Progress in the design and synthesis of biobased epoxy covalent adaptable networks

Polymer Chemistry, Journal Year: 2022, Volume and Issue: 13(48), P. 6573 - 6588

Published: Jan. 1, 2022

The progress in design and synthesis of biobased covalent adaptable networks has been reviewed their opportunities challenges for future development are proposed.

Language: Английский

---

Mechanically Robust, Recyclable, and Self‐Healing Polyimine Networks

Advanced Science, Journal Year: 2023, Volume and Issue: 10(19)

Published: April 23, 2023

To achieve energy saving and emission reduction goals, recyclable healable thermoset materials are highly attractive. Polymer copolymerization has been proven to be a critical strategy for preparing high-performance polymeric materials. However, it remains huge challenge develop Here, polyimine dynamic networks based on two monomers with bulky pendant groups, which not only displayed mechanical properties higher than the strong tough polymers, e.g., polycarbonate, but also excellent self-repairing capability recyclability as thermosets developed. Owing stability of conjugation effect by aromatic benzene rings, final far more stable reported counterparts, exhibiting hydrolysis resistance under both alkaline condition most organic solvents. These structure can completely depolymerized into recovery in an acidic aqueous solution at ambient temperature. Resulting from units, this method allows exchange reactions vitrimer easily within minutes self-healing function. Moreover, introduction trifluoromethyl diphenoxybenzene backbones significantly increases tensile This work provides effective fabricating polymer multiple functions.

Language: Английский

---

Viscoelasticity of Polymers with Dynamic Covalent Bonds: Concepts and Misconceptions

Macromolecules, Journal Year: 2023, Volume and Issue: 56(21), P. 8688 - 8696

Published: Nov. 3, 2023

Polymers with dynamic covalent bonds are an exciting class of materials properties and potential applications that rapidly gain significant attention from diverse scientific communities. While the number publications on this emerging topic increases exponentially, navigating through literature reveals a series physical inconsistencies in previously established concepts some misconceptions data analysis interpretation. The current paper presents practices often applied to characterization systems emphasizes particular may lead critical divergences misinterpretations results. We particularly focus should be avoided interpretation stress–relaxation viscoelastic estimates bond dissociation energy. Instead, we suggest using traditional approaches have been polymer for decades. Lastly, emphasize challenges full understanding microscopic behavior vitrimers.

Language: Английский

---

Covalent adaptable networks from renewable resources: Crosslinked polymers for a sustainable future

Chem, Journal Year: 2023, Volume and Issue: 9(10), P. 2771 - 2816

Published: May 23, 2023

Language: Английский

---

Reprocessable, chemically recyclable, and flame-retardant biobased epoxy vitrimers

European Polymer Journal, Journal Year: 2023, Volume and Issue: 193, P. 112078 - 112078

Published: April 18, 2023

Language: Английский

---

Lignin-Based Covalent Adaptable Network Polymers─When Bio-Based Thermosets Meet Recyclable by Design

ACS Sustainable Chemistry & Engineering, Journal Year: 2023, Volume and Issue: 11(38), P. 13836 - 13867

Published: Sept. 2, 2023

Covalent adaptable networks (CANs) play an important role in polymer chemistry, as they provide innovative link between thermoplastics and thermosets. The breakthrough idea behind CANs is to at least partially replace irreversible crosslinks classic thermoset polymers with dynamic covalent bonds that allow for reversible character recyclability. Besides, also offer other popular features such self-healing, weldability, configurability, shape memory. Most are still petroleum-based, yet shifting toward more sustainable approaches of the utmost interest. Considering this high abundance lignocellulosic biomass, perspective focuses on all research found lignin-based CANs, including both those starting from fractionated lignin monomers. This clearly a new branch within bio-based holds great potential various industries. Additionally, some examples derived same building blocks given showcase chemical transformations can be used design future. Although CAN has been extended many different types bonds, imines disulfides largely prevail current literature. Lastly, SWOT (strengths, weaknesses, opportunities, threats) analysis presented, considering performance, competition, drawbacks lignin-derived CANs.

Language: Английский

---

Sustainable castor oil-based vitrimers: Towards new materials with reprocessability, self-healing, degradable and UV-blocking characteristics

Industrial Crops and Products, Journal Year: 2023, Volume and Issue: 193, P. 116210 - 116210

Published: Jan. 7, 2023

Vitrimers with reversible cross-links are emerging promising sustainable materials reprocessability and recyclability. Here, castor oil-based epoxy resin (EMCO) group carbon-carbon double bonds was prepared through a two-step process then cured itaconic acid (IA) epoxy-acid ring-opening reaction free radical polymerization to fabricate fully bio-based vitrimers containing transesterification bond. The thermal-mechanical properties, reprocessability, repairability, recyclability could be balanced by varying the molar ratio of EMCO IA. When carboxyl group/epoxy reached 1.0, EMCO-IA1.0 vitrimer exhibited highest tensile strength 14.39 MPa Tg 52.95 °C. Moreover, can effectively remodeled (2 h at 180 °C) prepare films self-healing thanks rapid mild stress relaxation (2.56 min 110 low activation energy (60.94 kJ·mol−1). More significantly, EMCO-IA degraded in ethanol solution recycled also excellent UV blocking ability. Overall, achieve highly efficient closed-loop recycling without significantly sacrificing mechanical which extend service life facilitate development polymeric material.

Language: Английский

---

High‐Performance, Light‐Stimulation Healable, and Closed‐Loop Recyclable Lignin‐Based Covalent Adaptable Networks

Small, Journal Year: 2023, Volume and Issue: 19(40)

Published: June 3, 2023

Abstract In this work, high‐performance, light‐stimulation healable, and closed‐loop recyclable covalent adaptable networks are successfully synthesized from natural lignin‐based polyurethane (LPU) Zn 2+ coordination structures (LPUxZy). Using an optimized LPU (LPU‐20 with a tensile strength of 28.4 ± 3.5 MPa) as the matrix for coordination, LPUs obtained that have different amounts Zn. When feed amount ZnCl 2 is 9 wt%, LPU‐20Z9 reaches 37.3 3.1 MPa toughness 175.4 4.6 MJ m −3 , which 1.7 times LPU‐20. addition, has crucial catalytic effect on “dissociation mechanism” in exchange reaction LPU. Moreover, ‐based bonds significantly enhance photothermal conversion capability lignin. The maximum surface temperature 118 °C under near‐infrared illumination 0.8 W −2 . This allows to self‐heal within 10 min. Due can be degraded recovered ethanol completely. Through investigation mechanisms design recycling method, work expected provide insight into development novel light‐stimulated heal ability, recyclability; applied toward expanded intelligent elastomers.

Language: Английский

---

Green and Catalyst-Free Cross-Linking of Bio-Based Elastomers toward Robust, Reprocessable Abilities and Improved Thermal Aging Resistance Enabled by β-Hydroxyl Esters

ACS Sustainable Chemistry & Engineering, Journal Year: 2023, Volume and Issue: 11(7), P. 2784 - 2796

Published: Feb. 3, 2023

The bio-based epoxidized natural rubber (ENR) is considered a promising platform to design and fabricate sustainable high-performance materials. epoxide sites in the ENR chains contribute designing green cross-linking strategy reduce release of toxic volatile organic compounds achieve recycling end-of-life rubbers. However, it still challenging catalyst-free effective obtain cross-linked with mechanically robust properties. Herein, series carboxylic acids different chain lengths degrees functionality were synthesized through solvent-free alcoholysis maleic anhydride served as cross-linkers for ENR. We demonstrated that increased conducive increasing rate efficiency epoxy–acid reaction improving mechanical properties compared those commercial acid. Hence, could be facilely effectively by modified without additional additives, producing β-hydroxy ester linkages. ENR/carbon black composites adjusted via changing structure content cross-linkers. Due introduction exchangeable linkages, covalently networks able topological rearrangements transesterifications, thus conferring good reprocessability. Moreover, acid-cured showed improved thermal-oxidative aging resistance sulfur-curd one because formed cross-links are thermally stable. This work provides catalyst-free, efficient elastomer, which open broad application scenario vitrimer-like

Language: Английский

---

Neighboring Molecular Engineering in Diels–Alder Chemistry Enabling Easily Recyclable Carbon Fiber Reinforced Composites

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(51)

Published: Sept. 28, 2023

Although a variety of dynamic covalent bonds have been successfully used in the development diverse sustainable thermosetting polymers and their composites, solving trade-off between recovery efficiency comprehensive properties is still major challenge. Herein, "one-stone-two-birds" strategy lower rotational energy barrier (Er ) phosphate-derived Diels-Alder (DA) cycloadditions was proposed for easily recyclable carbon fiber (CF)-reinforced epoxy resins (EPs) composites. In such strategy, phosphate spacer with Er accelerated segmental mobility DA exchange reaction network rearrangement to achieve high-efficiency repairing, reprocessing EPs matrix its composites rapid nondestructive recycling CF; meanwhile, incorporating phosphorus-based units especially reduced fire hazards. The resulting materials simultaneously showed excellent thermal/mechanical properties, superb safety facile recyclability, realizing concept high-performance This great significance understanding enriching molecular connotation chemistry, making it potentially applicable design wide range adaptable toward practical cutting-edge-tech applications.

Language: Английский

---