Poly PTMSP

Notes Cellulose (Whatman) PTMSP, poly(trimethyl silyl propine) PS, polystyrene PP, polypropylene PE, polyethylene PA 66, polyamide 66 PA 6, polyamide 6 PVP, poly(vinyl pyrrolidone) PPO, poly(2,6-dimetyl-l,4-phenylene oxide) PMMA, poly(methyl methacrylate) PETP, polyethylene terephthalate) Irganox 1010 is a Ciba anti-oxidant. 

A. Morisato, B.D. Freeman, I. Pinnau and C.G. Casillas, Pure Hydrocarbon Sorption Properties of Poly(l-trimethylsilyl-l-propyne) [PTMSP] and Poly(l-phenyl-l-propyne) [PPP] and PTMSP/PPP Blends, J. Polym. Sci., Polym. Phys. Ed. 34, 1925 (1996). 

In contrast, organophilic PV membranes are used for removal of (volatile) organic compounds from aqueous solutions. They are typically made of rubbery polymers (elastomers). Cross-linked silicone rubber (PDMS) is the state-of-the-art for the selective barrier [1, 43, 44]. Nevertheless, glassy polymers (e.g., substituted polyacetylene or poly(l-(trimethylsilyl)-l-propyne, PTMSP) were also observed to be preferentially permeable for organics from water. Polyether-polyamide block-copolymers, combining permeable hydrophilic and stabilizing hydrophobic domains within one material, are also successfully used as a selective barrier. 

The diffusion of gases through a polymer matrix is determined by the mobility of gas molecules through the matrix. The diffusion coefficient is therefore, at least partially determined by the free volume size of the polymer. It has been shown, for example, that there is a correlation between the free volume measured by PAL and the diffusivity of carbon dioxide in a seriers of polycarbonates [58], In a study of poly (trimethylsilyl propyne) (PTMSP), which has an extremely high gas permeability and diffusion coefficients, it was found that the lifetime data could be resolved into four components [59]. The longest lifetime component (T4) had a lifetime of... 

AA acrylic acid LDPE low density polyethylene NBR poly (butadiene-acrylonitrile) PA polyamide PAA poly(acrylic acid) PAN polyacrylonitrile PB polybutadiene PC polycarbonate PDMS polydimetylsiloxane PE polyester PEBA polyetheramide-block-polymer PI polyimide PMA poly(methyl acrylate) POUA poly(oxyethylene urethane acrylate) PP polypropylene PPO poly(phenylene oxide) PTMSP poly(trimethylsilylpropyne) PUR polyurethane PVA poly(vinyl alcohol) PVC poly(vinyl chloride). 

Because the so-called ultrahigh free volume polymers aroused much interest during the last 10 years, they will be briefly described in this introductory chapter. The publication of the physical properties of poly(l-trimethylsilyl-l-propyne) (PTMSP) in 1983 [281] aroused much interest in the field of membrane research. Up to this time it had been believed that the rubbery poly(dimethyl si-loxane) has by far the highest gas permeability of aU known polymers. Very surprisingly, the glassy PTMSP showed gas permeabilities more than 10 times higher than PDMS. This could be attributed to its very high excess-free volume and the interconnectivity of the free volume elements. Since then a number of... 

Two of these are under extensive investigation and are currently being studied for gas separation on a pilot scale. These are DuPonfs 2,2-bistrifluoromethyl-4,5-difluoro-l,3-dioxole/tetrafluorethylene copolymer (Teflon AF 2400 ) and poly(4-methyl-2-pentyne) (PMP). All three polymers, PTMSP, PMP and Teflon AF2400, are glassy with glass transition above 230°C and have a very high fractional free volume (FFV). Figure 7.4 shows the chemical structure and fractional free volume of these three polymers. 

R. Srinivasan, S.R. Auvil, and P.M. Burban, Elucidating the mechanism(s) of gas transport in poly[l-(trimethylsilyl)-1-propyne] (PTMSP) membranes. J. of Membrane Science, 86 (1994) 67-86. 

The preferential affinity to EtOH depends on the balance between the hydro-philicity and the hydrophobicity of the membrane s material (Huang 1991). Qiu and Peinemann (2006) developed novel organic nanocomposite membrane for PV. The basic polymers were PDMS and poly(l-trimethylsilyl-l-propyne) (PTMSP). By implanting the hydrophobic organic molecules in PTMSP and PDMS, permselectivity to EtOH was enhanced. For example, PDMS with 20 wt% a-cyclodextrins provides a separation factor of 12 for EtOH (5 wt%)-water (95 wt%). Similarly, PTMSP with only 8 wt% a-cyclodextrins improved the enrichment of the low concentration of EtOH from 5 to 48 wt% and maintained the flux at 9 kg pm/m h. They claimed that the increased performance in EtOH-water separation with this organic nanocomposite membrane may lead to the practical industrial application by means of the PV process to produce bioethanol. 

For the first time, siUca-filled poly(l-trimethylsilyl-l-propyne) (PTMSP) layers on top of UF membranes for the pervaporative separation of EtOH-water mixtures was reported by Claes et al. (2010). Reduction of the thickness of the separating PTMSP top layer and addition of hydrophobic silica particles resulted in a clear flux increase as compared with dense PTMSP membranes. The performances of the supported PTMSP-silica nanohybrid membranes were significantly better than the best conunercially available organophilic PV membranes. The developed composite PTMSP-silica nanohybrid membranes exhibited EtOH-water separation factors around 12 and fluxes up to 3.5 kg/m h, establishing a sevenfold to ninefold flux inCTcase as compared with dense PTMSP membranes. 

J. H. Zhou, R. X. Zhu, J. M. Zhou, M. B. Chen, Molecular dynamics simulation of diffusion of gases in pure and silica-filled poly(l-trimethylsilyl-l-propyne) [PTMSP], Polymer, 47, 5206-5212 (2006). 

Two methods are used for the preparation of capillary gas adsorption columns the suspension method, in which the inner walls of the column are coated with a suspension of the adsorbent, and the chemical method, in which an adsorption layer is formed on the walls of the column through a process of synthesis of the adsorbent in the capillary column. Recently, a new type of porous polymer (poly(l-(trimethylsilyl)-l-propin) (PTMSP)) has been suggested as an organic adsorbent and has been actively studied as a promising material in membrane technology. This polymer dissolves well in some volatile solvents, and a layer of it can be formed in a capillary column using simple techniques for coating from a solution of a stationary phase in a volatile solvent. 

GS, gas separation OSN, organic solvent nanofiltration RO, reverse osmosis BTB, Bromothymol Blue PTMSP, poly(trimethylsilyl propyne) PMP, Polym hylpentene PIMA, polymer of intrinsic microporosity. 

Another possible approach to indirectly characterize the membrane morphology is based on the investigation of the free volume within the matrix. Density measurements [119,120] and positron annihilation lifetime spectroscopy evaluation [47] are common methods. Typically, the comparison between the theoretical density or free volume (calculated by simple additivity rules) and the experimental one can reveal the presence of a good interfacial morphology or the presence of interface voids or clustering formation. Fig. 7.13 shows the influence of filler content on the morphology of poly(trimethylsilyl propyne) (PTMSP)/Ti02 NCMs in terms of the volumetric fraction of interface voids as calculated from a comparison of the expected and measured membrane density [119],... 

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