Chemical Engineering Journal, Год журнала: 2024, Номер unknown, С. 157795 - 157795
Опубликована: Ноя. 1, 2024
Язык: Английский
Macromolecules, Год журнала: 2025, Номер 58(4), С. 1923 - 1934
Опубликована: Фев. 5, 2025
Developing closed-loop recyclable thermosets and understanding their structure–property relationships are essential steps in advancing a circular materials economy. Here, we present vinylogous urethane (VU) thermoset with recyclability, synthesized through the reaction of polytetrahydrofuran bisacetoacetate (aPTHF) tris(2-aminoethyl)amine (TREN). These VU polymers exhibit high elasticity, only 3–9% residual strain observed after cyclic tensile testing at maximum 100%, depending on molecular weight aPTHF network cross-link density. The two structural parameters also allow modulation mechanical stress-relaxation properties elastomers. To investigate hydrolysis linkages within hydrophobic matrix, employed heterogeneous system using biphasic mixture HCl CDCl3. Our findings show that VUs remain stable pure water but can be dissociated under acidic conditions, dissociation rate accelerated higher temperatures and/or presence concentrations. detailed investigations indicate potential elastomers as sustainable substrates for wearable sensors. We therefore conduct case study synthesizing sensor incorporation multiwalled carbon nanotubes (MCNs) into elastomer matrix. robustly detect various movements. Moreover, treatment both neat polymer composite diethyl ether solvent allows excellent recovery (>90%) TREN (86%), without discernible damage to MCNs reclaimed from latter.
Язык: Английский
Процитировано
2
Angewandte Chemie International Edition, Год журнала: 2024, Номер unknown
Опубликована: Июнь 3, 2024
Covalent adaptable networks (CANs), leveraging the dynamic exchange of covalent bonds, emerge as a promising material to address challenge irreversible cross-linking in thermosetting polymers. In this work, we explore introduction catalyst-free and associative C=C/C=N metathesis reaction into polyurethanes, creating CANs with superior stability, solvent resistance, thermal/mechanical properties. By incorporating reaction, stress-relaxation is significantly accelerated compared imine-bond-only networks, rate adjustable by modifying substituents ortho position double bonds. The obtained plasticity enables recycle without altering chemical structure or mechanical properties, also found be vital for achieving shape memory functions complex spatial structures. This new crosslinker polymer has potential accelerate ongoing exploration malleable functional thermoset
Язык: Английский
Процитировано
7
Chemistry of Materials, Год журнала: 2025, Номер unknown
Опубликована: Апрель 24, 2025
Язык: Английский
Процитировано
0
Macromolecules, Год журнала: 2025, Номер unknown
Опубликована: Май 7, 2025
Язык: Английский
Процитировано
0
Chemical Communications, Год журнала: 2024, Номер 60(75), С. 10354 - 10357
Опубликована: Янв. 1, 2024
The presence of dynamic covalent bonds allows vitrimers to undergo topology alterations and display self-healing properties. Herein, we study the influence varying concentration on macroscopic properties hybrid vitrimer networks by subjecting them triaxial stretching tests using molecular simulations. Results show that for continuous stress relaxation in leading delayed craze development higher as compared permanently crosslinked networks. work highlights ability glassy relax tensile during deformation successfully.
Язык: Английский
Процитировано
2
Angewandte Chemie, Год журнала: 2024, Номер unknown
Опубликована: Июнь 3, 2024
Abstract Covalent adaptable networks (CANs), leveraging the dynamic exchange of covalent bonds, emerge as a promising material to address challenge irreversible cross‐linking in thermosetting polymers. In this work, we explore introduction catalyst‐free and associative C=C/C=N metathesis reaction into polyurethanes, creating CANs with superior stability, solvent resistance, thermal/mechanical properties. By incorporating reaction, stress‐relaxation is significantly accelerated compared imine‐bond‐only networks, rate adjustable by modifying substituents ortho position double bonds. The obtained plasticity enables recycle without altering chemical structure or mechanical properties, also found be vital for achieving shape memory functions complex spatial structures. This new crosslinker polymer has potential accelerate ongoing exploration malleable functional thermoset
Язык: Английский
Процитировано
0
European Polymer Journal, Год журнала: 2024, Номер unknown, С. 113463 - 113463
Опубликована: Сен. 1, 2024
Язык: Английский
Процитировано
0
Chemical Communications, Год журнала: 2024, Номер unknown
Опубликована: Янв. 1, 2024
A boronic ester vitrimer with high hydrolytic stability afforded by fluorinated side-chain protection is reported.
Язык: Английский
Процитировано
0
Advanced Science, Год журнала: 2024, Номер unknown
Опубликована: Ноя. 18, 2024
Abstract Plastic recycling is a critical step toward improving waste management and achieving economic recycling. Here, thermoset crosslinked by guanythiourea structure (GTUH network) reported, that addresses the issue of thermosets serial hybridization thiourea guanidine urea. The dual dissociative dynamic exchange reaction guanamine urea thiourea, combined with non‐covalent hydrogen bonding interactions, endows network rapid relaxation ability. GTUH networks, in particular, can be recycled through continuous extrusion processing due to multiple reversible mechanisms, as opposed hot pressing alone. Even if reprocessed pressing, only 5 min at 140 °C 10 MPa are required. oxidation enhancement mechanism contributes maintaining or even mechanical properties network. Moreover, reactions allow for closed‐loop chemical Research into recyclable carbon fiber‐reinforced composites indicates promising potential applications this material circular economy resources.
Язык: Английский
Процитировано
0
Macromolecules, Год журнала: 2024, Номер unknown
Опубликована: Ноя. 26, 2024
Vitrimers, as a novel class of dynamic polymers, require precise regulation their and mechanical properties to achieve optimal, comprehensive performance. This study utilizes coarse-grained vitrimer elastomer model, composed simple linear polymer chains by varying cross-link densities (ρ), systematically investigate the structural, dynamic, vitrimers. The results demonstrate that system number density decreases with increasing ρ due repulsion between reactive sites. characteristic glass transition temperature (Tg) increases linearly such Tg ∼ ρ, while topological Tv exhibits nonmonotonic changes versus ρ. Interestingly, bond exchange autocorrelation function indicates rate reaches maximum at intermediate attributed competition mobility Mean square displacement analysis reveals beads decreased logarithm diffusion coefficients ln D −ρ. chain segment relaxation times different can be described an exponential equation τα exp(ρ/C), whole are more sensitive density. viscoelasticity via equilibrium molecular dynamics simulations indicate higher lead greater elasticity energy dissipation capabilities, indicated storage loss moduli, derived viscosity for various barriers (ΔEsw) universal following relation η0 Uniaxial triaxial tensile tests both show high ΔEsw systems exhibit strength low strains tight stable network structure, whereas strains, voids occur stress concentration breakage covalent bonds, which reduces strength, toughness, elongation break, compared lower systems. Therefore, optimal tailoring barrier capability most excellent performance vitrimer. These findings provide crucial theoretical guidelines design optimization
Язык: Английский
Процитировано
0