Cross-linking and de-cross-linking of triarylimidazole-based polymer

Peng, Ya; Yu, Haiwen; Chen, Hongbiao; Huang, Zhichao; Li, Huaming

doi:10.1016/j.polymer.2016.07.065

Cited by 7 publications

(5 citation statements)

References 40 publications

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“…The utilization of reactive functional groups such as HABIs to afford intrinsically healable, covalently cross-linked polymers necessitates the incorporation of these functionalities in the network backbone. Cross-linked polymers incorporating HABI functional groups have been synthesized previously, − one approach being to treat polymers bearing triaryl-substituted imidazole pendant groups, synthesized via a radical-mediated, chain growth polymerization mechanism, with potassium ferricyanide to oxidize the imidazole groups and yield HABI cross-links. ,, Notably, this synthetic approach affords cross-linked particles which would require further treatment to yield monolithic materials. In contrast, the cross-linked gels examined here were synthesized by treating solutions of PEG tetra-azide and a dialkynyl monomer, where the polymerizable moieties flank either side of the monomer core, in DMF with CuSO 4 and sodium ascorbate to effect polymerization by Cu(I)-catalyzed azide–alkyne cycloaddition (CuAAC), thereby ensuring incorporation of either the HABI or the bisphenol A functional groups in the backbone of the resultant cross-linked, monolithic gels.…”

Section: Resultsmentioning

confidence: 99%

Rapid, Photomediated Healing of Hexaarylbiimidazole-Based Covalently Cross-Linked Gels

2017

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The intrinsic healing of covalently cross-linked polymer networks is commonly effected via the utilization of backbone-borne functional groups able to reversibly cleave or rearrange, thereby enabling mixing and coreaction of network strands that bridge contacted interfaces; however, such materials often exhibit slow healing rates and are susceptible to creep under load. To address these deficiencies, we incorporated hexaarylbiimidazole (HABI) functionalities, groups that are homolytically cleavable, to yield relatively low reactivity lophyl radicals under UV or visible light irradiation and which, in the absence of light, spontaneously recombine without significantly participating in deleterious side reactions, into the backbone of poly(ethylene glycol)-based polymeric gels. Whereas the network connectivity of these HABI-incorporating gels was stable in the dark, they exhibited significant creep upon irradiation. The influence of swelling solvent on the reaction kinetics of backbone-borne HABI photolysis and lophyl radical recombination was examined and revealed that gels swollen with 1,1,2-trichloroethane (TCE) exhibited higher radical concentrations than those swollen with either acetonitrile or water under equivalent irradiation conditions, attributable to the relative solvent affinity for the hydrophobic HABI functionalities affording more rapid HABI cleavage and slower radical recombination rates in TCE than in water. The fastest healing rates for cleaved samples brought into contact and irradiated with visible light were observed for TCE-swollen gels, although rapid restoration of mechanical integrity was achieved for gels swollen with any of the solvents examined where tensile strengths approached those of the pristine materials after 1 to 3 min of light exposure.

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Section: Resultsmentioning

confidence: 99%

Rapid, Photomediated Healing of Hexaarylbiimidazole-Based Covalently Cross-Linked Gels

2017

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“…The controlled polymerizations often used in PILs synthesis for membrane-based gas separation are reversible-deactivation polymerization, nitroxide mediated polymerization [145,172], and ring-opening metathesis polymerization (ROMP) [137,145]. The reversible-deactivation polymerization technique further differentiates reversible addition-fragmentation chain transfer (RAFT), employing a chain transfer agent (i.e., thiocarbonyl) [150,151,[173][174][175], and atom transfer radical polymerization (ATRP), employing initiator, catalyst, and ligand [113,176].…”

Section: Polymerization Of Il Monomersmentioning

confidence: 99%

A Review on Ionic Liquid Gas Separation Membranes

et al. 2021

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Ionic liquids have attracted the attention of the industry and research community as versatile solvents with unique properties, such as ionic conductivity, low volatility, high solubility of gases and vapors, thermal stability, and the possibility to combine anions and cations to yield an almost endless list of different structures. These features open perspectives for numerous applications, such as the reaction medium for chemical synthesis, electrolytes for batteries, solvent for gas sorption processes, and also membranes for gas separation. In the search for better-performing membrane materials and membranes for gas and vapor separation, ionic liquids have been investigated extensively in the last decade and a half. This review gives a complete overview of the main developments in the field of ionic liquid membranes since their first introduction. It covers all different materials, membrane types, their preparation, pure and mixed gas transport properties, and examples of potential gas separation applications. Special systems will also be discussed, including facilitated transport membranes and mixed matrix membranes. The main strengths and weaknesses of the different membrane types will be discussed, subdividing them into supported ionic liquid membranes (SILMs), poly(ionic liquids) or polymerized ionic liquids (PILs), polymer/ionic liquid blends (physically or chemically cross-linked ‘ion-gels’), and PIL/IL blends. Since membrane processes are advancing as an energy-efficient alternative to traditional separation processes, having shown promising results for complex new separation challenges like carbon capture as well, they may be the key to developing a more sustainable future society. In this light, this review presents the state-of-the-art of ionic liquid membranes, to analyze their potential in the gas separation processes of the future.

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“…Our choice of triphenylimidazole as the building block was based on the fact that: 1) it has a rigid molecular structure and 2) the imidazole rings can coordinate with metal ions, thereby facilitating the loading with metal NPs. In addition, previous investigations have demonstrated that triphenylimidazole‐containing linear polymers possess high thermal and chemical stability . Owing to the coordinative interactions between the imidazole rings and Pd precursors, Pd NPs with an average diameter of 2.7 nm were well‐grown inside the PTPI‐Me frameworks.…”

Section: Introductionmentioning

confidence: 99%

“…In addition, previousi nvestigationsh ave demonstrated that triphenylimidazole-containing linear polymers possess high thermal and chemical stability. [30,31] Owing to the coordinativei nteractions between the imidazole rings and Pd precursors, Pd NPsw ith an average diameter of 2.7 nm were well-growni nside the PTPI-Me frameworks. The resultant Pd@PTPI-Me catalyst, which had aP dl oading of 0.13 mmol g À1 , exhibited superior catalytic activity for the cyanation of aryl iodides.…”

Section: Introductionmentioning

confidence: 99%

A Porous Organic Poly(triphenylimidazole) Decorated with Palladium Nanoparticles for the Cyanation of Aryl Iodides

Chen

2018

Chemistry An Asian Journal

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A new porous organic poly(triphenylimidazole), PTPI-Me, was prepared through a Yamamoto self-coupling reaction of 2,4,5-tris-(4-bromophenyl)-1-methyl-1H-imidazole (TPI-Me) in the presence of bis(1,5-cyclooctadiene)nickel(0). The polymer was subsequently decorated with Pd nanoparticles (NPs) to afford a heterogeneous cyanation catalyst, Pd@PTPI-Me. Pd NPs with an average diameter of 2.7 nm were grown within the PTPI-Me framework, owing to the coordination of the imidazole rings to the Pd species. The resultant Pd@PTPI-Me catalyst, with a Pd loading of 0.13 mmol g , exhibited superior catalytic activity for the cyanation of aryl iodides. More importantly, the heterogeneous catalyst was also readily recycled and displayed negligible deactivation after five cycles.

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Cross-linking and de-cross-linking of triarylimidazole-based polymer

Cited by 7 publications

References 40 publications

Rapid, Photomediated Healing of Hexaarylbiimidazole-Based Covalently Cross-Linked Gels

Rapid, Photomediated Healing of Hexaarylbiimidazole-Based Covalently Cross-Linked Gels

A Review on Ionic Liquid Gas Separation Membranes

A Porous Organic Poly(triphenylimidazole) Decorated with Palladium Nanoparticles for the Cyanation of Aryl Iodides

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