Reprocessable and Chemically Recyclable Hard Vitrimers Based on Liquid‐Crystalline Epoxides

Advanced Materials, Journal Year: 2022, Volume and Issue: 35(11)

Published: Dec. 23, 2022

The rapid increase in demand for recyclable and reusable thermosets has necessitated the development of materials with chemical structures that exhibit these features. Thus, functional mesogenic epoxide monomers bearing both ester imine groups can be vitrimerized recycled are reported herein. compounds show mesophase characteristics at 100-200 °C converted into hard epoxides by a common curing reaction. obtained have high isotropic thermal conductivity (≈0.64 W m-1 K-1 ), which is derived from their highly ordered microstructures. cured products easily reprocessed through metathesis transesterification, decomposed hydrolysis under acidic or basic conditions subsequently re-cured. Surprisingly, repeatedly chemically decomposed. retain properties pristine counterparts, preserve advantages without alteration to any unique properties. A dehydration reaction occurs between residual hydroxyl during re-hardening, dramatically increases glass transition temperature ≈60 °C. These reprocessable vitrimers demonstrate effectiveness environmental friendliness molecular design strategy

Language: Английский

---

Fully biomass-derived vitrimeric material with water-mediated recyclability and monomer recovery

Green Chemistry, Journal Year: 2022, Volume and Issue: 24(15), P. 5978 - 5986

Published: Jan. 1, 2022

Fully bio-based monomers are used in the green synthesis of a vitrimeric poly(acetal) which can undergo both closed-loop mechanical and chemical recycling, fulfilling 11 out 12 chemistry principles.

Language: Английский

---

Reprocessable and degradable bio-based polyurethane by molecular design engineering with extraordinary mechanical properties for recycling carbon fiber

Polymer, Journal Year: 2022, Volume and Issue: 258, P. 125313 - 125313

Published: Sept. 11, 2022

Language: Английский

---

High‐Performance Vitrimeric Benzoxazines for Sustainable Advanced Materials: Design, Synthesis, and Applications

Macromolecular Materials and Engineering, Journal Year: 2022, Volume and Issue: 308(4)

Published: Oct. 26, 2022

Abstract Polybenzoxazines are high‐performance materials capable of replacing conventional thermosets such as phenolics, epoxies, and bismaleimides in composites manufacturing due to their excellent thermomechanical chemical behavior. Their versatility compatibility with biobased precursors make them an attractive option composite matrices. Like other thermosets, polybenzoxazines not recyclable cannot be reprocessed. Incorporating dynamic bonds benzoxazine monomers can produce vitrimeric polybenzoxazines, which potentially overcome this limitation tuned exhibit smart functionalities self‐healing shape memory. Dynamic bond exchange mechanisms for vitrimer development transesterification, imine bond, disulfide exchange, transamination, transcarbamoylation, transalkylation, olefin metathesis, transcarbonation, siloxane‐silanol boronic ester, silyl ether dioxaborolane metathesis applicable chemistry, transesterification having successfully vitrimerized benzoxazines topological transitions at −8.5 88 °C, respectively. Benzoxazine vitrimers featuring glass 193, 224, 222–236 °C now known. These place the forefront reprocessable thermosetting polymers

Language: Английский

---

Sustainable Bio-Based UV-Cured Epoxy Vitrimer from Castor Oil

Polymers, Journal Year: 2023, Volume and Issue: 15(4), P. 1024 - 1024

Published: Feb. 18, 2023

Vitrimers brought new properties in thermosets by allowing their reshaping, self-healing, reprocessing, and network rearrangement without changing structural integrity. In this study, epoxidized castor oil (ECO) was successfully used for the straightforward synthesis of a bio-based solvent-free vitrimer. The based on UV-curing process, which proceeded at low temperatures absence any solvents, within short time. Real time Fourier-transformed infrared spectroscopy photo-DSC were exploited to monitor cationic photocurable process. UV-cured polymer networks able efficiently undergo thermo-activated bond exchange reactions due presence dibutyl phosphate as transesterification catalyst. Mechanical properties, thermal resistance, glass transition temperature, stress relaxation investigated function amount determined both DMTA tensile tests. Glass temperature (Tg) evaluated DMTA. Thermal stability assessed thermogravimetric analysis, whilst vitrimeric studied experiments. Overall, ECO-based vitrimer showed high resistance (up 200 °C) good mechanical (elastic modulus about 10 MPa) can therefore be considered promising starting point obtaining more sustainable vitrimers.

Language: Английский

---

Upcycling Waste Polycarbonate to Poly(carbonate imine) Vitrimers with High Thermal Properties and Unprecedented Hydrolytic Stability

ACS Sustainable Chemistry & Engineering, Journal Year: 2023, Volume and Issue: 11(23), P. 8580 - 8591

Published: May 27, 2023

The global market for polycarbonate (PC) increases steadily because of its heat resistance, toughness, and optical transparency. To achieve sustainability, the waste (WPC) should be recycled. This work reports a 100% atom-efficiency upcycling WPC to WPC-derived aldehyde (WPC-CHO). Then, poly(carbonate imine) vitrimers (PCIs) based on WPC-CHO two aromatic diamines were prepared. Generally, polyimines can cleave in mild acidic conditions such as 0.1 M HCl(aq) seldom show good thermal tensile properties. PCIs this showed properties an unprecedented resistance toward acid hydrolysis. They survive even immersing 5 H2SO4 THF/H2O solution 6 months. unusual hydrolysis expands application environment. Small pieces compression-molded into newly formed polymer film at 240 °C. reprocessability demonstrates vitrimer characteristic PCIs. degraded through simultaneous aminolysis carbonate transimination imine by hexylamine (HA) catalyst-free condition. Based transimination, we cross-linking network PCI-based carbon fiber-reinforced (CFRP) recovered undamaged fiber. environmentally friendly will attract attention researchers who are interested sustainability circularity.

Language: Английский

---

From biomass to vitrimers: Latest developments in the research of lignocellulose, vegetable oil, and naturally-occurring carboxylic acids

Industrial Crops and Products, Journal Year: 2023, Volume and Issue: 206, P. 117690 - 117690

Published: Oct. 28, 2023

Language: Английский

---

Eugenol-based dual-cured materials with multiple dynamic exchangeable bonds

European Polymer Journal, Journal Year: 2024, Volume and Issue: 206, P. 112782 - 112782

Published: Jan. 19, 2024

In the present work, preparation of sustainable thermosets has been approached simultaneously from three different points view: a) use bio-based monomers chemically modified through green methodologies, b) adoption dual curing click-type reactions to implement more efficient manufacturing processes, and c) inclusion interchangeable groups in network, enable reuse recycling material at end its useful life avoid waste generation. The first goal by synthesizing a greener way an acrylate-epoxy derivative eugenol (AEEU) glycerol triacrylate (GTA), both biobased resources. Then, second approach was addressed using cystamine as crosslinker obtain materials dual-curing procedure based on "click" aza-Michael reaction epoxy-amine reaction. Intermediate final could be prepared with tailorable properties controlling molar ratio AEEU GTA. By DSC rheology, we evaluate sequentiality gelation process. Finally, covalent adaptable networks (CANs) contained types dynamic bonds (disulfide, esters, β-aminoesters) their thermomechanical were tested DMA revealing Tgs above room temperature 47 70 °C. Bending tests break performed mechanical reaching values up 90 MPa stress 7 % deformation. Stress relaxation showed that all relax relatively low temperatures (120 °C) less than 21 min. associative dissociative behavior these investigated rheology clear drop modulus high frequencies when used crosslinker. Moreover, reprocessability obtaining homogeneous samples no significant changes chemical thermal highlighting great potential wide range possibilities many fields CANs.

Language: Английский

---

Sustainable Benzoxazine-Sulfur Copolymer with Dynamic Linkages: Recycling, Reprocessing, Self-Healing, and Shape Recovery (R²S²)

ACS Sustainable Chemistry & Engineering, Journal Year: 2024, Volume and Issue: 12(18), P. 7126 - 7135

Published: April 24, 2024

Improving the sustainability of thermosets is a crucial challenge in polymer science due to overdependence on petrochemical-based feedstocks and their infusible cross-linked networks, which limit reprocessing after use. Implementing renewable recyclability production networks paves way for development next-generation sustainable materials. Polybenzoxazines (PBzs) provide superior alternative traditional phenolic resin, with opportunities incorporation dynamic linkages owing high molecular design flexibility, endowing reprocessability. Incorporating sulfide bonds PBz can produce smart functionalities reversible bond exchange mechanism, may unique solution address issue end-of-life by enabling processability. The present work employs biobased cardanol-cystamine industrial byproduct sulfur construct reusable thermoset poly(benzoxazine-random-sulfur) intrinsic undergoing dual (associative dissociative) mechanisms. copolymer showed recycling (R), reshaping self-healing (S), shape recovery (S) was explored as load-bearing flexible film debondable adhesive features showcasing appreciable mechanical strength. flexibility reprocessability synthesized copolymers will benefit quest benign polymers serving wide arena applications.

Language: Английский

---

Vegetable oils as monomeric and polymeric materials: A graphical review

Current Research in Green and Sustainable Chemistry, Journal Year: 2022, Volume and Issue: 5, P. 100343 - 100343

Published: Jan. 1, 2022

Vegetable oils have been extensively researched, and many reviews published about them. However, most of them are focused on soybean linseed reactions, such as epoxidation, but do not take into account other potential sources or reactions that can provide high value products. Therefore, the present work aims to cover these overlooked topics illustrating different vegetable including baru, macaw, andiroba, grape, passion fruits, neem, so on. Furthermore, some chemical modifications their resulting monomers discussed, for instance, maleinization, acrylation, carbonatation, click chemistry, forth. Consequently, there several ways use produce renewable polymers in technological fields, photopolymerisation vitrimers. The latter has received great attention recent research due recovering, reshaping, welding properties.

Language: Английский

---