• 《若干精细化学品的新型绿色合成工艺研究》
  • 作者:肖建军著
  • 单位:南昌大学
  • 论文名称 若干精细化学品的新型绿色合成工艺研究
    作者 肖建军著
    学科 工业催化
    学位授予单位 南昌大学
    导师 邱祖民,杨维冉指导
    出版年份 2018
    中文摘要 随着化石资源、能源的大肆消耗,生态环境迅速恶化,人类正面临有史以来最严重的资源和环境危机,绿色化学成为人类社会可持续发展的必然选择。在精细化工行业大力推行绿色化学具有重要意义。本文从“原料绿色化”、“原子经济性”、“无毒害溶剂体系”等角度出发制备了几种医药和涂料领域的重要精细化学品。 一方面,首先以廉价的H₃PO₃为助还原剂,优化了H₃PO₃/HI两相体系催化转化果糖制备5-甲基糠醛的工艺参数;在较优条件下,5-甲基糠醛产率可达到79.6%;考察了水相体系的循环利用,循环使用3次,5-甲基糠醛无明显降低,循环使用5次,5-甲基糠醛产率降至66.4%;反应体系对葡萄糖、菊粉、蔗糖、纤维素等生物质基糖类底物也有较好的适用性。采用聚乙烯吡咯烷酮配位稳定还原钯胶体涂覆活性炭然后再炭化的方法制备了钯炭催化剂,其中钯的负载量为4.86%,钯粒子尺寸小且均匀(3~5nm),对于5-甲基糠醛与苯胺直接还原胺化制取N-(5-甲基糠基)苯胺的反应表现出很高的催化活性,可循环回收至少4次;常压条件下,所述直接还原胺化反应在表观上由脱水缩合和催化加氢两步连串进行;在较优的加压条件下,N-(5-甲基糠基)苯胺的产率可达到99%以上;研究发现,反应体系对苯环上不同空间位阻和电子效应取代基取代的苯胺衍生物大多具有较好的普适性。取果糖“一锅”转化制备5-甲基糠醛反应的上层有机相,经简单纯化处理后,以所得含5-甲基糠醛的甲苯溶液与苯胺在加压条件下进行还原胺化反应,最终实现从“原料绿色化”的生物质糖类两步转化合成N-(5-甲基糠基)苯胺。论文还探讨了H₃PO₃/HI水相-甲苯体系协同作用下果糖转化制备5-甲基糠醛的反应路径及钯炭催化5-甲基糠醛直接还原胺化的反应机理。 另一方面,尝试在“无溶剂体系”中,以传统的Speier’s催化剂催化“原子经济性”的硅氢加成反应得到1,1,1,3,5,5,5-七甲基三硅氧烷改性甲基丙烯酸烯丙酯,并将其用于水性自消光苯丙乳液的制备。结果表明,在无溶剂条件下,加入阻聚剂2,6-二叔丁基对甲酚和Speier’s催化剂,以七甲基三硅氧烷硅氢加成改性甲基丙烯酸烯丙酯,制备得到了含C=C键的有机硅功能单体,且在较优条件下,七甲基三硅氧烷与甲基丙烯酸烯丙酯的转化率分别达到88%、92%;在实验条件下,添加七甲基三硅氧烷改性甲基丙烯酸烯丙酯后,涂膜表面光泽度可降低71%,而水接触角提高63%,表现出较好的哑光效果和一定的耐水擦洗性,这与有机硅链段向空气界面迁移并富集的行为有关。 关键词:精细化学品;绿色合成;5-甲基糠醛;N-(5-甲基糠基)苯胺;水性自消光苯丙乳液
    英文摘要 With the reckless consumption of fossil resources and energy, the ecological en-vironment is rapidly deteriorating, and humans are facing the most serious resource and environmental crisis ever. To develop green chemistry is the inevitable choice for human existence and social sustainable development. It is very important and mean-ingful for vigorously promoting green chemistry in the fine-chemical industry. Sever-al important fine chemicals for fields of medicine and coatings were synthesized from the point of view of green chemistry. On the one hand, the process parameters for the preparation of 5-methylfurfural from fructose in solution of H₃PO₃/I⁻ acid aqueous/ toluene were optimized with us-ing cheap H3PO3 as co-reductant. The highest 5-methylfurfural molar yield was 79.6% under better reaction conditions. The recycle of the aqueous phase was inves-tigated. Furthermore, the yields of 5-methylfurfural from bio-based glucose, inulin, sucrose, and cellulose in the reaction system were examined, and got satisfactory re-sults. Activated carbon supported palladium catalyst was prepared through coating activated carbon with colloidal palladium stabilized by polyvinylpyrrolidone before carbonization. The loading of palladium on activated carbon was 4.86%, and the size of Pd particles is small and uniform (3~5 nm). The synthesized catalyst was found to be highly effective to the direct re-ductive amination of 5-methylfurfural with aniline, and catalyst can be reused at least four times without significant loss of catalytic activity. The synthesis of N-(5-methylfurfuryl)aniline was a consecutive reaction including dehydration condensation reaction and catalytic hydrogenation reaction. N-(5-methylfurfuryl)aniline molar yield was over 99% under better pressurized conditions. Besides, the scope of the substrate amines was examined, and most of them showed very good results. The toluene solution of fruc-tose-derived 5-methylfurfural from the top organic layer of the reaction system of fructose to 5-methylfurfural was used as raw material for pressurized reductive amination with aniline after simple purification. Thus, with this two-step approach, renewable N-(5-methylfurfuryl)aniline was produced from fructose. We deduced the plausible reaction pathway for production of 5-methylfurfural from fructose and the collaborative mechanism of solution of H₃PO₃/I⁻ acid aqueous/ toluene. And the reaction mechanism of direct reductive amination of 5-methylfurfural catalyzed by activated carbon supported palladium was also discussed. On the other hand, we provided a solvent-free method to modify allyl methacry-late (AMA) with 1,1,1,3,5,5,5-heptamethyltrisiloxane (MD〓M) through atomic eco-nomic hydrosilylation reaction catalyzed by Speier's catalyst. We also studied the ap-plication of MD〓M modified AMA in waterborne self-matting styrene-acrylic emul-sions. It turned out that MD〓M modified AMA contains unsaturated isopropenyl cat-alyzed synthesized by catalyst and using 2,6-di-tert-butyl-4-methylphenol as polymerization inhibitor without any other solvent. The conversion of MD〓M and AMA reach 88% and 92% respectively under optimized conditions. As for the formulas used in this paper, the surface gloss of emulsion coating film with MD〓M modified AMA comparatively decreased 71% with that without modified AMA and considered as semi-gloss, and the water contact angle of film with MD〓M modified AMA increased 63% compared with blank controller. These results were associated with the structure of the silicone chain segments exposing to the air-film interface. Key Words: fine chemical; green synthesis; 5-methylfurfural; N-(5-methylfurfu-ryl)aniline; waterborne self-matting styrene-acrylic emulsion
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