二氧化碳与己二胺反应合成二氧化碳基聚脲

发布时间：2017-12-28 04:30

本文关键词：二氧化碳与己二胺反应合成二氧化碳基聚脲　出处：《长春工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：二氧化碳的活化与转化是绿色化学领域的一个热点问题。以二氧化碳为碳源合成高附加值化学品具有广阔的应用前景。聚脲是一种新型的聚合物,结构中含有强极性的脲基并且可以形成大量的氢键,具有优异的性能和广泛的应用。但是,聚脲的工业合成过程涉及到剧毒的二异氰酸酯的使用,给环境以及操作人员的安全带来威胁。因此,由二氧化碳作为碳氧资源取代异氰酸酯的合成路线具有重要的科学研究意义和实际应用价值。本论文选择己二胺为反应物,研究了己二胺与二氧化碳直接反应合成聚脲的影响因素,如温度、压力、反应时间等。通过一系列表征手段确定了产物的化学结构、凝聚态结构、热稳定性,并探讨了催化剂和溶剂对反应的影响。为了提高产物分子量,合成具有一定强度的聚脲产品,设计了两段聚合反应过程:(1)合成聚脲齐聚物的预聚合反应;(2)合成聚脲材料的后聚合反应。研究结果表明,己二胺与二氧化碳的反应受温度和压力的影响较大,随着温度或压力的增加,聚脲的产率均呈现增加的趋势,但温度或压力增加到某一程度后,收率出现相应的降低。延长反应时间到一定程度,收率不再增加,这与逆反应的发生和产物的热稳定性有关。催化剂和溶剂的引入可以提高产物的收率。与齐聚物相比,后聚合得到的聚脲结晶程度降低,热稳定性以及耐溶剂性有较大的提高,说明后聚合过程一定程度上解决了副产物水的脱出问题,使反应向分子链增长的方向进行。根据拉伸测试的结果来看,最终产物是脆性材料,具有一定的拉伸强度,断裂伸长率较低。
[Abstract]:The activation and transformation of carbon dioxide is a hot issue in the field of green chemistry. The synthesis of high added value chemicals with carbon dioxide as carbon source has a broad application prospect. Polyurea is a new type of polymer. It contains a strong polar urea group and can form a large number of hydrogen bonds. It has excellent properties and wide application. However, the industrial synthesis of polyurea involves the use of highly toxic diisocyanate, which threatens the safety of the environment and the operators. Therefore, the synthesis route of carbon dioxide as carbon and oxygen resource instead of isocyanate has important scientific research significance and practical application value. This paper choose hexanediamine as reactants, study the influence factors of hexamethylenediamine and carbon dioxide to synthesize polyurea direct reaction, such as temperature, pressure, reaction time etc.. The chemical structure, the condensed structure and the thermal stability of the products were determined by a series of characterization methods, and the effects of the catalyst and solvent on the reaction were also discussed. In order to improve the molecular weight of products and synthesize polyurea products with certain strength, two stage polymerization process was designed: (1) pre polymerization of polyurea oligomers; (2) synthesis of polyurea materials after polymerization. The results show that the influence of hexamethylenediamine and carbon dioxide was affected by temperature and pressure greatly, with the increase of pressure or temperature, the yield of polyurea showed an increase trend, but the temperature or pressure increases to a certain extent, reduce the corresponding yield. When the reaction time is extended to a certain extent, the yield is no longer increased, which is related to the occurrence of the inverse reaction and the thermal stability of the product. The introduction of catalyst and solvent can improve the yield of the product. Compared with oligomers, the crystallization degree of polyurea obtained by post polymerization decreased, and the thermal stability and solvent resistance increased greatly, indicating that the process of post polymerization could solve the problem of water withdrawal of by-products to a certain extent, and make the reaction toward the direction of molecular chain growth. According to the results of the tensile test, the final product is brittle material, with a certain tensile strength, and the elongation at break is low.
【学位授予单位】：长春工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O631.5

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