Journal of membrane science 2024: Vinyl-addition polynorbornenes with glycerol and diethylene glycol moieties: synthesis and structure-property study

• A set of new norbornene-type monomers containing linear and branched substituents with three C–O–C fragments was synthesized in good yields from commercially available glycerol and diethylene glycol monomethyl ether.

• As a result of optimizing the reaction conditions, a series of robust thin membranes was successfully prepared directly from the polymerization mixtures in the air.

• Gas separation performance for a wide range of gases was evaluated for the synthesized polymers, and new valuable structure-property relationships were found.

• Such membranes display the facilitated transport of CO2 and solubility-controlled hydrocarbon separation selectivity. The increase in the amount of C–O–C fragments in side chains enhances these effects, but only in the case of the linear structure of the substituents.

• The facilitated transport of CO2 is due to the specific dipole-quadrupole interaction between CO2 molecules and polymer matrix. For the studied polymers, the contribution of this specific interaction to the solubility of CO2 achieves 64 %.

Learn more in Journal of Membrane Science 2024
Polymers 2023: Vinyl-addition homopolymerization of norbornenes with bromoalkyl groups

• Vinyl-addition polymers from norbornenes with bromoalkyl groups are widely used as precursors of anion exchange membranes; however, high-molecular-weight homopolymers from such monomers are often difficult to prepare.

• In the present paper, the systematic study of vinyl-addition polymerization of norbornenes with various bromoalkyl groups in the presence of Pd-NHC catalysts was performed.

• Norbornenes with different lengths of hydrocarbon linker (one, two, and four CH2 groups) between the bicyclic norbornene moiety and the bromine atom were used as model monomers. The relative reactivity of such monomers in copolymerization was assessed.

• Variation of polymerization conditions allowed obtaining of high-molecular-weight homopolymers based on norbornenes with bromoalkyl groups (Mn up to 1.4 × 106).

• The basic physico-chemical properties of the prepared polymers were studied and considered together with the results of vinyl-addition polymerization.

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Journal of Membrane Science 2023: CO2-selective vinyl-addition polymers from nadimides: Synthesis and performance for membrane gas separation

• Polymers combining saturated rigid main chains and imide moieties were synthesized through vinyl-addition polymerization of substituted nadimides (VAP polymers) and assessed as potential membrane materials for gas separation for the first time

• Valuable structure-property relationships were established. VAP polynorbornene with fluoroaryl-groups in imides moieties exhibited the combination of high CO2 permeability with attractive CO2/N2 and CO2/CH4 selectivities.

With CO2 permeability of >1300 Barrer and CO2/CH4 separation selectivity of 29, the performance of the polymer exceeded that of other VAP and metathesis nadimide polymers.

Learn more in Journal of Membrane Science 2023
Polymer 2023: Microporous polynorbornenes bearing carbocyclic substituents: Structure-property study

• Structure-property study of polynorbornenes with various carbocycles in side chains.

• Soluble and readily available microporous polymers with large surface area.

• The effect of main- and side-chains on the porosity was studied.

• Large values of surface area are for polymers with framed carbocyclic groups.

Learn more in Polymer 2023
ACS Catalysis 2022: Air-Stable Single-Component Pd-Catalysts for Vinyl-Addition Polymerization of Functionalized Norbornenes

• Cationic Pd-complexes with N-heterocyclic carbene ligands (NHC ligands) and weak coordinating anion ligands were prepared and shown to be an effective catalysts for vinyl-addition polymerization of norbornenes.

• Air stable (solid and in solution) complexes are extremely efficient in polymerization of functionalized norbornenes containing reactive functional groups.

Such single component catalysts remain effective even at concentrations as low as 2 ppm.

Tuning the nature of NHC and allyl ligands in [(NHC)Pd(allyl)L]+A complexes let perform living VAP, yielding block copolymers.

Learn more in ACS Catalysis 2022
Polymers 2022: Chiral Polymers from Norbornenes Based on Renewable Chemical Feedstocks

• A set of new chiral monomers from cis-5-norbornene-2,3-dicarboxylic anhydride and chiral alcohols of various natures was prepared.

• High molecular weight metathesis polymers ( Mw in the range 1.9 × 105–5.8 × 105) were obtained.

The polymers exhibited high thermal stability and good film-forming properties. Glass transition temperatures for the prepared polymers varied from −30 °C to +139 °C.

The prepared polymers represent a new attractive platform of chiral polymeric materials for enantioselective membrane separation and chiral stationary phases for chromatography.•

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Polymer 2022: Polymers from organosilicon derivatives of 5-norbornene-2-methanol for membrane gas separation

• A simple synthesis of norbornene monomers with Si–O–C motifs.

• Structure-property study of polynorbornenes with trialkylsiloxy groups.

• Opposite effects of substituent on permeability for glassy and rubbery polymers.

• Solubility-controlled dependence of permeability on the length of alkyl groups.

• Alk3SiO-groups are preferable for membranes rather than (AlkO)Alk2Si-groups.

Learn more in Polymer 2022
European Polymer Journal 2022: Olefin cross-metathesis of polynorbornene with polypentenamer: New norbornene–cyclopentene multiblock copolymers

• Multiblock PNB–PCP copolymers were synthesized by cross-metathesis.

• Inclusion of CP units into copolymer is hampered by PCP depolymerization.

• Polymer concentration during the reaction determines the copolymer chain structure.

• Other key factors are type of the catalyst and temperature.

• Copolymer hydrogenation allows to reveal the details of its structure.

Learn more in European Polymer Journal 2022
Journal of Membrane Science and Research 2022: Molecular mobiluty of Polynorbornenes with Trimethylsiloxyxilyl side groups: Influence of the polymerization mechanism

Dielectric and calorimetric studies on metathesis and addition-type polytricyclononenes, both based on the same monomer bearing three pendant -OSiMe3 groups, are reported.

• For the addition-type polymer, dielectric spectroscopy reveals a ß*-process related to the microporosity, whereas for its metathesis counterpart, the segmental dynamics (α-process) manifests.

• A significant conductivity contribution is detected for both samples which for the microporous addition-type polymer is three orders of magnitude greater than for the metathesis polymer.

• The calorimetric methods detected the glass transition for the metathesis polymer in agreement with the observed dielectric α-process.

• The discussed results reflect significant differences in molecular mobility of the two polymers affecting the appearance of microporosity which strongly determines the gas transport properties.

Learn more in Journal of Membrane Science and Research 2022
Polymers 2022: Gas-Transport and the Dielectric Properties of Metathesis Polymer from the Ester of exo-5-Norbornenecarboxylic Acid and 1,1′-Bi-2-naphthol

We synthesized a new metathesis polymer from exo-5-norbornenecarboxylic acid and 1,1′-bi-2-naphthol.

• The polymer is amorphous and glassy (Tg = 161 °C), and it shows good thermal stability. Unlike most, polyNBi is a classic low-permeable glassy polymer.

• Being less permeable than polyNB, polyNBi unexpectedly showed a lower value of dielectric permittivity (2.7 for polyNBi vs. 5.0 for polyNB).

• Molecular design of polynorbornenes has great potential to obtain polymers with desired properties in a wide range of required characteristics.

Learn more in Polymers 2022
Energy and Fuels 2022: High-Energy-Density Liquid Spiro-Norbornanes from Methylenenorbornane

New spiro-hydrocarbons obtained from a versatile norbornane derivative.

The effect of introducing a spiro-center is dependent on the nature of carbocycles at a spiro-carbon atom.

Spirocycloalkenes with two norbornane motifs at a spiro-center have exhibited much higher values of densities and energy densities
than the related hydrocarbons without a spiro-center and JP-10.

Learn more in Energy & Fuels 2022
Journal of Membrane Science 2022: Polynorbornenes bearing ether fragments in substituents: Promising membrane materials with enhanced CO2 permeability

Norbornenes with cellosolve moieties are involved in vinyl-addition polymerization.

• Structure-property study of polynorbornenes with ether groups for CO2/N2 separation.

• Ether fragments improve permeability of gaseous hydrocarbons.

• Cellosolve moieties provide facilitated transport of CO2.

• Specific interactions between CO2 and cellosolve moieties are confirmed.

Learn more in Journal of Membrane Science 2022
Fuel Processing Technology 2022:
Design and preparation of liquid polycyclic norbornanes as potential high performance fuels for aerospace propulsion

• Four new liquid polycyclic norbornane-containing hydrocarbons were designed and prepared.

• Relationships between molecular structure and fuel properties were studied.

• The hydrocarbons exhibited density up to 1.0799 g/mL, kinematic viscosity up to 1.89 mm2·s−1 and low freezing points.

• Energy densities of the polycyclic norbornane-containing hydrocarbons were up to 45.38 MJ/L.

Learn more in Fuel Processing Technology 2022
Polymer Chemistry 2021: Cocatalyst versus precatalyst impact on the vinyl-addition polymerization of norbornenes with polar groups: looking at the other side of the coin
We report our examination of the precatalyst and cocatalyst influence on vinyl-addition polymerization of two types of norbornene monomers with bulky and polar groups (substituted nadimides and norbornenes with cellosolve motif)

• The key to successful vinyl addition polymerization of these monomers is the proper combination of a cocatalyst and a Pd precatalyst. Both components of a catalytic system seem to play equal roles.

Impact of the cocatalyst depends on the monomer nature and can be different for norbornenes with nonpolar and polar groups.

These results provide an insight and opportunity for further work expansion in order to obtain new high-performance polymers based on strained cycloalkenes with polar groups, which are not currently available

Learn more in Polymer Chemistry 2021
Polymer Chemistry 2021: Substituted polynorbornene membranes: a modular template for targeted gas separations

The modular nature of norbornene-based systems provides a facile route towards the synthesis of diverse polymeric materials.

•Tremendous progress has been realized in the preparation of stable and highly selective polynorbornenes for membrane-based gas separations

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.

Learn more in Polymer Chemistry 2021
Chemical Communications 2021: Activation of Pd-precatalysts by organic compounds for vinyl-addition polymerization of a norbornene derivative

An approach to activating Pd-complexes without using organometallic additives has been developed for addition polymerization of norbornenes

• Aryl iodides and aryl diazonium salts were efficiently applied as cocatalysts to Pd(0)- and Pd(2+)-complexes.

Novel approach is closely connected to Pd-catalyzed coupling reactions from organic chemistry. That can shed light on previously unknown processes in catalysis on vinyl-addition polymerization of norbornene derivatives.

• New systems catalyzed polymerization of norbornenes containing bulky and polar functional groups both in an inert atmosphere and air resulting in soluble and high-molecular-weight saturated polymers

Learn more in Chemical Communications 2021
Fuel Processing Technology 2021: Design and preparation of liquid polycyclic norbornanes as potential high performance fuels for aerospace propulsio
Four new liquid polycyclic norbornane-containing hydrocarbons were designed and prepared.

• Relationships between molecular structure and fuel properties were studied.

• The hydrocarbons exhibited density up to 1.0799 g/mL, kinematic viscosity up to 1.89 mm2·s−1 and low freezing points.

• Energy densities of the polycyclic norbornane-containing hydrocarbons were up to 45.38 MJ/L.

Learn more in Fuel Processing Technology 2021
Journal of Membrane Science 2021: Microscopic dynamics of highly permeable super glassy polynorbornenes revealed by quasielastic neutron scattering
•The molecular mobility of highly permeable polynorbornenes is considered.

• Bulky side groups lead to an intrinsic microporosity.

• Qusielastic neutron scattering is chosen as experimental method.

• The observed mobility is assigned to the rotation of methyl groups

Learn more in Journal of Membrane Science 2021
Journal of Membrane Science 2021: Switching on/switching off solubility controlled permeation of hydrocarbons through glassy polynorbornenes by the length of side alkyl groups
• Structure-property study of vinyl-addition poly(5-alkyl-2-norbornenes) was performed.

• Permeability of permanent gases changed non-linearly with the size of alkyl groups.

• The highest gas permeability was achieved for the polymers with short side-alkyl groups.

• No traditional trade-off between gas permeability and selectivity was for these polymers.

• Truly solubility-controlled permeability of hydrocarbons appeared for the polymers with butyl or larger side-groups.

Learn more in Journal of Membrane Science 2021
Fuel 2021: Metal chlorides supported on silica as efficient catalysts for selective isomerization of endo-tetrahydrodicyclopentadiene to exo-tetrahydrodicyclopentadiene for JP-10 producing

Metal chlorides on SiO2 were prepared as catalysts for synthesis of JP-10 fuel.

• Properties of the catalysts were studied by SEM, low temperature N2 adsorption, NH3-TPD.

• Activity of the catalysts was evaluated in endo-/exo-THDCPD isomerization.

• AlCl3 on SiO2 exhibited the highest catalytic activity, selectivity was higher 99%.

• Thermodynamic and kinetic parameters for the isomerization reaction were evaluated.

Learn more in Fuel 2021
Journal of Membrane Science 2021: Polymers based on exo-substituted norbornenes for membrane gas separation
A simple and selective approach to Si-substituted poly(exo-norbornenes) was developed.

• Structure-property study of poly(siloxanylnorbornenes) for C4H10/CH4 separation.

• Si–O–Si-moieties improved light hydrocarbons permeability.

• Effect of exo-/endo-orientation of substituent on gas permeability was studied.

Learn more in Journal of Membrane Science 2021
Polymer reviews 2021: Design and Synthesis of Porous Organic Polymeric Materials from Norbornene Derivatives
This comprehensive review surveys recent research trends in the development of porous polynorbornenes.

  • A rational design was achieved in metathesis, addition, and CANAL polymers as an extension of the modular strategy using norbornene motifs as building blocks.

  • Tuning the structure of norbornene-containing monomer units allowed obtaining high-free-volume polymers with apparent Brunauer–Emmett–Teller (BET) surface areas up to 1000 m2/g that made these materials promising for various engineering applications such as membrane gas separation, gas sorbents, CO2 capture, scaffolds to support catalysts, or reagents for catalysis.

  • The synthesis and porous characteristics of polynorbornenes are presented along with the discussion of correlations between the chemical structure of these materials and their porous structures.

  • Possible important applications of porous polynorbornenes are also emphasized

Learn more in Polymer reviews 2021
Fuel 2021: Synthesis and properties of high-energy-density hydrocarbons based on 5-vinyl-2-norbornene
A norbornane derivative, exo-tetrahydrodicyclopentadiene, is the main component of the high-density liquid fuel called JP-10. In the current communication, we describe the preparation of some related norbornane-containing hydrocarbons and their energetic properties.

  • An approach to high-energy-density hydrocarbons based on 5-vinyl-2-norbornene was developed.

  • Structure-property study of norbornane hydrocarbons for high-energy-density liquid fuels was performed.

  • High densities (0.856–0.977 g/cm3) and low freezing points (below −60 °C) were disclosed for the studied hydrocarbons.

  • A high energy density (up to 41.24 MJ/L) was achieved, which is noticeably higher than that of JP-10

Learn more in Fuel 2021
Polymers 2020: Synthesis and Gas Transport Properties of Addition Polynorbornene with Perfluorophenyl Side Groups
Addition polynorbornene with fluoroorganic substituents was synthesized for the first time. A study on the gas transport properties of the polymer was executed.

  • A norbornene-type monomer with a pentafluorophenyl group was involved in addition polymerization. The products are soluble, high-molecular-weight polymers obtained in good or high yields.

  • The molecular structure was confirmed by NMR and FTIR analysis.

  • The hydrophobic nature of the synthesized polymer was revealed by the study of contact angle with distilled water was studied.

  • A study of the permeability of various gases (He, H2, O2, N2, CO2, and CH4) through the prepared polymer was studied. Addition poly(3-pentafluorophenyl-exo-tricyclononene-7) was more permeable than its metathesis analogue by a factor of 7–21.

  • The effect achieved is due to the presence of both bulky perfluorinated side groups and rigid saturated main chains.

Therefore, this investigation opens the door to fluorinated addition polynorbornenes as new potential polymeric materials for membrane gas separation.

Learn more in Polymers 2020
ACS Catalysis 2020: Polymerization of 5-Alkylidene-2-norbornenes with Highly Active Pd–N-Heterocyclic Carbene Complex Catalysts: Catalyst Structure–Activity Relationships
We studied the addition polymerization of readily available bifunctional norbornene derivatives, 5-alkylidene-2-norbornenes, in the presence of modified Pd complexes with N-heterocyclic carbene ligands activated by borates. The structure–catalytic activity relationships were established for Pd–N-heterocyclic carbene complexes.

  • New catalytic systems (Pd–N-heterocyclic carbene complex/phosphine/borate) selectively catalyze the addition polymerization of 5-methylene-2-norbornene and 5-ethylidene-2-norbornene.

  • Only endocyclic norbornene double bond took part in polymerization. The exocyclic double bond remained intact.

  • The catalysts exhibited extremely high activity and durability: the activity was higher than 100 million g polymer/(molPd·h) and some catalysts were active at a very high monomer/Pd molar ratio of 20 millions.

  • Pd complexes bearing five-membered heterocyclic rings and/or less sterically hindered aryl groups at nitrogen atoms in carbene ligands exhibited the highest activity.

  • The polymerization can be performed in an atmosphere of air and in wet solvents.

  • The resulting polymers are amorphous and high-molecular-weight products consisting of rigid saturated main chains and reactive side groups. They can be considered as promising intermediates in the production of polymeric materials with high glass-transition temperatures and desired properties by targeted modifications.

Learn more in ACS Catalysis 2020
Polymer 2020: Dielectric properties of addition and metathesis polynorbornenes with bulky side-substituents
  • Structure-property study of polynorbornenes for low dielectric constant materials.

  • Dielectric properties of two groups of polymers derived from Si-, F- and alkenyl-substituted norbornenes were studied.

  • Incorporation of Me3Si- and perfluoroalkyl-groups as side groups in polynorbornenes results in a lower dielectric constant.

  • The lowest dielectric constants among polynorbornenes were achieved, and they were observed on PTCNSi2g and MPF16 films.

  • Polynorbornenes studied possess a promising combination of properties: dielectric constant, water uptake, stability, etc.

Learn more in Polymer 2020
Reactive and functional polymers 2020: Modifications of addition poly(5-vinyl-2-norbornene) and gas-transport properties of the obtained polymers
We prepared four modified polymers derived from readily available addition poly(5-vinyl-2-norbornene) (PVNB). Properties of the modified polymers were studied.

  • Hydrogenation, epoxidation, cyclopropanation and thiol-en reactions of addition poly(5-vinyl-2-norbornene) were performed.

  • The modifications were carried out in high yields without the destruction of main chains.

  • Structure-property study of polynorbornenes for membrane gas separations.

  • Cyclopropanation and hydrogenation increase permeability with a minimal decrease in selectivity.

  • Epoxidation or thioacetylation gave a substantial increase in CO2/N2 selectivity with a decrease in permeability.

Learn more in Reactive and functional polymers 2020
Macromolecular Rapid Communications 2020: Addition Polyalkylnorbornenes: A Promising New Class of Si-Free Membrane Materials for Hydrocarbons Separation
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.

  • The obtained polymers display low‐fraction free volume, stable gas permeability over time.

  • Polyalkylnorbornenes possess a unique feature for the glassy polymers—solubility controlled permeation of hydrocarbons and enhanced C4H10/CH4 selectivity.

Learn more in Macromolecular Rapid Communications 2020
Polymer Engineering and Science 2019: Crosslinking of addition copolymers from tricyclononenes bearing (CH3)3Si- and (C2H5O)3Si-groups as a modification of membrane gas separation materials

We report the synthesis and the study of gas‐transport properties of crosslinked highly permeable addition copolymers derived from Si‐containing norbornenes

  • The obtained copolymers included up to 10 mol% of units bearing reactive Si–O–C‐containing substituents.

  • The crosslinking was readily realized by using simple sol–gel chemistry in the presence of Sn‐catalyst.

  • Only a small reduction of gas‐permeability was observed when TNCSiOEt units were incorporated into the main chains, and the copolymers were crosslinked.

  • Selectivity for C4H10/CH4 pair was increased.

  • The suggested approach has allowed obtaining crosslinked polymers from Si‐containing monomers without a loss of the main membrane characteristics.

Learn more in Polymer Engineering and Science 2019
RSC Advances 2019: The selective hydrosilylation of norbornadiene-2,5 by monohydrosiloxanes
A simple one-step approach for the selective synthesis of exo-norbornenes with organosilicon substituents is suggested through the direct hydrosilylation of norbornadiene-2,5 with chlorine-free silanes.

  • The possibility of obtaining exo-isomers of Si-containing norbornenes with 100 exo-/endo-selectivity is shown

  • The investigation of Pt-, Rh-, and Pd-complexes in combination with various ligands as catalysts was performed.

  • The hydrosilylation of norbornadiene-2,5 in the presence of Pt- or Rh-catalysts was not selective and led to a mixture consisting of three isomers

  • The selectivity of exo-norbornene/nortricyclane formation strongly depended on the nature of the ligand in the Pd-catalyst.

  • The best selectivity was revealed when R-MOP was the ligand

  • The highest catalytic activity was reached with a dioxalane-containing ligand.

Learn more in RSC Advances 2019
Polymer 2018: Metathesis-type poly-exo-tricyclononenes with fluoroorganic side substituents: Synthesis and gas-transport properties
We executed a detailed study of the synthesis and properties of metathesis polytricyclononenes. New correlations between the structure of the side chain and polymer's membrane performance were revealed.

  • Novel highly reactive fluoro-containing exo-tricyclononenes were synthesized via [2 + 2+2]-cycloaddition reaction.

  • A group of new metathesis polytricyclononenes bearing side fluoroorganic-substituents was prepared.

  • The obtained polymers possessed both chemical and thermal stability.

  • The synthesized metathesis polytricyclononenes with fluorooganic-substituents exhibited improved gas permeability and selectivity towards H2/CH4.

  • Polymer bearing four rigid CF3-groups turned out to be the most permeable among the described fluorinated polynorbonenes known to date.

Learn more in Polymer 2018
Progress in Polymer Science 2018: Addition polymerization of functionalized norbornenes as a powerful tool for assembling molecular moieties of new polymers with versatile properties

This comprehensive review surveys recent research trends in the addition polymerization of functionalized norbornenes for the macromolecular design of high-performance materials in terms of catalyst activity, monomer reactivity, modifications, and potential applications of addition polynorbornenes bearing functional groups.

The structure of addition polynorbornene backbones is responsible for their high thermal resistance and chemical stability. In order to impart desired properties to the polymers, various functional side groups can be incorporated into the monomer units by the Ti-, Ni-, or Pd-catalyzed polymerization of norbornenes, which are available via cycloaddition reactions or norbornadiene-2,5 modifications.

Based on the use of different substituents in the norbornene monomer units and different polymer compositions, the addition polynorbornenes have been successfully developed for the preparation of pervaporation, gas separation, and proton-conducting membranes, sensors, catalyst supports, and for applications as photoresist, electrooptical, and dielectric materials, etc.

Learn more in Progress in Polymer Science 2018:
Polymers 2018: Metathesis-type poly-exo-tricyclononenes with fluoroorganic side substituents: Synthesis and gas-transport properties
New microporous homopolymers were readily prepared from norbornadiene-2,5, its dimer and trimer by addition (vinyl) polymerization of the corresponding monomers.

  • The synthesized polynorbornenes are cross-linked and insoluble.

  • They are glassy and amorphous polymers. Depending on the nature of the catalyst applied, BET surface areas were in the range of 420–970 m2/g.

  • The polymers with the highest surface area were obtained in the presence of Pd-catalysts from the trimer of norbornadiene-2,5.

  • The total pore volume of the polymers varies from 0.39 to 0.79 cm3/g, while the true volume of micropores was 0.14–0.16 cm3/g according to t-plot.

  • These polymers gave CO2 uptake from 1.2 to 1.9 mmol/g at 273 K and 1 atm.

  • The porous structure of new polymers was studied.

Learn more in Polymers 2018
Journal of Materials Chemistry A 2018: Janus tricyclononene polymers bearing tri(n-alkoxy)silyl side groups for membrane gas separation

A new type of polymers containing 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.

  • High-molecular weight metathesis and addition polynorbornenes were obtained with good yields.

  • 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.

  • Change of the polymer main chain structure and the length of tri(n-alkoxy)silyl side groups led to the dramatic tuning of polymer gas-transport properties.

  • For the first time we obtained metathesis polynorbornenes being more permeable than their addition isomers.

  • 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).

Learn more in Journal of Materials Chemistry A 2018
Macromolecular Chemistry and Physics 2018: Addition Homo- and Copolymerizations of Dicyclopentadiene and 5-n -Hexylnorbornene in the Presence of Pd-N-Heterocyclic Carbene Complexes

For the first time addition homopolymerization of dicyclopentadiene (DCPD) and its copolymerization with 5‐n‐hexylnorbornene in the presence of different Pd‐N‐heterocyclic carbene complexes activated by a borate (NaBARF) or methylaluminoxane (MAO) are investigated.

  • Systems based on Pd‐N‐heterocyclic carbene complex in combination with NaBARF or MAO are an effective catalyst

  • Polymerization can proceed in the air.

  • The influence of the N‐heterocyclic carbene structure, the nature of cocatalyst, and solvent on the catalyst activity of a system based on Pd‐N‐heterocyclic carbene complex is determined.

  • Thermal stability, solid‐state structure, and porosity of the obtained addition polydicyclopentadiene are studied. The material possessed a high surface area.

  • The addition polymerization of DCPD can be considered as a single‐step and convenient way to synthesize porous polymers from a norbornene derivative.

Learn more in Macromolecular Chemistry and Physics 2018
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