References of "Grignard, Bruno"
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See detailCO2-sourced α-alkylidene cyclic carbonates: a Step forward in the quest for functional regioregular poly(urethane)s and poly(carbonate)s
Gennen, Sandro ULg; Grignard, Bruno ULg; Tassaing, Thierry et al

in Angewandte Chemie International Edition (in press)

We describe a robust platform for the synthesis of a large diversity of novel functional CO2 -sourced polymers by exploiting the regio-controlled and site selective ring-opening of α- alkylidene ... [more ▼]

We describe a robust platform for the synthesis of a large diversity of novel functional CO2 -sourced polymers by exploiting the regio-controlled and site selective ring-opening of α- alkylidene carbonates by various nucleophiles. The remarkable reactivity of α-alkylidene carbonates is dictated by the exocyclic olefinic group that selectively orients the cyclic carbonate ring- opening with the formation of an enol species. The polyaddition of CO2 -sourced bis-α-alkylidene carbonates (bis-αCCs) with primary and secondary diamines provides novel regioregular functional poly(urethane)s. The reactivity of bis-αCCs is also exploited for producing new poly(β-oxo-carbonate)s by organocatalyzed polyaddition with a diol. All polyadditions were feasible under ambient conditions. This synthesis platform provides new functional variants of world-class leading polymers families (polyurethanes, polycarbonates) and valorises CO2 as a chemical feedstock. [less ▲]

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See detailOn the phase behaviour of oxetane-CO2 and propargylic alcohols-CO2 binary mixtures by in situ infrared micro-spectrometry
Zaky, Mohamed; Boyaval, Amélie ULg; Grignard, Bruno ULg et al

in Journal of Supercritical Fluids (in press)

The phase behaviour of carbon dioxide/propargylic alcohols and carbon dioxide/oxetanes mixtures has been investigated using in-situ FTIR microspectrometry that allows us determining the evolution of the ... [more ▼]

The phase behaviour of carbon dioxide/propargylic alcohols and carbon dioxide/oxetanes mixtures has been investigated using in-situ FTIR microspectrometry that allows us determining the evolution of the concentration of each component in the liquid phase as a function of temperature and pressure. It was at the same time possible to look inside the cell and to visualize the expansion of the liquid phase during the increase of the pressure. The measurements were performed at three different temperatures (40, 70 and 100◦C) for pressures ranging between 0.1 and 15 MPa. Propargylic alcohol (PA), 2-methyl-3-butyn-2-ol (MBOL), 3-butyn-1-ol (BOL) and trimethylene oxide (TMO) were selected as these molecules are used in the synthesis of cyclic or polycarbonates by coupling with CO2. Thus, we determined the CO2 sorption and the concentration of the substrate in the liquid phase. Thanks to these measurements, we established the pressure-composition phase diagram for the liquid phase of these substrate/CO2 binary mixtures. [less ▲]

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See detailMerging supercritical carbon dioxide and organocatalysis for the precision and green synthesis of poly(lactide)-based (co)polymers
Grignard, Bruno ULg; De Winter, Julien; Gerbaux, Pascal et al

in European Polymer Journal (in press)

Well-defined poly(lactide)-based block copolymers were synthesized by a heterogeneous solvent and metal-free green approach by using organocatalysts in supercritical carbon dioxide (scCO2). We first ... [more ▼]

Well-defined poly(lactide)-based block copolymers were synthesized by a heterogeneous solvent and metal-free green approach by using organocatalysts in supercritical carbon dioxide (scCO2). We first report on the homopolymerization of both L- and D,L- lactide by organocatalyzed Ring-Opening Polymerization (o-ROP) by using a bicomponent organocatalyst composed of a thiourea derivative and various tertiary amines as cocatalysts. Control over the molar mass and dispersity is achieved until high monomer conversion although the polylactides are insoluble in the polymerization medium. The precision synthesis of PLA-based block copolymers from various CO2-phobic hydroxyl end-capped macroinitiators such as polyethylene glycol, polycaprolactone, polybutylene succinate and polyphosphoester was then reported. Merging scCO2 with this organocatalytic system provides therefore a unique tool for the design under solvent-free conditions of poly(lactide)-based block copolymers that are insoluble in scCO2. [less ▲]

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See detailBio- and CO2-sourced polyhydroxyurethanes for hydrogels coatings, foams and high performance adhesives
Gennen, Sandro ULg; Panchireddy, Satyannarayana ULg; Grignard, Bruno ULg et al

Poster (2017, June 09)

Due to concerns about global warming combined with the decrease of fossil resources, the chemical transformation of carbon dioxide (CO2) into added-value products has gained interest in both academic and ... [more ▼]

Due to concerns about global warming combined with the decrease of fossil resources, the chemical transformation of carbon dioxide (CO2) into added-value products has gained interest in both academic and industrial fields. Indeed, CO2 can be viewed as a cheap, non-toxic and renewable C1 building block precursor of sophisticated organic molecules and polymers. One representative example of CO2 transformation includes the synthesis of various (bis)cyclic carbonates via CO2/epoxide coupling.1-3 Bis-cyclic carbonates were then valorized as monomers for the synthesis of series of novel low carbon footprint poly(hydroxyurethane)s (PHUs). These polymers are now exploited to produce sustainable materials including foams for thermal insulation,4 hydrogels (for potential biomedical use)5 and high performance adhesives and glues (for metal, glass and wood). [less ▲]

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See detailMerging CO2 transformation and utilization with renewable bio-resources: a step forward to a double vision of sustainable chemistry
Grignard, Bruno ULg; Poussard, Loïc; Raquez, Jean-Marie et al

Conference (2017, May 22)

Valorizing waste CO2 as a cheap, inexhaustible and renewable C1 feedstock is an early stage technology with strong innovation potential that imposes itself as a strategic driver for developing future low ... [more ▼]

Valorizing waste CO2 as a cheap, inexhaustible and renewable C1 feedstock is an early stage technology with strong innovation potential that imposes itself as a strategic driver for developing future low carbon footprints materials. Beside its use as raw chemical, the “physical” valorization of CO2 in a series of industrial cost-efficient processes will also accelerate the development of a low carbon economy and support the elaboration of a global low carbon vision scheme. The synergistic and paradigm-transforming holistic project we propose perfectly illustrates these concepts by encompassing a “cradle” to “grave” vision, i.e. from the products conception from CO2 and bio-resources to their production and processing through sustainable processes compatible with existing industrial relevant infrastructures. It focuses on the elaboration of sustainable isocyanate-free polyurethane foams with promising thermal insulation properties. By its objectives, this study also proposes an ideal alternative to the conventional synthesis of PUs and a practical answer to the challenge the PU sector is facing due to changes in the REACH regulations limiting the use of isocyanates. The success of the project relies on 3 key steps involving: i) The synthesis of bio- and CO2-sourced cyclic carbonates monomers: Due to the low reactivity of CO2 versus epoxides, addition of catalysts is necessary. To overcome this limitation, we developed a new highly-efficient bicomponent homogeneous organocatalyst that showed unexpected activity for the fast (within a few minutes) and selective addition of CO2 onto model epoxides and epoxidized vegetable oil under solvent-free and mild experimental conditions at the multiKg scale. The use of this powerful dual organocatalyst was further extended to the first organocatalytic coupling of CO2 with less reactive oxetanes to produce hydroxyl telechelic oligocarbonate entering the synthesis of CO2-sourced conventional PUs. - The synthesis of sustainable bio- and CO2- sourced isocyanates-free polyurethanes (NIPU): Sustainable NIPUs were produced by step-growth polymerization between the so-produced bio- and CO2-sourced cyclic carbonates and biosourced amino-telechelic comonomers derived from linseed fatty acids according to a process compatible with existing industrial infrastructures (extrusion). - The foaming of NIPUs: Sustainable foams with thermal insulation were produced by the supercritical CO2 assisted foaming technology. Due to its solubility in polymers, CO2 can replace conventional flammable VOCs and ozone depletion physical blowing agents as hydro- or fluorocarbons exhibiting long atmospheric life-time and/or mean global warming potential 2800 higher than CO2. By finely choosing the CO2 impregnation and the foaming conditions, low density microcellular NIPU foams with a thermal conductivity as low as 0.050 Wm-1K-1 were produced. Our study shows that CO2 is not only sequestered in the material for long-term application, but is also valorized as a blowing agent in the production of sustainable thermally insulating NIPU foams. Such low carbon footprints materials will contribute to energy conservation and savings by reducing CO2 emissions. [less ▲]

Detailed reference viewed: 38 (3 ULg)
See detailSimple, cheap but highly efficient organo catalysts for the fixation of CO2 on propargylic alcohols
Ngassam Tounzoua, Charlene Gabriela ULg; Gilbert, Bernard ULg; Detrembleur, Christophe ULg et al

Poster (2017, May 04)

In the last years, many efforts have been devoted to the valorisation of CO2 as an abundant and renewable C1 building block for cyclic carbonate synthesis. Many synthetic routes have been proposed to ... [more ▼]

In the last years, many efforts have been devoted to the valorisation of CO2 as an abundant and renewable C1 building block for cyclic carbonate synthesis. Many synthetic routes have been proposed to convert CO2 into five or six-membered cyclic carbonates finding applications as green solvent, electrolytes for Li-ion batteries, intermediates for organic synthesis, monomers for the production of polycarbonates or isocyanate-free synthesis of poly(hydroxyrethane)s, etc. Although the 100% atom economy synthesis of 5-membered cyclic carbonates from CO2 and epoxides/oxetanes has been widely reported in the literature, the carboxylative coupling of CO2 with alkynols remains unexplored. Transition metal-based complexes, organic bases (guanidine, amidine, phosphine), N-heterocyclic carbenes or olefins, and K2CO3 have been proposed as catalysts. However they generally present sufficient activity at high pressure and/or temperature or require a high catalyst loading. Additionally some of them are toxic and/or sensitive to hydrolysis or oxidation. In this work, we designed novel, cheap, easily customizable and highly efficient organocatalysts for the synthesis of cyclic α-methylene carbonates from CO2 and alkynols. Kinetics of the CO2/alkynol coupling reaction were followed by Raman spectroscopy with organocatalysts of different structures, and the best candidate was identified. The main parameters that influenced the system reactivity and selectivity have been identified and will be presented in this poster. [less ▲]

Detailed reference viewed: 28 (5 ULg)
See detailReinforced poly(hydroxyurethane) coatings and high performance adhesive
Panchireddy, Satyannarayana ULg; Grignard, Bruno ULg; Thomassin, Jean-Michel ULg et al

Poster (2017, May 04)

Polyurethane (PU) is one of the most widely used polymeric materials and largely valorised in coating applications as paints or as adhesives. Because toxicity issues of isocyanates and changes in the ... [more ▼]

Polyurethane (PU) is one of the most widely used polymeric materials and largely valorised in coating applications as paints or as adhesives. Because toxicity issues of isocyanates and changes in the environmental and REACH regulations, there is a need today to develop new greener and safer alternatives to produce PU. One of the most promising way relies on the synthesis of polyurethane by a non-isocyanate route (NIPU) by copolymerization between a bicyclic carbonate monomers and a diamine. This study reports on the synthesis of new sustainable NIPU coatings for Al anti-corrosion protection and for metal adhesion. In a first step, (bio- and) CO2-sourced cyclic carbonates will be synthesized by coupling of multifunctional epoxides with CO2 using a new efficient bicomponent organocatalyst. In a second step, various cyclic carbonates/amines formulations were developed and cured in presence of fillers to produce reinforced NIPUs thermosets which anti-corrosion and adhesive properties are evaluated and benchmarked with existing formulations. Some formulations present outstanding adhesions to various substrates. [less ▲]

Detailed reference viewed: 38 (5 ULg)
See detailHow to exploit bio- and CO2-based isocyanates-free polyurethanes for environmental and biomedical applications?
Gennen, Sandro ULg; Grignard, Bruno ULg; Alves, Margot et al

Poster (2017, May 04)

Polyurethane (PU) is one of the most important family of polymers that is largely used in coatings, foams, elastomers, sealants/adhesives in the building, automotive, household and biomedical sectors ... [more ▼]

Polyurethane (PU) is one of the most important family of polymers that is largely used in coatings, foams, elastomers, sealants/adhesives in the building, automotive, household and biomedical sectors. Classically, PU is produced by a step-growth polymerization between di- or polyols and di- or polyisocyanates. However, isocyanates are toxic and produced from even more toxic phosgene. To avoid the use of isocyanates, different synthetic alternatives for PUs have been developed. One of the most studied approaches relies on the step-growth polymerization between di- or polyamines and CO2-sourced di- or polycyclic carbonates, affording poly(β-hydroxyurethane)s (PHUs) that showed improved thermal, chemical and mechanical properties compared to conventional PUs. In this study, we would like to show how PHUs can be exploited to design (bio- and) CO2-based foams for thermal insulation as well as novel reinforced hydrogels for potential biomedical applications. First, we developed a highly efficient binary organocatalyst for the fast and selective synthesis of cyclic carbonates under very mild conditions from CO2 and various epoxides, including bio-based ones. Secondly, these cyclic carbonates were valorised as monomers for the preparation of foams and hydrogels based on PHUs. In this poster, we will describe the preparation and characterization of these PHU foams and hydrogels, and highlight their huge potential as thermal insulating materials (PHU foams) or as biomaterials for shock absorption properties (PHU hydrogels). [less ▲]

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See detailDFT investigation of the reaction mechanism for the guanidine catalyzed ring-opening of cyclic carbonates by aromatic and alkyl-amines
Alves, Margot ULg; Méreau, Raphaël; Grignard, Bruno ULg et al

in RSC Advances (2017), 7(31), 18993-19001

The guanidine catalysed aminolysis of propylene carbonate has been investigated using the density functional theory (DFT) and highlights that different reaction pathways are involved depending on the ... [more ▼]

The guanidine catalysed aminolysis of propylene carbonate has been investigated using the density functional theory (DFT) and highlights that different reaction pathways are involved depending on the aromatic or aliphatic nature of the amine. The structural ability of 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) to simultaneously give and receive protons was demonstrated by a detailed mechanistic investigation. The bifunctional activity (base/H-bond donor) of TBD significantly reduces the Gibbs energy of the reaction and allows understanding its higher efficiency compared to its methyl counterpart (MTBD). [less ▲]

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See detailOrganocatalytic coupling of CO2 with a propargylic alcohol: a comprehensive study of the reaction mechanism combining in- situ ATR-IR spectroscopy and DFT calculations
Boyaval, Amélie ULg; Méreau, Raphaël; Grignard, Bruno ULg et al

in ChemSusChem (2017), 10(6), 1241-1248

The metal-free coupling of propargylic alcohols with carbon dioxide catalysed by guanidine derivatives was investigated in detail through the combination of online kinetic studies by in-situ ATR-IR ... [more ▼]

The metal-free coupling of propargylic alcohols with carbon dioxide catalysed by guanidine derivatives was investigated in detail through the combination of online kinetic studies by in-situ ATR-IR spectroscopy and DFT calculations. Bicyclic guanidines, namely TBD and MTBD, are effective catalysts for the conversion of 2-methyl-3-butyn-2-ol to α-methylene cyclic carbonate and oxoalkyl acyclic carbonate under mild reaction conditions. The lower selectivity of TBD in comparison with MTBD towards the formation of α-methylene cyclic carbonate was elucidated from DFT calculations and is related to the bifunctional activity (base/H-bond donor) of TBD decreasing the Gibbs free energy of the reaction path for the formation of the acyclic carbonate. Introduction [less ▲]

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See detailOrganocatalytic coupling of CO2 with oxetane
Alves, Margot ULg; Grignard, Bruno ULg; Boyaval, Amélie ULg et al

in ChemSusChem (2017), 10(6), 1128-1138

The organocatalytic coupling of CO2 with oxetanes is investigated under solvent-free conditions. The influence of the main reaction parameters (type of organocatalytic system, pressure and temperature) on ... [more ▼]

The organocatalytic coupling of CO2 with oxetanes is investigated under solvent-free conditions. The influence of the main reaction parameters (type of organocatalytic system, pressure and temperature) on the yield, the product formed and the selectivity of the reaction are discussed. An onium salt combined with a fluorinated alcohol promotes the efficient and selective organocatalytic synthesis of α,ω-hydroxyl oligocarbonates by coupling CO2 with oxetanes at 130 °C and at a CO2 pressure as low as 2 MPa. NMR characterizations were correlated with MALDI-ToF analyses for elucidating the structure of the oligomers. Online FTIR studies under pressure, NMR titrations and DFT calculations allowed an in-depth understanding of the reaction mechanism. Finally, CO2- based poly(carbonate-co-urethane)s were synthesized by step- growth polymerization of hydroxyl telechelic oligocarbonates with MDI. The organocatalytic system described in this paper constitutes an innovative sustainable route to the selective preparation of hydroxyl telechelic carbonates, of high interest for many applications, notably for the polyurethane business, especially for coatings or foams. [less ▲]

Detailed reference viewed: 80 (26 ULg)
See detailOils and CO2, a promising combination for designing insulating foams and high performance coatings
Detrembleur, Christophe ULg; Alves, Margot ULg; Grignard, Bruno ULg et al

Conference (2017, March 21)

Making plastics more sustainable by valorizing waste CO2 as a cheap, inexhaustible and renewable feedstock is an early stage technology with strong innovation potential that imposes itself as a strategic ... [more ▼]

Making plastics more sustainable by valorizing waste CO2 as a cheap, inexhaustible and renewable feedstock is an early stage technology with strong innovation potential that imposes itself as a strategic driver for developing future low carbon footprint materials and technologies. With a global production estimated to 18 million tons for 2016, polyurethane (PU) is one of the most important polymers in our everyday life applications (automotive, building and construction, coatings, etc.). Industrially, PU is produced by step-growth polymerization between di- or polyisocyanates and di- or polyols. However, isocyanates are toxic and drastic changes in the REACH regulations limiting/banning the use of isocyanates are expected. There is a need today to develop new greener and safer alternatives to produce PU. Valorizing CO2 as C1 feedstock for producing precursors entering in the synthesis of polyurethanes by a non-isocyanate route (NIPU) is a promising strategy to solve this challenge. In this talk, we will focus on the synthesis and characterization of novel NIPUs foams for thermal insulation, and NIPUs coatings for metal protection. Our research highlights benefit of merging bio-resources (such as vegetable oils) with carbon dioxide transformation. In the first part of this talk, we will report on the fast synthesis of bio- and CO2-sourced cyclic carbonates by coupling CO2 with epoxides using a new highly efficient bicomponent homogeneous organocatalyst under solvent-free and mild experimental conditions. The mechanism of the activation of the reaction will be discussed, and scaling up of the technology will be demonstrated (15kg scale). In the second part, we will illustrate the use of these bio- and CO2-sourced cyclic carbonates for the production of microcellular NIPU foams with closed cells morphology for thermal insulating applications, but also for preparing hybrid NIPUs coatings for metal protection. [less ▲]

Detailed reference viewed: 58 (2 ULg)
See detailInvestigation of the copolymerization behavior of a cyclic carbonate with vinyl acetate using CMRP
Scholten, Philip ULg; Demarteau, Jérémy ULg; Debuigne, Antoine ULg et al

Poster (2017, March)

Ethylene is an unconjugated monomer difficult to copolymerise in a controlled fashion using common radical or coordination-insertion polymerisation. Cobalt-mediated radical polymerisation (CMRP) provides ... [more ▼]

Ethylene is an unconjugated monomer difficult to copolymerise in a controlled fashion using common radical or coordination-insertion polymerisation. Cobalt-mediated radical polymerisation (CMRP) provides a powerful means to radically copolymerise ethylene in a controlled fashion under mild conditions.[1][2] In addition, different copolymer structures, such as block or alternating, can be accessed. ACO2-based cyclic carbonate was chosen as a promising comonomer but conflicting reports on the copolymer structure have been reported.[3][4] To better understand the copolymerisation behaviour of this monomer, model copolymerisations with vinyl acetate were performed and are reported below with the aim of gaining insights into the copolymersiation behaviour, which will allow us to better tackle ethylene copolymerisations. [less ▲]

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See detailPhotocleavable stabilizer for the preparation of PHEMA nanogels by dispersion polymerization in supercritical carbon dioxide
Alaimo, David; Grignard, Bruno ULg; Kuppan, Chandrasekar et al

in Polymer Chemistry (2017), 8(3), 581-591

A new photo-sensitive diblock copolymer composed of a hydrophilic sequence of poly(ethylene oxide) (PEO) linked to a CO2-philic sequence of poly(1H,1H,2H,2H-heptadecafluorodecyl acrylate) (PFDA) by a ... [more ▼]

A new photo-sensitive diblock copolymer composed of a hydrophilic sequence of poly(ethylene oxide) (PEO) linked to a CO2-philic sequence of poly(1H,1H,2H,2H-heptadecafluorodecyl acrylate) (PFDA) by a light sensitive o- nitrobenzyl group was successfully synthesized by RAFT polymerization and used as stabilizer for the free radical polymerization of 2-hydroxyethyl methacrylate (HEMA) in dispersion in ?,?,?-trifluorotoluene and supercritical carbon dioxide (scCO2). Thanks to this fluorinated stabilizer, well-defined particles of PHEMA down to 350 nm of diameter were produced in scCO2. Advantageously, the photocleavable group at the block junction of the stabilizer could be cleaved by exposing the particles to UV light so that the fluorinated block could be extracted in TFT or scCO2. As supported by X-ray photoelectron spectroscopy (XPS) analysis, up to 80 % of the fluorinated block of the stabilizer can be removed, leading to efficient swelling and dispersion of the resulting PHEMA nanogels in water. [less ▲]

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See detailOrganocatalyzed coupling of carbon dioxide with epoxides for the synthesis of cyclic carbonates: catalyst design and mechanistic studies
Alves, Margot ULg; Grignard, Bruno ULg; Méreau, Raphaël et al

in Catalysis Science & Technology (2017), 7

The coupling of carbon dioxide (CO2) with epoxides with the formation of cyclic carbonates is a highly attractive 100% atom economy reaction. It represents a greener and safer alternative to the ... [more ▼]

The coupling of carbon dioxide (CO2) with epoxides with the formation of cyclic carbonates is a highly attractive 100% atom economy reaction. It represents a greener and safer alternative to the conventional synthesis of cyclic carbonates from diols and toxic phosgene. Today, cyclic carbonates find many applications as intermediates for fine chemicals synthesis, as electrolytes in Li-ion batteries, and polar aprotic solvents, but also serve for the synthesis of important polymers such as polycarbonates and polyurethanes. In view of their broad scope and their strong economic potential, there is a strong need to improve their synthesis and decrease their production costs. However, CO2 is a thermodynamically stable molecule, the use of catalysts is therefore mandatory for activating and facilitating the CO2/epoxide coupling reaction in a selective manner and under mild conditions. Recently organocatalysts deserved more and more interest in this field, and are viewed as alternatives to metal-based ones. Enormous progress has been made these last years to boost their performances, and some organocatalysts are now very competitive, cheap, readily available and exhibit good chemical stability towards moisture, water and air. This review is focusing on the recent advances in the development of metal-free organocatalysts for the synthesis of cyclic carbonates by CO2/epoxide coupling. Most of the state-of-the art organocatalysts used for this reaction are discussed, with a special emphasis to highlight the various routes employed to boost their performances. Their mode of action is also reported based on mechanistic considerations, supported by density functional theory (DFT) calculations that are becoming essential tools for modern catalysts design. Such detailed understanding of the mechanisms involving CO2 transformation should pave the way towards the definition of new modes of activation for converting CO2 with a large scope of substrates into various chemicals, monomers and polymers. [less ▲]

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See detailPolyhydroxyurethane hydrogels: synthesis and characterizations
Gennen, Sandro ULg; Grignard, Bruno ULg; Thomassin, Jean-Michel ULg et al

in European Polymer Journal (2016), 84

Hydrogels based on polyurethane (PU) are promising (bio-) materials because of their bio- compatibility, biodegradation and excellent mechanical properties. In this publication, polyurethane hydrogels ... [more ▼]

Hydrogels based on polyurethane (PU) are promising (bio-) materials because of their bio- compatibility, biodegradation and excellent mechanical properties. In this publication, polyurethane hydrogels were produced for the first time by a non-isocyanate route by solvent-free step-growth copolymerization between a CO2-sourced hydrophilic polyethy- lene glycol bi-cyclic carbonate with diamines in the presence of a cross-linker. Kinetic of poly(hydroxyurethane) (PHU) synthesis was monitored by ATR-IR and the chemical cross-linking was confirmed by rheology and gel contents measurements. Hydrogels were obtained by immersion of PHUs in water and the influence of the diamine/cross-linker ratio and the nature of diamine on the water swelling and compression properties (compression modulus, strain and stress at break) of PHU hydrogels was evaluated. Additionally, the compression properties of the hydrogels were improved by the addition of Montmorillonite as nanofiller in the PHU formulation. This work opens new application fields for CO2-sourced PHUs. [less ▲]

Detailed reference viewed: 66 (19 ULg)
See detailNovel promising way to synthesize non-isocyanate polyurethanes (NIPUs) for innovative coating applications against corrosion protection of metal surfaces
Panchireddy, Satyannarayana ULg; Grignard, Bruno ULg; Thomassin, Jean-Michel ULg et al

Poster (2016, October 13)

Polyurethanes (PUs) are one of the most widely used polymeric materials with applications in automotive, as sealants, adhesives, decorative, aircraft topcoats, for coatings or as foams for thermal and/or ... [more ▼]

Polyurethanes (PUs) are one of the most widely used polymeric materials with applications in automotive, as sealants, adhesives, decorative, aircraft topcoats, for coatings or as foams for thermal and/or acoustic insulation. Industrially, PUs are produced by copolymerization between polyols and polyisocyanates. Because of the toxicity issues related to the use of isocyanates, there is a need to develop greener and safer route to produce such polymers. This study reports on the synthesis of new sustainable isocyanates-free PU (NIPU) coatings for aluminium anticorrosion. In a first step, bio- and CO2-sourced cyclic carbonates monomers were synthesized by coupling of epoxydized vegetable oils with CO2 using a new efficient bicomponent organocatalyst. In second step formulations including cyclic carbonates/amines/additives were optimized to produce highly adhesive cross-linked NIPU coatings that show good resistance against solvents and long-term barriers preventing the corrosion of the aluminiumsubstrate [less ▲]

Detailed reference viewed: 139 (3 ULg)
See detailSynthesis and characterization of non-isocyanate polyurethane (NIPU) hydrogels
Gennen, Sandro ULg; Grignard, Bruno ULg; Thomassin, Jean-Michel ULg et al

Poster (2016, October 13)

Due to its good biocompatibility, biodegradation and excellent mechanical properties, polyurethane (PU) is a material of choice for biomedical applications (gloves, tubing, artificial membranes…) and, as ... [more ▼]

Due to its good biocompatibility, biodegradation and excellent mechanical properties, polyurethane (PU) is a material of choice for biomedical applications (gloves, tubing, artificial membranes…) and, as hydrogels, it was used as wound dressing, soft contact lenses, drug delivery systems and scaffolds for tissue engineering. Classically, PU are synthesized by a step-growth polymerization between poly (di-)ols and poly (di-) isocyanates. Due to the toxicity of isocyanates, REACH regulations have changed and, today, there is a need to develop greener and safer route to produce isocyanate-free PUs. This contribution focus on the synthesis of NIPU hydrogels by copolymerizing a bifunctional CO2-sourced hydrophilic PEG bi-cyclic carbonate with diamines in presence of a cross- linker. The PEG bi-cyclic carbonates was prepared via a CO2/epoxide coupling reactions using a new efficient organocatalytic system based on the use of an ammonium salt (TBAI) in combination with a fluorinated alcohol. [less ▲]

Detailed reference viewed: 97 (7 ULg)