Selective copolymerization of carbon dioxide with propylene oxide catalyzed by a nanolamellar double metal cyanide complex catalyst at low polymerization temperatures

Porous Hexacyanometallate(III) Complexes as Catalysts in the Ring-Opening Copolymerization of CO2 and Propylene Oxide

In this work, six porous hexacyanometallate complexes (Ni3[Co(CN)6]2, Co3[Co(CN)6]2, Fe3[Co(CN)6]2, Ni3[Fe(CN)6]2, Co3[Fe(CN)6]2, Fe4[Fe(CN)6]2) were synthesized by a complexing agent assisted coprecipitation method and thoroughly characterized via X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), in situ high-temperature X-ray diffraction (HT-XRD), elemental analysis (EA), X-ray fluorescence (XRF), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 physisorption, and gas–solid phase titration with NH3. The thermal stability, chemical composition, pore size and volume, crystallite size and density of surface acid sites were strongly sensitive to both the transition metal and the cyanometallate anion employed. On that basis, transition metal hexacyanometallates must be perceived as an adaptable class of zeolite-like microporous materials. The catalytic properties of these compounds were tested by copolymerization of propylene oxide and CO2, a green route to obtain biodegradable aliphatic polycarbonates. All compounds under study showed moderate activity in the target reaction. The obtained copolymers were characterized by modest CO2 content (carbonate units ranging from 16 to 33%), random structure (RPEC ≈ 70%), and moderate molecular weight (Mw = 6000–85,400 g/mol) with broad dispersity values (ĐM = 4.1–15.8).

Cat-CrNP as new material with catalytic properties for 2-chloro-2-propen-1-ol and ethylene oligomerizations

The contemporary search for new catalysts for olefin oligomerization and polymerization is based on the study of coordinating compounds and/or organometallic compounds as post-metallocene catalysts. However known catalysts are suffered by many flaws, among others unsatisfactory activity, requirement of high pressure or instability at high temperatures. In this paper, we present a new catalyst i.e. the crystalline complex compound possesing high catalytic activity in the oligomerization of olefins, such as 2-chloro-2-propen-1-ol and ethylene under very mild conditions (room temperature, 0.12 bar for ethylene oligomerization, atmospheric pressure for 2-chloro-2-propen-1-ol oligomerization). New material—Cat-CrNP ([nitrilotriacetato-1,10-phenanthroline]chromium(III) tetrahydrate) has been obtained as crystalline form of the nitrilotriacetate complex compound of chromium(III) with 1,10-phenanthroline and characterized in terms of its crystal structure by the XRD method and by multi-analytical investigations towards its physicochemical propeties The yield of catalytic oligomerization over Cat-CrNP reached to 213.92 g · mmol⁻¹ · h⁻¹· bar⁻¹ and 3232 g · mmol⁻¹ · h⁻¹ · bar⁻¹ for the 2-chloro-2-propen-1-ol and ethylene, respectively. Furthemore, the synthesis of Cat-CrNP is cheap, easy to perform and solvents used during preparation are environmentally friendly.

A biodegradable CO2-based polymeric antitumor nanodrug via a one-pot surfactant- and solvent-free miniemulsion preparation

In the present study, low molecular weight poly(propylene carbonate) (PPC, Mn = 3500), a biodegradable liquid polymer easily prepared from carbon dioxide (CO2), was modified into poly(propylene carbonate)diacrylate (PPC-DA) by acylation, and methoxy poly(ethylene glycol) (mPEG) was modified into methoxy poly(ethylene glycol) acrylate (mPEG-A). Using PPC-DA as the dispersant to dissolve hydrophobic doxorubicin (DOX) and the initiator, and with mPEG-A as the co-monomer and polymerisable surfactant, a biodegradable nanodrug with excellent biocompatibility was prepared by shear emulsification polymerization without surfactants or organic solvent residues. The nanodrug can be efficiently endocytosed by tumor cells and can rapidly release doxorubicin triggered by the acidic endosomal pH. As evidenced by experiments in tumor-bearing mice, such a nanodrug is stealthy during blood circulation, and targets tumor sites with high efficiency. Moreover, this nanodrug is more effective and less toxic than free doxorubicin. This study provides a green and versatile approach for preparing biodegradable nanodrugs via a simple and efficient process. Moreover, this study extends the applications of CO2 based polymers in the biomedical field, promoting the development of CO2 polymerization fixation.

Facile Room-Temperature Preparation of Flexible Polyurethane Foams from Carbon Dioxide Based Poly(ether carbonate) Polyols with a Reduced Generation of Acetaldehyde

Carbon dioxide (CO₂) is becoming more attractive as a renewable feedstock for chemical synthesis. In this study, CO₂ was incorporated into poly(ether carbonate) (PEC) polyols by using a double-metal-cyanide catalyst. By adjusting the CO₂ pressure, the content of propylene carbonate units in the PEC polyols was controlled, indicating successful and semiquantitative incorporation of CO₂ into the PEC polyols. Polyurethane foams (PUFs) with different propylene carbonate content were easily prepared at room temperature by employing the PEC polyols due to their adequate viscosity under ambient conditions. The firmness of the PUFs increased as the amount of propylene carbonate units increased due to the rigidity of the carbonate linkage, representing predictable mechanical properties. Interestingly, reduced generation of volatile organic compounds (VOCs) from the PUFs, namely acetaldehyde, was observed with a high content of propylene carbonate units at 120 °C, indicating good stability of the carbonate units against thermo-oxidative decomposition. This study demonstrates the importance of CO₂ as an environmental-friendly and renewable resource that can provide not only industrially important but also problem-solving products in terms of processability and low generation of VOCs.

Advances in the use of CO2 as a renewable feedstock for the synthesis of polymers

Carbon dioxide offers an accessible, cheap and renewable carbon feedstock for synthesis. Current interest in the area of carbon dioxide valorisation aims at new, emerging technologies that are able to provide new opportunities to turn a waste into value. Polymers are among the most widely produced chemicals in the world greatly affecting the quality of life. However, there are growing concerns about the lack of reuse of the majority of the consumer plastics and their after-life disposal resulting in an increasing demand for sustainable alternatives. New monomers and polymers that can address these issues are therefore warranted, and merging polymer synthesis with the recycling of carbon dioxide offers a tangible route to transition towards a circular economy. Here, an overview of the most relevant and recent approaches to CO2-based monomers and polymers are highlighted with particular emphasis on the transformation routes used and their involved manifolds.

Synthesis of Zn–Fe double metal cyanide complexes with imidazolium-based ionic liquid cocatalysts via ball milling for copolymerization of CO2 and propylene oxide

In this work, Zn–Fe double metal cyanide (DMC) catalysts were successfully synthesized via clean and efficient ball milling. Imidazolium-based ionic liquids as cocatalysts were incorporated into the structure of the DMC catalysts during the grinding process. The modified Zn–Fe DMC catalysts were effective for the alternating copolymerization of carbon dioxide and propylene oxide under controlled reaction conditions. The properties and structures of the Zn–Fe DMC catalysts and the resulting polymers were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, elemental analysis, ¹H and ¹³C NMR spectroscopy, gel permeation chromatography, and thermogravimetric analysis. The results indicate that the Zn–Fe DMC catalysts exhibit higher thermal stability compared to the DMC catalysts without imidazolium-based ionic liquids (DMC-Blank). We determined that the introduction of a small amount of imidazolium-based ionic liquids can increase the carbonate content of the poly(propylene carbonate) (PPC) copolymer in the range of 18.48–29.00%. The turnover numbers of PPC were ∼4.40. In addition, the measured number-average relative molecular mass was in the range of 2.96 × 10³–4.98 × 10³ with a narrow polydispersity index of 1.00–1.08.

Zn–Fe DMC complexes with imidazolium-based ionic liquid cocatalysts were prepared by a clean and efficient ball milling process for the copolymerization of CO₂ and propylene oxide.

Synthesis of vegetable-oil based polymer by terpolymerization of epoxidized soybean oil, propylene oxide and carbon dioxide

Although carbon dioxide (CO₂) is well known as one of the major green-house gases, it is also an economical C1 resource. Thus, CO₂ has been regarded as an appealing starting material for the synthesis of polymers, like polycarbonates by the reaction with epoxides. Herein the reaction between natural epoxidized soybean oil (ESO), propylene oxide (PO) and CO₂ under high pressure (4.0MPa) with the presence of Co-Zn double metal cyanide (Co-Zn DMC) catalyst was studied. Temperature and reaction time were varied accordingly and the products obtained were characterized by FTIR, GPC and ¹H NMR. The results obtained indicate the formation of polycarbonates in the samples collected with yields vary from 60 to 85%. The number average molecular weight (M_n) of the resultant polymer prepared at reaction temperature of 80°C and reaction time of 6h can reach up to 6498g/mol.

Alternating and regioregular copolymers with high refractive index from COS and biomass-derived epoxides

The catalytic synthesis of well-defined COS- and biomass-derived copolymer with a high refractive index is described.

Catalysts for CO2/epoxide ring-opening copolymerization

This article summarizes and reviews recent progress in the development of catalysts for the ring-opening copolymerization of carbon dioxide and epoxides. The copolymerization is an interesting method to add value to carbon dioxide, including from waste sources, and to reduce pollution associated with commodity polymer manufacture. The selection of the catalyst is of critical importance to control the composition, properties and applications of the resultant polymers. This review highlights and exemplifies some key recent findings and hypotheses, in particular using examples drawn from our own research.

Cheap and fast: oxalic acid initiated CO2-based polyols synthesized by a novel preactivation approach

Preactivation: an interesting means to shorten the copolymerization time of the CO₂-based polyols synthesized by strongly acidic but cheap oxalic acid.

Simple synthesis of Prussian blue analogues in room temperature ionic liquid solution and their catalytic application in epoxidation of styrene

Synthesis and characterization of CoFePBAs in ionic liquid solution and their catalytic properties of styrene epoxidation are presented.

Synthesis of fully alternating polycarbonate with low Tg from carbon dioxide and bio-based fatty acid

Perfectly alternating copolymerization of CO₂ with a bio-based epoxide is reported with a heterogeneous Zn–Co(iii) DMCC, affording copolymers with low T_g values of −38 to −44 °C and two end hydroxyl groups.

Regio-selective synthesis of polyepichlorohydrin diol using Zn–Co(iii) double metal cyanide complex

This work describes the first regio-selective synthesis of poly(epichlorohydrin) diol via a simple one-pot bulk polymerization with a heterogeneous catalyst.

One-pot controllable synthesis of oligo(carbonate-ether) triol using a Zn-Co-DMC catalyst: the special role of trimesic acid as an initiation-transfer agent

Oligo(carbonate-ether) triol with controllable M_n and CU was synthesized by using TMA as a novel chain initiation-transfer agent catalyzed by Zn-Co-DMC.