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Paper, print media and biomaterials

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> Research > Doctorate, post-doctorate

LGP2 - Ph.D. thesis defended in 2013

Zied MARRAKCHI

December 1, 2013 - Materials, Mechanical, Civil Engineering, Electrochemistry
Ph.D. title
Valorization of Alfa fibers.
Supervision
Evelyne MAURET, Professor, Grenoble INP-Pagora / LGP2 ♦♦ Farouk MHENNI, Professor, University of Monastir (Tunisia) ♦♦ Naceur BELGACEM, Professor, Grenoble INP-Pagora / LGP2
Abstract
This thesis aims at valorizing herbaceous plant called Alfa (Stipa tenacissima) in added value application. This raw material is very abundant in Tunisia. Thus, the main idea of this work is to use Alfa fibers as reinforcing elements in bio-composites.
The literature review revealed that this plant has not been extensively studied, which motivated undertaking a comprehensive study of these fibers. A systematic and deep study of the chemical composition, the morphological properties, the electrical charges, the refining kinetics of pulp as well as the physical properties of the paper produced from these fibers was performed and gave several rational insights on Alfa fibers in the context of papermaking.
The second part of this work was devoted to the use of Alfa fibers, as reinforcing fiber mat in composite materials based on biodegradable polymer matrices. In this context, an impregnation technique of the paper films in solutions of two biodegradable polymers – polycaprolactone (PCL) and poly-L-lactide (PLLA) – was chosen. The structural, morphological, thermal and mechanical properties of these new composites were analyzed and discussed.
In addition, an original microwave-assisted grafting of surface chemical modification of Alfa fibers was proposed. In this context, stearic acid was used as a coupling agent. Finally, the effect of the surface modification of the reinforcement on composites properties was assessed and analyzed.
Other members of the jury
Limam ALOUI, Professor, University of Gafsa (Tunisia) ♦♦ Jean-Yves DREAN, Professor, Université de Haute Alsace ♦♦ Sami BOUFI, Professor, University of Sfax (Tunisia)

Bertrand QUESNE

December 5, 2013 - Fluid Mechanics, Energy, Processes
Ph.D. title
Study of the marbling phenomenon on flexible PVC printed in rotogravure
Supervision
Didier CHAUSSY, Professor, Grenoble INP-Pagora / LGP2 ♦♦ Nadège REVERDY-BRUAS, Associate Professor, Grenoble INP-Pagora / LGP2 ♦♦ Davide BENEVENTI, CNRS Researcher, LGP2
Abstract
The objective of this thesis is to study a recurrent printing defect when industrial printing of PVC flooring, the marbling. This defect appears randomly in the printing production line with variable levels. It appears like a textured print instead of normally uniform solid print which generates many nonconformities of the products. The purpose of this work is to understand the origin of the phenomenon of marbling in order to identify the cause(s).
To achieve this objective, it was necessary to develop a reliable and non-subjective tool to quantify the defect based on an image analysis technic. This was used to study the main parameters that may be the cause of the marbling: the substrate wettability, the printing process parameters as well as the inks properties (surface tension, rheology). All of this work has highlighted the role of the formulated inks flow threshold, the phenomenon being linked to instabilities like Saffman-Taylor type raising in the cleavage of the ink film during the printing step of the flooring.
Other members of the jury
Roberta BONGIOVANNI, Associate Professor, Politecnico di Torino (Italy) ♦♦ Salaheddine SKALI-LAMI, Associate Professor, LEMTA, Université de Lorraine ♦♦ Thierry FOURNEL, Professor, Laboratoire Hubert Curien, Université Jean Monnet (Saint-Étienne) ♦♦ Philippe DOUCY, Engineer, Gerflor (Saint-Paul-Trois-Châteaux)

Nathalie LAVOINE

November 15, 2013 - Materials, Mechanical, Civil Engineering, Electrochemistry [Thesis online]
Ph.D. title
Design, processing and characterization of innovative functional bio-nano-materials for packaging.
Supervision
Julien BRAS, Associate Professor, Grenoble INP-Pagora / LGP2 ♦♦ Isabelle DESLOGES, Research Engineer, Grenoble INP-Pagora / LGP2
Abstract
The present work investigates the potential of microfibrillated cellulose (MFC) coated onto cellulosic substrates as controlled delivery system (CDS) of antibacterial molecules for food-packaging.
Two coating processes and three substrates were compared. MFC was coated onto paper and cardboard substrates, enhancing their air resistance and bending stiffness with a minimum coat weight of 8 g/m². Microscopic analyses at nanoscale underlined the nanoporous MFC network preserved onto the substrate surface even after coating. For the first time, this network was used as CDS of various molecules and proved its efficiency by releasing molecules more progressively and over a longer period. The antibacterial activity was effective against non-pathogenic bacteria, leading to the improvement of the food shelf-life. The application of this new material was broadened up by using simultaneously cyclodextrins and MFC, which also led to very promising results.
This PhD proposing 8 articles in scientific journals, paves the way for new high-added value applications in the field of controlled delivery systems by using MFC-based materials, within active packaging or medical fields.
Other members of the jury
Nathalie GONTARD, Professor, Université Montpellier 2 ♦♦ Kristin SYVERUD, Professor, NTNU (Trondheim, Norvège) ♦♦ Véronique COMA, Associate Professor, Université Bordeaux 1 ♦♦ Eliane ESPUCHE, Professor, Université Lyon 1 ♦♦ Nicolas TABARY, Associate Professor, Université Lille 1

Antoine DUVAL

November 15, 2013 - Materials, Mechanical, Civil Engineering, Electrochemistry
Ph.D. title
Contribution to the study of gluten as material: contribution of different types of lignins
Supervision
Christine CHIRAT, Associate Professor, Grenoble INP-Pagora / LGP2 ♦♦ Sonia BOISSEAU, Associate Professor, CERMAV
Abstract
Wheat gluten, a set of proteins from the wheat kernel, is commonly used to process polymeric materials, usually in the presence of glycerol as a plasticizer. Its use is however limited, because of its high sensitivity to water and relatively poor mechanical properties when compared to synthetic polymers. The influence of the glycerol content on the water absorbance, the phase separation and their glass transition were first studied.
Then, another biopolymer, wood lignin, has been incorporated into the materials in order to enhance their properties. The influence of different types of lignin from the paper pulp industry, Kraft lignin and lignosulfonates, have been investigated. Kraft lignin addition enhances materials rigidity and thermal properties, and reduces the water sensitivity, whereas lignosulfonates allow to decrease the glycerol content, resulting in better mechanical properties and reduced water sensitivity.
To gain insights into the interactions between gluten and lignins, several fractionation procedures have then been carried out. The influence of the protein type and lignin molecular mass could be pointed out, and were correlated to the materials macroscopic properties.
Other members of the jury
Denis LOURDIN, Research Director, INRA Nantes ♦♦ Stéphanie BAUMBERGER, Professor, AgroParisTech ♦♦ Dominique LACHENAL, Professor, Grenoble-INP Pagora / LGP2 ♦♦ Marie-Hélène MOREL, Research Director, INRA Montpellier

Cyril MARULIER

October 17, 2013 - Materials, Mechanical, Civil Engineering, Electrochemistry [Thesis online]
Ph.D. title
Multiscale study of the coupling between hygroelastic properties of papers and their microstructure.
Supervision
Pierre DUMONT, Associate Professor, Grenoble INP-Pagora / LGP2 ♦♦ Denis CAILLERIE, Professor, Grenoble INP / 3SR ♦♦ Laurent ORGEAS, Senior Researcher, CNRS / 3SR
Abstract
The objective of this work is to study the coupling between the hygroelastic properties of papers and their microstructure. The use of images of model paper acquired by X-ray microtomography allowed the characterization in an unprecedented manner of the evolution of microstructural properties of these materials according to their production conditions and during tests where they were placed in atmosphere at controlled relative humidity.
These results provide a new contribution to the knowledge of the statistical nature of the descriptors of fibre properties (size and orientation) and their contacts (surface, bonding degree ratio), of the architecture of fibrous networks that papers constitute (number of fibre-to-fibre bonds) as well as of the size of the representative elementary volumes of microstructural and elastic properties. Based on this information, various models, more or less sophisticated, were developed in the framework of the theory of homogenisation of discrete periodic structures to describe the mechanical properties of paper. This approach sheds new light on the role of fibre-to-fibre bonds on the mechanical behaviour of these materials.
Other members of the jury
Olivier ARNOULD, Associate Professor, Université de Montpellier ♦♦ Frédéric JACQUEMIN, Professor, Université de Nantes ♦♦ Steven LE CORRE, Professor, Université de Nantes ♦♦ Dominique POQUILLON, Associate Professor, INP Toulouse

Elsa CORROYER

September 16, 2013 - Fluid Mechanics, Energy, Processes
Ph.D. title
Using the flexographic process for the printing on flexible materials for decorations of laminated glazing.
Supervision
Didier CHAUSSY, Professor, Grenoble INP-Pagora / LGP2 ♦♦ Naceur BELGACEM, Professor, Grenoble INP-Pagora / LGP2
Abstract
The objective of this project is to offer laminated glass incorporating decorations. To do this, the printing of a polymeric insert by flexographic process is studied. Initially, commercial inserts are thoroughly analyzed (composition, mass and surface properties), as well as consumables inherent in flexographic process (inks and print form). Then, the printing of different types of patterns shows that flexography provides prints with most optical specifications. In addition, adhesion and mechanical strength properties of different types of laminated glass, and durability of these, are studied. Finally, the results of industrial tests are used to define a concept of printing press allowing the integration of flexographic process in production lines of laminated glass.
Other members of the jury
Etienne FLEURY, Professor, INSA Lyon ♦♦ Yves GROHENS, Professor, Université de Bretagne Sud ♦♦ Antonio L. TORRES, Professor, Universitat Politècnica de Catalunya (Spain) ♦♦ Sébastien WERY, Head of R&D, Saint Gobain Glass

Marion SANGLARD

January 11, 2013 - Fluid Mechanics, Energy, Processes
Ph.D. title
Simultaneous production of bleached cellulose fibers and polyxylosides alkyl through a biorefinery paper.
Supervision
Christine CHIRAT, Associate Professor, Grenoble INP-Pagora / LGP2 ♦♦ Dominique LACHENAL, Professor, Grenoble INP-Pagora / LGP2
Abstract
This project aims at converting a Kraft pulp mill into a biorefinery by removing hemicelluloses from Hardwood in order to convert them into surface-active agents, namely alkylpolyxylosides, while high quality bleached pulps must still be obtained.
Industrial Eucalyptus globulus woodchips were submitted to different autohydrolysis conditions so as to extract a substantial amount of hemicelluloses, composed mainly of xylose. The prehydrolysis liquors were purified with activated charcoal and concentrated. Then the extracted saccharides were successfully used to synthesise alkylpolyglycosides. These surfactants have a saccharide as their hydrophilic part, while their lipophilic part is a fatty alcohol. Moreover, the impact on the glycosylation reaction of the saccharides' concentration and of the other species found in the prehydrolysates was studied.
In parallel, the pretreated woodchips were much easier to delignify using Kraft cooking than the control ones. This allowed the use of soda-anthraquinone cooking at reduced alcali and temperature. The resulting pulps had lower lignin and hexenuronic acid content than the pulps from untreated wood, with higher DPv and brightness. The pulps from prehydrolysed wood reacted as well as the control pulps to oxygen delignification. All pulps were fully bleached to a 90% ISO brightness through an ODEPD sequence.
Other members of the jury
Yves QUENEAU, Research Director, CNRS ♦♦ Dmitry EVTUGUIN, Associate Professor, Universidade de Aveiro (Portugal) ♦♦ Jérôme GUILBOT, Scientific Coordinator Sugars, Protein and Green Chemistry, SEPPIC

Date of update May 18, 2018

Grenoble INP Institut d'ingénierie Univ. Grenoble Alpes