聚苯硫醚微孔膜结构调控与性能研究

发布时间：2018-04-22 03:02

  本文选题：聚苯硫醚膜 + 热致相分离(TIPS)　； 参考：《天津工业大学》2017年硕士论文

【摘要】：膜分离技术是一种简便,节能,高效的分离技术并且应用于很多领域。然而,常规膜材料在耐强酸、强碱、极性溶剂方面性能不佳。聚苯硫醚(PPS)是一种具有优良热性能及耐溶剂性能的材料,因此,在高温酸碱腐蚀性液体、有机溶剂处理领域,PPS有望成为一种新的膜分离材料。本文主要是通过热致相分离的方法制备PPS膜,基于相平衡热力学与动力学理论分析了膜形成机理,研究了各种成膜因素对膜结构与性能的影响,通过掺杂亲水性纳米粒子实现了 PPS膜抗污染性能的改善。首先,筛选了六种稀释剂包括己内酰胺(CPL)、二苯甲酮(DPK)、1-氯萘、安息香(BZ)、二苯醚(DPE)及二苯砜(DPS),研究不同稀释剂制备的膜微观结构与分离性能的内在关联。其中,CPL、DPK、1-氯萘制备的PPS平板膜的相分离形式属于固-液(S-L)分相,BZ、DPE、DPS制备的PPS平板膜的相分离形式属于液-液(L-L)分相。以PPS/CPL平板膜体系为例,剖析了聚合物浓度、致孔剂种类与含量、凝固浴温度对膜制备与膜分离过程的影响。其次,采用PPS/DBS/DPK三元体系制备了 PPS膜,研究了稀释剂配比组成、聚合物浓度、冷却速率及凝固浴种类对膜制备与分离过程的影响。随着DBS与DPK的质量比从10/66到17/59,PPS/DBS/DPK三元体系的浊点温度从250℃增加到263.5℃,结晶温度从225.4℃降到了 219.2℃,聚合物与稀释剂之间的相互作用参数由1.57降到1.91,延长了 L-L相分离时间,优化了膜结构类型。当DBS的含量为16wt%,DPK含量为60wt%时,制备了一种拥有通量高、孔隙率大、力学性能优异及抗污染能力强的多层结构的PPS、平板膜,而且降低冷却速率、聚合物浓度及传质过程中稀释剂含量均能够提高PPS平板膜的孔隙率,强化膜分离过程。高温、高腐蚀环境下的膜分离性能评价研究表明PPS膜具有常规过滤膜材料无法比拟的耐高温、耐酸碱及耐有机溶剂的性能。最后,通过掺杂部分还原的氧化石墨烯(GO)与TiO_2纳米粒子,制备了PPS/TiO_2、PPS/GO和PPS/GO/TiO_2纳米复合膜,通过膜分离过程研究发现,纳米粒子的适量掺杂能够显著提高膜渗透性、力学性能及抗污染性能。膜抗污染性能研究表明:当膜中GO/TiO_2的质量分数为0.7wt%时,膜的抗污染效果最佳。与PPS/Ti02、PPS/GO膜相比,PPS/GO/TiO_2膜具有更高的水通量与抗污染性能。
[Abstract]:Membrane separation technology is a simple, energy-saving and efficient separation technology and has been applied in many fields. However, conventional membrane materials have poor resistance to strong acid, alkali and polar solvents. Polyphenylene sulfide (PPS) is a kind of material with excellent thermal properties and solvent resistance. Therefore, PPS is expected to become a new membrane separation material in the field of high temperature acid-base corrosive liquid and organic solvent treatment. In this paper, PPS membranes were prepared by thermally induced phase separation. Based on the theory of phase equilibrium thermodynamics and kinetics, the mechanism of membrane formation was analyzed, and the effects of various film forming factors on the structure and properties of the membranes were studied. The antifouling performance of PPS membrane was improved by doping hydrophilic nanoparticles. Firstly, six kinds of diluents, including caprolactam (CPL), benzophenone (DPKK) 1-chloronaphthalene, benzoin (BZ), diphenyl sulfone (DPE) and diphenyl sulfone (DPS), were selected to study the relationship between the microstructures and the separation properties of the membranes prepared with different diluents. The phase separation form of PPS flat membrane prepared by DPK1-chloronaphthalene belongs to solid-liquid S-L) phase separation form of PPS flat membrane prepared by BZDPEPE-DPS belongs to liquid-liquid L-L phase separation. Taking PPS/CPL flat membrane system as an example, the effects of polymer concentration, kinds and contents of pore-forming agents and coagulation bath temperature on the process of membrane preparation and membrane separation were analyzed. Secondly, the PPS films were prepared by PPS/DBS/DPK ternary system. The effects of diluent composition, polymer concentration, cooling rate and coagulation bath on the preparation and separation of the membranes were studied. With the mass ratio of DBS to DPK from 10 / 66 to 17 / 59, the cloud point temperature of DBS / DBS / DPK ternary system increases from 250 鈩，

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