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Excessive carbon dioxide (CO2) emissions pose a serious threat to the natural environment; hence CO2 capture and utilization have been widely concerned in industrial production. At present, the high value‐added utilization of CO2 after capture has become a hot issue. Bio‐based carbonate materials with high commercial value can be generated by the reaction of CO2 and bio‐based compounds, which provides a promising, green, and sustainable material synthetic route. Bio‐based carbonate materials, which are suitable for applications in various industries, have excellent thermodynamic and mechanical properties compared with those prepared from petroleum. In this manuscript, the synthesis and utilization of bio‐based carbonates from a variety of bio‐based compounds and CO2 were briefly described, and the existing problems were put forward in the field. It provided a direction for the green utilization of CO2. [ABSTRACT FROM AUTHOR]

Polyurethanes (PUs) are a class of materials usually synthesized from isocyanates, diols, and water. Water is essential for producing carbon dioxide (CO2) which is used for the self‐blowing of the foams. Due to safety concerns with the production of isocyanates, alternative chemistries have been evaluated and cyclic carbonate systems have shown great promise. In a recent advancement by Bourguignon, Grignard, and Detrembleur, a cyclic carbonate and diamine system is capable of generating CO2 for self‐blowing through hydrolysis of the carbonate‐based monomer. The authors demonstrate that with a simple variation of the diamine monomer a wide range of physical and thermo‐mechanical properties were achievable. This work represents a significant step towards safer and more environmentally friendly PUs. [ABSTRACT FROM AUTHOR]

Polyurethanes (PUs) are a class of materials usually synthesized from isocyanates, diols, and water. Water is essential for producing carbon dioxide (CO2) which is used for the self‐blowing of the foams. Due to safety concerns with the production of isocyanates, alternative chemistries have been evaluated and cyclic carbonate systems have shown great promise. In a recent advancement by Bourguignon, Grignard, and Detrembleur, a cyclic carbonate and diamine system is capable of generating CO2 for self‐blowing through hydrolysis of the carbonate‐based monomer. The authors demonstrate that with a simple variation of the diamine monomer a wide range of physical and thermo‐mechanical properties were achievable. This work represents a significant step towards safer and more environmentally friendly PUs. [ABSTRACT FROM AUTHOR]

This work reports on the use of gallium aminotrisphenolate compounds as catalysts for the synthesis of cyclic carbonates from epoxides and CO2. The results show that they are highly active, and more so than the corresponding aluminium congeners. The catalyst system is applicable at low and elevated temperatures across a wide substrate scope including terminal, internal, multiple and fully deuterated epoxides. Applying low catalyst loadings has allowed for a TON of 344,000 to be obtained, highlighting their stability. A DFT investigation has confirmed that the gallium catalysts have lower energetic profiles compared to the aluminium congeners. Measurement of the Lewis acidity of both the gallium and aluminium aminotrisphenolate compounds using the Gutmann‐Beckett method provides the experimental proof that the gallium compounds are more Lewis acidic than their aluminium congeners. Finally, Ab‐Initio Molecular Dynamic (AIMD) simulations have investigated and quantified the dynamic behaviour of the catalytic systems, highlighting an important increase in fluxionality in some cases which helps to explain the increase in catalytic activity. [ABSTRACT FROM AUTHOR]

Tungstate catalysts are well established for olefin epoxidation reactions, while their catalytic activity for CO2 insertion in epoxides is a more recent discovery. This dual reactivity of tungstate prompted the present development of a catalytic tandem process for the direct conversion of olefins into the corresponding cyclic organic carbonates (COCs). Each of the two steps was studied in the presence of the ammonium tungstate ionic liquid catalyst – [N8,8,8,1]2[WO4] – obtained via a benign procedure starting from ammonium methylcarbonate ionic liquids. The catalytic epoxidation first step was optimised on 1-decene as model substrate, using H2O2 as benign oxidant, [N8,8,8,1]2[WO4] as catalyst and phosphoric acid as promoter affording quantitative conversion with 92% selectivity towards decene oxide. Unfortunately, the addition of CO2 from the start (auto-tandem catalysis) gave low yields of decene carbonate (<10%). On the contrary, the addition of 1 atm CO2 and tetrabutyl ammonium iodide after completion of the epoxidation first step without any intermediate work-up (assisted-tandem catalysis) afforded a 94% yield in decene carbonate. The protocol could be scaled up to a 10 gram scale. The scope of the reaction was demonstrated for primary aliphatic olefins with different alkyl chain lengths (C6–C16), while cyclic and aromatic activated olefins such as cyclohexene and styrene suffered from the formation of undesired overoxidation products in the first step. [ABSTRACT FROM AUTHOR]

The aminolysis of five-membered cyclic carbonates, which results in polyhydroxyurethanes (PHUs), is one of the most promising synthetic pathways to achieve isocyanate-free polyurethanes (NIPUs), one of the main industrial challenges over the coming years. This study highlights the higher reactivity of β-hydroxylamines toward cyclic carbonates compared to classical alkylamines through the determination of their reaction rate constants. The key role of the β-OH substituent in the aminolysis was revealed by DFT investigation. Polyfunctional alkylamine and β-hydroxyamine were then used for the synthesis of fully biobased PHU thermosets. The higher reactivity of β-hydroxylamines was confirmed by the gelation time gap between the two formulations studied. After curing, the thermal and thermo-mechanical properties of the thermosets were compared. [ABSTRACT FROM AUTHOR]

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. These reactions are first validated on model compounds and rationalized by DFT calculations. Various foams are then prepared and characterized in terms of morphology and mechanical properties, and the scope of the process is illustrated by modulating the composition of the reactive formulation. With impressive diversity and accessibility of the main components of the formulations, this new robust and solvent‐free process could open avenues for construction of more sustainable PU foams, and offers the first realistic alternative to the traditional isocyanate route. [ABSTRACT FROM AUTHOR]

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. These reactions are first validated on model compounds and rationalized by DFT calculations. Various foams are then prepared and characterized in terms of morphology and mechanical properties, and the scope of the process is illustrated by modulating the composition of the reactive formulation. With impressive diversity and accessibility of the main components of the formulations, this new robust and solvent‐free process could open avenues for construction of more sustainable PU foams, and offers the first realistic alternative to the traditional isocyanate route. [ABSTRACT FROM AUTHOR]

The lysine functionalization of ultrathin γ‐Al(OH)3 single‐crystal nanoplatelets (ly‐gibbsite) having an average thickness below 100 nm and a width ranging between 0.5 and 1.5 µm renders them organophilic and enables their agglomerate‐free dispersion in nonisocyanate polyhydroxyurethane (NIPU) thermosets prepared by amine cure of polyfunctional cyclic carbonates. Whereas most other nanoparticles drastically increase viscosity even at very low content, NIPU processing tolerates up to 40 wt% ly‐gibbsite without impairing its uniform dispersion. The amine groups of ly‐gibbsite can react with cyclic carbonate groups of NIPU to afford interfacial coupling. Contrary to the NIPU composites containing corundum and spherical gibbsite particles, ly‐gibbsite/NIPU nanocomposites exhibit substantially higher stiffness as reflected by high Young's modulus up to 9500 MPa. Moreover, ly‐gibbsite/NIPU coatings remain translucent even at high ly‐gibbsite content when the nanoplatelet length is below 1 µm. As verified by transmission electron microscopic imaging of coatings, the ly‐gibbsite nanoplatelets are aligned parallel to the surface. At high ly‐gibbsite content, NIPU thermosets are rendered flame retardant in the absence of halogen and other flame retardants. The NIPU coatings tolerate the addition of aluminum flakes to produce metallic NIPU varnishes. [ABSTRACT FROM AUTHOR]

An aminopyridinium ionic liquid is presented as a green, tunable, and active metal-free one-component catalytic system for the atom-efficient transformation of oxiranes and CO2 to cyclic carbonates. Inclusion of a positively charged moiety into aminopyridines, through a simple single-step synthesis, provides a one-component ionic liquid catalytic system with superior activity; effective in ring opening of epoxide, CO2 inclusion, and stabilization of oxoanionic intermediates. An efficiency assessment of a variety of positively charged aminopyridines was pursued, and the impact of temperature, catalyst loading, and the kind of nucleophile on the catalytic performance was also investigated. Under solvent-free conditions, this bifunctional organocatalytic system was used for the preparation of 18 examples of cyclic carbonates from a broad range of alkyl- and aryl-substituted oxiranes and CO2, where up to 98% yield and high selectivity were achieved. DFT calculations validated a mechanism in which nucleophilic ring-opening and CO2 inclusion occur simultaneously towards cyclic carbonate formation. [ABSTRACT FROM AUTHOR]

Bifunctional ammonium and phosphonium salts have been identified as potential organocatalysts for the synthesis of glycerol carbonate methacrylate (GCMA). Three of these catalysts showed high efficiency and allowed the conversion of glycidyl methacrylate with CO2 to the desired product in >99 % conversion and selectivity. Subsequently, immobilized analogues of selected catalysts were prepared and tested. A phenol‐substituted phosphonium salt on a silica support proved to be a promising candidate in recycling experiments. The same catalyst was used in 12 consecutive runs, resulting in GCMA yields of up to 88 %. Furthermore, a life cycle assessment was conducted for the synthesis of GCMA starting from epichlorohydrin (EPH) and methacrylic acid (MAA). For the functional unit of 1 kg GCMA, 15 wt % was attributed to the incorporation of CO2, which led to a reduction of the global warming potential of 3 % for the overall process. [ABSTRACT FROM AUTHOR]

Given the large amount of anthropogenic CO2 emissions, it is advantageous to use CO2 as feedstock for the fabrication of everyday products, such as fuels and materials. An attractive way to use CO2 in the synthesis of polymers is by the formation of five‐membered cyclic organic carbonate monomers (5CCs). The sustainability of this synthetic approach is increased by using scaffolds prepared from renewable resources. Indeed, recent years have seen the rise of various types of carbonate syntheses and applications. 5CC monomers are often polymerized with diamines to yield polyhydroxyurethanes (PHU). Foams are developed from this type of polymers; moreover, the additional hydroxyl groups in PHU, absent in classical polyurethanes, lead to coatings with excellent adhesive properties. Furthermore, carbonate groups in polymers offer the possibility of post‐functionalization, such as curing reactions under mild conditions. Finally, the polarity of carbonate groups is remarkably high, so polymers with carbonates side‐chains can be used as polymer electrolytes in batteries or as conductive membranes. The target of this Review is to highlight the multiple opportunities offered by polymers prepared from and/or containing 5CCs. Firstly, the preparation of several classes of 5CCs is discussed with special focus on the sustainability of the synthetic routes. Thereafter, specific classes of polymers are discussed for which the use and/or presence of carbonate moieties is crucial to impart the targeted properties (foams, adhesives, polymers for energy applications, and other functional materials). Make 5CCs from CO2: Renewable scaffolds and CO2 are combined to produce five‐membered cyclic organic carbonates that serve as building blocks for the preparation of ubiquitous polymeric materials, including foams, adhesives, components of solid electrolytes in lithium batteries, and sensors. Recent advances are reviewed herein with a focus on the sustainable synthesis of monomers from renewable starting materials and on polymer applications. [ABSTRACT FROM AUTHOR]

The reaction between carbon dioxide and epoxides is an attractive pathway for CO2-utilisation as it can lead to the formation of two different, yet valuable, products: cyclic and polymeric carbonates. In this review, the advancements made within this field are critically discussed with special attention to the potential of these two classes of compounds as green chemical products. First, an overview is provided of the various types of homogeneous and heterogeneous catalytic systems developed for achieving the reaction of carbon dioxide with epoxides with high activity and selectivity towards either the cyclic or the polymeric carbonate products. Then, the chemical and physical properties of the cyclic and polycarbonate products are discussed, focussing on the correlation between such properties and the potential applications of each class of compounds. Finally, the most relevant applications of these materials, both potential and industrially implemented, are critically reviewed covering the fields of polymer products, energy storage devices, and biomedical and pharmaceutical applications. [ABSTRACT FROM AUTHOR]

Three types of bifunctional 6-membered cyclic carbonates bearing ester, acyclic carbonate or ether moieties have been derived from nonexpensive trimethylolpropane or di(trimethylolpropane) through phosgene-free routes and used for the polyaddition reaction with 1,3-diaminopropane to design polyhydroxyurethanes (PHUs) containing the corresponding linkages in their main chains. Furthermore, these PHUs have been chemically modified via their OH groups to afford water-soluble PHUs (WSPHUs) and characterized for their hydrolytic properties at different pH conditions. Carbonate and ester bonds in these WSPHUs are easily hydrolyzed under basic conditions and their hydrolytic rates depend on their main chain structures; WSPHUs bearing carbonate structures are degraded faster than WSPHUs with ester linkages, while WSPHUs having ether bonds are slowest hydrolyzed. Moreover, the hydrolytic rates of these WSPHUs can be modulated by the copolymerization of these monomers at different feed ratios. [ABSTRACT FROM AUTHOR]

Numerous bifunctional organocatalysts were synthesized and tested for the atom-efficient addition of carbon dioxide and epoxides to produce cyclic carbonates. These catalysts are based on phosphonium salts containing an alcohol moiety in the side chain for substrate activation through hydrogen bonding. In the model reaction, converting 1,2-butylene oxide with CO2, 19 catalysts were tested to determine structure-activity relationships. In total, 28 epoxides were converted with CO2 to give the respective cyclic carbonates in yields of up to 99 %. Even at 45 °C, the most active catalyst was able to produce cyclic carbonates selectively in high yields. The carbonates were generally obtained as analytically pure products after simple filtration over silica gel. This single-component catalyst system works under neat and mild reaction conditions and tolerates several useful moieties. [ABSTRACT FROM AUTHOR]