Ring opening metathesis polymerization of triazole‐bearing cyclobutenes: Diblock copolymer synthesis and evaluation of the effect of side group size on polymerization kinetics

Jia, Wei; Trout, William S.; Simon, Yoan C.; Granados-Fócil, Sergio

doi:10.1002/pola.28565

Cited by 7 publications

(1 citation statement)

References 54 publications

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“…Two of the main categories of catalysts are well-defined Schrock [ 16 ] and Grubbs [ 17 ] metal carbenes (tungsten, molybdenum and ruthenium complexes). The choice of catalyst depends on its ability to control molecular weights and their distributions, tolerance to high temperature and moisture, ability to polymerize monomers bearing functional groups, solubility in common organic solvents and ability to keep a polymerization “living” [ 18 , 19 , 20 , 21 ]. Also, depending on the catalyst (e.g., 1st or 2nd generation Grubbs catalyst, or mononuclear versus dinuclear tungsten compounds), the configuration of the double bonds along the polymer chain can vary ( cis , trans or a mixture of both) [ 9 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ], thereby allowing for further refinement of the properties to the resulting polymers/aerogels.…”

Section: Introductionmentioning

confidence: 99%

Poly(urethane-norbornene) Aerogels via Ring Opening Metathesis Polymerization of Dendritic Urethane-Norbornene Monomers: Structure-Property Relationships as a Function of an Aliphatic Versus an Aromatic Core and the Number of Peripheral Norbornene Moieties

et al. 2018

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We report the synthesis and characterization of synthetic polymer aerogels based on dendritic-type urethane-norbornene monomers. The core of those monomers is based either on an aromatic/rigid (TIPM/Desmodur RE), or an aliphatic/flexible (Desmodur N3300) triisocyanate. The terminal norbornene groups (three at the tip of each of the three branches) were polymerized via ROMP using the inexpensive 1st generation Grubbs catalyst. The polymerization/gelation conditions were optimized by varying the amount of the catalyst. The resulting wet-gels were dried either from pentane under ambient pressure at 50 °C, or from t-butanol via freeze-drying, or by using supercritical fluid (SCF) CO2. Monomers were characterized with high resolution mass spectrometry (HRMS), 1H- and solid-state 13C-NMR. Aerogels were characterized with ATR-FTIR and solid-state 13C-NMR. The porous network was probed with N2-sorption and SEM. The thermal stability of monomers and aerogels was studied with TGA, which also provides evidence for the number of norbornene groups that reacted via ROMP. At low densities (<0.1 g cm−3) all aerogels were highly porous (porosity > 90%), mostly macroporous materials; aerogels based on the aliphatic/flexible core were fragile, whereas aerogels containing the aromatic/rigid core were plastic, and at even lower densities (0.03 g cm−3) foamy. At higher densities (0.2–0.7 g cm−3) all materials were stiff, strong, and hard. At low monomer concentrations all aerogels consisted of discrete primary particles that formed spherical secondary aggregates. At higher monomer concentrations the structure consisted of fused particles with the size of the previous secondary aggregates, due to the low solubility of the developing polymer, which phase-separated and formed a primary particle network. Same-size fused aggregates were observed for both aliphatic and aromatic triisocyanate-derived aerogels, leading to the conclusion that it is not the aliphatic or aromatic core that determines phase separation, but rather the solubility of the polymeric backbone (polynorbornene) that is in both cases the same. The material properties were compared to those of analogous aerogels bearing only one norbornene moiety at the tip of each branch deriving from the same cores.

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Section: Introductionmentioning

confidence: 99%

Poly(urethane-norbornene) Aerogels via Ring Opening Metathesis Polymerization of Dendritic Urethane-Norbornene Monomers: Structure-Property Relationships as a Function of an Aliphatic Versus an Aromatic Core and the Number of Peripheral Norbornene Moieties

et al. 2018

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Non‐Symmetrical Tetrafluoroalkadienes Synthesized by ROCM of 3,3,4,4‐Tetrafluorocyclobutene

Kučnirová

Kvı́čala

Svoboda

et al. 2023

Chemistry A European J

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As the first known example of ring‐opening cross metathesis (ROCM) of polyfluorinated strained cyclobutenes, ROCM of 3,3,4,4‐tetrafluorocyclobutene with electronically rich alkenes, catalyzed by Grubbs or Hoveyda‐Grubbs 2nd generation precatalysts, gave a small library of non‐symmetrical isolated dienes bearing a tetrafluoroethylene spacer between the double bonds. 1‐Butoxy‐3,3,4,4‐tetrafluorohexa‐1,5‐diene thus formed underwent subsequent regioselective cross metathesis (CM) with a series of styrenes, catalyzed by Hoveyda‐Grubbs 2nd generation precatalyst, leading to non‐symmetrically substituted dienes. 6,6‐Dibutoxy‐3,3,4,4‐tetrafluorohex‐1‐ene, formed by regioselective butoxylation of 1‐butoxy‐3,3,4,4‐tetrafluorohexa‐1,5‐diene, was dihydroxylated and cyclized to the corresponding 3,3,4,4‐tetrafluorohexopyranose.

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Modification of narrow‐spectrum peptidomimetic polyurethanes with fatty acid chains confers broad‐spectrum antibacterial activity

Peng

Zhang

Ortiz‐Ortiz

et al. 2019

Polymer International

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Each year, thousands of patients die from antimicrobial-resistant bacterial infections that fail to respond to conventional antibiotic treatment. Antimicrobial polymers are a promising new method of combating antibiotic-resistant bacterial infections. We have previously reported the synthesis of a series of narrow-spectrum peptidomimetic antimicrobial polyurethanes that are effective against Gram-negative bacteria, such as Escherichia coli; however, these polymers are not effective against Gram-positive bacteria, such as Staphylococcus aureus. With the aim of understanding the correlation between chemical structure and antibacterial activity, we have subsequently developed three structural variants of these antimicrobial polyurethanes using post-polymerization modification with decanoic acid and oleic acid. Our results show that such modifications converted the narrow-spectrum antibacterial activity of these polymers into broad-spectrum activity against Gram-positive species such as S. aureus, however, also increasing their toxicity to mammalian cells. Mechanistic studies of bacterial membrane disruption illustrate the differences in antibacterial action between the various polymers. The results demonstrate the challenge of balancing antimicrobial activity and mammalian cell compatibility in the design of antimicrobial polymer compositions.

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Ring opening metathesis polymerization of triazole‐bearing cyclobutenes: Diblock copolymer synthesis and evaluation of the effect of side group size on polymerization kinetics

Cited by 7 publications

References 54 publications

Poly(urethane-norbornene) Aerogels via Ring Opening Metathesis Polymerization of Dendritic Urethane-Norbornene Monomers: Structure-Property Relationships as a Function of an Aliphatic Versus an Aromatic Core and the Number of Peripheral Norbornene Moieties

Poly(urethane-norbornene) Aerogels via Ring Opening Metathesis Polymerization of Dendritic Urethane-Norbornene Monomers: Structure-Property Relationships as a Function of an Aliphatic Versus an Aromatic Core and the Number of Peripheral Norbornene Moieties

Non‐Symmetrical Tetrafluoroalkadienes Synthesized by ROCM of 3,3,4,4‐Tetrafluorocyclobutene

Modification of narrow‐spectrum peptidomimetic polyurethanes with fatty acid chains confers broad‐spectrum antibacterial activity

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