聚酯（PET）硅橡胶复合膜制备及改性与分离性能的研究

发布时间：2018-09-07 18:05

【摘要】：膜分离作为一个具有发展前景的技术,近年来已逐渐被应用于现实生产中,其中,渗透气化是膜分离技术中的一个分支,对于难以分离的体系具有很广泛的研究价值,很多学者在这方面做了很多研究,取得了很大的进展,如苯酚的分离、氢气的提纯等,常用的材料基本以聚砜、聚丙烯腈等为主,开发新的膜分离材料已成为当务之急。近年来对聚酯分离材料的研究很少,本文着重介绍了以聚对苯二甲酸乙二醇酯(polyethylene terephthalate)为支撑层的硅橡胶复合膜的制备过程中,硅橡胶(PDMS107)、正硅酸乙酯(TAOS,交联剂)、二月桂酸二丁基锡(DD,催化剂)在其成膜过程中的影响,发现硅橡胶含量的增加使得分离系数逐渐增加,渗透通量却逐渐减小,正硅酸乙酯含量的增加导致分离系数逐渐降低,渗透通量却逐渐增加,催化剂含量的变化量对分离效果没有影响,但随其增加,渗透通量逐渐减小,从而总结出了最佳的制膜条件。在此基础上,考察了分离乙醇水物系时,乙醇浓度、膜下侧压力、温度等几个因素对复合膜分离性能的影响,结果表明,与以往的研究不同,随着乙醇浓度的增加,分离系数和渗透通量都不是线性递增或递减的,分离系数先增加后减小,渗透通量则先减小后增加。而温度及膜下侧压力对分离系数和渗透通量的影响则是线形的,温度的增加导致膜分离系数增加,渗透通量也增加,膜下侧压力的增加则使得分离系数和渗透通量都减小。为了使此复合膜的分离性能有所改善,对其进行了改性,在制备过程中,填充了纳米气相法二氧化硅(又称气相法白炭黑),研究了影响其在硅橡胶溶液中分散性的因素,发现添加白炭黑的同时,放入正硅酸乙酯,可以加快其分散速度,催化剂的加入只是促进了其分散速度,单独加入催化剂对分散性没有影响。随后对改性硅橡胶复合膜进行了检测,结果表明,分离因子确实有所提高,极值位置也有所改变,但渗透通量却有所降低。
[Abstract]:Membrane separation, as a promising technology, has been gradually applied in practical production in recent years. Among them, permeation gasification is a branch of membrane separation technology, which has a wide range of research value for difficult separation systems. Many scholars have made great progress in this field, such as the separation of phenol, purification of hydrogen and so on. The common materials are mainly polysulfone and polyacrylonitrile. It is urgent to develop new membrane separation materials. In recent years, few studies have been done on polyester separation materials. In this paper, the preparation of silicone rubber composite membrane with polyethylene terephthalate (polyethylene terephthalate) as the supporting layer was introduced. The effects of silicone rubber (PDMS107), ethyl orthosilicate (TAOS,) crosslinking agent and diDing Ji tin dilaurate (DD,) on the film formation were investigated. It was found that the increase of silicone rubber content increased the separation coefficient and decreased the permeation flux. The increase of ethyl orthosilicate content led to the decrease of separation coefficient and the increase of permeation flux, but the change of catalyst content had no effect on the separation effect, but with the increase of catalyst content, the permeation flux gradually decreased. The optimum conditions of film preparation were summarized. On this basis, the effects of several factors, such as ethanol concentration, lateral pressure and temperature, on the separation performance of the composite membrane were investigated. The results showed that the separation performance of the composite membrane was different from previous studies, with the increase of ethanol concentration. The separation coefficient and permeation flux are not linearly increased or decreased. The separation coefficient first increases and then decreases, while the permeation flux decreases first and then increases. The effects of temperature and pressure under membrane on separation coefficient and permeation flux are linear. The increase of temperature leads to the increase of membrane separation coefficient and permeation flux, while the increase of undermembrane lateral pressure makes the separation coefficient and permeation flux decrease. In order to improve the separation performance of the composite membrane, the composite membrane was modified. In the process of preparation, silica was filled with nano-gas phase method (also known as silica by gas phase method), and the factors affecting its dispersity in silicone rubber solution were studied. It was found that the addition of silica at the same time, the addition of ethyl orthosilicate could accelerate the dispersing rate of silica, but the addition of catalyst only promoted the dispersion rate, but the addition of catalyst alone had no effect on the dispersity. Then the modified silicone rubber composite membrane was tested. The results showed that the separation factor was improved and the extreme position was changed, but the permeation flux was decreased.
【学位授予单位】：上海师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ051.893

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