Research
Maxim Bermeshev
Head of Lab 10
Since its foundation, our lab deals with the investigation of valuable products based on available petrochemical semi-products. At the moment we deal with four global challenges:
- Functional materials with polar and reactive groups
- Design of polymers for membrane gas separation
- Late-transition metal-catalysts for cycloolefin (co)polymerization
- High-energy-density liquid hydrocarbons
Norbornene-based functional materials
with polar and reactive groups
with polar and reactive groups
The presence of polar or reactive side-groups in polymers provides the desired properties for advanced materials derived from these polymers.
Improved properties of polynorbornenes. Vinyl-addition (co)polymerization of cycloalkenes leads to polymers with saturated main chains displaying :
However, vinyl-addition polymerization of cycloalkenes bearing a polar or reactive side-group is usually a challenge.
Therefore, our research focuses on the development of approaches to selective vinyl-addition polymerization of norbornenes with reactive substituents and the creation based on these polymers high-performance polymers for optoelectronics, membrane gas separation, and other applications.
Learn more in related papers:
Improved properties of polynorbornenes. Vinyl-addition (co)polymerization of cycloalkenes leads to polymers with saturated main chains displaying :
- high glass-transition temperatures
- high transparency
- high thermal and chemical stability
- low free volume
- enhanced gas permeability.
However, vinyl-addition polymerization of cycloalkenes bearing a polar or reactive side-group is usually a challenge.
Therefore, our research focuses on the development of approaches to selective vinyl-addition polymerization of norbornenes with reactive substituents and the creation based on these polymers high-performance polymers for optoelectronics, membrane gas separation, and other applications.
Learn more in related papers:
Polymers for membrane gas separation
At present, a great number of selectively permeable glassy polymers are known. Only over the past 15 years, several new classes of glassy highly gas permeable polymers for membrane gas separation have been synthesized. The high gas permeability of these polymers is due to their microporous structure and the presence of large free volume. But at the same time namely owing to the porous structure, these polymers tend to be aging and their properties should be stabilized.
Now the search for new materials for membrane technologies is actively continuing. There are several reasons for the driving force behind such studies:
Polynorbornenes macromolecular design. Rich synthetic possibilities in norbornene derivatives synthesis afford targeted synthesis of series of monomers with the desired structure. The unique ability to polymerize by different mechanisms leads to the formation of polymers with different structures of the main chain. Thus the researcher has the power to vary both structures of the main and side chain of the polymers.
Our group aims to design and synthesize new polymeric materials from norbornene derivatives, which should combine either the high performance of membrane properties, the stability of properties over time, and synthetic availability.
Recently we have developed several groups of polynorbornenes with promising membrane properties.
Learn more in related papers:
Now the search for new materials for membrane technologies is actively continuing. There are several reasons for the driving force behind such studies:
- The significant growth in the market of membrane technologies.
- The need to eliminate the disadvantages of existing polymers that do not fully possess the required operational characteristics of membrane materials, for example, high and selective permeability, which does not change during long-term operations.
- Desire to use cheap and available polymers, which are obtained employing an environmentally friendly synthesis.
Polynorbornenes macromolecular design. Rich synthetic possibilities in norbornene derivatives synthesis afford targeted synthesis of series of monomers with the desired structure. The unique ability to polymerize by different mechanisms leads to the formation of polymers with different structures of the main chain. Thus the researcher has the power to vary both structures of the main and side chain of the polymers.
Our group aims to design and synthesize new polymeric materials from norbornene derivatives, which should combine either the high performance of membrane properties, the stability of properties over time, and synthetic availability.
Recently we have developed several groups of polynorbornenes with promising membrane properties.
Learn more in related papers:
Late-transition metal-catalysts
for cycloolefin (co)polymerization
for cycloolefin (co)polymerization
Cycloalkenes can be polymerized according to metathesis (ROMP) and vinyl-addition polymerization. Well-defined catalysts have been successfully developed for ROMP polymerization. These catalysts can catalyze the polymerization of cycloalkenes with various functional groups and in a living manner.
Challenge in vinyl polymerization catalysis. Although many different catalysts have been studied for vinyl-addition polymerization of cycloalkenes, there are still no catalysts that have similar characteristics to those developed for ROMP polymerization of cycloalkenes. Therefore, the development of new catalysts for vinyl-addition (co)polymerization of cycloolefins is another challenge.
Recently, we have shown that Pd–N-heterocyclic carbene complexes in combination with a borate exhibited extremely high activity and durability: the activity was higher than 100 million g polymer/(mol Pd∙h).
The structure–catalytic activity relationships were established for Pd–N-heterocyclic carbene complexes. The highest catalytic activity was found for the following Pd-NHC complexes that contain:
The polymerization can be performed in an atmosphere of air and in wet solvents that make the process more attractive from the perspective of industry.
Find out more in the related papers:
Polymerization of 5-Alkylidene-2-norbornenes with Highly Active Pd–N-Heterocyclic Carbene Complex Catalysts: Catalyst Structure–Activity Relationships
Activation of Pd-precatalysts by organic compounds for vinyl-addition polymerization of a norbornene derivative
Challenge in vinyl polymerization catalysis. Although many different catalysts have been studied for vinyl-addition polymerization of cycloalkenes, there are still no catalysts that have similar characteristics to those developed for ROMP polymerization of cycloalkenes. Therefore, the development of new catalysts for vinyl-addition (co)polymerization of cycloolefins is another challenge.
Recently, we have shown that Pd–N-heterocyclic carbene complexes in combination with a borate exhibited extremely high activity and durability: the activity was higher than 100 million g polymer/(mol Pd∙h).
The structure–catalytic activity relationships were established for Pd–N-heterocyclic carbene complexes. The highest catalytic activity was found for the following Pd-NHC complexes that contain:
- Five-membered heterocyclic rings
- Less sterically hindered aryl groups at nitrogen atoms in carbene ligands.
The polymerization can be performed in an atmosphere of air and in wet solvents that make the process more attractive from the perspective of industry.
Find out more in the related papers:
Polymerization of 5-Alkylidene-2-norbornenes with Highly Active Pd–N-Heterocyclic Carbene Complex Catalysts: Catalyst Structure–Activity Relationships
Activation of Pd-precatalysts by organic compounds for vinyl-addition polymerization of a norbornene derivative
High-energy-density liquid hydrocarbons
The recent progress in the development of advanced aircraft, racing engines, and military vehicles makes a challenge for seeking the next generation of high-energy-density hydrocarbon fuels.
Fuels challenge. Meanwhile, it is a well-known problem to produce a fuel with a high energy content and suitable low-temperature properties. For example, often high-energy density liquid fuels exhibit high freezing points. Regarding possible increased costs of synthetic high-energy-density liquid fuels, enhanced energetic properties become of crucial importance. The possibility of using the smaller fuel tanks, provided by high volumetric heat of combustion, can give benefits that may outweigh the higher costs of this type of fuel.
Cyclic hydrocarbons-based fuels. We have prepared a number of hydrocarbons containing two norbornane moieties or norbornyl and cyclopropyl groups from commercially available 5-vinyl-2-norbonene. The synthesis of these hydrocarbons is simple and it uses well-known tools of organic chemistry like the Diels-Alder reaction and cyclopropanation reaction. The altering of the structure of norbornane-type hydrocarbons allowed us to combine two contradictory properties:
high fuel density + low freezing point
At the same time, the energy density was noticeably higher than that of the related fuel, JP-10. Altogether these factors make norbornene-based fuels the possible fuel for the future's needs.
Learn more in the related papers:
Synthesis and properties of high-energy-density hydrocarbons based on 5-vinyl-2-norbornene
Metal chlorides supported on silica as efficient catalysts for selective isomerization of endo-tetrahydrodicyclopentadiene to exo-tetrahydrodicyclopentadiene for JP-10 producing
Fuels challenge. Meanwhile, it is a well-known problem to produce a fuel with a high energy content and suitable low-temperature properties. For example, often high-energy density liquid fuels exhibit high freezing points. Regarding possible increased costs of synthetic high-energy-density liquid fuels, enhanced energetic properties become of crucial importance. The possibility of using the smaller fuel tanks, provided by high volumetric heat of combustion, can give benefits that may outweigh the higher costs of this type of fuel.
Cyclic hydrocarbons-based fuels. We have prepared a number of hydrocarbons containing two norbornane moieties or norbornyl and cyclopropyl groups from commercially available 5-vinyl-2-norbonene. The synthesis of these hydrocarbons is simple and it uses well-known tools of organic chemistry like the Diels-Alder reaction and cyclopropanation reaction. The altering of the structure of norbornane-type hydrocarbons allowed us to combine two contradictory properties:
high fuel density + low freezing point
At the same time, the energy density was noticeably higher than that of the related fuel, JP-10. Altogether these factors make norbornene-based fuels the possible fuel for the future's needs.
Learn more in the related papers:
Synthesis and properties of high-energy-density hydrocarbons based on 5-vinyl-2-norbornene
Metal chlorides supported on silica as efficient catalysts for selective isomerization of endo-tetrahydrodicyclopentadiene to exo-tetrahydrodicyclopentadiene for JP-10 producing
Credits
Editor — Gleb Karpov
Illustrations — Dmitry Alentiev, Alyona Wozniak
Illustrations — Dmitry Alentiev, Alyona Wozniak
