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1、河北工业大学 硕士学位论文 负载型N,N,N,N-四甲基-N”-丙基胍及其离子液体的合成 与表征 姓名:郑金颖 申请学位级别:硕士 专业:化学工艺 指导教师:耿艳楼 20080301 河北工业大学硕士学位论文 i 负载型负载型负载型负载型 N,N,N,N-四甲基四甲基四甲基四甲基-N-丙基胍及其离子液体的合成与表征丙基胍及其离子液体的合成与表征丙基胍及其离子液体的合成与表征丙基胍及其离子液体的合成与表征 摘摘摘摘 要要要要 采用不同方法分别制备了氨丙基功能化二氧化硅(APS)、二氧化硅负载 N,N,N,N-四甲 基-N-丙基胍(STMPG)及其离子液体,利用 FTIR、BET、元素分析、13C
2、 MAS NMR 和 TG 等技术对所制备样品进行了结构表征,并对制备方法进行了对比分析。 分别采用以二甲苯为溶剂的液相法和溶胶-凝胶法制备了 APS。在液相法的制备过程 中,为了使二氧化硅表面有更多的稳定的羟基基团与氨丙基三乙氧基硅烷(APTES)发生反 应,采用四种方法对二氧化硅表面进行了预处理。结果表明:微波辐射效果最好,使二氧 化硅表面羟基数由 1.08(个/nm2)增加到 1.29(个/nm2)。 采用液相法制备的 APS 中氨丙基负载 量为 8.59wt%,活性位(氨丙基)浓度为 1.49mmol/g,APS 的 pKa 值为 9.3-15.0。对溶胶-凝 胶法制备 APS 过程中
3、各影响因素进行了考察,得出制备 APS 的最佳条件为:溶剂为乙醇、 硅醇摩尔比为 1:6、 硅水摩尔比为 1:7、 APTES 与正硅酸乙酯质量比为 0.07、 反应温度 35、 pH=9、采用二氯甲烷抽提 4h、干燥时间 6h、干燥温度 100、真空干燥、陈化时间为 72h。 在此条件下制备的 APS 中氨丙基负载量为 6.88wt%,活性位(氨丙基)浓度为 1.19mmol/g, APS 的 pKa 值为 4.8,均低于液相法制备的 APS。 分别采用三种方法制备了 STMPG。一种方法以 APS 和四甲基脲(TMU)为原料,在三 氯氧磷的作用下生成 STMPG。 其他两种方法是以氯丙基三
4、乙氧基硅烷(CPTES)和四甲基胍 (TMG)为原料制备 STMPG。利用 FTIR、Uv-vis、BET、13C MAS NMR、元素分析、TG 等 方法对所制备样品的结构进行了表征,并对三种方法进行了对比分析。结果表明,所制备 STMPG 的最大负载量为 8.33wt%, 活性位 N,N,N,N-四甲基-N-丙基胍(TMPG)浓度为 0.53 mmol/g,STMPG 的 pKa 值为 6.87.2。 在制备 STMPG 的基础上,采用两种方法制备了阴离子分别为 CF3SO3 , PF 6 和 CH3COO 的 STMPG 离子液体,利用 FTIR、BET 和元素分析等方法对上述负载型离子
5、 液体及其前体进行了结构表征,并测定了负载型离子液体表面酸碱强度。结果表明, STMPGCH3COO 的 pKa 值最大,为 4.86.8。 关键词关键词关键词关键词:二氧化硅;氨丙基功能化二氧化硅;氯丙基功能化二氧化硅;二氧化硅负载 N,N,N,N-四甲基-N-丙基胍;二氧化硅负载 N,N,N,N-四甲基-N-丙基胍盐离子液体 负载型 N,N,N,N-四甲基-N-丙基胍及其离子液体的合成与表征 ii SYNTHESIS AND CHARACTERIZATION OF SILICA-SUPPORTED N,N,N,N- TETRAMETHYL -N- PROPYL GUANIDINE AND
6、ITS IONIC LIQUID ABSTRACT Aminopropylated silica (APS), silica-supported N,N,N,N-tetramethyl-N-propyl guanidine (STMPG) and STMPG ionic liquids with different anions including PF6-, CH3COO- and CF3SO3- were prepared. The structures of APS, STMPG and its ionic liquids were characterized by means of F
7、TIR, BET, 13C MAS NMR, TG and elemental analysis. The different preparation methods were compared. APS was synthesized separately by liquid-phase method and sol-gel method, and was characterized by means of FTIR, BET, elemental analysis and TG analysis. The surface of silica was pretreated via four
8、kinds of methods to increase the quantity of hydroxyl group content and the result showed that microwave-activating was the most effective method: the number of hydroxyl group on the silica surface increased from 1.08 /nm2 to 1.29 /nm2. The loading of aminopropyl in the APS synthesized via liquid-ph
9、ase method was 8.59wt%, the functional group concentration of aminopropyl was 1.49mmol/g and the pKa of APS was 9.3-15.0. The effects of some parameters on the sol-gel process were investigated and the optimal conditions were as follows: tetraethylorthosilicate(TEOS)/H2O=1/7 (molar ratio), TEOS/EtOH
10、(ethanol)=1/6(molar ratio), aminopropyltriethoxysilane(APTES)/ TEOS=0.07 (mass ratio), T=35, pH=9, aging time 72h. APS was extracted with dichloromethane for 4 h and dried at 393 K in vacuum for 6h. The loading and functional group concentration of aminopropyl in the APS synthesized via sol-gel meth
11、od was 6.88wt% and 1.19mmol/g, respectively. The pKa of APS was 4.8, lower than that of APS synthesized via liquid-phase method. STMPG was prepared through three different methods. One synthetic method started with APS and tetramethylurea(TMU) in the presence of phosphorus oxy chloride (POCl3). The
12、other two methods started with chloropropyltriethoxysilane (CPTES) and N,N,N,N-tetramethy lguanidine (TMG). The structure of STMPG was characterized by means of FTIR, Uv-vis, BET, 13C MAS NMR, elemental analysis and TG analysis. The results showed that the maximum loading of N,N,N,N-tetramethyl -N-p
13、ropyl guanidine (TMPG) was 8.33 wt%, the functional 河北工业大学硕士学位论文 iii group concentration of TMPG was 0.53 mmol/g and the pKa of STMPG was 6.8 7.2. STMPG ionic liquids with different anions including PF6-, CH3COO- and CF3SO3- were prepared through different methods on the basis of STMPG. The structur
14、es of the ionic liquids and their precursors were determined by means of FTIR, BET and elemental analysis. The acidity and basicity of the ionic liquids were determined and the results showed that the pKa of STMPGCH3COO was the highest, about 4.86.8. KEYWORDS: silica; aminopropylated silica; chlorop
15、ropylated silica; SiO2-supported N,N,N,N-tetramethyl-N-propyl guanidine; SiO2-supported N,N,N,N-tetramethyl-N-propyl guanidinium ionic liquid 天- 2 字位论又_ 暇秋仪用f 3 芝t v 削仇明 本人完全了解河北工业大学关于l 发集、保存、使用学位论文的规定。同意如 下各项内容:按照学校要求提交学位论文的印刷本和电子版本;学校有权保存学 位论文的印刷本和电子版,并采用影印、缩印、扫描、数字化或其它手段保存论 文;学校有权提供目录检索以及提供本学位论文全
16、文或者部分的阅览服务:学校 有权按有关规定向国家有关部门或者机构送交论文的复印件和电子版;在不以赢 利为目的的前提下,学校可以适当复制论文的部分或全部内容用于学术活动。 ( 保密的学位论文在解密后适用本授权说明) l k 厶编 河北工业大学硕士学位论文 1 第一章第一章第一章第一章 绪论绪论绪论绪论 1-1 前言前言前言前言 离子液体是一类可取代传统有机溶剂和液体酸碱的环境友好的新型反应介质, 但其应用过程中仍存 在使用量较大和潜在的环境污染问题1。离子液体的制备成本较高,因此,在保证应用效果的前提下, 减少离子液体的用量显得尤为重要。离子液体固载化无疑是达到此目标的有效途径。 1-2 氨丙基功能化的二氧化