超高交联非织造布对挥发性有机气体吸附性能的研究

发布时间：2018-05-11 14:17

本文选题：聚丙烯非织造布 + 超高交联　；参考：《天津工业大学》2017年硕士论文

【摘要】：挥发性有机化合物(VOCs)是构成大气污染的重要组成部分,它主要来源于工业生产过程和日常生活中,对生态环境和人类健康都具有较大的危害。在处理VOCs的诸多方法中,吸附法因其具有设备简单、能耗低、处理效率高等优点被广泛用于有机废气治理中。吸附法的应用关键在于吸附剂的选择,非织造布材料具有良好的过滤性能广泛应用于气体净化过程,吸附性非织造材料在具有过滤性能基础上同时具有吸附性能。本论文主要采用化学方法使聚丙烯(PP)非织造布表面形成苯乙烯(ST)和二乙烯苯(DVB)的接枝层,然后分别选择4'4-二甲基联苯(CMDP)、二氯甲基苯(DCX)、二甲氧基甲烷(FDA)三种不同分子结构和分子量的交联剂进行后交联反应,制备出三种超高交联非织造布材料(HCN-CMDP、HCN-DCX、HCN-FDA)。研究发现PP非织造布接枝反应阶段,引发剂用量、单体浓度和固液体积比对ST和DVB接枝率均具有影响。研究发现,在非织造布接枝层后交联的反应中,溶胀时间、交联剂用量、交联反应时间及交联剂类型对接枝层的交联程度具有影响,最终影响到材料的比表面积。结果表明采用ST和DVB接枝率为200%非织造布,引发剂用量为0.6%、溶胀时间及交联反应时间均为24h、CMDP为交联剂时,超高交联非织造布的比表面积最大,可达到446.68m~2/g。研究采用SEM、激光共聚焦显微镜、BET、FT-IR、TGA和接触角测量仪对非织造布表面形貌及结构进行了表征,结果表明,交联非织造布表面形成了具有0.5nm左右均一孔径的三维多孔交联层,材料比表面积可达到446.68 m~2/g,是原非织造布的288倍。采用动态吸附方法重点研究了 HCN的比表面积、气体浓度、气体流速及湿度对苯乙烯吸附性能的影响。另外,为了探讨吸附质与吸附剂之间的作用力,研究了三种不同交联结构的非织造布对不同类型VOCs(苯乙烯、丙酮、正己烷)的吸附和脱附性能的影响。结果表明,HCN-CMDP、HCN-DCX和HCN-FDA对VOCs均有较好的吸附作用,其中HCN-CMDP对苯乙烯、丙酮和正己烷的吸附效果最佳,且对苯乙烯的吸附能力最强,最大吸附量可达到353.6 mg/g。HCN-CMDP脱附苯乙烯的活化能最大,为22.7KJ/mol,表明HCN-CMDP与苯乙烯之间的作用力最大。
[Abstract]:Volatile organic compounds (VOCs) are important components of air pollution. They are mainly derived from industrial production and daily life, which are harmful to the ecological environment and human health. Among the methods of VOCs treatment, adsorption method is widely used in organic waste gas treatment because of its advantages of simple equipment, low energy consumption and high treatment efficiency. The key to the application of adsorption method lies in the selection of adsorbent. Nonwovens have good filtration performance and are widely used in the process of gas purification. The adsorptive nonwovens have adsorption properties on the basis of filtration properties. In this paper, a chemical method was used to form graft layers of styrene (St) and divinylbenzene (DVB) on the surface of PP / PP nonwovens. Then three kinds of crosslinking agents with different molecular structure and molecular weight were selected respectively, namely, four kinds of crosslinker, four kinds of crosslinking agents of different molecular structure and molecular weight, and three kinds of ultra-high crosslinking nonwovens, HCN-CMDPU, HCN-DCXHCN-FDAA, respectively. It was found that the graft ratio of St and DVB was affected by the amount of initiator, monomer concentration and solid / liquid volume ratio during the grafting reaction of PP nonwovens. It was found that the swelling time, the amount of crosslinking agent, the crosslinking time and the crosslinking degree of the grafted layer of nonwovens had an effect on the crosslinking of the grafted layer, and the specific surface area of the material was finally affected by the swelling time, the amount of crosslinking agent and the crosslinking time. The results showed that when St and DVB were grafted with 200% nonwovens, the amount of initiator was 0.6, the swelling time and crosslinking reaction time were both 24 h and CMDP was used as crosslinking agent, the surface area of ultra-high crosslinked nonwovens was the largest, reaching 446.68 mg / g. The surface morphology and structure of nonwovens were characterized by means of SEM, laser confocal microscope, BETFT-IRGA and contact angle measuring instrument. The results showed that the surface of cross-linked nonwovens formed a three-dimensional porous crosslinking layer with 0.5nm about uniform pore size. The specific surface area of the material can reach 446.68 mm2 / g, 288 times the original nonwovens. The effects of specific surface area, gas concentration, gas flow rate and humidity of HCN on the adsorption properties of styrene were studied by dynamic adsorption method. In addition, the effects of three kinds of nonwovens with different cross-linking structures on the adsorption and desorption properties of different VOCs (styrene, acetone, n-hexane) were studied in order to investigate the force between adsorbents and adsorbents. The results showed that both HCN-CMDP- DCX and HCN-FDA had better adsorption on VOCs, and HCN-CMDP had the best adsorption effect on styrene, acetone and n-hexane, and had the strongest adsorption capacity for styrene, and the maximum adsorption capacity could reach the maximum activation energy of 353.6 mg/g.HCN-CMDP desorption of styrene. It was 22.7 KJ / mol, indicating that the interaction force between HCN-CMDP and styrene was the largest.
【学位授予单位】：天津工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X701

【参考文献】