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New film-forming copolymers PIM-1 with 2,3,6,7-tetrahydroxy-9,10-(p-fluorophenyl)anthracene units in the main chain have been synthesized and investigated. The investigated gas separation characteristics of these copolymers show that despite a decrease in permeability, the copolymer containing 20% tetrahydroxyanthracene is a highly selective material that goes beyond the upper bounds in Robeson’s plots as compared to the initial PIM-1.

A chemical modification of PIM-1 polybenzodioxane (a polymer with intrinsic microporosity) is performed by reactions with the involvement of the nitrile group and using a selective quinazoline synthesis reaction. A number of benzanilide-substituted derivatives of PIM-1 are obtained based on the high-molecular-weight samples of PIM-1. The gas transport properties of the membranes based on substituted PIM-1 polymers with a degree of substitution of up to 50% are studied. It is shown that the values of the gas separation parameters for O2 and N2 are on the upper bound of the Robeson diagram (2008) for a sample with a degree of substitution of 50%. According to estimates, these values should be significantly above the upper bound of the Robeson diagram (2008) at a degree of substitution of 100%.

A series of addition copolymers of 3-trimethylsilyltricyclo[4.2.1.02.5]non-7-ene with a bifunctional comonomer—2,5-norbornadiene dimer—are synthesized. It is shown that, with the introduction of a small amount of the 2,5-norbornadiene dimer (up to 0.3 mol %), the molecular weight of the polymer increases. When using a large amount of the 2,5-norbornadiene dimer, crosslinked insoluble polymers are formed. As exemplified by a copolymer containing 0.3 mol % 2,5-norbornadiene dimer units, the introduction of the bifunctional comonomer does not lead to a significant decrease in gas permeability, and the developed method can be used to increase the molecular weights of polymers, improve their mechanical properties, and make polymers resistant against plasticization.

A ladder polymer with the intrinsic microporosity PIM-1 has been synthesized via precipitation polycondensation in dimethylsulfoxide and via polycondensation in N,N,N ',N '-tetramethylurea. The molecular weight characteristics of PIM-1 samples have been determined using gel permeation chromatography method. It has been shown that the synthesized polymers are characterized by a high molecular weight (~90 × 103) and by a bimodal molecular weight distribution; in this case, molecular weights of the high-molecular-weight fraction of polymer with the polydispersion coefficient of 2.1–2.4 are practically independent of the nature of the reaction medium. The weight content of the oligomer fraction in the obtained samples has been estimated from gel permeation chromatograms. Gas permeability coefficients of He, H2, O2, N2, CO2, and CH4 for the initial films of the synthesized polymers and the films treated with ethanol have been measured by the chromatographic method at 22 ± 2°С. It has been shown that, for all samples under investigation, the gas permeability coefficients are higher than for the PIM-1 samples described previously in the literature. In this case, the gas permeability and its increase during treatment with ethanol depend on the content of the low-molecular-weight fraction in the sample.

A new metathesis polynorbornene containing bulky and reactive silatrane side groups is synthesized, and its gas-transport properties are investigated. The metathesis polymerization of 3-silatranyltricyclo[ 4.2.1.02.5]non-7-ene is conducted in the presence of the first-generation Grubbs catalyst. The homopolymer is obtained with a nearly quantitative yield of 98% and a molecular mass of Mw = 1.3 × 106 (Ð = 3.7). According to X-ray phase analysis, the homopolymer is amorphous and its glass-transition temperature is 232°С (DSC). The gas permeability of the metathesis polymer for a set of gases, including He, H2, O2, N2, CO2, and CH4, is investigated, and the corresponding diffusion and solubility coefficients are determined.

The effect of postpolymerization epoxidation of metathesis polynorbornenes on their gas-transport behavior is studied. For two polymers, unsubstituted polynorbornene and poly(trimethylsilylnorbornene), postpolymerization modification via double bonds is implemented by epoxidation under the action of m-chloroperbenzoic acid to high conversions (95–100%). For initial polymers and their epoxidation products, the permeability and diffusion coefficients are measured and the solubility coefficients are estimated. It is shown that, for both initial polymers, functionalization leads to a marked reduction in permeability (by a factor of 2–10) and diffusion coefficients (by a factor of 3–10); simultaneously, the separation factors increase by a factor of 2–6. Although for all gases the solubility coefficients decrease as a result of epoxidation, the coefficients of CO2 solubility in both epoxidated polymers increase. This effect may be explained by specific interactions of a СО2 molecule possessing the quadrupole moment with С–О–С bonds appearing in a polymer.

A new silicon-containing bicyclic monomer 5-trimethylsilylbicyclo[2.2.2]oct-2-ene has been synthesized, and its metathesis polymerization and gas transport properties of the polymer based on it have been studied. The monomer is synthesized by the two-step scheme using the Diels–Alder reaction from 1,3-cyclohexadiene and vinyltrichlorosilane followed by methylation with a Grignard reagent. The resulting 5-trimethylsilylbicyclo[ 2.2.2]oct-2-ene is inactive in metathesis homopolymerization in the presence of first- and second- generation Grubbs catalysts and a Hoveyda–Grubbs catalyst, but it slowly polymerizes when norbornene is present in the reaction mixture. The high-molecular-mass copolymer (M w = 3.0 × 105, M w/M n = 2.8) of 5-trimethylsilylbicyclo[2.2.2]oct-2-ene and norbornene possesses good film-forming properties, and its glass transition temperature is 126°C. The gas-transport properties of the copolymer have been studied.

Polymer of intrinsic microporosity (PIM-1) was prepared according to a new procedure – precipitation polycondensation in DMSO solution. The permeability coefficients were determined in the “as cast” and ethanol treated samples of this material. It was shown that permeability of the novel polymer is higher than that of PIM-1 samples prepared according to the traditional methods, while selectivity was lower. Free volume in the novel PIM-1 was studied using the PALS technique. Positron life time parameters and the radii of free volume elements were virtually the same as in PIM-1 samples investigated earlier. The samples of novel PIM-1 were subjected to treatment by supercritical CO2 and annealing of free films and films in strained state. The treatment with scCO2 leads qualitatively to the same results as insertion of the films into EtOH (increase in gas permeability) although the observed Pi values are somewhat lower. Annealing of the films in strained and free state causes significant decrease in gas permeability with respect to all the gases but increase in selectivity. This effect is rather strong, so some the data points are even located above the Upper Bound 2008 in Robeson diagrams. Aging of PIM-1 samples for 30–60 days was also studied, and its mechanism is considered.

The possibility of formation of the mixed matrix membranes NH2—MIL-101(Al) under the conditions of microwave activation of the reaction mixture at atmospheric pressure is studied. Microwave irradiation affects the morphology and crystallite size and significantly shortens the synthesis time (from tens of hours to 10—30 min). The obtained samples of NH2—MIL-101(Al) with a crystallite size of 100 nm were used as nanofillers for polymer matrix based on the PIM-1 polymer with intrinsic microporosity for the preparation of hybrid membrane materials. Gas permeability for a series of gases was measured on the synthesized membranes.

In this work we report the preparation and properties of composite materials for gas separation membranes based on highly permeable addition poly(3-trimethylsilyltricyclononene-7) (PTCNSi1) as a matrix and substituted cyclodextrines (CD) as fillers. CD studied had different structure and this allowed us to explore correlations between the structure of the fillers and gas permeation parameters of the resulting compositions. Namely α-, β-, and γ-cyclodextrines with Me- or Me3Si-substituents were synthesized and the composites containing them were prepared. Permeability coefficients of the obtained composites were determined for He, H2, O2, N2, CO2, CH4. It was found that the introduction of cyclodextrines with bulky Me3Si-groups rather weakly influenced the permeability coefficients for He and H2, while for other gases a marked decrease in permeability was observed. On the other hand, in the case of the composites containing Me-substituted CD decreases in permeability were observed for all the studied gases. The changes of gas permeability dramatically depend on the size of gas molecules and this results in an increase in selectivities for some gas pairs. Thus, introduction of α-CD with Me-groups resulted in an increase in selectivity α(H2/N2) from 5.2 for pure polymer to 9.1. The increase in CD content in a composite gave an extra growth of selectivities. BET, TEM, WAXD, positron annihilation data (free volume) and mechanical properties of the composites were also studied and discussed. POLYM. COMPOS., 36:1029–1038, 2015. © 2015 Society of Plastics Engineers

In this work we report the synthesis and polymerization of new norbornenes containing trialkoxysilyl groups. These monomers were reactive both in ROMP and in addition polymerization. Obtained polymers possessed interesting properties. So despite of low surface area they were good permeable, and some of them exhibited a low tendency to aging. The solubility controlled selectivity for hydrocarbons was observed. These properties would allow finding industrial application of obtained polymers for the membrane gas separation of hydrocarbon mixtures.

Hybrid composite membrane materials and membranes on their basis containing various nanoparticles dispersed in polymer matrices attract significant attention of researchers. Different types of these materials in relation to their use for membrane gas separation are surveyed. The behavior of different types of additives is considered: nonporous oxides such as SiO2 and TiO2, metal-organic frameworks, and carbon nanotubes. It is shown that introduction of nanoparticles in many cases results in simultaneous enhancement of permeability and gas separation selectivity. The results obtained with hollow fiber membranes of this type are discussed. Problems arising during operation with this type of materials and possible ways of resolving them are considered.

Polymers of different classes are considered as membrane materials for separation of hydrocarbons C1–C4. It has been known for a long time that solubility controlled permeation is characteristic of rubbery polymers and in particular of the most permeable rubber polydimethylsiloxane. The transport properties of these polymers are considered. Discovery of poly(trimethylsilyl propyne) and other polyacetylenes showed that similar properties can be revealed in glassy polymers. As is discussed in this review, the most important properties are reduction of the permeability of light components (CH4) in the presence of more condensable penetrant (C4H10) and higher selectivity of mixture separation as compared with ideal separation factors measured in the experiments with pure gases. Recently, two other classes of glassy polymers with solubility controlled permeation were discovered: addition type Si-containing norbornene polymers and metathesis polynorbornenes with flexible Si–O bonds in side groups. The transport properties of these novel polymers are considered in detail. It was shown that for the former group of norbornene polymers the reasons for solubility controlled permeation is great and opened porosity just as is the case for polyacetylenes. For the latter group, the presence of flexible Si–O bonds in side groups is responsible for their transport properties.

The membrane separation of the four-component mixture of gaseous alkanes C1–C4 is studied. Homogeneous films based on two high-permeable polymers, namely, addition-type poly[3-(trimethylsilyl)tricyclononene-7] and poly[3,4-bis(trimethylsilyl)tricyclononene-7], are used as membranes. Separation of the multicomponent mixture of hydrocarbons on these polymers follows the same trends as separation of binary mixtures CH4-C4H10 on polyacetylenes. In the presence of higher hydrocarbons, the permeability coefficients of methane decrease and the permeates become enriched with higher hydrocarbons. During separation of the multicomponent mixture, permeability coefficients P(C4H10) attain high values (up to 12000 Barrers).

Addition and ring-opening metathesis polymerizations of new monomers (Me3Si- and Me3Ge-substituted tricyclononene and tricyclononadienes) were studied. Addition polymerization was carried out on Pd- and Ni-catalyst systems activated by B(C6F5)3 and/or methylalumoxane. New addition polymers were obtained with good yields up to 70% and with molecular weights (Mw) up to 5.6 × 105. Metathesis polymerization was performed using the first-generation Grubbs catalyst. The yields of the first obtained metathesis polymers were higher than 80%, and the Mw values were up to 8.8 × 105. It was revealed that the cyclobutene double bond in the studied tricyclononadienes is inactive in both metathesis and addition polymerizations. The relative activities of the substituted tricyclononene-7 and the corresponding tricyclononadiene-3,7 in the metathesis copolymerization were defined using 1H NMR spectroscopy. It was found that the novel addition polymer poly[(3-trimethylgermyl)tricyclononene-7] possesses high gas-transport parameters (for example, P(O2)=660 Barrers, P(CO2)=3850 Barrers) and solubility-controlled permeation of gaseous hydrocarbons (α (n-C4H10/CH4)=17.3). Addition and ring-opening metathesis polymerizations of new monomers (Me3Si- and Me3Ge-substituted tricyclononene and tricyclononadienes) were carried out on Pd- or Ni-catalyst systems and Grubbs first-generation catalyst, respectively. New addition polymers were obtained with good yields up to 70% and molecular weight (Mw) up to 5.6 × 105. The yields of the first obtained metathesis polymers were higher than 80% and Mw were up to 8.8 × 105. It was shown that the novel addition polymer poly[(3-trimethylgermyl)tricyclononene-7] possesses high gas-transport parameters and solubility-controlled permeation of gaseous hydrocarbons.

The transport parameters (permeability coefficients, separation factors) were determined for the separation of mixtures of n-butane and methane. The content of butane in the feed was in the range 3.7–7.9% and simulated the composition of associated petroleum gas. The experiments were carried out at room temperature and feed pressure of 2–6 atm. Novel membrane materials – poly(trimethylsilylnorbornene) and poly(bis-(trimethylsilyl)tricyclononene) – were studied in the form of dense films. Both polymers reveal a distinct solubility controlled permeation: the permeate streams were strongly enriched (up to 58%) with the heavier component (C4H10), the permeability of methane was reduced by a factor 3–4 as compared to the permeability of pure methane, and high permeability of butane was observed. Novel Si-containing poly(cycloolefins) as membrane materials were compared with high permeability polyacetylenes.

Published results concerning the synthesis and study of the transport characteristics of polynorbornenes are considered and analyzed. Conclusions are drawn regarding the effect of the backbone rigidity and the nature of side groups on the gas permeability level. The prospects of using addition organosilicon polynorbornenes as gas separating membrane materials are discussed.

An approach to the manufacture of highly permeable polymers based on the synthesis and polymerization of norbornenes, norbornadienes, and tricyclononenes with different numbers and different positions of silicon-containing substituents has been developed. It has been found that these monomers are readily involved in metathesis polymerization yielding high-molecular-mass polymers possessing good filmforming properties. The addition (vinyl) polymerization of norbornenes is a more complex process; however, the product silylated polynorbornenes exhibit a higher gas permeability than the corresponding metathesis polynorbornenes. By the level of the gas-transport parameters, the silylated addition polynorbornenes obtained in the study are grouped with the most advanced high-permeability polymers. It has been shown that the presence of Me3Si substituent groups, their amount, and the main-chain structure are responsible for the enhancement of the gas permeability of polynorbornenes. Thus, a series of polymers with a regularly changing structure has been obtained, a result that makes it possible to reveal the polymer structure-property relations.

Addition polymerization of two tricyclononene monomers bearing one and two Si(CH3)3 groups was performed in the presence of Pd-containing catalysts. The polymers were obtained with high yields and were completely saturated. Good mechanical and film forming properties are observed for the polymers prepared in the presence of Pd(OAc)2/B(C6F5)3 catalyst. Their glass transition temperature was not observed until the onset of thermal decomposition (>370 °C) and the molecular weights are high (Mw up to 7 × 105). Study of gas permeation parameters of the obtained poly[3-(trimethylsilyl)tricyclononene-7] and poly[3,4- bis(trimethylsilyl)tricyclononene-7] showed that both glassy polymers revealed substantially high gas permeability. Other transport characteristics (increase in permeability in the series C1−C4 alkanes and negative activation energies of permeation) indicate that these polymers reveal so-called solubility controlled permeation, which is typical for some extra-high permeability polymers. Positron ann...

The metathesis polymerization of 5,5-bis(trimethylsilyl)norbornene, 2,3-bis(trimethylsilyl)norbornadiene, and exo,endo-3,4-bis(trimethylsilyl)tricyclo[4.2.1.02,5]non-7-ene with the catalysts WCl6/1,1,3,3-tetramethyl-1,3-disilacyclobutane, RuCl3/EtOH, and the Grubbs Ru-carbene complex Cl2(PCy3)2Ru=CHPh has been studied. New polymers with yields of up to 98% and M w = (2−39) × 105 are prepared. New metathesis copolymers of 5-trimethylsilylnorbonene with 5-(hydroxymethyl)norbornene and 5-(trimethylsiloxymethyl)norbornene are synthesized in the presence of the Cl2(PCy3)2Ru=CHPh catalyst with yields of 78 and 98%. The gas-permeability study of the above series of the metathesis polymers containing one or two Me3Si substituents in each monomer unit shows that the introduction of the second SiMe3 group markedly improves their transport characteristics. A change in the character of the backbone (polynorbornadiene, polytricyclononene) has a small effect on the permeability of the polymers. The metathesis polynorbornene with two vicinal SiMe3 groups exhibits higher gas-permeability coefficients than its isomer with germinal substituents. The homopolymer of 5-trimethylsilylnorbornene is characterized by better transport parameters than its copolymers with -OSiMe3 and -OH substituents.

Polymerization of norbornene bearing Si(CH 3 ) 3 groups in the five position with the opening of double bonds was performed. By accurate selection of the ratios catalyst/co-catalyst and monomer/catalyst the samples with increased molecular mass (about 400,000) were obtained. Transport parameters of this, addition type poly(trimethylsilyl norbornene) (PTMSN) were measured using the gas chromatographic and mass spectrometric methods for different gases (H 2 , He, O 2 , N 2 , CO 2 , CH 4 , C 2 H 6 , C 3 H 8 and n -C 4 H 10 ). Temperature dependence of the permeability coefficients ( P ) indicated that low activation energies of permeation ( E P ) and diffusion ( E D ) are characteristic for PTMSN. In some cases (CO 2 , C 2 H 6 ) negative E P values were observed. Thermodynamics of vapor sorption in this polymer was studied using the inverse gas chromatography method. It was shown that PTMSN is characterized by very large solubility coefficients S similar to those of poly(trimethylsilyl propyne) (PTMSP). The comparison of the P , D , and S values of these highly permeable polymers showed that the greater permeability of PTMSP is determined by the larger D values. Application of different approaches for the determination of the size of microcavities in PTMSN indicated that this polymer is characterized by large size of microcavity (800–1200 Ǻ 3 ).

Physicochemical properties of a cis-polypentenamer—a hydrocarbon polymer with a low glass transition temperature (T g = 168.8 K)—have been studied. Measurements of permeability coefficients P in rubbery material for a wide range of gases (He, H2, O2, N2, CO2, CH4, C2H6, C3H8, and n-C4H10) indicate a high permeability of this polymer for which the values of P are only slightly lower than those of the most permeable rubber—poly(dimethylsiloxane). The method of inverse gas chromatography has been employed to estimate solubility coefficients S for n alkanes C3–C10 and cycloalkanes in cis-polypentenamer in the range from 25 to 150°C. It has been shown that the solubility coefficients linearly increase in lnS-T cr 2 coordinates, where T cr is the critical temperature of a solute. In terms of the above correlation, the solubility coefficients of light gases have been estimated and the diffusion coefficients D of gases in the same polymer have been calculated via the formula P=DS. The free volume in cis-polypentenamer has been studied by positron annihilation lifetime spectroscopy. The temperature dependence of the positronium lifetime τ 3 that characterizes the size of the free volume element in a polymer demonstrates saturation at temperatures above 250 K. This effect is probably related to a rapid migration of fluctuation holes in the rubbery polymer at temperatures remote enough from its glass transition temperature.

The gas-separation behavior of a semicrystalline polydimethylsiltrimethylene—one of the family of silmethylene rubbers—has been studied. The permeability of O2, N2, and CH4 through this polymer at temperatures below and above the melting temperature of the crystalline phase has been investigated, and the activation energy of permeability has been calculated. The gas permeability of the semicrystalline polydimethylsiltrimethylene depends on the prehistory of the sample. At the melting temperature of crystals, the permeability coefficients of the tested gases increase sharply. The transition of the polymer from the semicrystalline state to the melt leads to an appreciable reduction in the activation energy of permeability.

Polymerization of norbornene bearing Si(CH3)3 groups in the 5-position with the opening of double bonds and its copolymerization with 5-(n-hexyl)norbornene were realized in the presence of nickel(II) naphthenate/methylaluminoxane catalyst system. The completely saturated homopolymer containing Si(CH3)3 group (APNSi) and a copolymer containing both Si(CH3)3 and n-hexyl side groups (ACPNHSi) were prepared. The polymers have molecular mass of about 300 000 and a high glass transition temperature (Tg > 340 °C). Gas permeation properties of the polymers obtained were studied. APNSi reveals unusually high gas permeation parameters, e.g., P(O2) of about 800 Barrer for different samples. This polymer also exhibits solubility controlled gas permeation: the permeability coefficients increase in the series of n-alkanes C1−C4 when the size of the penetrant increases. Free volume in addition type substituted polynorbornenes was studied using positron annihilation lifetime spectroscopy (PALS). This method indicated th...

The effects of different mechanisms of aging of poly[1-(trimethylsilyl)-1-propyne] (PTMSP), namely, chemical aging (oxidation), physical and absorption aging, on gas permeability of the polymer were studied. For this purpose, the PTMSP samples obtained in the presence of various catalysts (TaCl5/BuLi, TaCl5/i-Bu3Al, and NbCl5) and stored at ambient temperature for 2–8 years were investigated. The procedure involving the stages of sequential dissolving, precipitation and recasting allowed us to recognize the contributions of different mechanisms of aging. It was shown that a long-term storage of PTMSP at ambient conditions results in oxidation of the polymer with formation of various functional groups (aldehyde, acid, ether, and epoxy groups). The dissociation of the main chain takes place as well with formation of low molecular mass products. It was shown, however, that is not the main reason for a reduction of gas permeability of PTMSP. The absorption aging of PTMSP provides the main contribution in decreases in gas permeability of aged PTMSP samples. Its consequences can be eliminated by the re-precipitation of the polymer from its solutions and subsequent recasting. Unusual behavior of aged PTMSP samples in separating of the C1–C3 hydrocarbons is also observed and discussed.

Pervaporation of binary mixtures (CH 2 Cl 2 –CHCl 3 , CHCl 3 –CCl 4 , CH 2 Cl 2 –CCl 4 ) through two amorphous copolymers of 2,2-bis-trifluoromethyl-4,5-difluoro-1,3-dioxole and tetrafluoroethylene was studied at different temperatures, feed composition, and downstream pressure. It was shown that the copolymer with the larger content of the dioxole comonomer and having the greater free volume (AF 2400) is more permeable, whereas selectivity of separation of the two copolymers are similar for some regimes. The dependence of permeation rate and selectivity on the process parameters of the AF copolymers indicated that mobility selectivity prevails for pervaporation of the mixtures studied through these membrane materials. The deviation coefficients used for analysis of mixed permeation indicated strong interactions of the components in pervaporation of binary mixtures. Pervaporation separation index (PSI), which depends on permeability and selectivity of pervaporation, was used to characterize the performance of the process. It was shown that PSI increases for higher contents of the components enriched in the permeate and at higher temperatures.

Composite films based on the polyvinyltrimethylsilane (PVTMS) with polyaniline (PANI) coating were obtained by borderline polymerization of aniline. The obtained coating was shown to differ from the polymer forming in the reaction mixture bulk both in chemical structure and morphology. Ratio and concentration of the reagents, mixing rate, reaction time, and condition of support surface were among the investigated factors affecting the growth and quality of PANI coating. The gas separation characteristics of composite membranes, as affected by the process conditions and the type of PANI, were investigated. It is shown that the proposed method provides a means for obtaining composite membranes that combine high selectivity, especially in O2/N2, He/CH4, and CO2/CH4 separation, with permeability higher than that of known composite materials. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1379–1384, 2003

Permeation and sorption of various organic liquids (chlorinated hydrocarbons, lower alcohols, hydrocarbons, etc.) in amorphous copolymers of 2,2-bis-trifluoromethyl-4,5-difluoro-1,3-dioxole and tetrafluoroethylene (amorphous Teflons AF) were studied in the temperature range 5–95 °C. Based on permeation rate and solubility coefficients, the diffusion coefficients of organic penetrants in AF copolymers AF were estimated. It was shown that the copolymer with a higher content (87%) of the dioxole component (AF2400), as distinguished by a larger free volume, is much more permeable to liquids than the copolymer AF1600 containing 65% of the dioxole comonomer. In contrast, solubility of organic compounds in both copolymers is hardly affected by their composition. The effects of penetrant parameters, such as critical volume ( V c ) and critical temperature ( T c ) were analyzed. The variation in permeation rates of liquids and gases through these materials are consistent with a mobility (diffusion) controlled mechanism for mass transfer. A trade-off between the Arrhenius parameters for permeability and the van’t Hoff parameters for solubility is demonstrated for pervaporation. On this basis, novel correlations are obtained that enable a determination of the activation energy for permeation E P and the enthalpy of sorption H S from the permeability ( P ) and solubility ( S ) coefficients. Long term tests (up to 12 months) showed excellent time stability of the transport parameters, a property unexpected and quite important for a high flux, high free volume pervaporation material.

Metathesis polytricyclononenes were synthesized via ROMP polymerization in the presence of the 1-st generation Grubbs catalyst and their gas-transport properties were studied for the first time. The aim of this work was to evaluate the influence of Me3E-groups (E = C, Si, Ge) on gas permeation parameters of ROMP materials. New metathesis poly(3-tert-butyltricyclononene-7) and poly(3-trimethylgermyltricyclononene-7) were obtained with high yields (up to 95%) and high-molecular weights (Mw∼3–7×105 g mol−1). The glass transition temperatures of the ROMP polytricyclononenes with Me3E-groups decreased when E was changed from C to Si and then to Ge. It was shown that the polytricyclononene containing Me3Si-groups has the highest gas permeability while the polytricyclononene containing Me3C-substituents has the lowest gas permeability. In addition, the gas permeation parameters were estimated for ROMP Me3Si- and Me3Ge-substituted polytricyclonona-3,7-dienes. So the influence of the second double bond in the monomer units on the permeability of the polymers obtained was studied. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41395.

The modification of polyvinyltrimethylsilane (PVTMS) has been carried out using the radiation-induced graft polymerization. PVTMS is applied as a basis for gas-separating membranes. Acrylonitrile, acrolein, ethyl acrylate, acrylic acid and acrylamide were used as monomers. The grafting was performed both from vapour and liquid phase of monomers and their solutions by the direct radiation method. Some kinetic regularities of radiation graft polymerization of monomers and the character of distribution of grafted polymers along the thickness of PVTMS films were studied. It was shown that grafting improves the chemical resistance, the selective permeability of gases and some mechanical properties of PVTMS films.

The selectivity of Al-Pt catalysts (0.25% Pt) in the dehydrogenation of n-decane and n-hexane to n-alkenes depends on the properties of the aluminum oxide and increases in the order: Pt/η-Al2O3 Pt/θ-Al2O3.