Spatio-Selective Reconfiguration of Mechanical Metamaterials Through the Use of Dynamic Covalent Chemistries.

Mechanical metamaterials achieve unprecedented mechanical properties through their periodically interconnected unit cell structure. However, their geometrical design and resulting mechanical properties are typically fixed during fabrication. Despite efforts to implement covalent adaptable networks (CANs) into metamaterials for permanent shape reconfigurability, emphasis is given to global rather than local shape reconfiguration.

Nonconventional Fluorescent Non-Isocyanate Polyurethane Foams for Multipurpose Sensing Applications.

Fluorescent foams with interconnected pores are attractive for the detection and quantification of various products. However, many fluorescent probes are suffering from aggregation-caused fluorescence quenching in their solid/aggregated state, are costly, and/or not straightforward to incorporate in foams, limiting their utility for this application. Herein, non-isocyanate polyurethane foams, prepared by the simple water-induced self-blowing process, present a nonconventional fluorescence behaviour, i.

Solid Polymer Electrolytes with Sacrificial End Groups for a Wide Oxidative Potential and Stable Interface in Lithium Metal Batteries.

Poly(ethylene glycol) (PEG), despite being the most studied polymer electrolyte, suffers from serious drawbacks, which require fundamental studies behind its underperformance in lithium batteries. Here, we report the effect of the terminal group on triarm PEG stars bearing either hydroxyl (TPEG-OH) or carbonate-ketone (TPEG-Carb-ket) terminal groups. The latter is synthesized by a ring-opening reaction triggered by the -OH end group of TPEG-OH and results in a carbonate-ketone functionality.

Intensified Continuous Flow Process for the Scalable Production of Bio-Based Glycerol Carbonate.

A subtle combination of fundamental and applied organic chemistry toward process intensification is demonstrated for the large-scale production of bio-based glycerol carbonate under flow conditions. The direct carbonation of bio-based glycidol with CO is successfully carried out under intensified flow conditions, with Barton's base as a potent homogeneous organocatalyst. Process metrics for the CO coupling step (for the upstream production, output: 3.

Cascade Exotherms for Rapidly Producing Hybrid Nonisocyanate Polyurethane Foams from Room Temperature Formulations.

For decades, self-blown polyurethane foams─found in an impressive range of materials─are produced by the toxic isocyanate chemistry and are difficult to recycle. Producing them in existing production plants by a rapid isocyanate-free self-blowing process from room temperature (RT) formulations is a long-lasting challenge. The recent water-induced self-blowing of nonisocyanate polyurethane (NIPU) formulations composed of a CO-based tricyclic carbonate, diamine, water, and a catalyst successfully addressed the isocyanate issue, however failed to provide foams at RT.

Covalent Adaptable Networks through Dynamic ,-Acetal Chemistry: Toward Recyclable CO-Based Thermosets.

Finding new chemistry platforms for easily recyclable polymers has become a key challenge to face environmental concerns and the growing plastics demand. Here, we report a dynamic chemistry between CO-sourced alkylidene oxazolidones and thiols, delivering circular non-isocyanate polyurethane networks embedding ,-acetal bonds. The production of oxazolidone monomers from CO is facile and scalable starting from cheap reagents.

Facile Access to CO -Sourced Polythiocarbonate Dynamic Networks And Their Potential As Solid-State Electrolytes For Lithium Metal Batteries.

Poly(monothiocarbonate)s are an interesting class of sulfur-containing materials whose application as solid polymer electrolytes was barely studied, certainly due to the elusive production of diversified polymer architectures. Herein, a new liquid CO -sourced bis(α-alkylidene cyclic carbonate) monomer was designed at high yield to allow its one-step and solvent-free copolymerization with thiols to produce linear and cross-linked polymers in mild conditions. The influence of the monomer structure on the thermal properties and the ionic conductivity of linear polymers was assessed.

Accelerating the Curing of Hybrid Poly(Hydroxy Urethane)-Epoxy Adhesives by the Thiol-Epoxy Chemistry.

The polyaddition between dicyclic carbonates and diamines leading to poly(hydroxy urethane)s (PHUs) has emerged as the preferred method for the synthesis of green, non-isocyanate polyurethanes. However, when proposed for use as structural adhesives, the long times for completion of aminolysis of the 5-membered cyclic carbonates under ambient conditions force the use of complementary chemistries to accelerate the curing process. In this work, a system that combines an amino-terminated PHU (NH-PHU-NH), an epoxy resin, and a thiol compound was employed to develop high-shear strength PHU-epoxy hybrid adhesives able to cure at room temperature in short times.

Water-Induced Self-Blown Non-Isocyanate Polyurethane Foams.

For 80 years, polyisocyanates and polyols were central building blocks for the industrial fabrication of polyurethane (PU) foams. By their partial hydrolysis, isocyanates release CO that expands the PU network. Substituting this toxic isocyanate-based chemistry by a more sustainable variant-that in situ forms CO by hydrolysis of a comonomer-is urgently needed for producing greener cellular materials.

Bio-Based Solid Electrolytes Bearing Cyclic Carbonates for Solid-State Lithium Metal Batteries.

Green resources for lithium-based batteries excite many researchers due to their eco-friendly nature. In this work, a sustainable bio-based solid-state electrolyte was developed based on carbonated soybean oil (CSBO), obtained by organocatalyzed coupling of CO to epoxidized soybean oil. CSBO coupled with lithium bis(trifluoromethanesulfonyl)imide salt on a bio-based cellulose separator resulted in free-standing membranes.

Enhanced and Reusable Poly(hydroxy urethane)-Based Low Temperature Hot-Melt Adhesives.

Poly(hydroxy urethane)s (PHUs) based on 5-membered cyclic carbonates have emerged as sustainable alternatives to conventional isocyanate-based polyurethanes. However, while from the point of view of sustainability they represent an improvement, their properties are still not competitive with conventional polyurethanes. In this work, the potential of PHUs as reversible hot-melt adhesives is discussed.

Poly(hydroxyurethane) Adhesives and Coatings: State-of-the-Art and Future Directions.

Polyurethane (PU) adhesives and coatings are widely used to fabricate high-quality materials due to their excellent properties and their versatile nature, which stems from the wide range of commercially available polyisocyanate and polyol precursors. This polymer family has traditionally been used in a wide range of adhesive applications including the bonding of footwear soles, bonding of wood (flooring) to concrete (subflooring), in the automotive industry for adhering different car parts, and in rotor blades, in which large surfaces are required to be adhered. Moreover, PUs are also frequently applied as coatings/paints for automotive finishes and can be applied over a wide range of substrates such as wood, metal, plastic, and textiles.

Divergent Aminolysis Approach for Constructing Recyclable Self-Blown Nonisocyanate Polyurethane Foams.

We report an approach to fabricate self-blown nonisocyanate polyurethane (NIPU) foams by capitalizing on the divergent chemistries of amines with cyclic carbonates─creating the polymer network─and thiolactone─delivering a thiol that generates the blowing agent (CO) by reaction with a cyclic carbonate. Multiple linkages (hydroxyurethanes, thioethers, and amides) are created within the polymer network by this domino process. This one-pot methodology furnishes flexible to rigid foams with open-cell morphology at moderate temperature.

Exovinylene Cyclic Carbonates: Multifaceted CO -Based Building Blocks for Modern Chemistry and Polymer Science.

Carbon dioxide is a renewable, inexhaustible, and cheap alternative to fossil resources for the production of fine chemicals and plastics. It can notably be converted into exovinylene cyclic carbonates, unique synthons gaining momentum for the preparation of an impressive range of important organic molecules and functional polymers, in reactions proceeding with 100 % atom economy under mild operating conditions in most cases. This Review summarizes the recent advances in their synthesis with particular attention on describing the catalysts needed for their preparation and discussing the unique reactivity of these CO -based heterocycles for the construction of diverse organic building blocks and (functional) polymers.

Introducing Polyhydroxyurethane Hydrogels and Coatings for Formaldehyde Capture.

Formaldehyde (FA) is a harmful chemical product largely used for producing resins found in our living spaces. Residual FA that leaches out the resin contributes to our indoor air pollution and causes some important health issues. Systems able to capture this volatile organic compound are highly desirable; however, traditional adsorbents are most often restricted to air filtration systems.

Functional Polyethylenes by Organometallic-Mediated Radical Polymerization of Biobased Carbonates.

Partly or fully renewable (co)polymers are gaining interest in both academia and industry. Polyethylene is a widely used polymer, classically derived from fossil fuels, with a high versatility stemming from the introduction of comonomers altering the mechanical properties. The introduction of renewable functionalities into this polymer is highly attractive to obtain functional, tunable, and at least partially renewable polyethylenes.

Synergetic Effect of Dopamine and Alkoxysilanes in Sustainable Non-Isocyanate Polyurethane Adhesives.

The preparation of non-isocyanate polyurethanes (NIPUs) by polyaddition of (poly)cyclic carbonates to (poly)amines represents one of the most optimistic alternatives for replacing conventional polyurethanes prepared by the toxic isocyanate chemistry. However, the limited reactivity of conventional five membered cyclic carbonates even in the presence of catalysts restricts their industrial implementation. One way to mitigate this lack of reactivity is to combine with other chemistries to create hybrid-NIPUs with superior performance.

A supercritical fluid technology for liposome production and comparison with the film hydration method.

Liposomes were produced by an innovative method using supercritical carbon dioxide as a dispersing agent. A quality by design strategy was used to find optimal production conditions with specific parameters (lipid concentration, dispersion volume, agitation rate, temperature and pressure) allowing the production of liposomes with predicted physicochemical characteristics (particles size and PdI). Two conditions were determined with specific production parameters.

Water-Borne Isocyanate-Free Polyurethane Hydrogels with Adaptable Functionality and Behavior.

Polyurethane hydrogels are attractive materials finding multiple applications in various sectors of prime importance; however, they are still prepared by the toxic isocyanate chemistry. Herein the facile and direct preparation in water at room temperature of a large palette of anionic, cationic, or neutral polyurethane hydrogels by a non-isocyanate route from readily available diamines and new hydrosoluble polymers bearing cyclic carbonates is reported. The latter are synthesized by free radical polymerization of glycerin carbonated methacrylate with water-soluble comonomers.

Chemo- and Regioselective Additions of Nucleophiles to Cyclic Carbonates for the Preparation of Self-Blowing Non-Isocyanate Polyurethane Foams.

Polyurethane (PU) foams are indisputably daily essential materials found in many applications, notably for comfort (for example, matrasses) or energy saving (for example, thermal insulation). Today, greener routes for their production are intensively searched for to avoid the use of toxic isocyanates. An easily scalable process for the simple construction of self-blown isocyanate-free PU foams by exploiting the organocatalyzed chemo- and regioselective additions of amines and thiols to easily accessible cyclic carbonates is described.