HFP等离子体改性PTMSP-PMDSP膜及其氧氮选择性

在外极管式电容耦合反应器中,进行了三甲基硅烷基丙炔与五甲基二硅烷基丙炔共聚物(DTMSP-PMDSP)膜的六氟丙烯(HFP)等离子体改性,改性膜的气体透过性研究表明,氧氮选择性显著提高。用XPS谱分析改性后的膜表面,其表面结构发生了显著的变化。

等离子体改性提高PTMSP膜氧氮选择性

膜材料中迄今以聚三甲基硅基丙炔(PTMSP)的透气速率最大,其氧透过速率比PDMS高一个数量级,但氧氮分离系数小,透气性不稳定。改性PTMSP,以提高其透气选择性和透气速率稳定性引起人们的极大关注。本文报道,在外极管式电容耦合反应器中

CF_4等离子体表面氟化PTMSP膜

本文对聚三甲基硅基丙炔(PTMSP)膜进行CF_4等离子体表面氟化研究。改性的PTMSP膜氧氮选择性显著提高(P_(O_2)/P_(N_2)=4-5,P_(O_2)=10~2-10~3barrer)。等离子体改性条件,如处理时间、单体压力、放电功率对PTMSP膜透气性的影响进行了研究。XPS谱分析表明改性后,膜表层化学组成发生了显著变化、碳硅含量大幅度减小,氟含量随着处理程度的增加而增加,氟碳比与膜的选择性有着密切的关系,当 F/C>1时,膜的P_(O_2)/P_(N_2)可达4以上。

三甲硅基丙炔的合成、聚合及聚合物膜的透气性能和改性

在现有的聚合物材料中，聚（1-三甲硅基丙炔）（PTMSP）具有最高的气体透过性能，这种非常有趣的玻璃态聚合物在混合气体的选择透过分离（包括渗透蒸发混合液体分离）例如空气中的氧氮分离、水中溶解氧的富集、醇水分离等方面具有广阔的发展前途。本工作对1-三甲硅基丙炔（TMSP）的合成和聚合、聚合物的制膜及膜的透气性能和改性等方面作了初步探索。1 参考文献中的格氏反应合成法，通过增加对反应产物的氨气后处理这一关键性的改进，有效地避免了严重影响催化聚合反应的杂质M_2的生成，高质量地合成出纯度大于99.8%的TMSP单体。2 采用两步格氏反应合成法，首先合成TMSA，然后合成TMSP，巧妙地避开了TMSP与M_2的分馏分离，开创了一条更适合制备TMSP单体的新路线。3 详细研究了环境对PTMSP膜透气性能的影响，发现透气不稳定的原因除了结构松驰的影响外，主要是由于环境的影响，尤其是存在有机气氛的环境影响非常大。4 热处理对膜的结构松驰有加速作用，使膜的透气性能快速向PDMS的水平靠近。5 PTMSP分子中存在交替双键和丙二烯结构的构型转化，这种构型转化受热力学控制。6 PTMSP膜经过氢氟酸表面处理以后，选择透气性能明显变好。7 PTMSP膜经过表面溴化以后，氧气透过系数有所下降（>10~3 barrer）氧氮选择分离系数可提高到2甚至3以上，透气稳定性提高。8 PTMSP膜经过CF_4等离子体表面处理以后，表面硅含量大幅度减少，氟含量可达50%，膜的氧气透过系数保持在～10~3 barrer，氧氮选择分离系数提高到4甚至5以上，而且透气稳定性良好。9 PTMSP膜表面等离子体聚合一层六氟丙烯形成复合膜。氧气透过系数下降幅度不大，氧氮选择分离系数提高到3以上。

高聚物的等离子体表面处理及表面接枝

本论文基于等离子体改性基本原理，以高聚物表面改性为中心，通过对高聚物透气性，以及高聚物表面接枝聚合物合成的系统研究，从整体上来认识高聚物表面的等离子体处理及表面接枝，开发分离膜材料，以及聚乙烯接枝聚合物的制备方法。第二章综述介绍了等离子体改性的基本原理，详细总结了等离子体技术制备分离膜（主要是气体分离膜）近年来的进展。第二章是关于等离子体聚合制备气体分离复合膜。以六甲基二硅氧烷作单体，研究了等离子体聚合参数对复合膜透气性的影响，制备了高透气性和良好选择性的气体分离复合膜。第三章是有关聚三甲基硅基丙炔（PTMSP）等离子体改性膜透气性的研究。六氟内烯、八氟环丁烷和三氟甲基苯含氟单体等离子体改性PTMSP，在PTMSP膜表面形成含氟复合层，膜的氧气透过系数下降不大，氧氮选择性可以提高到3～5以上。苯、甲苯、苯乙烯等离子体改性PTMSP膜的P_(O_2)/P_(N_2) = 1.5。第四章是有关等到离子体改性亲水微孔膜用于膜蒸馏。首次将亲水微孔膜改性为疏水微孔膜，成功地用于膜蒸馏。第五章研究了等离子体处理原生态聚乙烯粉料的接枝共聚反应。首次采用等离子体对原生态聚乙烯粉料进行处理接枝聚合甲基丙烯酸甲酯、苯乙烯单体。

含有机硅多嵌段共聚物的合成形态结构和性能及其共混物的研究

本文以PSF，PES-C，PHS，PA，PHE，PHES和PPHE分别为硬段，PDMS为软段，通过过羟胺缩聚不可逆反应合成了7种线性和非线性的二元多嵌段共聚物。以PPO，PSF，PEK-C和PES-C分别为硬段，PHS，PA，PHE和PHES分别为半硬段，PDMS为软段，合成了10种具有多样化结构的三元多嵌段共聚物。此外还在嵌段共聚物基础上引入接枝的PDMS，得到了在同一高分子链上具有PDMS嵌段和接枝两种结构的共聚物。并对不同聚合体系的反应条件及不同类型羟基的反应活性进行了详细的讨论，得到的产物分子量高，成膜性好。力学性能的研究表明，这些多嵌段共聚物都在很宽的温度范围内具有较高且稳定的模量，特别是在硬段-软段的嵌段共聚物中引入具有增容作用的半硬段，得到的三元多嵌段共聚物的动态力学性能和抗张性能都优于同等条件下相对应的二元多嵌段共聚物，其中PPO-PDMS-PHS三元多嵌段共聚物以三种嵌段不同组成的相容相为连续相，PDMS和PPO与PHS相容相为两种分散相，具有较高的力学强度，较好地解决了含有机硅类嵌段共聚物强度低的弱点，同时又保留了嵌段共聚物微相分离的特性。利用TEM观察证实，三元多嵌段共聚物的形态结构出现了许多新的现象。除具有微相分离的基本特征外，还表现出双连续双分散的特征，在适当的嵌段长度和含量时，在PSF-PDMS-PHS体系中观察到一种新的形态-蜂窝状结构，并首次利用TEM在嵌段共聚物中直接观察到非常清晰的界面相。通过XPS和SEM-EDS对含有机硅多嵌段共聚物与空气接触表面的研究证实，在其表面都存在PDMS的富集现象，并较详细地讨论了组成、键接结构、相间相容性和溶剂处理对PDMS表面富集的影响。对PSF-PDMS-PHS/PSF共混物膜表面的研究表明，表面PDMS的富集情况与共混相容性有关，不相容的共混体系，表面PDMS的含量随共混物中PDMS含量的变化出现一临值。对本工作合成的含有机硅多嵌段共聚物的功能性研究表明，各种嵌段之间具有协同性和加和性，作为富氧膜材料，较之PDMS强度和α_(O_2/N_2)提高，其中PHE-PDMS和PPO-PDMS-PHS表现出优异的气体透过行为，可替代现有的富氧膜材料，具有一定应用意义和开发价值。PSF-PDMS-PHS与PTMSP的超薄复合膜，提高了PTMSP的α_(O_2/N_2)和经时稳定性，并且J_(O_2)也稳定在比较高的值。另外，作为高分子表面活性剂、渗透蒸发材料、阻尼材料和抗凝血材料也表现也良好的功能性。通过DSC，DMA对几种不同共混体系的研究证实，具有热效应的共混体系PHS-PDMS/PPO，在PPO分子量高于PHS嵌段的分子量时，仍能得到一共混相容体系。均聚物与三元多嵌段共聚物中两种嵌段有相容性的共混体系PPO-PDMS-PHS/PPO。在均聚物与对应嵌段的分子量相同时，也能得到一相容体系。另外，PPO均聚物对PPO-PDMS-PHS/PS共混体系具有增容作用。

IMPROVEMENT OF OXYGEN NITROGEN PERMSELECTIVITY OF POLY[1-(TRIMETHYLSILYL)-1-PROPYNE] MEMBRANE BY PLASMA POLYMERIZATION

The oxygen permselectivity of a poly[1-(trimethylsilyl)-1-propyne) (PTMSP) membrane was drastically improved by plasma polymerization of fluorine-containing monomers. The effects of such plasma polymerization conditions as deposition time, plasma power an

GAS PERMEABILITIES OF POLY(TRIMETHYLSILYLPROPYNE) MEMBRANES SURFACE MODIFIED WITH CF4 PLASMA

Surface fluorination of poly (trimethylsilylpropyne) (PTMSP) membranes by CF4 plasma was studied. The surface fluorination of the membranes was carried out in an atmosphere of CF4 in a capacitively coupled discharge apparatus with external electrodes. Dramatic increase in selectivity (P(O2)/P(N2)) was observed. The effect of fluorination conditions such as duration of treatment and discharge power on the permeabilities of the membranes was studied. X-ray photoelectron spectrometric data of modified PTMSP membranes showed a drastic alternation in the surface layer. The P(O2) and P(O2)/P(N2) of the membranes were observed to be dependent on the F/C atomic ratio. At F/C > 1, the P(O2/P(N2) value of the membranes could be more than four.

聚1-三甲硅基丙炔膜的溴化和气体透过性

在新的气体分离膜材料中,聚1-三甲硅基丙炔(PTMSP)以其高的气体透过性和优异的成超薄膜性而引起各方面的兴趣。目前的研究热点是如何提高PTMSP的氧氮透过分离系数(ao_2/N_2)和气体透过稳定性。Langsam用氮稀释的氟气对PTMSP膜进行表面氟化处理,大幅度地提高了膜的ao_2/N_2,但处理过程中伴随着剧烈的裂解,控制困难。Gozds以N-溴代丁

等离子体改性聚三甲基甲硅烷基丙炔膜的气体透过性

研究了八氟环丁烷(OFCB)等离子体改性聚三甲基甲硅烷基丙炔(PTMSP)膜的气体透过性及等离子体处理条件对膜透气性的影响。改性膜的氧氮选择性有了显著提高。处理条件为功率250W,单体压力5.2 Pa,处理时间5min,膜的氧气透过系数和氧氮选择系数分别为1020 barrer和4.18。改性膜的表面组成用XPS谱进行了表征。XPS谱分析表明,改性膜表面形成了含氟致密薄层,氧氮选择性与F/C元素比没有直接关系。

聚[1-(三甲硅基)1-丙炔]——一种有希望的气体分离膜材料

聚[1-(三甲硅基)]-丙炔(PTMSP)膜的气体透过速率高于目前已知的,不管在室温是玻璃态还是橡胶态的任何聚合物.PTMSP在室温是玻璃态.PTMSP的高透气性主要来源于极高的对气体溶解度及高扩散系数,而这是因为在这种玻璃态聚合物中,有大量处于非松弛区域的自由体积.PTMSP的最大问题是它的高透气性随着时间的过去和热历史而衰减.近来,为解决这一问题进行了大量的努力,如加入低挥发材料,氟化、溴化,与其它单体共聚,与其它聚合物共混等.

聚1-三甲硅基丙炔的改性及其氧氮透过性

80年代才研制的聚1-三甲硅基丙炔(PTMSP)的T_g高于200℃,而它在室温的气体透过性呈橡胶态聚合物的特性,透氧和透醇速率极高,Po_2达5×10~3Barrer,是一代新型富氧膜材料。但TMSP制备和聚合难度大。目前尚只有日、美等国取得一些进展,他们

聚1-三甲硅基丙炔超薄膜的形态结构

聚1-三甲硅基丙炔(PTMSP)是当今透氧率最高的聚合物,为世界各国争先研究的新一代最有希望的燃烧用高分子富氧膜材料。有人对它的合成,均质膜的结构与性能的关系进行了较多的研究,而关于在应用上具有重要意义的超薄膜的形态结构研究部分很少见公开报道。本文以电子显微镜为手段,探讨了水面展开成超薄膜时,PTMSP的成膜液展开特性,超薄膜的形态,厚度与成膜液的浓度、成膜介质水的温度间的关系,为制备超薄复合膜提供了科学依据。水面展开成超薄膜的操作在超净室里进行,样品在H-500型电子显微镜上观察与拍照,超薄膜厚度测定采用折叠投影法。

Trasporto di materia in membrane polimeriche e nanocomposite per la separazione di gas

Membrane-based separation processes are acquiring, in the last years, an increasing importance because of their intrinsic energetic and environmental sustainability: some types of polymeric materials, showing adequate perm-selectivity features, appear rather suitable for these applications, because of their relatively low cost and easy processability. In this work have been studied two different types of polymeric membranes, in view of possible applications to the gas separation processes, i.e. Mixed Matrix Membranes (MMMs) and high free volume glassy polymers. Since the early 90’s, it has been understood that the performances of polymeric materials in the field of gas separations show an upper bound in terms of permeability and selectivity: in particular, an increase of permeability is often accompanied by a decrease of selectivity and vice-versa, while several inorganic materials, like zeolites or silica derivates, can overcome this limitation. As a consequence, it has been developed the idea of dispersing inorganic particles in polymeric matrices, in order to obtain membranes with improved perm-selectivity features. In particular, dispersing fumed silica nanoparticles in high free volume glassy polymers improves in all the cases gases and vapours permeability, while the selectivity may either increase or decrease, depending upon material and gas mixture: that effect is due to the capacity of nanoparticles to disrupt the local chain packing, increasing the dimensions of excess free volume elements trapped in the polymer matrix. In this work different kinds of MMMs were fabricated using amorphous Teflon® AF or PTMSP and fumed silica: in all the cases, a considerable increase of solubility, diffusivity and permeability of gases and vapours (n-alkanes, CO2, methanol) was observed, while the selectivity shows a non-monotonous trend with filler fraction. Moreover, the classical models for composites are not able to capture the increase of transport properties due to the silica addition, so it has been necessary to develop and validate an appropriate thermodynamic model that allows to predict correctly the mass transport features of MMMs. In this work, another material, called poly-trimethylsilyl-norbornene (PTMSN) was examined: it is a new generation high free volume glassy polymer that, like PTMSP, shows unusual high permeability and selectivity levels to the more condensable vapours. These two polymer differ each other because PTMSN shows a more pronounced chemical stability, due to its structure double-bond free. For this polymer, a set of Lattice Fluid parameters was estimated, making possible a comparison between experimental and theoretical solubility isotherms for hydrocarbons and alcoholic vapours: the successfully modelling task, based on application of NELF model, offers a reliable alternative to direct sorption measurement, which is extremely time-consuming due to the relevant relaxation phenomena showed by each sorption step. For this material also dilation experiments were performed, in order to quantify its dimensional stability in presence of large size, swelling vapours.

Preparazione e proprietà di trasporto di gas di membrane a base di polimeri e nanoplatelets grafenici per la cattura di CO2 da processi energetici

Lo scopo di questo studio sperimentale è stato quello di determinare l’effetto dell’aggiunta di piccole quantità (1wt%) di grafene e ossido di grafene al poli(1-trimetilsilil-1-propino) (PTMSP). Il PTMSP è uno dei polimeri più promettenti per la separazione di gas tramite membrane polimeriche grazie al suo elevato volume libero (26%). Sono state studiate sia membrane spesse (60-180 micron) preparate per solvent casting che sottili (2-10 micron) preparate per spin coating supportate su un film poroso di polipropilene commerciale. L’ossido di grafene aumenta la permeabilità del PTMSP, mentre il grafene ha mostrato un comportamento variabile in funzione del protocollo di preparazione che è risultato dipendere fortemente dalla velocità di evaporazione del solvente. Le membrane così ottenute sono state testate al permeometro. È stata osservata una dipendenza della permeabilità in funzione dello spessore del film e del grado di invecchiamento. In particolare, la presenza di nanofiller riduce il grado di invecchiamento dei film di PTMSP. Nel caso specifico della coppia di gas permeanti He/CO2, i campioni hanno mostrato un comportamento intercambiabile di selettività all’He o alla CO2, modulabile in funzione della temperatura tra 30-60°C e del filler utilizzato.