the Kappa number of the pulp is 18.9. The lignin is isolated from the pulping waste liquor by the means of acid-precipitation and extracted by centrifuge.2. FTIR and 1H-NMR analyses of lignin. The OLG and the hydrogenolysis wheat alkali-oxygen lignin (HLG) are compared. By the means of FTIR and 1H-NMR, it is cleared that the total hydroxyl of HLG is more than that of OLG. HLG has more Al-OH and Ph-OH too, which can increase reaction activity of lignin (for example , the synthesis of epoxy resins ).3. The synthetical method and analyses of lignin based epoxy resins. Prior to the synthesis of lignin based epoxy resin, lignin is to be modified, then reacted with epichlorohydrin.a. The synthesis of lignin based epoxy resins from phenol. The conditions of lignin modification are the ratio of lignin and phenol 4:6 (lignin, 5 g: phenol 7.5 g), the time of reaction 3 hours, temperature 95C, catalyst 20 ml of 2mol/L H2S04. The conditions of synthesis of epoxy resin are the catalyst 50ml NaOH (20%, by weigh); 20 ml epichlorohydrin, the temperature 80 C, reaction time 3 hours. The synthesis mechanism is also discussed by the means of FTIR and ’H-NMR, and shown in the chemical equation 1.b. The synthesis of lignin based epoxy resin from 2, 2-di(4-hydroxy phenyl)propane(ab. DA). The modification conditions are the ratio of lignin and DA is 5:5 (lignin 5 g: DA 5 g); the reaction time 1.5 hours; the temperature 90 C, the catalyst 10ml NaOH (20%, by weigh). The conditions of synthesis of epoxy resin are epichlorohydrin 10 ml, the catalyst 20 ml NaOH (20%, by weigh); the temperature 75癈, the reaction time 1.5 hours. The synthesis mechanism is discussed by the means of FTIR and ’H-NMR, and shown in the chemical equation 2.c: The synthesis of hydrogenolysis lignin based epoxy resins from DA. The method is the same as that of the synthesis of lignin based epoxy resins from DA. The synthesis mechanism is discussed too and is shown in the chemical equation 2.According to the results, we can know that the bagasse alkali-oxygen lignin is well fit for the synthesis of macromolecular material. The bagasse alkali-oxygen lignin is modified by phenol or DA and then synthesized into lignin based epoxy resins whose characteracations are equal to or even beyond those from saled epoxy resins. OLG or HLG can replace about 40% phenol or DA or more. After hydrogenolysis of wheat alkali-oxygen lignin, the lignin has more hydroxyl, which can easily promote the reaction activity of synthesis of macromolecular material.更多还原