【作者】 何友宝；

【导师】 詹世平；

【作者基本信息】 大连大学 ， 环境工程， 2008， 硕士

【摘要】 现今,大量废旧尼龙6产品不仅污染了环境,也造成原材料的浪费,因此,对废旧尼龙6的回收利用研究是近年来人们一直关注和不断探讨的一个重要课题。本文介绍了亚超临界流体的基本性质及其在废旧塑料化学循环回收中与传统方法相比所显的特性。综述了国内外废旧尼龙6及相似塑料在亚超临界流体中解聚的研究现状,并在自行设计、加工,组装的高温高压反应装置中研究了废旧尼龙6在亚超临界水中的解聚反应。解聚后液相产物的分析是研究反应过程及机理的关键。本文在查阅相关文献及分析几种实验方法后,决定分别采用气质联用仪和紫外分光光度计对所得液相产物进行定性分析和定量分析,根据实验结果所绘制的拟合图表可确定不同的反应温度、反应压力和反应时间对液相产物收率的影响,及尼龙6解聚的最适宜反应条件。实验数据分析结果表明:液相产物主要为氨基己酸和己内酰胺,最高收率分别可达6.6%和96%,且两者均为聚合生产尼龙6的原料,可实现废旧尼龙6的环保循环再利用;经过理论分析,可知尼龙6在亚超临界水中的解聚是连续反应,首先水解为中间产物氨基己酸,紧接着环化脱水为己内酰胺或分解为其他低分子物质,如环戊酮等。实验结果表明,在亚临界区,反应温度越高、压力越大、时间越长,解聚速率越快;在超临界区,反应条件为370℃,25Mpa时,氨基己酸和己内酰胺的收率达到最大值,符合一级连串反应规律。过长的反应时间,如反应温度超过370℃,压力大于等于30MPa,都会促进进一步的分解副反应。通过动力学分析和利用Arrhenius关系,计算得出的不同反应进程下的反应速率常数k和表观活化能Ea值,说明尼龙6在亚超临界水中的水解速率小于环化脱水反应速率,且反应均有较小的表观活化能。本文研究了尼龙6在亚超临界水中的解聚反应及反应条件对产物收率的影响,可以为工业化回收再利用废旧尼龙6材料提供一定的基础数据和工艺条件。更多还原

【Abstract】 Recently, a mass of products of waste nylon6 not only do pollute environment but alsosquander the raw and processed materials. So the research of reclaiming waste nylon6 is aimportant problem that researchers are concerning and discussing.The paper represents the basic characteristics of the sub- and supercritical fluids, and theproperties, what chemical recycling of waste plastic comparers with traditional processes. Italso reviews the actuality of research in the depolymerization of waste nylon6 and others insub-and supercritical fluids. The depolymerization of waste nylon6 in sub- and supercriticalwater is investigated, in the higher temperature and pressure experimental apparatus that wedesign construct and install.It is the key to the investigations on reaction pathway and mechanism to analyze theliquid product. According to relevant literatures and the results of the experiments in thiswork, GC-MS, ultraviolet spectrometry are used to analyze the products in liquid qualitativelyand quantitatively. The influences of temperature, pressure, and reaction time on the yield ofthe products are studied by the fit graph bastes on the reaction results, and find out theoptimized conditions of the reaction.The results showed that the main products in liquid were aminocaproic acid andcaprolactam; the maximum yield is 6.6% and 96%, respectively. And both are the material ofpolymerization nylon6, which actualize environment protection, cycling utilize of wastenylon6. The reaction scheme of decomposition is represented. Nylon6 is decomposed intoaminocaproic acid by hydrolysis followed by cyclodehydration to caprolactam ordecomposition further to lower molecules, as cyclopentanone and so on.In sub- region, the higher is the reaction temperature, pressure, and time, the faster is thedepolymerization rate. In supercritical region, the prime yield of aminocaproic acid andcaprolactam come forth at 370℃, 25Mpa, which tally with the rule of the first-orderconsecutive reaction. At temperature above 370℃, pressure above and up to 30Mpa,secondary reaction is promoted in long reaction time.At each reaction conditions, the Ea and k are calculated according to Arrheniusrelationship and the kinetic analysis. These results suggest that hydrolysis is slower thancycylodehydration and apparent active energy Ea is less in the sub- and supercritical water. The experiments analysis that the depolymerization of waste nylon6 in sub- andsupercritical water and the influence of reaction condition on the yield of the products. Thesecan provide basic datas and technics condition for the industrilisation recycle of waste nylon6.更多还原