丙烯腈—丙烯酸甲酯共聚物微孔膜的制备与表征

发布时间：2018-06-10 20:19

本文选题：可熔融丙烯腈-丙烯酸甲酯共聚物(AN-MA) + 热致相分离(TIPS)　；参考：《天津工业大学》2017年硕士论文

【摘要】：聚丙烯腈(PAN)具有耐惰性溶剂、耐细菌侵蚀性、化学稳定性好、机械性能优良等特点,已成为目前应用非常广泛的聚合物膜材料之一。PAN的结构特殊,目前主要采用传统的非溶剂致相分离(NIPS)工艺制备微孔膜。但是NIPS法制备PAN微孔膜往往需要大量的极性溶剂,造成溶剂的浪费和环境污染,且制备的微孔膜力学性能较差。与传统的NIPS工艺相比,热致相分离(TIPS)工艺成膜过程更易控制,且制备的微孔膜力学性能较好。传统的TIPS法采用单一的稀释剂,由于单一的稀释剂与聚合物组成的二元体系两者间的相容性已经固定,而稀释剂与聚合物之间相容性的差异对微孔膜的结构及性能有很大影响。本文分别选用碳酸乙烯酯(EC)与三甘醇二乙酸酯(TEGDA)和环丁砜(TMS)与碳酸二苯酯(DPC)组成两种复配稀释剂体系,通过调节复配稀释剂间的比例调节其与AN-MA共聚物的相互作用力。单一的PAN均聚物膜较脆,实用性较差。本文采用柔性第二单体丙烯酸甲酯(MA)与丙烯腈(AN)共聚,削弱氰基间的偶极作用力,制备可熔融AN-MA共聚物,并以此为基体,采用TIPS法制备AN-MA微孔膜。本论文分为两部分,首先,在TIPS成膜过程中引入溶胶凝胶(sol-gel)工艺,详细研究了共聚物、稀释剂、添加剂等对微孔膜结构与性能的影响。然后,选择结晶性的稀释剂复配体系,详细研究了成型温度、共聚物、稀释剂和添加剂对微孔膜结构与性能的影响。实验结果发现:以投料摩尔比为80/20的可熔融AN-MA共聚物(80/20 AN-MA)为基体,采用TIPS法sol-gel工艺制备80/20AN-MA微孔膜时,降低复配稀释剂中EC含量和聚合物浓度,增加正硅酸乙酯(TEOS)的含量,均有利于膜水通量的提高。复配稀释剂中EC含量为60 wt.%,聚合物浓度为9 wt.%,TEOS含量为5 wt.%时,AN-MA微孔膜的水通量最高可达120 L/(m2h);改变复配稀释剂种类,制备了管状孔和胞状孔相间分布的80/20AN-MA共聚物微孔膜,分别添加羟基化碳纳米管(MWNTs-OH)和埃洛石(HNTs),采用TIPS法制备了系列AN-MA微孔膜。研究发现,膜断面为两种孔结构相间分布的连通结构,当MWNTs-OH添加入量为1 wt.%时,微孔膜的纯水通量为563.7 L/(m2h);HNTS添加量为0.5 wt.%时,微孔膜的最大水通量为665.7 L/(m2h)。随着铸膜液体系中添加剂的加入,微孔膜的断裂强度和柔韧有所增加。当MWNTs-OH添加入量为3 wt.%,微孔膜的断裂强度为3.7 MPa,断裂伸长率为10%;HNTs添加量为1wt.%时,微孔膜的断裂强度为2.6 MPa,断裂伸长率为6%。
[Abstract]:Polyacrylonitrile (pan) has been widely used as one of the most widely used polymer membrane materials because of its inert solvent resistance, bacterial erosion resistance, good chemical stability and excellent mechanical properties. At present, the traditional non-solvent induced phase separation (NIPS) process is used to prepare microporous membranes. However, the preparation of pan microporous membranes by NIPS often requires a large number of polar solvents, resulting in waste of solvents and environmental pollution, and the mechanical properties of the prepared membranes are poor. Compared with the traditional NIPS process, the thermo-induced phase separation (TIPS) process is easier to control and the prepared microporous membranes have better mechanical properties. The traditional tips method uses a single diluent, because the compatibility between the single diluent and the polymer binary system has been fixed, and the difference of the compatibility between the diluent and the polymer has a great influence on the structure and properties of the microporous membrane. In this paper, two kinds of complex diluent systems are composed of ethylene carbonate (EC), triethylene glycol diacetate (TEGDA) and sulfolane sulfone (TMS320T) and diphenyl carbonate (DPC) respectively. The interaction force with AN-MA copolymers is adjusted by adjusting the proportion of the complex diluents. A single pan homopolymer film is brittle and less practical. In this paper, the flexible second monomer methyl acrylate (MAA) and acrylonitrile anhydride (ANN) were copolymerized to reduce the dipole force between cyanide groups and to prepare the meltable AN-MA copolymer. Based on this copolymer, AN-MA microporous membrane was prepared by tips method. This paper is divided into two parts. Firstly, the effects of copolymer, diluent and additive on the structure and properties of microporous membranes were studied by introducing sol-gel process into tips film forming process. Then, the effects of molding temperature, copolymer, diluent and additives on the structure and properties of microporous membranes were studied. The experimental results show that when 80 / 20AN-MA microporous films are prepared by tips sol-gel process, the EC content and polymer concentration in the composite diluent are decreased, and the content of tetraethyl orthosilicate (TEOS) is increased when the melt AN-MA copolymer with 80 / 20 molar ratio is used as the substrate, and 80 / 20 AN-MA microporous membrane is prepared by tips process. All of them are beneficial to the increase of membrane water flux. The maximum water flux of AN-MA microporous membrane was 120 L / m ~ (-2) h ~ (-1) when the concentration of polymer was 9 wt.and the concentration of polymer was 9 wt.The microporous membrane of 80 / 20 AN-MA copolymer with tubular pore and cellular pore phase distribution was prepared by changing the type of complex diluent, and the maximum water flux of the membrane was 120 L / m ~ (-2) h ~ (-1) when the concentration of TEOS was 5 wt.%. A series of AN-MA microporous membranes were prepared by tips method by adding hydroxylated carbon nanotubes (MWNTs-OH) and Ellostachys (HNTs) respectively. It is found that the cross-section of the membrane is a connected structure with the distribution of two pore structures. When the addition of MWNTs-OH is 1 wt.%, the pure water flux of the microporous membrane is 563.7 L / m ~ (2) h ~ (-1), the maximum water flux of the membrane is 665.7 L / m ~ (2) h. The fracture strength and flexibility of the microporous membrane increased with the addition of additives. When the addition amount of MWNTs-OH is 3 wt., the breaking strength of the microporous membrane is 3.7 MPA, the elongation at break is 10 wt.%, the fracture strength is 2.6 MPA and the elongation at break is 6 MPA.
【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】：TQ051.893

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