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Polynorbornenes are ideal materials for systematic structure–property investigations designed to correlate gas-transport properties to polymer structure. The modular nature of norbornene-based systems provides a facile route towards the synthesis of diverse polymeric materials. Though many valuable correlations between gas-permeability and polynorbornene structure have been summarized in a prior review (2017), many of these efforts focused heavily on the design of materials with high permeabilities. More recently, the design of next-generation polynorbornene membranes has shifted toward the development of materials that are highly selective for multiple targeted gas separations. Since 2017, tremendous progress has been realized in the preparation of stable and highly selective polynorbornenes for membrane-based gas separations. Examples include polynorbornene derivatives that exhibit very high selectivity for CO2/N2 and light hydrocarbon (e.g., C3+/C1) separations, some of which exhibit gas separation performances that approach or exceed the 2008 upper bound. Herein, we summarize prior findings, present recent developments in the field of advanced polynorbornene membrane materials for targeted gas separations, and provide an outlook for the future of this field of research.

New norbornene-based functional multiblock copolymers containing ethylene–vinyl acetate/vinyl alcohol sequences are synthesized via the olefin cross-metathesis reaction of polynorbornene with poly(5-acetoxy-1-octenylene) followed by CC bond hydrogenation and acetoxy group deprotection. Macromolecular cross-metathesis, a recently developed type of interchange reaction, was carried out in the presence of Grubbs’ ruthenium catalysts and monitored by in situ1H NMR and ex situ13C NMR spectroscopy. This results in copolymer formation and its gradual randomization by segment reshuffling promoted by polymer-based Ru-carbenes. The kinetic study reveals that, despite the presence of bulky acetoxy substituents in polyoctenamer chains, Grubbs’ catalyst interacts with them more easily than with polynorbornene chains, which have cyclopentane rings in the backbone. The rate of the subsequent interchange reaction is controlled by the interaction of [Ru]-poly(5-acetoxy-1-octenylene) carbenes with norbornene units. It is found that the acetoxy groups markedly slow down the interaction of [Ru]-polynorbornene carbenes with the CC bonds in octenamer units. Since these carbenes are relatively unstable, they cause a noticeable decay of the reaction active centers. Our study demonstrates that the chain structure and, therefore, physico-chemical characteristics of multiblock copolymers can be tailored by adjusting the cross-metathesis conditions, such as the polymer concentration, polymer to catalyst ratio, and reaction time. Polymer-analogous reactions of hydrogenation and deacetylation transform octenamer units into ethylene–vinyl acetate/vinyl alcohol segments and thus open up more possibilities for tuning the thermal, gas barrier, and hydrophobic/hydrophilic properties of the synthesized norbornene-based multiblock copolymers.

We investigate the structure–property relations of the multiblock copolymers of norbornene with cyclododecene synthesized via the macromolecular cross-metathesis reaction between amorphous polynorbornene and semicrystalline polydodecenamer in the presence of the first-generation Grubbs catalyst. By adjusting the reaction time, catalyst amount, and composition of the initial system, we obtain a set of statistical multiblock copolymers that differ in the composition and average length of norbornene and dodecenylene unit sequences. Structural, thermal, and mechanical characterization of the copolymers with NMR, XRD, DSC (including thermal fractionation by successive self-nucleation and annealing), and rotational rheology allows us to relate the reaction conditions to the average length of crystallizable unit sequences, thicknesses of corresponding lamellas, and temperatures of their melting. We demonstrate that isolated dodecenylene units can be incorporated into crystalline lamellas so that even nearly random copolymers should retain crystallinity. Weak high-temperature endotherms observed in the multiblock copolymers of norbornene with cyclododecene and other cycloolefins could indicate that the corresponding systems are microphase-separated in the melt state.

Polynorbornenes represent a fruitful class of polymers for structure&ndash, property study. Recently, vinyl-addition polynorbornenes bearing side groups of different natures were observed to exhibit excellent gas permeation ability, along with attractive C4H10/CH4 and CO2/N2 separation selectivities. However, to date, the gas transport properties of fluorinated addition polynorbornenes have not been reported. Herein, we synthesized addition polynorbornene with fluoroorganic substituents and executed a study on the gas transport properties of the polymer for the first time. A norbornene-type monomer with a C6F5 group, 3-pentafluorophenyl-exo-tricyclononene-7, was successfully involved in addition polymerization, resulting in soluble, high-molecular-weight products obtained in good or high yields. By varying the monomer concentration and monomer/catalyst ratio, it was possible to reach Mw values of (2.93&ndash, 4.35) &times, 105. The molecular structure was confirmed by NMR and FTIR analysis. The contact angle with distilled water revealed the hydrophobic nature of the synthesized polymer as expected due to the presence of fluoroorganic side groups. A study of the permeability of various gases (He, H2, O2, N2, CO2, and CH4) through the prepared polymer disclosed a synergetic effect, which was achieved by the presence of both bulky perfluorinated side groups and rigid saturated main chains. Addition poly(3-pentafluorophenyl-exo-tricyclononene-7) was more permeable than its metathesis analogue by a factor of 7&ndash, 21, or the similar polymer with flexible main chains, poly(pentafluorostyrene), in relation to the gases tested. Therefore, this investigation opens the door to fluorinated addition polynorbornenes as new potential polymeric materials for membrane gas separation.

The impact of double bond modification by gem-difluorocyclopropanation (gDFC) in poly(norbornenes) backbone on their gas transport properties was studied for the first time. With this aim the research of gDFC of polynorbornene (PNB) and poly(5-trimethylsilylnorbornene) (PNBSi) in the conditions of sodium chlorodifluoroacetate thermolyses at 180–190 °C in methyl benzoate solution were carried out. The starting poly(norbornenes) were synthesized via ring-opening metathesis polymerization of the corresponding monomers mediated by the first generation Grubbs’ catalyst. The degree of double bonds conversion into the gem-difluorocyclopropane and the molecular weight of modified polymers could be controlled by adjusting the reaction time, sodium chlorodifluoroacetate amount, and polymer concentration in reaction mixture, as well as by addition of inhibitor. The bulky Me3Si-substituent hindered the modification of double bonds in poly(norbornenes)’ backbone. The gDFC decreased the thermal stability of poly(norbornenes). However, the films of modified polymers demonstrated high stability during storage at the ambient conditions, especially in comparison with unmodified polynorbornene. The introduction of gem-difluorocyclopropane in poly(norbornenes) backbone increased their gas permeability coefficients P especially strongly for PNB. Simultaneously the values of ideal selectivity αij = Pi/Pj were not changed or slightly increased. The noted growth of P was caused by increases in the solubility coefficients S. To elucidate the role of the two types of modification fragment ( CF2 and O ) of double bonds a sample was prepared that included both types of the fragments. It was distinguished by increased P and αij values. So, a new and simple approach improving the gas permeation properties of metathesis polynorbornenes was developed. It may be extendable to broader families of polydienes and other polymers containing double bonds in the backbone.

A series of vinyl-addition poly(5-alkyl-2-norbornenes) with varied alkyl side group from methyl to tetradecyl was synthesized and systematically studied in terms of pure and mixed gas permeability. It was found that the length of the side group plays a key role in the gas separation performance. For instance, the permeability of permanent gases through these polymers changed non-linearly with the size of alkyl groups and the highest gas permeability was achieved for the polymers with short side-alkyl groups. Interestingly, a traditional trade-off between gas permeability and selectivity was not observed: vinyl-addition polynorbornene with methyl groups displayed both higher CO2 permeability and higher CO2/CH4 selectivity. The solubility-controlled permeability of hydrocarbons is another feature of these polymers, which is unusual for low free-volume and silicon-free glassy polymers. According to the results of the pure gas permeability study, this feature was realized for all investigated polymers with short and long alkyl-side groups. However, the study of mixed gas permeability through these polymers showed that truly solubility-controlled permeability of hydrocarbons appeared only for the polymers bearing alkyl-substituents larger than ethyl-groups and therefore it is possible to switch on/off this feature for vinyl-addition poly(5-alkyl-2-norbornenes) by the choice of the size of alkyl groups. The obtained results are considered and discussed along with WAXD data and free volume fraction in these polymers.

Silicon-substituted polynorbornenes are an unusual class of polymeric membrane materials, combining the properties of both glassy and rubbery polymers. They exhibit an attractive performance for CO2/N2 separation and for separation of gaseous hydrocarbons. However, addition polynorbornenes with Si-groups (for examples, having Si–O–C, or Si–O–Si-spacers) often suffer from poor film-forming properties due to low molecular weights of the polymers. Herein, by using a new simple and efficient approach to the synthesis of such polymers, we prepared two sets of novel high-molecular-weight polymers based on pure exo-isomers of Si-containing norbornenes and studied their gas transport properties in detail. The desired metathesis and addition polynorbornenes with (C2H5)3Si-, (CH3)3SiO(CH3)2Si- and ((CH3)3SiO)2(CH3)Si-side groups were readily obtained in good or high yields via selective hydrosilylation of norbornadiene-2,5 by commercial silanes followed by polymerization over Ru- or Pd-catalyst. Diffusion (D) and permeability (P) coefficients of these polynorbornenes were determined for permanent gases (He, H2, O2, N2, CO2) and C1–C4 alkanes. The influence of exo-/endo-orientation of substituents on gas transport properties and the relationship between nature of side-groups and membrane properties were evaluated. The data on BET, SEM, WAXD, and fractional free volumes of the polymers are also reported and discussed.

A series of polymers of a new type, which contain rigid polymer main chains (glassy nature) and long flexible side substituents (rubbery nature), were prepared from norbornene derivatives with (AlkO)3Si-groups of a different length (Alk = Me, Et, n-Pr, n-Bu) as promising materials for membrane separation of gaseous hydrocarbons. The 1st generation Grubbs complex and Pd–N-heterocyclic carbene complex in combination with Na+[(3,5-(CF3)2C6H3)4B]− and PCy3 were used as catalysts of metathesis and addition polymerization in the synthesis of high-molecular weight polymers (Mw ≤ 1.1 × 106) with good or high yields (up to 99%). The prepared addition polymers were glassy, while the glass transition temperature of metathesis polymers depended on the length of the alkyl-group in (AlkO)3Si-substituents and it varied in the range of −44 to 61 °C. The dramatic tuning of polymer gas-transport properties was demonstrated by the change of the polymer main chain structure and the length of tri(n-alkoxy)silyl side groups. For example, we have succeeded for the first time in obtaining metathesis polynorbornenes, which turned out to be more permeable than their addition isomers. Not being large free volume polymers, all studied metathesis and addition polytricyclononenes exhibited solubility controlled permeation of hydrocarbons (P(n-C4H10) up to 8100 barrer) and high C4/C1 selectivity (22–49).

Crystallinity of statistical multiblock copolymers of norbornene and cyclooctene with nearly equimolar composition and different degrees of blockiness is studied by differential scanning calorimetry including thermal fractionation by successive self-nucleation and annealing and by X-ray diffraction. The copolymers are synthesized via recently invented reaction of polymer cross-metathesis, as a result of interchain exchange between polynorbornene and polyoctenamer in the presence of Grubbs’ catalyst of the first generation. This catalyst raises the fraction of trans-octenylene units up to more than 80% promoting formation of triclinic crystals. The copolymer degree of crystallinity and melting peak temperature decrease with the cross-metathesis conversion. At the same time the equilibrium melting temperature predicted by the Flory theory of copolymer crystallization is not much affected by the interchange reaction. Compared with the pure polyoctenamer or its equimolar blend with polynorbornene, the norborene-cyclooctene copolymers form considerably smaller crystallites. Thermal fractionation makes it possible to find their size distribution, which correlates with the average length of trans-octenylene blocks. Short annealing the multiblock copolymers above their melting points gives rise to a small but persistent endotherm 5–10 degrees above the annealing temperature, which is absent in polyoctenamer and, therefore, may indicate mixing of segregated norbornene and cyclooctene blocks.

Cross-metathesis of 5-hydroxycyclooctene and norbornene homopolymers affords the multiblock copolymer possessing a broad range in the degree of blockiness (from 0.03 to 1).

Heterochain polycarbosilanes are well-known materials possessed important properties. Some of their applications, such as gas separation membranes, require polymers with high molecular weight that provide good film-forming and mechanical properties. In this research, the synthesis of poly(1,1-dimethyl-1-silapentene) via the ring-opening metathesis polymerization (ROMP) of 1,1-dimethyl-1-silacyclopentene and the acyclic dienes metathesis (ADMET) of diallyldimethylsilane mediated by Ru-carbene Grubbs complexes 1st - 3rd generations as well as Hoveyda-Grubbs 2nd generation catalyst were studied for the first time. High molecular weight poly(1,1-dimethyl-1-silapentene) was synthesized by ROMP of 1,1-dimethyl-1-silacyclopentene. Varying the type and loading catalyst, temperature and monomer concentration, we obtained poly(1,1-dimethyl-1-silapentene) with Mw = 100–143 kDa, which is significantly higher (5–7 times) than that reached previously by olefin metathesis polymerization. The activities of 1,1-dimethyl-1-silacyclopentene and cyclopentene in ROMP were compared using 1H NMR monitoring the conversion of their double bonds. The ADMET polymerization of diallyldimethylsilane led to oligomers with the average polymerization degree not exceeded 4.4.

Herein four modified polymers were prepared from readily available addition poly(5-vinyl-2-norbornene) (PVNB) and their gas-transport properties were studied in detail. Hydrogenation, epoxidation, cyclopropanation and thiol-en reactions were chosen for the modifications of PVNB. Hydrogenation of PVNB was performed using p-toluenesulfonyl hydrazide. Epoxidation of PVNB was realized employing m-chloroperoxybenzoic acid. Cyclopropanation of PVNB was carried out using diazomethane in the presence of a Pd-catalyst. For thiol-en reaction, thioacetic acid was applied as the source of a thiol and AIBN as an initiator. All listed modifications were performed in high yields (≥80%) without the destruction of polymer main chains. The degree of functionalizations was up to 99%. The influence of these modifications on the properties of the resulting polymers was evaluated. Cyclopropanation and hydrogenation of PVNB led to an enhancement of gas permeability with minimal decrease in selectivity, while epoxidation or thioacetylation gave a substantial increase in CO2/N2 selectivity with decrease in permeability. The modified polymers with polar side-groups exhibited attractive selectivities for CO2/N2, CO2/CH4 and H2/N2 gas separations.

The synthesis and gas permeation properties of addition-type poly(3,3-bis(trimethylsilyl)tricyclononene-7) (PTCNSi2g) are first reported. High molecular weight PTCNSi2g was obtained via addition polymerization of 3,3-bis(trimethylsilyl)tricylononene-7 on a Pd-containing catalyst. It possessed a BET surface area as high as 790 m2/g. This new polymer is distinguished by extra high gas permeability and solubility controlled permeation of hydrocarbons. Positron annihilation lifetime spectroscopy revealed extremely large size of free volume elements (8.3 A). PTCNSi2g is a promising membrane material for separation of natural gas.

A new fluorine-containing tricyclononene was synthesized by [2σ + 2σ + 2π]-cycloaddition of quadricyclane with perfluorocyclohexene. This cycloadduct was subjected to ring-opening metathesis polymerization. Gas-transport properties of the obtained polymer were estimated.

Herein we report a new approach to cross-link substituted addition polynorbornenes. The cross-linking was realized by the copolymerization of SiMe3-containing tricyclononene with low amounts of tricyclononene bearing triethoxysilyl groups followed by the hydrolysis of Si(OEt)3-groups with the formation of interchain siloxane bonds. The amount of cross-links proved to depend on the composition of copolymers and cross-linking conditions, which allowed to perform controlled cross-linking of polynorbornenes. The insoluble polymers with good film forming properties were obtained by cross-linking. The developed method could find further application for the modification of polynorbornenes.

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.

Herein the synthesis of a new series of fluorine containing tricyclononenes using [2σ+2σ+2π]-cycloaddition of quadricyclane with fluorine containing alkenes is described. According to the experiment the reactivity of fluorine containing alkenes in [2σ+2σ+2π]-cycloaddition reaction was established. The obtained cycloadducts were successfully involved in ring-opening metathesis polymerization on Ru-based catalytic systems. The obtained polymers were glassy and amorphous. The investigation of gas-transport properties of the new materials with improved selectivity towards different pairs of gases was executed.Herein the synthesis of a new series of fluorine containing tricyclononenes using [2σ+2σ+2π]-cycloaddition of quadricyclane with fluorine containing alkenes is described. According to the experiment the reactivity of fluorine containing alkenes in [2σ+2σ+2π]-cycloaddition reaction was established. The obtained cycloadducts were successfully involved in ring-opening metathesis polymerization on Ru-based catalytic systems. The obtained polymers were glassy and amorphous. The investigation of gas-transport properties of the new materials with improved selectivity towards different pairs of gases was executed.

The reaction of [2σ + 2σ + 2π]-cycloaddition of quadricyclane with olefins is an attractive way for regio- and sterospecific synthesis of norbornene derivatives (exo-tricyclononenes) with desired substituents. The presence of Cl3Si-containing groups in such compounds permits different monomer modifications for the development of new materials. Herein, for the first time the theoretical and experimental study of the behavior of different ethylenes containing three silyl-groups in the reaction of [2σ + 2σ + 2π]-cycloaddition with quadricyclane was systematically performed. Based on the data obtained for this reaction the activity scale of the ethylene derivatives was established, and the explanations for an ethylene activity were suggested. As a result, a new family of Si-containing tricyclononenes was successfully synthesized. As an example of a possible modification, the methylation of the sterically hindered cycloadducts was investigated and the conditions for full methylation were found. Considering that gas permeability of polymers increases with the increase of a number of the side Me3Si-groups, the compounds are interesting monomers for synthesis of membrane polymers possessing high gas permeability values.

To improve organic solvent preferential permeation of poly[1-(trimethylsilyl)-1-propyne] (PTMSP) and to provide efficient separation of dilute 1-butanol/water mixtures, the membranes were modified by the addition of minor amounts of a soft elastomeric filler, poly(dimethylsilmethylene) (PDMSM), to the host polymeric matrix. As compared with virgin PTMSP membranes, the modified membranes demonstrate better 1-butanol/water pervaporation selectivity and permeability. This unique coupled phenomenon is observed at low concentrations of the elastomeric filler (~1–3 wt%) in the host matrix and for the feed aqueous mixtures containing 0.6–3.6 wt% of butanol. For vacuum pervaporation of butanol solutions, introduction of only 1.2 wt% of PDMSM into the PTMSP matrix makes it possible to increase the permeate flux up to 75% and the separation factor up to 67%. When studying pervaporation of the feed solution containing 2 wt% of butanol, the dependences of the permeate flux and separation factor on the elastomeric filler content in the host matrix show the well-pronounced maxima at 1.2–3 wt% (MW of the elastomer is 83–1000 kg/mol). In this case, the attained permeate flux is 1.5–1.8 times higher than that of the virgin PTMSP, and the separation factor increases by a factor of 1.4–1.7. The corresponding values of thickness-corrected flux and separation factor for the PTMSP/PDMSM membranes are 3.5–4.0 kg m/(m 2 h) and 112–136, respectively. More specifically, the 30 µm thick PTMSP/PDMSM (98/2) membrane exhibited permeate flux 0.12 kg/(m 2 h) and separation factor 128 upon pervaporation of 2 wt% aqueous butanol solution at 25 °C. The experiments on the equilibrium sorption of butanol solutions on the PTMSP membranes modified by the elastomeric filler revealed similar dependences with their well-pronounced maxima in the same region of the PDMSM content. The highest value of membrane selectivity α mem for PTMSP/PDMSM is 8.9 as compared with 5.3 for the virgin PTMSP membranes. Qualitative explanation of the enhanced pervaporation selectivity coupled with the improved permeate flux for the PTMSP/PDMSM membranes was advanced.

Cationic polymerization of 5-methylene-2-norbornene, 5-ethylidene-2-norbornene, 5-vinyl-2-norbornene, dicyclopentadiene, and norbornadiene-2,5 in the presence of boranes was systematically studied. It was found that B(C6F5)3 in combination with caprylic acid, 1-phenylethanol or water was a highly active catalyst for the polymerization of 5-alkylidene-2-norbornenes. The corresponding cationic polymers were obtained with up to yields 95% and with high molecular weights (Mw ≤ 430 000). The activity of 5-alkylidene-2-norbornenes in the polymerization using B(C6F5)3 containing systems was the highest among the other monomers (5-vinyl-2-nobornene, dicyclopentadiene, and norbornadiene-2,5). BF3·O(C2H5)2 based catalysts turned out to be not so active for cationic polymerization of monomers compared with the systems containing B(C6F5)3. They produced polymers predominantly containing the addition (vinyl) units instead of isomerization units. The structure of the polymer main chain units depended on the nature of t...

Nanoporous glassy polymers are perspective materials for the fabrication of gas separation membranes, especially for the application of gaseous hydrocarbon separation. However, the drawback of such materials is the pronounced physical aging resulting in the dramatic drop of gas transport properties due to relaxation of high-free-volume fraction in time. Herein, a novel and readily available group of such glassy polymers is reported based on 5-alkylnorbornenes. These polymers are easily synthesized from dicyclopentadiene and α-olefins by Diels-Alder reaction and vinyl (addition) polymerization of the formed cycloadducts in the presence of ([(η3 -C3 H5 )PdCl]2 /PCy3 /Na+ [B(3,5-(CF3 )2 C6 H3 )4 ]- catalyst. The obtained polymers display low-fraction free volume, stable gas permeability over time, and possess a unique feature for the glassy polymers-solubility controlled permeation of hydrocarbons and enhanced C4 H10 /CH4 selectivity.

Polymers of a new class of glassy materials that demonstrate unusual solubility controlled permeability—metathesis Si–O–Si containing polynorbornenes—are synthesized. The introduction of bulky Si(OSiMe3)3 substituents into the polynorbornene backbone is shown to provide the polymers with increased gas permeability, higher than all other known metathesis polynorbornenes. The prepared glassy polymers reveal behavior similar to that known for rubbers and, in particular, siloxanes: permeability coefficients increase for the penetrants of larger size. That is, these polymers are capable to remove higher hydrocarbons from natural and associated petroleum gases.

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 sorption and transport properties of n -alkane and alkyl-alcohol vapors in addition-type poly(trimethyl silyl norbornene) (PTMSN) were studied at 35 °C and at various activity values. PTMSN is a high free volume polymer that shows very high solubility to the condensable vapors and can be considered a promising material for several applications, such as gas/vapor membrane separations. Sorption and diffusion experiments with n -alkanes ( n -C 4 , n -C 5 , n -C 6 ) and alkyl alcohols (CH 3 OH, C 2 H 5 OH, n -C 3 H 7 OH) were performed as well as dilation measurements with n -C 5 and n -C 6 , at 35 °C. The behavior of the alcohol vapors differs from that of alkanes, mainly for the shape of the solubility, diffusivity and mobility isotherms: this phenomenon, as well as the diffusion trend of the different vapors, was explained by the different interactions between the penetrants and the hydrocarbon-based polymer. The permeability isotherms were also estimated from solubility and diffusivity data, showing that the permeability of PTMSN lies in between those of AF2400 and PTMSP. Finally, the dependence of the transport parameters of n -alkanes in PTMSN on penetrant pressure and molecular weight was analyzed, and compared to that observed in other high free volume glassy polymers. The activity-based solubility coefficients as well as permeabilities of alkanes in PTMSN show a weak dependence on molecular weight, while in PTMSP permeability increases and in AF2400 decreases with increasing the number of carbon atoms.

N and its derivatives can be polymerized, producing high molecular weight products of entirely different structure of the main chain depending on the choice of the catalysts. In the presence of the catalysts such as WCl6, RuCl3, Re2O7/Al2O3, or Grubbs Ru carbene complexes, ring-opening metathesis polymerization (ROMP) proceeds leading to formation of cyclolinear unsaturated polymers. On the other hand, norbornenes can be also polymerized via opening of double bonds like vinyl monomers in the presence of Ni and Pd catalysts. This addition-type polymerization leads to bulky bicyclic repeat units that do not contain unsaturated bonds. Most of the ROMP polynorbornenes are glassy polymers (Tg in the range ca. 40 100 C) with relatively small gas permeability (P(O2) = 1 100 barrer). However, introduction of silicon-containing substituents in monomer units significantly increases this parameter. Addition-type polynorbornenes have rigid main chains, their glass transition temperatures in most cases are above the onset of thermal decomposition (>400 C), and those that contain bulky Me3Si groups are characterized by much higher gas permeability (P(O2) = 90

A novel class of silicon-containing rubbers is proposed as membrane materials for separation of hydrocarbons of natural and associated petroleum gas. Homo-polymers of general formulas –Si(CH 3 ) 2 CH 2 – (PDMSM) and –Si(CH 3 ) 2 CH 2 CH 2 CH 2 – (PDMSTM) and the copolymers with the same randomly alternating repeat units were prepared by thermal initiated polymerization of strained silicon-containing four-member cycles. These polymers have low glass transition temperatures and reveal solubility controlled gas permeation properties. The highest permeability is characteristic for PDMSM, however, it has poor film forming properties. On the other hand, amorphous copolymers exhibit combination of good film forming properties and relatively high permeability. Transport properties of PDMSM were successfully simulated by molecular dynamics using a very efficient united-atom force field.

Consequitive treatment of quadricyclane with trichlorovinylsilane and methanol affords 3-trimethoxysilyltricyclo[4.2.1.02,5]non-7-ene which on reaction with triethanolamine gives a new silatrane promising as a gas separation membrane 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.

A novel syntheses of Z-5-decenol, Z-5-decenyl acetate, Z-7-dodecenol, Z-7-dodecenyl acetate, Z-9-tricosene, Z-7,8-epoxy-2-methyloctadecane which are sex pheromone components of Lepidoptera and Diptera orders, have been realized via stereoselective cometathesis of 1,5-cyclooctadiene with ethylene in the presence of MoCl 5 /SiO 2 -SnMe 4 as a key reaction. The main cometathesis product, 1,Z-5,9-decatriene, has been converted into pheromone components mentioned above by regioselective partial hydroboration or hydrozirconation with help of 9-BBN and Cp 2 ZrHCl, correspondingly. The protonolysis of the obtained zirconosene derivative gave 1,Z-5-decadiene. Hydroboration-oxidation or hydroboration-C 2 -homologation of the latter led to Z-5- or Z-7 monoene pheromone components. Hydroboration-iodination of terminal double bond in 1,Z-5,9-decatriene, and further cross-coupling of the obtained iodine derivative with convenient lithium cuprates resulted in Z-9-tricosene, the main sex pheromone component of House Fly ( Musca Domestica ), or in 2-methyl-Z-7-octadecene, the precursor of Gypsy Moth ( Lymantria Dispar ) sex attractant.

[2σ + 2σ + 2π]-Cycloaddition of quadricyclane to trissilylated ethenes Cl3 – nMenSiCH=CSiMenCl3 – n(SiMe3 – nCln) (n = 1, 2) at 95 °C affords 3,3,4-trissilylated exo-tricyclo[4.2.1.02,5]non-7-enes. Tetrakis(trichlorosilyl)ethene does not react with quadricyclane.

Herein we describe new materials for membrane gas separation process with improved selectivities towards different pairs of gases. Organic nature fillers (modified calix[4]arenes, calix[8]arenes and modified α-, β-, γ-cyclodextrins) were used as additives to poly(trimethylsilyltricyclononene-7) (PTCNSi1)in order to study correlations between structure of the filling agent and gas transport parameters of the composite membranes. It was shown a positive influence of calixarenes and cyclodextrins as additives on permselectivity of the membranes. For instance, selectivity towards H2/CH4 gas pair increased almost in 2.4 times when calix[4]arene with Et- and tert-Bu- group was introduced into polymeric matrix. Detailed study of the PTCNSi1 adsorbtion/desortion data is presented. The obtained composites were characterized by TEM, WAXD, PALS and BET analysis.

A new polymer, poly[5-(trimethylgermylmethyl)-1,3-cyclopentylenevinylene], was synthesized via ROMP of 5-(trimethylgermylmethyl)-2-norbornene in the presence of RuCl 3 .3H 2 O, RuCl 3 (PPh 3 ) 3 and RuCl 2 (PPh 3 ) 3 catalysts. The structure of the synthesized polymer was determined on the basis of IR, 1 H NMR and 13 C NMR spectra. The gas transport properties for this polymer have been studied.

In this work the authors report the preparation of new addition copolymers based on 3-trimethylsilyltricyclononene-7 (TCNSi1) and 3,3,4-tris(trimethylsilyl)tricyclononene-7 (TCNSi3). A number of high molecular weight copolymers are synthesized with the content of TCNSi3 units from 5 up to 20 mol% in the presence of catalyst Pd(OAc)2/[Ph3C]+[B(C6F5)4]− with the yields of 50%–80%. The obtained copolymers are amorphous. They possess large free volume elements (R 3/R 4) based on positron annihilating lifetime spectroscopy analysis and Brunauer–Emmett–Teller surface area up to 640 m2 g−1. Permeability coefficients of the obtained copolymers are determined for a wide range of gases He, H2, O2, N2, CO2, CH4, C2H6, C3H8, n-C4H10. The correlation between the content of TCNSi3 units and gas permeation parameters of the resulting copolymers is explored. It is found that the introduction of TCNSi3 moieties results in the rise in gas permeability of the corresponding copolymers. Moreover, increase in TCNSi3 content in the copolymer leads to an increase of gas permeability.

Unusually high vapor solubilities of hydrocarbons in the rubbery polymer [Si(Me)(CH 2 SiMe 3 )CH 2 CH 2 CH 2 ] n are reported

A novel syntheses of Z-5-decenol, Z-5-decenyl acetate, Z-7-dodecenol, Z-7-dodecenyl acetate, Z-9-tricosene, Z-7,8-epoxy-2-methyloctadecane which are sex pheromone components of Lepidoptera and Diptera orders, have been realized via stereoselective cometathesis of 1,5-cyclooctadiene with ethylene in the presence of MoCl 5 /SiO 2 -SnMe 4 as a key reaction. The main cometathesis product, 1,Z-5,9-decatriene, has been converted into pheromone components mentioned above by regioselective partial hydroboration or hydrozirconation with help of 9-BBN and Cp 2 ZrHCl, correspondingly. The protonolysis of the obtained zirconosene derivative gave 1,Z-5-decadiene. Hydroboration-oxidation or hydroboration-C 2 -homologation of the latter led to Z-5- or Z-7 monoene pheromone components. Hydroboration-iodination of terminal double bond in 1,Z-5,9-decatriene, and further cross-coupling of the obtained iodine derivative with convenient lithium cuprates resulted in Z-9-tricosene, the main sex pheromone component of House Fly ( Musca Domestica ), or in 2-methyl-Z-7-octadecene, the precursor of Gypsy Moth ( Lymantria Dispar ) sex attractant.

Addition polymerization of norbornenes bearing Me3Si-substituents was studied in the presence of Ni and Pd-containing catalyst systems. The main attention was paid to synthesis of bis(trimethylsilyl)norbornenes and their behaviour in the addition polymerization conditions. Unlike mono(trimethylsilyl)norbornene they were inactive in addition homopolymerization. However, their copolymerization with norbornene and its alkyl derivatives was successfully realized. Poly(5-(trimethylsilyl)norbornene) demonstrated high gas transport parameters in respect to hydrocarbon gases.

Kinetics of α-olefin metathesis in the presence of binary (MoCl5/ SiO2-Me4Sn) and ternary catalytic systems (MoCl5/SiO2-Me4Sn-ECl4, E = Si or Ge) was studied. Specifically, kinetics and reactivity of 1-decene, 1-octene, and 1-hexene in the metathesis reaction at 27°C and 50°C in the presence of MoCl5/ SiO2-SnMe4 were examined and evaluated in detail. It was shown that experimental data comply well with the simple kinetic equation for the rate of formation of symmetrical olefins with allowance for the reverse reaction and catalyst deactivation: \(r = \left( {k_1 \cdot c_\alpha - k_{ - 1} \cdot c_s } \right) \cdot e^{ - k_d \cdot \tilde n_{tot} } \). The coefficients for this equation were determined, and it was shown that these α-olefins had practically the same reactivity. It was found that reactivation in the course of metathesis took place due to the addition of a third component (silicon tetrachloride or germanium tetrachloride in combination with tetramethyltin) to a partially deactivated catalyst. The number of active centers was determined (5–6% of the amount of Mo) and the mechanisms of formation, deactivation, and reactivation were proposed for the binary and ternary catalytic systems. The role of individual components of the catalytic systems was revealed.

Green metathesis chemistry , Green metathesis chemistry , کتابخانه مرکزی دانشگاه علوم پزشکی تهران

Ring-opening metathesis polymerization of a series of substituted norbornenes was carried out. Special attention was paid to the polymerization of monomers bearing silicon-containing groups, e.g., trimethylsilylnorbornene. Various heterogeneous and homogeneous tungsten-, rhenium- and ruthenium-based systems were used as catalysts. It was possible to obtain polymers of some norbornenes having reactive SiCl and SiOR bonds as well as groups capable of polymerizing via different mechanisms. The latter remained unchanged during the ring-opening of the norbornenes and could be used for the further modification of these polymers. Some data on the polymerization of various cycloolefin pairs are presented. It was found that some of the new silicon-containing polynorbornenes belong to the group of the most permeable and rather permselective polymers.