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See detailDesign, synthesis, and properties of novel bio-based and ethylene-based copolymers
Scholten, Philip ULiege

Doctoral thesis (2019)

Renewable monomers have the potential to replace petroleum-derived monomers for reversible deactivation radical polymerisations (RDRP) for a variety of applications, such as adhesives and coatings. Yet ... [more ▼]

Renewable monomers have the potential to replace petroleum-derived monomers for reversible deactivation radical polymerisations (RDRP) for a variety of applications, such as adhesives and coatings. Yet, challenges in the polymerisation of non-activated and often internal double bonds found in natural molecules still remain. Moreover, functionalisation pathways attaching renewably-sourced double bonds to natural molecules are rare and sustainable strategies using catalytic or enzymatic reactions are sought after. This thesis aims to introduce a set of renewable monomers for reversible deactivation radical polymerisation (RDRP), namely organometallic-mediated radical polymerisation (OMRP) using a cobalt complex, in the quest for renewable and functional (co)polymers. This particular type of OMRP was chosen because it controls the polymerisation of a large range of non-activated monomers with excellent control over the chain growth process under mild experimental conditions. The monomers prepared in this thesis were obtained from plant oils and/or CO2 via catalytic reactions and contain ester and carbonate functionalities of interest for post-polymerisation modifications. Successful copolymerisations with monomers bearing non-activated double bonds, namely vinyl acetate and ethylene, were performed using OMRP under mild conditions and the comonomer content was tuned via the initial polymerisation feed or the ethylene working pressure. The introduction of carbonate moieties into vinyl acetate copolymers allowed for the synthesis of three discrete functional poly(vinyl alcohol) copolymers. Moreover, the ability to incorporate such carbonate functionalities into polyethylene copolymers by OMRP was shown for the first time. Highly linear ethylene copolymers over a broad range of carbonate content were obtained with significantly altered properties compared to homo-polyethylene. Particularly the ability to finely tune the molecular copolymer parameters, such as molecular weight and copolymer architecture, allows a systematic study of their influence on the compatibilisation capability of such copolymers. The potential of polyethylene copolymers bearing functional groups as compatibilisers was highlighted for poly(ethylene-co-vinyl acetate) copolymers. Finally, a fully renewable compatibiliser, based on starch and high oleic sunflower oil, obtained by non-radical means was applied to cellulose/LDPE composites. An improved cellulose dispersion within the matrix was observed by rheology, while the mechanical properties, notably Young’s modulus, was increased. This work aims to highlight the unexplored potential of renewable resources for the synthesis of functional polymers for their application in polyolefin composites. [less ▲]

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See detailPlant-based non-activated olefins: a new class of renewable monomers for controlled radical polymerisation
Scholten, Philip ULiege; Detrembleur, Christophe ULiege; Meier, Michael A. R.

in ACS Sustainable Chemistry and Engineering (2019), 7(2), 2751-2762

In light of fossil fuel depletion and a general necessity for sustainable development, the synthesis of polymers from renewable resources is gaining more and more importance. Yet, industrially relevant ... [more ▼]

In light of fossil fuel depletion and a general necessity for sustainable development, the synthesis of polymers from renewable resources is gaining more and more importance. Yet, industrially relevant radical polymerisations still struggle with the incorporation of renewable resources as the number of natural molecules containing suitable double bonds is limited. Herein, we present the sustainable synthesis of non-activated allylic and olefinic carbonate monomers from renewable resources in a solventless one-pot transesterification reaction. We subsequently confirm the first controlled radical copolymerisation of such challenging non-activated monomers with vinyl acetate, in which molecular weights above 10,000 g.mol-1 were reached. The controlled nature of the copolymerisations was verified by the low dispersities obtained and the linear increase in molecular weights with conversion. The so-prepared copolymers were purified using sustainable extractions by supercritical carbon dioxide (scCO2), which allowed to recover unused monomer in up to 58%. Using FT-IR and NMR spectroscopy, the incorporation of the renewable monomers into the copolymer in up to 49 mol% was confirmed, which is the highest reported to date. The combination of a sustainable double bond functionalisation pathway with controlled radical polymerisations highlights the potential of radical polymerisations in the quest for renewable polymers and introduces a new set of monomers for this technique. [less ▲]

Detailed reference viewed: 47 (10 ULiège)
See detailSynthesis of functional copolymers from cyclic carbonates using controlled radical polymerisation
Scholten, Philip ULiege; Meier, Michael A. R.; Detrembleur, Christophe ULiege

Poster (2018, October 03)

Detailed reference viewed: 25 (2 ULiège)
See detailSynthesis of functional copolymers from cyclic carbonates using controlled radical polymerisation
Scholten, Philip ULiege; Detrembleur, Christophe ULiege; Meier, Michael A. R.

Conference (2018, October 02)

Detailed reference viewed: 21 (4 ULiège)
See detailSynthesis and controlled raddical copolymerisation of renewably-sourced carbonates
Scholten, Philip ULiege; Detrembleur, Christophe ULiege; Meier, Michael A. R.

Conference (2018, September 19)

Non-phosgene derived carbonates are an extremely promising and attractive class of molecules that have found numerous applications. Especially in polymer chemistry, ROP or polyadditions of carbonate ... [more ▼]

Non-phosgene derived carbonates are an extremely promising and attractive class of molecules that have found numerous applications. Especially in polymer chemistry, ROP or polyadditions of carbonate monomers are extremely effective for the synthesis of poly(carbonate)s or non-isocyanate poly(urethane)s. Yet these polymerisation pathways utilise the carbonate functionality for the synthesis of the copolymer backbone and thus exclude post-polymerisation modifications on the carbonate functionality. A strategy for retaining the carbonate is to attach a double bond to the carbonate and perform a radical polymerisation which results in copolymers containing pendant carbonates available for post-polymerisation functionalisation. However, few examples of this approach can be found in the literature, one of the reasons being that efficient and sustainable synthetic pathways for the combination of carbonates and double bonds are still rare. Additionally, such molecules often contain double bonds, which are extremely challenging to control by most CRP techniques. Herein we report on the one-pot synthesis of several allylic carbonate monomers from sustainable resources and, for the first time, report on the controlled radical polymerisation (CRP) of these novel allylic monomers with less activated monomers (LAMs), such as vinyl acetate. [less ▲]

Detailed reference viewed: 25 (5 ULiège)
See detailControlled radical (co)polymerisation of allylic- and vinylic monomers originating from renewable resources
Scholten, Philip ULiege; Demarteau, Jérémy; Gennen, Sandro ULiege et al

Conference (2018, May 29)

In light of recent efforts of applying principles of green and sustainable chemistry within macromolecular engineering, a large number of novel bio-sourced monomers are available. Especially cyclic ... [more ▼]

In light of recent efforts of applying principles of green and sustainable chemistry within macromolecular engineering, a large number of novel bio-sourced monomers are available. Especially cyclic carbonates (CCs), because of their effective ring-opening polymerisation to yield polymers such as non-isocyanate poly(urethane)s, has seen rapid progress during the past decade. Yet, very few examples exist of controlled radical polymerisations (CRP) of CCs bearing a double bond, part of the reason being that (i) up to now only some sustainable synthetic routes to such molecules are known and (ii) some interesting monomers contain an allylic-double bond that is challenging to control by most radical polymerization techniques. In this communication, we report on the synthesis of new bio-sourced polymers by the preparation of novel cyclic carbonate monomers from renewable resources followed by their controlled radical polymerization. Mainly bio-sourced allyl- or unconjugated vinyl-type cyclic carbonates are investigated. Cobalt-mediated radical polymerisation (CMRP) is used as a powerful CRP technique that is active for the polymerization of highly unreactive non-conjugated monomers under mild experimental conditions. [less ▲]

Detailed reference viewed: 39 (7 ULiège)
See detailControlled radical (co)polymerisation of vinylic monomers originating from renewable resources
Scholten, Philip ULiege; Demarteau, Jérémy; Gennen, Sandro ULiege et al

Poster (2018, May 29)

In light of recent efforts of applying principles of green and sustainable chemistry within macromolecular engineering, a large number of novel bio-sourced monomers are available. Especially cyclic ... [more ▼]

In light of recent efforts of applying principles of green and sustainable chemistry within macromolecular engineering, a large number of novel bio-sourced monomers are available. Especially cyclic carbonates (CCs), because of their effective ring-opening polymerisation to yield polymers such as non-isocyanate poly(urethane)s, has seen rapid progress during the past decade. Yet, very few examples exist of controlled radical polymerisations (CRP) of CCs bearing a double bond, part of the reason being that (i) up to now only some sustainable synthetic routes to such molecules are known and (ii) some interesting monomers contain an allylic-double bond that is challenging to control by most radical polymerization techniques. In this communication, we report on the synthesis of new bio-sourced polymers by the preparation of novel cyclic carbonate monomers from renewable resources followed by their controlled radical polymerization. Mainly bio-sourced allyl- or unconjugated vinyl-type cyclic carbonates are investigated. Cobalt-mediated radical polymerisation (CMRP) is used as a powerful CRP technique that is active for the polymerization of highly unreactive non-conjugated monomers under mild experimental conditions. [less ▲]

Detailed reference viewed: 13 (5 ULiège)
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See detailMerging CO2‑based building blocks with cobalt-mediated radical polymerization for the synthesis of functional poly(vinyl alcohol)s
Scholten, Philip ULiege; Demarteau, Jérémy ULiege; Gennen, Sandro ULiege et al

in Macromolecules (2018), 51(9), 3379-3393

The use of CO2-based α-alkylidene cyclic carbonates in controlled radical polymerization has so far not been exploited, despite the fact that the cyclic carbonate ring offers a multitude of possible ... [more ▼]

The use of CO2-based α-alkylidene cyclic carbonates in controlled radical polymerization has so far not been exploited, despite the fact that the cyclic carbonate ring offers a multitude of possible modifications. Herein, the synthesis of well-defined copolymers of vinyl acetate (VAc) and 4,4-dimethyl-5-methylene-1,3-dioxolan-2-one (DMMDO) using cobalt-mediated radical polymerization (CMRP) at 40 °C is reported. The controlled nature of the polymerization was confirmed while molecular weights of up to 25 000 g mol−1 and narrow dispersities (<1.4) were obtained. The copolymer structure was elucidated combining NMR, FT-IR, and MALDI-TOF analyses and consists of a polymer backbone with pendant carbonate rings. Further insights into the copolymer structure were gained through the monomers’ reactivity ratios, and a homogeneous distribution of the DMMDO monomer along the polymer chain was observed. A highly water-soluble poly(vinyl alcohol)-based copolymer was obtained by basic hydrolysis, whereas the chemoselective acidic hydrolysis of the acetate groups left the cyclic carbonate rings untouched, which were then exploited for further postmodification with amines. The precise copolymerization of VAc with CO2-sourced five-membered cyclic carbonates bearing an exomethylene moiety is therefore a powerful tool for the synthesis of new variants of poly(vinyl alcohol)-based copolymers. [less ▲]

Detailed reference viewed: 89 (24 ULiège)
See detailControlled radical (co)polymerisation of allylic and vinylic monomers originating from renewable resources
Scholten, Philip ULiege; Demarteau, Jérémy ULiege; Gennen, Sandro ULiege et al

Conference (2018, March 22)

In light of recent efforts of applying principles of green and sustainable chemistry within macromolecular engineering, a large number of novel bio-sourced monomers are available. Especially cyclic ... [more ▼]

In light of recent efforts of applying principles of green and sustainable chemistry within macromolecular engineering, a large number of novel bio-sourced monomers are available. Especially cyclic carbonates (CCs), because of their effective polyaddition with polyamines to yield polymers such as non-isocyanate poly(urethane)s, have seen rapid progress during the past decade. Yet, very few examples exist of controlled radical polymerisations (CRP) of CCs bearing a double bond, part of the reason being that (i) up to now only some sustainable synthetic routes to such molecules are known and (ii) some interesting monomers contain reactive double bonds which are challenging to control by most radical polymerisation techniques. Herein we report on how cobalt-mediated radical polymerisation (CMRP) proves a powerful method for the (co)polymerisation of such monomers. Furthermore, the unique characteristics of the resulting (co)polymers and their value for applications in composites are highlighted. [less ▲]

Detailed reference viewed: 31 (2 ULiège)
See detailInvestigation of the copolymerisation behaviour of bio-sourced vinylic and allylic cyclic carbonates
Scholten, Philip ULiege; Demarteau, Jérémy ULiege; Gennen, Sandro ULiege et al

Poster (2018, March 21)

Cyclic carbonates belong to a versatile class of compounds, that are widely used for the synthesis of non-isocyanate polyurethanes and as precursors for chiral building blocks. Their incorporation as ... [more ▼]

Cyclic carbonates belong to a versatile class of compounds, that are widely used for the synthesis of non-isocyanate polyurethanes and as precursors for chiral building blocks. Their incorporation as pendant groups in polymer chains is highly attractive for post-polymerisation functionalisation. The controlled radical polymerisation (CRP) of allylic or vinylic CCs is a route for the precision design of such type of polymers. Very few reports on the controlled copolymerisation of CCs are found in the literature part of the reason being that (i) up to now only some sustainable synthetic routes to such molecules are known and (ii) some interesting monomers contain reactive double bonds which are extremely challenging to control by most radical polymerisation techniques. Herein we report the synthesis of a new class of glycerol-based allylic cyclic carbonates and additionally report on the CRP of such and other CCs using cobalt-mediated radical polymerisation (CMRP). [less ▲]

Detailed reference viewed: 27 (6 ULiège)
See detailPrecision synthesis and characterization of novel functional polymers
Scholten, Philip ULiege; Debuigne, Antoine ULiege; Demarteau, Jérémy ULiege et al

Poster (2017, May 23)

Among controlled radical polymerisation techniques, cobalt-mediated radical polymerisation (CMRP) has proven to be a valuable alternative in polymerising unreactive and unconjugated monomers of many ... [more ▼]

Among controlled radical polymerisation techniques, cobalt-mediated radical polymerisation (CMRP) has proven to be a valuable alternative in polymerising unreactive and unconjugated monomers of many different monomer classes under mild conditions, including α-olefins. In a reversible deactivation mechanism, a cobalt complex reversibly traps the active growing chains and converts them into dormant species, avoiding side reactions and allowing for a controlled polymerisation. A fine control over the architecture is possible and allows to synthesise a large diversity of unprecedented block and alternating copolymers. Furthermore, functionalisation of the α- and ω-chain ends is now also possible. In this poster, the polymerization of different vinyl monomers using CMRP has been investigated to design highly functional materials under mild experimental conditions. The copolymerisation behaviour of these novel monomers was examined, and the structure and thermal properties of the new copolymers were investigated. [less ▲]

Detailed reference viewed: 44 (11 ULiège)
See detailPrecision design of novel bio-based and ethylene-based copolymers: application to advanced nanocomposites
Scholten, Philip ULiege; Detrembleur, Christophe ULiege; Demarteau, Jérémy ULiege et al

Conference (2017, March 30)

Polyolefins are an inexpensive class of compounds that can be used to prepare a plethora of different materials. Poly(ethylene) is the worldwide most produced polymer and is mostly synthesised by free ... [more ▼]

Polyolefins are an inexpensive class of compounds that can be used to prepare a plethora of different materials. Poly(ethylene) is the worldwide most produced polymer and is mostly synthesised by free radical polymerisation or catalytic coordination insertion using high temperature and pressure. The controlled radical polymerisation of ethylene is very difficult to achieve because of secondary reactions of this unconjugated monomer, e.g. chain transfer and termination reactions. Cobalt-mediated radical polymerisation (CMRP) represents a solution to control its polymerisation in mild conditions: in a reversible deactivation mechanism, a cobalt complex reversibly traps the active growing chains and converts them into dormant species, avoiding side reactions and allowing for a controlled polymerisation. Using CMRP, statistical copolymers of ethylene and vinyl acetate (VAc) have been synthesised, as well as block-like and block copolymers. Furthermore, functionalisation of the α- and ω-chain ends are now possible. Polymerising a vinyl bio-based monomer using CMRP has also been investigated, with the goal of forming ethylene copolymers. The copolymerisation behaviour of this novel monomer was investigated using vinyl acetate as a model and the structure and thermal properties were analysed. The monomer is very promising and copolymerisations with ethylene are undergoing. It is expected, that these completely new and highly interesting materials may act as compatibilisers for the dispersion of natural polymers, such as cellulose, into various polymer matrices. [less ▲]

Detailed reference viewed: 31 (3 ULiège)
See detailCatalytic functionalisation of starch and amylose using plant oils: towards polymeric materials and composites
Scholten, Philip ULiege; Söyler, Zafer; Detrembleur, Christophe ULiege et al

Poster (2017, March 19)

Fossil fuels have been the main source of starting materials for the chemical industry over the last century. Especially synthetic polymers rely on this feedstock and are indispensible for mankind’s ... [more ▼]

Fossil fuels have been the main source of starting materials for the chemical industry over the last century. Especially synthetic polymers rely on this feedstock and are indispensible for mankind’s technological advances and status quo. However, a shift to renewable and sustainable resources is needed, as the end of the fossil fuel era is in sight. Biomass presents one possible alternative to fossil fuels, as it consists of a large pool of different chemicals and is inexhaustible. Cellulose, and the closely related starch and amylose, are available cheaply from plants and have favourable properties, such as high strength, thermal stability and biodegradability. However, such poly(saccharides) have been difficult to use directly as materials because of the lack of thermoplasticity, low solubility and high hydrophilicity. Modifications are thus necessary to be able to exploit their advantageous properties. Recently, our group published the catalytic transesterification of maize starch with different plant oils to obtain fully renewable fatty acid starch esters in a sustainable fashion. Polymeric materials with glass transition temperatures (Tgs), soluble in common organic solvents and an increased hydrophobicity were obtained. Compatibilisation tests of the modified starch and amylose with low-density poly(ethylene) (LDPE) and cellulose are being investigated to obtain composites of commodity plastics with improved mechanical properties. [less ▲]

Detailed reference viewed: 53 (5 ULiège)
See detailInvestigation of the copolymerization behavior of a cyclic carbonate with vinyl acetate using CMRP
Scholten, Philip ULiege; Demarteau, Jérémy ULiege; Debuigne, Antoine ULiege 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 ▲]

Detailed reference viewed: 34 (6 ULiège)
See detailPrecision design of novel bio-based and ethylene-based copolymers: application to advanced nanocomposites
Scholten, Philip ULiege; Detrembleur, Christophe ULiege; Meier, Michaël et al

Conference (2016, March 18)

Polyolefins are an inexpensive class of compounds that can be used to prepare a plethora of different materials. Poly(ethylene) is the worldwide most produced polymer and is mostly synthesised by free ... [more ▼]

Polyolefins are an inexpensive class of compounds that can be used to prepare a plethora of different materials. Poly(ethylene) is the worldwide most produced polymer and is mostly synthesised by free radical polymerisation or catalytic coordination insertion using high temperature and pressure. The controlled radical polymerisation of ethylene is very difficult to achieve because of secondary reactions of this unconjugated monomer, e.g. chain transfer and termination reactions. Cobalt-mediated radical polymerisation (CMRP) represents a solution to control its polymerisation in mild conditions: in a reversible deactivation mechanism, a cobalt complex reversibly traps the active growing chains and converts them into dormant species, avoiding side reactions and allowing for a controlled polymerisation. Using CMRP, statistical copolymers of ethylene and vinyl acetate (VAc) have been synthesised, as well as block-like and block copolymers. Furthermore, functionalisation of the α- and ω-chain ends are now possible. Incorporating other monomers, e.g. vinyl esters or vinyl amides, into an ethylene copolymer by CMRP will lead to completely new and highly interesting materials which may act as compatibilisers for the dispersion of natural polymers, such as cellulose, into various polymer matrices. The goal of this work is to design novel well-defined functional polyethylenes that are expected to improve the dispersion of natural polymers into polyolefins. [less ▲]

Detailed reference viewed: 47 (13 ULiège)