Luc Avérous | University of Strasbourg (original) (raw)
Papers by Luc Avérous
Polymer Degradation and Stability, 2013
The biodegradation of neat chitosan, glycerol plasticised chitosan films and their corresponding ... more The biodegradation of neat chitosan, glycerol plasticised chitosan films and their corresponding claybased nano-biocomposites has been studied in simulated aerobic soil and composting environments using a respirometric method. The rate of biodegradation was much faster in soil and all test samples achieved close to 100% biodegradation within 70 days. During biodegradation under aerobic composting conditions the neat chitosan samples achieved approx 65% biodegradation and the plasticised chitosan samples achieved >85% biodegradation within 180 days. Additionally, nano-clay additives had no significant effect on the overall biodegradability of the chitosan-based materials during composting. Highresolution solid-state NMR studies were performed to examine the chemical structures of the plasticized chitosan and their nano-biocomposites. NMR studies indicated that the glycerol plasticizer was extracted into wet compost within first few days while acetic acid remained through strong hydrogen bonding with chitosan during the degradation process.
Plackett/Biopolymers - New Materials for Sustainable Films and Coatings, 2011
ABSTRACT Export Date: 16 December 2013, Source: Scopus
From Blends and Composites to Gels and Complex Networks, 2013
ABSTRACT Export Date: 16 December 2013, Source: Scopus
Polymer, 2014
Nanocomposites of biobased thermoplastic polyurethane (TPU) from dimer fatty acids and halloysite... more Nanocomposites of biobased thermoplastic polyurethane (TPU) from dimer fatty acids and halloysite nanotubes (HNT) were elaborated by different melt processing routes such as direct mixing (1 step process) and masterbatch/dilution (2 steps process), at different temperatures (150 and 180 C). Rheological and transmission electron microscopy (TEM) analyses indicated that the HNT distribution and dispersion were dependent on the processing conditions: the 2 steps process produced well dispersed nanocomposites and the masterbatch dilution at 180 C improved the HNT distribution through the TPU. Consequently, a high reinforcement was achieved, with a 40% increase in the elastic modulus and 8 C increase in the relaxation temperature related to the glass transition of the TPU soft segments. Furthermore, a percolated network was attained, even if a large extent of HNT breaking was observed during processing, suggesting that a synergistic effect between the HNT particles and the TPU's hard segments in the molten state occurred. Thus, HNT nanotubes can be seen as highly reinforcing nanofillers when good dispersion and distribution are achieved through the polymeric matrix.
L'Actualité chimique
Polymer materials and sustainable development The second half of the 20(th) century, sometimes ca... more Polymer materials and sustainable development The second half of the 20(th) century, sometimes called "the plastic age", knew a boom of polymer materials in all the sectors of industrial activity. Nowadays, although polymer production is continuously growing, all the developed countries are facing new challenges regarding the rarefaction of fossil resources and the sustainable development. Many research works performed in the institutions affiliated to the "Federation Gay-Lussac" aim to contribute to this field by exploring some new aspects of polymer science. They include: unusual polymerization reactions, new types of tri-dimensional networks, valorization of natural polymers, biocomposites and nano-biocomposites, durability of polymeric products.
Export Date: 3 April 2014, Source: Scopus, References: Averous, L., Boquillon, N., (2004) Carbohy... more Export Date: 3 April 2014, Source: Scopus, References: Averous, L., Boquillon, N., (2004) Carbohydrate Polymers, 56 (2), pp. 111-122;
Export Date: 3 April 2014, Source: Scopus, References: Schmid, R., Verger, R., (1998) Angewandte ... more Export Date: 3 April 2014, Source: Scopus, References: Schmid, R., Verger, R., (1998) Angewandte Chemie International Edition, 37, pp. 1608-1633;
Export Date: 23 March 2011, Source: Scopus, CODEN: CAPOD, doi: 10.1016/j.carbpol.2010.09.003, Lan... more Export Date: 23 March 2011, Source: Scopus, CODEN: CAPOD, doi: 10.1016/j.carbpol.2010.09.003, Language of Original Document: English, Correspondence Address: Avérous, L.; LIPHT-ECPM, EAc(CNRS) 4379, Université de Strasbourg, 25 rue Becquerel, 67087 Strasbourg Cedex 2, France; email: luc.averous@unistra.fr, References: Avérous, L., Biodegradable multiphase systems based on plasticized starch: A review (2004) Journal of Macromolecular Science: Polymer Reviews, 44 (3), pp. 231-274;
Bien que prometteur pour l'emballage alimentaire, l'acide polylactique (PLA) présente des proprié... more Bien que prometteur pour l'emballage alimentaire, l'acide polylactique (PLA) présente des propriétés mécaniques et barrière modérées qui doivent être améliorées . Deux voies ont été envisagées : i) la plastification par 20% d'acétyl citrate de tributyle (ATBC) [4], ii) la cristallisation, par l'ajout d'agent nucléant (talc) . La formulation du PLA induit une forte augmentation de l'élongation à la rupture par rapport au PLA pur (de 8 à 400%). Cependant la cristallisation subséquente de ces échantillons réduit fortement cette élongation qui passe ainsi de 400 % pour le PLA formulé amorphe à 50% pour le PLA formulé cristallisé. Les tests de perméabilité à l'hélium et à l'oxygène montrent que le PLA pur présente un comportement intermédiaire entre le poly(éthylène téréphthalate (PET) et le polystyrène (PS) qui sont considérés respectivement comme des matériaux d'emballage moyennement et faiblement barrière à l'oxygène. La plastification du PLA ne modifie pas sa valeur de perméabilité à l'hélium alors qu'elle induit un doublement de la perméabilité à l'oxygène. Quant à la cristallisation, elle permet une diminution de la perméabilité à l'hélium pour le PLA pur alors qu'aucune modification n'a été observée pour celle du PLA formulé.
Export Date: 24 September 2013, Source: Scopus
Macromolecular rapid communications, 2015
Herein, it is demonstrated that star pseudopolyrotaxanes (star-pPRs) obtained from the inclusion ... more Herein, it is demonstrated that star pseudopolyrotaxanes (star-pPRs) obtained from the inclusion complexation of α-cyclodextrin (CD) and four-branched star poly(ε-caprolactone) (star-PCL) organize into nanoplatelets in dimethyl sulfoxide at 35 °C. This peculiar property, not observed for linear pseudopolyrotaxanes, allows the processing of star-pPRs while preserving their supramolecular assembly. Thus, original PCL:star-pPR core:shell nanofibers are elaborated by coaxial electrospinning. The star-pPR shell ensures the presence of available CD hydroxyl functions on the fiber surface allowing its postfunctionalization. As proof of concept, fluorescein isothiocyanate is grafted. Moreover, the morphology of the fibers is maintained due to the star-pPR shell that acts as a shield, preventing the fiber dissolution during chemical modification. The proposed strategy is simple and avoids the synthesis of polyrotaxanes, i.e., pPR end-capping to prevent the CD dethreading. As PCL is widely us...
Journal of Molecular Catalysis B: Enzymatic, 2015
ABSTRACT Lipase-based catalysts were tested for the ring-opening polymerization of D-, L- and D,L... more ABSTRACT Lipase-based catalysts were tested for the ring-opening polymerization of D-, L- and D,L-lactide isomers, highlighting the different specificity of the enzyme toward these isomers. Free form of Candida antarctica lipase B (CALB) and its clay- and acrylic resin- immobilized forms were compared. For L- and D,L-lactide monomers only short oligomers were obtained. The acrylic resin immobilized form of CALB (NOVO-435) led to a complete conversion of D-lactide to PDLA with a Mn of 2|600 g/mol, whereas the clay-immobilized and free forms of CALB exhibited slower kinetics and produced chains of lower Mn. Copolymerization reactions between ɛ-caprolactone and lactide isomers were performed using NOVO-435 as bio-catalyst. Random copolyesters were successfully synthesized by copolymerizing D-lactide with ɛ-caprolactone. Better results were obtained with a two-step reaction, starting from presynthesized polycaprolactone chains, compared with the one-pot copolymerization. Conducting this two-step copolymerization in the presence of organo-modified montmorillonite allowed the successful synthesis of copolymer/clay nanohybrids.
Carbohydrate Polymers, 2015
The incorporation of nano-sized sepiolite clays into thermoplastic starch/poly(butylene adipate-c... more The incorporation of nano-sized sepiolite clays into thermoplastic starch/poly(butylene adipate-coterephthalate) (TPS/PBAT) blends has been investigated with the goal of improving the matrix properties. TPS/PBAT nano-biocomposites were elaborated with two different proportions of the polymeric phases. The influence of the sepiolite nanoclays on the mechanical, thermal and structural properties of the corresponding blends was evaluated. SEM images confirmed the good dispersion of the sepiolite clay, with a low occurrence of small aggregates in the polymeric matrix. Wide-angle X-ray diffraction showed no significant alteration of the crystalline structures of PBAT and starch induced by the sepiolite clay. The addition of sepiolite slightly affected the thermal degradation of the nano-biocomposites; however, the mechanical tests revealed an increase in some mechanical properties, demonstrating that sepiolite is a promising nanofiller for TPS-based materials.
according to the journal that you are submitting your paper to) 2 ABSTRACT Plasma polymerization ... more according to the journal that you are submitting your paper to) 2 ABSTRACT Plasma polymerization is a powerful coating technology for many technological areas, notably in the coating of biomaterials, particularly when it is applied under atmospheric pressure conditions which allow to avoid expensive pumping systems. In the present investigation, the properties of coatings based on acrylic acid and methacrylic acid prepared using atmospheric pressure plasma in dielectric barrier discharge conditions and at atmospheric pressure under various operating parameters was compared.
Bien que prometteur pour l'emballage alimentaire, l'acide polylactique (PLA) présente des proprié... more Bien que prometteur pour l'emballage alimentaire, l'acide polylactique (PLA) présente des propriétés mécaniques et barrière modérées qui doivent être améliorées . Deux voies ont été envisagées : i) la plastification par 20% d'acétyl citrate de tributyle (ATBC) [4], ii) la cristallisation, par l'ajout d'agent nucléant (talc) . La formulation du PLA induit une forte augmentation de l'élongation à la rupture par rapport au PLA pur (de 8 à 400%). Cependant la cristallisation subséquente de ces échantillons réduit fortement cette élongation qui passe ainsi de 400 % pour le PLA formulé amorphe à 50% pour le PLA formulé cristallisé. Les tests de perméabilité à l'hélium et à l'oxygène montrent que le PLA pur présente un comportement intermédiaire entre le poly(éthylène téréphthalate (PET) et le polystyrène (PS) qui sont considérés respectivement comme des matériaux d'emballage moyennement et faiblement barrière à l'oxygène. La plastification du PLA ne modifie pas sa valeur de perméabilité à l'hélium alors qu'elle induit un doublement de la perméabilité à l'oxygène. Quant à la cristallisation, elle permet une diminution de la perméabilité à l'hélium pour le PLA pur alors qu'aucune modification n'a été observée pour celle du PLA formulé.
Polymer Degradation and Stability, 2013
The biodegradation of neat chitosan, glycerol plasticised chitosan films and their corresponding ... more The biodegradation of neat chitosan, glycerol plasticised chitosan films and their corresponding claybased nano-biocomposites has been studied in simulated aerobic soil and composting environments using a respirometric method. The rate of biodegradation was much faster in soil and all test samples achieved close to 100% biodegradation within 70 days. During biodegradation under aerobic composting conditions the neat chitosan samples achieved approx 65% biodegradation and the plasticised chitosan samples achieved >85% biodegradation within 180 days. Additionally, nano-clay additives had no significant effect on the overall biodegradability of the chitosan-based materials during composting. Highresolution solid-state NMR studies were performed to examine the chemical structures of the plasticized chitosan and their nano-biocomposites. NMR studies indicated that the glycerol plasticizer was extracted into wet compost within first few days while acetic acid remained through strong hydrogen bonding with chitosan during the degradation process.
Plackett/Biopolymers - New Materials for Sustainable Films and Coatings, 2011
ABSTRACT Export Date: 16 December 2013, Source: Scopus
From Blends and Composites to Gels and Complex Networks, 2013
ABSTRACT Export Date: 16 December 2013, Source: Scopus
Polymer, 2014
Nanocomposites of biobased thermoplastic polyurethane (TPU) from dimer fatty acids and halloysite... more Nanocomposites of biobased thermoplastic polyurethane (TPU) from dimer fatty acids and halloysite nanotubes (HNT) were elaborated by different melt processing routes such as direct mixing (1 step process) and masterbatch/dilution (2 steps process), at different temperatures (150 and 180 C). Rheological and transmission electron microscopy (TEM) analyses indicated that the HNT distribution and dispersion were dependent on the processing conditions: the 2 steps process produced well dispersed nanocomposites and the masterbatch dilution at 180 C improved the HNT distribution through the TPU. Consequently, a high reinforcement was achieved, with a 40% increase in the elastic modulus and 8 C increase in the relaxation temperature related to the glass transition of the TPU soft segments. Furthermore, a percolated network was attained, even if a large extent of HNT breaking was observed during processing, suggesting that a synergistic effect between the HNT particles and the TPU's hard segments in the molten state occurred. Thus, HNT nanotubes can be seen as highly reinforcing nanofillers when good dispersion and distribution are achieved through the polymeric matrix.
L'Actualité chimique
Polymer materials and sustainable development The second half of the 20(th) century, sometimes ca... more Polymer materials and sustainable development The second half of the 20(th) century, sometimes called "the plastic age", knew a boom of polymer materials in all the sectors of industrial activity. Nowadays, although polymer production is continuously growing, all the developed countries are facing new challenges regarding the rarefaction of fossil resources and the sustainable development. Many research works performed in the institutions affiliated to the "Federation Gay-Lussac" aim to contribute to this field by exploring some new aspects of polymer science. They include: unusual polymerization reactions, new types of tri-dimensional networks, valorization of natural polymers, biocomposites and nano-biocomposites, durability of polymeric products.
Export Date: 3 April 2014, Source: Scopus, References: Averous, L., Boquillon, N., (2004) Carbohy... more Export Date: 3 April 2014, Source: Scopus, References: Averous, L., Boquillon, N., (2004) Carbohydrate Polymers, 56 (2), pp. 111-122;
Export Date: 3 April 2014, Source: Scopus, References: Schmid, R., Verger, R., (1998) Angewandte ... more Export Date: 3 April 2014, Source: Scopus, References: Schmid, R., Verger, R., (1998) Angewandte Chemie International Edition, 37, pp. 1608-1633;
Export Date: 23 March 2011, Source: Scopus, CODEN: CAPOD, doi: 10.1016/j.carbpol.2010.09.003, Lan... more Export Date: 23 March 2011, Source: Scopus, CODEN: CAPOD, doi: 10.1016/j.carbpol.2010.09.003, Language of Original Document: English, Correspondence Address: Avérous, L.; LIPHT-ECPM, EAc(CNRS) 4379, Université de Strasbourg, 25 rue Becquerel, 67087 Strasbourg Cedex 2, France; email: luc.averous@unistra.fr, References: Avérous, L., Biodegradable multiphase systems based on plasticized starch: A review (2004) Journal of Macromolecular Science: Polymer Reviews, 44 (3), pp. 231-274;
Bien que prometteur pour l'emballage alimentaire, l'acide polylactique (PLA) présente des proprié... more Bien que prometteur pour l'emballage alimentaire, l'acide polylactique (PLA) présente des propriétés mécaniques et barrière modérées qui doivent être améliorées . Deux voies ont été envisagées : i) la plastification par 20% d'acétyl citrate de tributyle (ATBC) [4], ii) la cristallisation, par l'ajout d'agent nucléant (talc) . La formulation du PLA induit une forte augmentation de l'élongation à la rupture par rapport au PLA pur (de 8 à 400%). Cependant la cristallisation subséquente de ces échantillons réduit fortement cette élongation qui passe ainsi de 400 % pour le PLA formulé amorphe à 50% pour le PLA formulé cristallisé. Les tests de perméabilité à l'hélium et à l'oxygène montrent que le PLA pur présente un comportement intermédiaire entre le poly(éthylène téréphthalate (PET) et le polystyrène (PS) qui sont considérés respectivement comme des matériaux d'emballage moyennement et faiblement barrière à l'oxygène. La plastification du PLA ne modifie pas sa valeur de perméabilité à l'hélium alors qu'elle induit un doublement de la perméabilité à l'oxygène. Quant à la cristallisation, elle permet une diminution de la perméabilité à l'hélium pour le PLA pur alors qu'aucune modification n'a été observée pour celle du PLA formulé.
Export Date: 24 September 2013, Source: Scopus
Macromolecular rapid communications, 2015
Herein, it is demonstrated that star pseudopolyrotaxanes (star-pPRs) obtained from the inclusion ... more Herein, it is demonstrated that star pseudopolyrotaxanes (star-pPRs) obtained from the inclusion complexation of α-cyclodextrin (CD) and four-branched star poly(ε-caprolactone) (star-PCL) organize into nanoplatelets in dimethyl sulfoxide at 35 °C. This peculiar property, not observed for linear pseudopolyrotaxanes, allows the processing of star-pPRs while preserving their supramolecular assembly. Thus, original PCL:star-pPR core:shell nanofibers are elaborated by coaxial electrospinning. The star-pPR shell ensures the presence of available CD hydroxyl functions on the fiber surface allowing its postfunctionalization. As proof of concept, fluorescein isothiocyanate is grafted. Moreover, the morphology of the fibers is maintained due to the star-pPR shell that acts as a shield, preventing the fiber dissolution during chemical modification. The proposed strategy is simple and avoids the synthesis of polyrotaxanes, i.e., pPR end-capping to prevent the CD dethreading. As PCL is widely us...
Journal of Molecular Catalysis B: Enzymatic, 2015
ABSTRACT Lipase-based catalysts were tested for the ring-opening polymerization of D-, L- and D,L... more ABSTRACT Lipase-based catalysts were tested for the ring-opening polymerization of D-, L- and D,L-lactide isomers, highlighting the different specificity of the enzyme toward these isomers. Free form of Candida antarctica lipase B (CALB) and its clay- and acrylic resin- immobilized forms were compared. For L- and D,L-lactide monomers only short oligomers were obtained. The acrylic resin immobilized form of CALB (NOVO-435) led to a complete conversion of D-lactide to PDLA with a Mn of 2|600 g/mol, whereas the clay-immobilized and free forms of CALB exhibited slower kinetics and produced chains of lower Mn. Copolymerization reactions between ɛ-caprolactone and lactide isomers were performed using NOVO-435 as bio-catalyst. Random copolyesters were successfully synthesized by copolymerizing D-lactide with ɛ-caprolactone. Better results were obtained with a two-step reaction, starting from presynthesized polycaprolactone chains, compared with the one-pot copolymerization. Conducting this two-step copolymerization in the presence of organo-modified montmorillonite allowed the successful synthesis of copolymer/clay nanohybrids.
Carbohydrate Polymers, 2015
The incorporation of nano-sized sepiolite clays into thermoplastic starch/poly(butylene adipate-c... more The incorporation of nano-sized sepiolite clays into thermoplastic starch/poly(butylene adipate-coterephthalate) (TPS/PBAT) blends has been investigated with the goal of improving the matrix properties. TPS/PBAT nano-biocomposites were elaborated with two different proportions of the polymeric phases. The influence of the sepiolite nanoclays on the mechanical, thermal and structural properties of the corresponding blends was evaluated. SEM images confirmed the good dispersion of the sepiolite clay, with a low occurrence of small aggregates in the polymeric matrix. Wide-angle X-ray diffraction showed no significant alteration of the crystalline structures of PBAT and starch induced by the sepiolite clay. The addition of sepiolite slightly affected the thermal degradation of the nano-biocomposites; however, the mechanical tests revealed an increase in some mechanical properties, demonstrating that sepiolite is a promising nanofiller for TPS-based materials.
according to the journal that you are submitting your paper to) 2 ABSTRACT Plasma polymerization ... more according to the journal that you are submitting your paper to) 2 ABSTRACT Plasma polymerization is a powerful coating technology for many technological areas, notably in the coating of biomaterials, particularly when it is applied under atmospheric pressure conditions which allow to avoid expensive pumping systems. In the present investigation, the properties of coatings based on acrylic acid and methacrylic acid prepared using atmospheric pressure plasma in dielectric barrier discharge conditions and at atmospheric pressure under various operating parameters was compared.
Bien que prometteur pour l'emballage alimentaire, l'acide polylactique (PLA) présente des proprié... more Bien que prometteur pour l'emballage alimentaire, l'acide polylactique (PLA) présente des propriétés mécaniques et barrière modérées qui doivent être améliorées . Deux voies ont été envisagées : i) la plastification par 20% d'acétyl citrate de tributyle (ATBC) [4], ii) la cristallisation, par l'ajout d'agent nucléant (talc) . La formulation du PLA induit une forte augmentation de l'élongation à la rupture par rapport au PLA pur (de 8 à 400%). Cependant la cristallisation subséquente de ces échantillons réduit fortement cette élongation qui passe ainsi de 400 % pour le PLA formulé amorphe à 50% pour le PLA formulé cristallisé. Les tests de perméabilité à l'hélium et à l'oxygène montrent que le PLA pur présente un comportement intermédiaire entre le poly(éthylène téréphthalate (PET) et le polystyrène (PS) qui sont considérés respectivement comme des matériaux d'emballage moyennement et faiblement barrière à l'oxygène. La plastification du PLA ne modifie pas sa valeur de perméabilité à l'hélium alors qu'elle induit un doublement de la perméabilité à l'oxygène. Quant à la cristallisation, elle permet une diminution de la perméabilité à l'hélium pour le PLA pur alors qu'aucune modification n'a été observée pour celle du PLA formulé.