【作者】 郝敬梅；

【导师】 邓宇；

【作者基本信息】 天津科技大学 ， 应用化学， 2009， 硕士

【摘要】 喷涂聚脲弹性体(Spray Polyurea Elastomer,以下简称SPUA)技术是国外近十年来,为适应环保需求而研制、开发的一种新型无溶剂、无污染的绿色施工技术。在我国研制成功后,以其优异的综合性能和先进的施工工艺,引起了国内材料界和工程界的极大关注。但目前存在因聚脲高反应活性造成凝胶时间过短、涂层不均匀的问题。本文采用酰基化对二胺扩链剂进行了改性,并用改性扩链剂和端氨基聚醚、4,4’-二苯甲烷二异氰酸酯(MDI)合成了一种新型聚脲,有效控制其凝胶时间。本文采用酰基化对二胺扩链剂进行了化学改性,合成了新型酰胺扩链剂二乙酰己二胺和二乙酰间苯二胺。通过实验确定了对产率具有显著影响的三个因素,酸胺比、反应温度及时间。通过实验得到二乙酰己二胺合成反应的最佳优化条件：酸胺比3：1,温度150℃,时间6h,产率可达到94%左右。二乙酰间苯二胺合成反应的最优化条件：酸胺比3.5：1,反应温度130℃,时间6h,产率可达到74%左右。并用凯氏定氮法、傅里叶变换红外光谱和1H核磁共振确定了合成产物的化学结构。本文采用自制的二胺扩链剂合成了聚脲弹性体,采用FTIR表征了产物结构,采用DSC和TGA考察了产物的性能,并测试了产物的各项物理机械性。结果表明,与未改性的扩链剂相比,新型扩链剂可有效控制聚脲的反应速率,制备的聚脲软硬段相混合程度较好,脲羰基的氢键化程度降低,具有较好的力学性能。此外,本文通过凝胶时间的测定表征聚脲的反应活性,实验结果表明,可以通过调整自制扩链剂的复配比例,来实现聚脲弹性体的凝胶时间的预设控制,达到有效控制聚脲反应的目的。最后,本文用FTIR"原位”跟踪新型聚脲反应过程的固化反应动力学。结果表明,本体扩链反应时,二乙酰己二胺在反应初期表现为良好的二级动力学关系,二乙酰间苯二胺在反应初期表现为良好的一级动力学关系,其固化反应的活化能分别为43.41kJ·mo1-1和58.95 kJ·mo1-1。更多还原

【Abstract】 Spray Polyurea Elastomer (SPUA) technology is a new solvent-free and pollution-free green construction technique to meet the needs of environmental protection over the past decade on abroad. After successfully developed in China, its excellent performance and advanced construction technology caused great concern on the domestic materials and engineering. In order to resolve the shorten gelation time and non-uniform coatings caused by the highly reactive of polyurea, diamine extenders were modified by acylation. Aromatic polyureas were synthesized through the reaction of 4,4’-diphenymethane diisocyanate with modified chain extenders, and its gel time was effectively controlled.In this paper, diamine chain extenders were chemical modified by acylation. Diacetyl hexamethylene diamine and diacetyl m-phenylene diamine were synthesized. Three factors, acid amine ratio, reaction temperature and time, which have significant impacts on the production rate, were determined by experiments. The most optimum condition for synthesis of diacetyl hexamethylene diamine is as follows:the ratio of acid amine is 3:1, the reaction temperature is 150℃, and the reaction time is 6hrs. The yield reach 94% under these conditions. The most optimum condition for synthesis of diacetyl m-phenylene diamine is as follows:the ratio of acid amine is 3.5:1, the reaction temperature is 130℃, and the reaction time is 6hrs. The yield reach 74% under these conditions. Micro-kjeldahl method,1H NMR and FTIR were employed to characterize the chemical structure of the as-synthesized products.A series of polyureas with various chain extenders were prepared. FTIR was employed to characterize the structure of the products, DSC and TGA were employed to characterize the properties of the products, and its physical mechanical properties were measuerd. The results show that, the reaction rate of polyureas was effectively controlled by the new type of chain extender. The polyureas synthesized with modified chain extenders show better miscibility between soft and hard segments as well as lower degree of hydrogen bonding, compared to those of prepared with the previous chain extenders. The mechanical properties of polyureas also have been improved.Besides, gelation time was employed to characterize the reactivity of polyureas. To achieve the default control of gelation time of polyurea elastomer, the compound ratio of chain extenders were adjusted.Finally, the kinetics of curing reaction of polyurea elastomers was studied by in-situ FTIR. In the initial reaction, diacetyl hexamethylene diamine followed second-order kinetics, and diacetyl m-phenylene diamine followed first-order kinetics. The activation energy is 43.41 kJ·mol-1 and 58.95 kJ-mol-1, respectively.更多还原