【作者】 李芳；

【导师】 丛津生；

【作者基本信息】 河北工业大学 ， 化学工艺， 2002， 硕士

【摘要】 1，5-萘二异氰酸酯（简称NDI）为合成高级聚氨酯的原料，潜在的市场需求量大。目前NDI的合成采用光气法，光气剧毒，污染严重。而利用“绿色化学品”——碳酸二甲酯（简称DMC）代替光气两步合成NDI具有反应条件温和，催化剂便宜，仅副产甲醇等优点，若与甲醇和一氧化碳、氧气气相氧化羰基化合成DMC的工艺相结合，可作到化工过程的“零排放”，实现原子经济。本文对该合成路线的第一步反应，即用DMC和1，5-二氨基萘（简称NDA）合成1，5-萘二氨基甲酸甲酯（简称NDC）的反应进行了研究。 制备了NDC的纯品，经MS、NMR、IR和元素分析予以确定，并制备出反应中的部分副产物，实现了对该反应的主产物和部分副产物的定性分析。产物采用高效液相色谱进行分析，条件为：流动相：V（甲醇）：V（水）=60：40；色谱柱：Kromasil^TMC-18，φ4.6mm×150mm，5μm；流速：0.4ml／min；紫外检测波长：254nm。以外标法对产物进行定量分析，确定了其外标曲线，并经实验验证是可靠的。 鉴于对该反应知之甚少，对该反应体系进行了热力学分析。用UNIFAC及相关方法估算了反应体系所需的热力学数据。计算结果表明：主产物自聚是主反应的主要竞争反应，并且主反应在热力学上处于劣势。为提高NDC的收率，应选用对NDC合成具有良好选择性的催化剂，并且在实际操作中，应控制适宜的反应温度；同时，还应创造条件使主反应的平衡向生成NDC的方向移动，其中及时移出反应中生成的甲醇及选择可促使NDC在反应中析出的溶剂是较为可行的方法。 筛选适宜的溶剂和催化剂是保证该反应良好进行的关键因素，首先筛选了溶剂，选取那些对NDA有较好的溶解性而对NDC溶解度甚小而且化学稳定的物质，所筛选的溶剂对NDC溶解性排序为：异丁醇＜异丙醇＜甲醇＜甲醇＜丙酮＜碳酸二甲酯＜乙睛＜四氢呋喃＜环丁砜＜二氧六环＜毗啶＜二甲基亚砜＜二甲基甲酰胺。所筛选的催化剂活性排序为：氧化锌、碱式碳酸锌、钛酸四丁酯＜氯化锌＜氧化铅＜乙酸钴＜环烷酸锌＜乙酸锌＜硬脂酸锌。针对实验中锌盐具有良好的活性，分别优化了以乙酸锌、硬脂酸锌、 河北工业大学硕士学位论文一丙酸锌和三甲基乙酸锌为催化剂的反应条件。对反应后的催化剂进行表征，发现乙酸锌和硬脂酸锌失活的原因是它们在反应中转变为对该反应没有催化活性的氧化锌。 在实验中发现，锌的有机酸盐对该反应具有良好催化活性。考察了几种有机酸锌催化剂，比活性顺序为：苯甲酸锌＜乙酸锌＜三甲基乙酸锌＜戊酸锌＜辛酸锌＜硬脂酸锌。同时，发现Zn印。的结合能和有机酸锌相应衍生酸的PKa值是影响有机酸锌催化活性的因素之一。实验数据表明，当 Zn印。的结合能小于等于 1022．seV，或有机酸锌对应衍生酸的 pKa值大于 4刁 9时，其具有催化活性。更多还原

【Abstract】 1,5-Naphthalene diisocyanate (NDI) is taken as the excellent raw material for synthesizing advanced polyurethane. Recently, the industrial production of NDI uses phosgene as raw material. This process is harmful to environment and difficult to control. Dimethyl carbonate(DMC), which is called "Green Chemicals ", can substitute phosgene for the synthesis of NDI. This route has distinct advantages, such as moderate conditions, inexpensive catalyst and unique by-product ?methanol. If it is combined with the synthesis of DMC by gas-phase oxidative carbonylation of methanol, the high atom economics process can be acquired. The key step of this method is the synthesis of 1,5-naphthalene dicarbamate (NDC) from DMC and 1,5-naphthalene diamine (NDA). So the emphasis is put on the synthesis of NDC in this thesis.The purified product of NDC was prepared and verified by IRs MS> NMR et al. The qualitative determination of main-product and partial by-product was realized. And a set of suitable and effective HPLC analysis condition was set up. As follows: chromatographic column: Kromasil?C-18, 04.6mmX 150mm, Sum; mobile phase: V(CH3OH):V(H2O)=60:40; flow speed: 0.4ml/min; wavelength of ultraviolet detector:254nm. The quantitative analysis of NDC was carried out by external standard method. The result was reliable after verification.Since the reaction was new to us , the thermodynamics analysis of the reaction system was done. The basic thermodynamic data was estimated by the method of UNIFAC and other methods. The result showed that compared with the secondary-reaction of main-product’ s self-polymerization, main-reaction was in disadvantage. In order to improve the yield of NDC, it isnecessary to screen the catalysts having better selectivity , to control the proper temperature in experiment and to transform the equilibrium of the main-reaction to the production of NDC. The effective method of transforming the equilibrium of the main-reaction was distillation methanol timely and using the solvent which had the lower dissolubility of NDC .It was important to the reaction that the proper solvents and the catalysts were screened. The sequencing of the dissolubility of NDC was as follows: isobutanoK isopropanoK methanoK ethanol < acetone < DMC < acetonitrile < THF < sulfolane < dioxane < pyridine < DMSO < DMF. The sequencing of activity of catalysts was as follows: zinc oxide,basic zinc carbonate,tetrabutyl titanate < zinc chloride < lead oxide < cobalt acetate < zinc naphthenate < zinc acetate < zinc stearate.For zinc salts having better activity to the reaction, the reaction condition was optimized using zinc acetate, zinc stearate, zinc propionate and zinc trimethylacetate as catalyst. After reaction zinc acetate and zinc stearate were characterized by XRD. ZnO was founded to be produced, which had no activity to NDC synthesis. This was the reason of the deactivation of zinc acetate and zinc stearate.Zinc salts of organic acid had the better activity to NDC synthesis. The activity of zinc salts of organic acid has been compared. The sequence was as follows: zinc benzoate <zinc acetate<zinc trimethylacetate<zinc pentanoate<zinc octoate<zinc stearate. We found that the binding energy of Zn2p3 and pKa of the derived organic-acid of the catalyst had some effect on the activity. Based on the data of experiment, when binding energy of Zn2p3 was greater than or equal to 1022.5eV,or pKa of the derived organic acid of the catalyst was greater than 4.19, the zinc salts of organic acid had activity to NDC synthesis.更多还原