PET醇解反应工艺研究

发布时间：2018-04-21 19:26

本文选题：PET + 醇解　；参考：《华东理工大学》2017年硕士论文

【摘要】：聚酯(PET)产量很大且在环境中很难被微生物降解,对PET的回收再利用不仅可以缓解环境压力,减少环境污染,而且还可以变废为宝减少资源浪费,所以在PET的循环再利用中找出一种新型高效的催化剂仍是目前研究的重点。本文将沸石咪唑酯骨架结构材料(ZIFs)作为催化剂应用于PET的催化醇解过程中,并取得了良好的效果。通过FTIR,XRD,TGA,BET以及NH3-TPD等一系列表征方法对制备出的三种ZIFs材料(ZIF-7,ZIF-8与ZIF-67)的结构以及表面性质进行分析表征,并将其应用于PET的催化醇解反应中,通过分析比较确定三种ZIFs材料的最佳原料配比。当ZIF-7,ZIF-8和ZIF-67的原料摩尔比分别为3:1,4:1和4:1时,PET的降解效率最高。除此之外,本文还在ZIFs材料的催化作用下,探讨聚酯PET醇解的工艺流程,研究催化剂用量、溶剂用量、反应温度以及反应时间四个反应因素对于原料PET转化率以及目标产物收率的影响,并确定最佳反应条件。反应结束后,本文对残留溶剂乙二醇(EG)与催化剂进行分离回收重复再利用并就其循环使用次数进行分析研究。结果表明,在PET的醇解过程中本文所制备的三种ZIFs材料均可以重复使用至少3次且催化活性没有明显的减弱,而重复回收的溶剂EG也仍然保持原有溶剂的性质。对PET醇解反应得到的主产物与副产物分别进行定性和定量分析,确定醇解主产物为单体BHET,而醇解的主要副产物是单体BHET的二聚体。除此之外,本文还对PET醇解反应动力学进行分析研究,确定在ZIFs材料的催化作用下,PET醇解的反应动力学级数为一级,且通过分析计算确定在ZIF-7,ZIF-8和ZIF-67的催化作用下,PET醇解的反应活化能 Ea 分别为 231.04 kJ/mol,137.64 kJ/mol 和 191.63 kJ/mol。
[Abstract]:The recycling and reuse of PET can not only relieve the environmental pressure and reduce environmental pollution, but also reduce the waste of resources. Therefore, it is still the focus of current research to find a new type of high-efficient catalyst in the recycling and reuse of PET. In this paper, zeolites imidazolyl ester framework material (ZIFs) was used as catalyst for the alcoholysis of PET, and good results were obtained. The structure and surface properties of three kinds of ZIFs materials, ZIF-7, ZIF-8 and ZIF-67, were characterized by FTIR and NH3-TPD, and applied to the catalytic alcoholysis of PET. Through analysis and comparison, the optimum raw material ratio of three kinds of ZIFs materials was determined. When the molar ratio of ZIF-7, ZIF-8 and ZIF-67 is 3: 1, 4: 1 and 4:1, respectively, the degradation efficiency of ZIF-7, ZIF-8 and ZIF-67 is the highest. In addition, under the catalysis of ZIFs, the technological process of the alcoholysis of polyester PET, the amount of catalyst, the amount of solvent, The effects of reaction temperature and reaction time on the conversion of PET and the yield of the target product were investigated and the optimum reaction conditions were determined. After the reaction, the residual solvent ethylene glycol (EGG) and the catalyst were separated and reused and their recycling times were analyzed. The results show that the three kinds of ZIFs materials prepared in this paper can be reused for at least three times during the alcoholysis of PET, and their catalytic activity is not obviously weakened, while the reclaimed solvent EG still retains the original solvent properties. The main product and by-product obtained from PET alcoholysis were qualitatively and quantitatively analyzed. It was determined that the main product of alcoholysis was monomer BHET.The main by-product of alcoholysis was dimer of monomer BHET. In addition, the kinetics of alcoholysis of PET was analyzed and studied. The order of kinetics of alcoholysis of PET was determined as the first order under the catalysis of ZIFs. The activation energy (EA) of the alcoholysis of ZIF-67 was determined to be 231.04 KJ / mol ~ (137.64) kJ/mol and 191.63 KJ / mol ~ (-1), respectively, under the catalysis of ZIF-7, ZIF-8 and ZIF-67.
【学位授予单位】：华东理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ316.2

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