Polythiourethanes: Synthesis, applications, and opportunities

Progress in Polymer Science, Journal Year: 2023, Volume and Issue: 145, P. 101735 - 101735

Published: Aug. 22, 2023

Language: Английский

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Molecular Simulation of Covalent Adaptable Networks and Vitrimers: A Review

Polymers, Journal Year: 2024, Volume and Issue: 16(10), P. 1373 - 1373

Published: May 11, 2024

Covalent adaptable networks and vitrimers are novel polymers with dynamic reversible bond exchange reactions for crosslinks, enabling them to modulate their properties between those of thermoplastics thermosets. They have been gathering interest as materials recycling self-healing properties. In this review, we discuss different molecular simulation efforts that used over the last decade investigate understand nanoscale behaviors covalent vitrimers. particular, dynamics, Monte Carlo, a hybrid dynamics Carlo approaches model reaction, which is main mechanism since it controls both mechanical rheological behaviors. The techniques presented yield sufficient results structure well responses such networks. benefits each method highlighted. use other tools theoretical models machine learning has included. We noticed, amongst most prominent results, stress relaxes reaction happens, at temperatures higher than glass transition temperature, better more BERs observed. lifetime crosslinks follows, moderate high temperatures, an Arrhenius-like temperature dependence. note modeling certain like melt viscosity topology freezing according behavior ruled by either Williams–Landel–Ferry equation or Arrhenius equation. Discrepancies in dissociative associative discussed. conclude stating material parameters atomistic factors, nanoscale, not yet taken into account lacking current literature.

Language: Английский

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Foam-to-Elastomer Recycling of Polyurethane Materials through Incorporation of Dynamic Covalent TAD–Indole Linkages

ACS Applied Polymer Materials, Journal Year: 2024, Volume and Issue: 6(5), P. 2604 - 2615

Published: Feb. 19, 2024

Polyurethane (PU) foams are a large volume commodity product and as such pose considerable recycling challenge for the polymer manufacturing industry. The incorporation of dynamic covalent bonds within PU network chemistry is possible strategy to improve sustainable development foams. Herein, we report outcome research program aimed at thermoreversible triazolinedione (TAD)-indole linkages an industrial standard foam formulation. A scalable synthesis required TAD–indole building blocks was developed, aiming maximizing their physicochemical compatibility with polyol isocyanate ingredients. pilot scale TAD-based cross-linker affording more than 50 kg IPDI-derived bis-urazole block. Propoxylation indole fragments proved be key technology enabling kilogram production based polyols. innovative polyols were successfully used produce range flexible elastomers in solvent-free Owing nature linkers, could processed into through thermal compression molding, which further recycled up 7 times same manner. We studied effect compositions on foaming process efficiency. mechanical properties materials have been analysis, tensile measurements, rheology. This work demonstrates that viable polyurethane but also points out some critical aspects obstacles related design

Language: Английский

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Dynamic Heterogeneity and Cooperativity in Polyurethane-Based Vitrimers

Polymer, Journal Year: 2025, Volume and Issue: unknown, P. 128192 - 128192

Published: Feb. 1, 2025

Language: Английский

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Assessing the Impact of the Off-Stoichiometric Epoxy/Amine Ratio on the Curing Kinetics and Properties of Space-Grade Disulfide-Based Vitrimer Resins

ACS Applied Polymer Materials, Journal Year: 2025, Volume and Issue: unknown

Published: April 16, 2025

Language: Английский

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Polyurethane Adhesives with Chemically Debondable Properties via Diels–Alder Bonds

Polymers, Journal Year: 2023, Volume and Issue: 16(1), P. 21 - 21

Published: Dec. 20, 2023

Covalent adaptable networks (CANs) represent a pioneering advance in polymer science, offering unprecedented versatility materials design. Unlike conventional adhesives with irreversible bonds, CAN-based polyurethane have the unique ability to undergo chemical restructuring through reversible bonds. One of strategies for incorporating these types reactions polyurethanes is by functionalisation Diels–Alder (DA) adducts. By taking advantage nature DA chemistry, adhesive undergoes controlled crosslinking and decrosslinking processes, allowing precise modulation bond strength. This adaptability critical applications requiring reworkability or recyclability, as it allows easy disassembly reassembly bonded components without compromising integrity material. study focuses on sustainable synthesis characterisation solvent-based adhesive, obtained functionalising prepolymer diene dienophiles. The was carried out using different experimental techniques: nuclear magnetic resonance spectroscopy (NMR), Brookfield viscosity, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) T-peel strength testing leather/adhesive/rubber joints determine properties, both before after application external stimuli. conversion retro-Diels–Alder (r-DA) confirmed 1H-NMR. properties were not altered prepolymer, showing similar thermal resistance good rheological even exceeding most demanding technical requirements upper-to-sole footwear. After an stimuli, separated difficulty damage, thus facilitating their separation, recovery recycling.

Language: Английский

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Fully bio-sourced catalyst-free covalent adaptable networks from epoxidized soybean oil and L-tartaric acid

European Polymer Journal, Journal Year: 2024, Volume and Issue: 212, P. 113074 - 113074

Published: May 1, 2024

Epoxidized vegetable oil (EVO)-based epoxy systems offer a promising avenue for replacing non-recyclable petroleum-based thermoset elastomers. Looking towards future prospects, they also hold potential to evolve into sustainable covalent adaptable networks (CANs). Typically, transesterification-based CANs require catalysts achieve crosslinked structures that are reprocessable at relatively high temperatures (T ≥ 150 °C). In this study, epoxidized soybean (ESBO) was cross-linked with eutectic hardener composed of L-tartaric acid (TAR) and ethyl lactate (in an aqueous solution), resulting in the development fully bio-based 3D network capable reprocessing without need exogenous catalyst. addition, it demonstrated peculiar structure acid, –OH groups linked its backbone, plays prominent role reactivity system. These free hydroxyl functions facilitate both ring-opening epoxides transesterification reactions, thus enhancing curing exchange kinetics.

Language: Английский

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Biobased and aromatic Covalent Adaptable Networks: When architectures meet properties, within the framework of a circular bioeconomy

Materials Science and Engineering R Reports, Journal Year: 2024, Volume and Issue: 161, P. 100882 - 100882

Published: Nov. 9, 2024

Language: Английский

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Imine-containing Self-healing Waterborne Polyurethane Elastomeric Coating Derived from Bio-based Polyester Polyol

Journal of Polymers and the Environment, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 21, 2024

Language: Английский

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Internal hydrogen bonding of imines to control and enhance the dynamic mechanical properties of covalent adaptable networks

European Polymer Journal, Journal Year: 2023, Volume and Issue: 195, P. 112209 - 112209

Published: June 10, 2023

Covalent Adaptable Networks (CANs) have the potential to replace current thermoset materials, as dynamic covalent bonds in CANs enable reprocessability and recycling of crosslinked polymer networks. A limitation is, however, that they are generally susceptible towards creep, bond exchange reactions facilitate stress relaxation. In this work, we propose use internal hydrogen bonding polyimine an efficient tool enhance creep resistance (at operating temperature) further control mechanical properties, while still enabling malleability at elevated temperatures. We able show on a small-molecule level ortho-substituted hydroxy groups aromatic imines stabilise imine result is formed between group. Furthermore, with incorporated ortho significantly enhanced material can be seen glass transition temperature (Tg), elastic modulus (G'), solvent resistance. While also consider additional steric electronic effects might arisen due installation groups, find stabilising effect primarily dictating performance.

Language: Английский

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