1. Investigations by AFM of Ageing Mechanisms in PLA-Flax Fibre Composites during Garden Composting
- Author
-
Delphin Pantaloni, Eric Balnois, Christophe Baley, Alessia Melelli, Olivier Arnould, Frédéric Jamme, Darshil U. Shah, Alain Bourmaud, Johnny Beaugrand, Shah, Darshil [0000-0002-8078-6802], Apollo - University of Cambridge Repository, Melelli, Alessia [0000-0003-0618-0041], Arnould, Olivier [0000-0001-8328-0359], Jamme, Frédéric [0000-0002-7398-7868], Shah, Darshil U [0000-0002-8078-6802], Bourmaud, Alain [0000-0003-4584-4242], Shah, Darshil U. [0000-0002-8078-6802], Institut de Recherche Dupuy de Lôme (IRDL), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Biotechnologie et Chimie Marines (LBCM), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Bois (BOIS), Laboratoire de Mécanique et Génie Civil (LMGC), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Unité de recherche sur les Biopolymères, Interactions Assemblages (BIA), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), University of Cambridge [UK] (CAM), INTERREG IV Cross Channel programme through the FLOWER project : 23., and École Nationale d'Ingénieurs de Brest (ENIB)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Materials science ,Morphology (linguistics) ,Polymers and Plastics ,Scanning electron microscope ,Composite number ,Organic chemistry ,Modulus ,Mechanical properties ,02 engineering and technology ,Surface finish ,010402 general chemistry ,01 natural sciences ,Article ,QD241-441 ,stomatognathic system ,Indentation ,Composite material ,Porosity ,Structural Degradation ,[CHIM.MATE]Chemical Sciences/Material chemistry ,General Chemistry ,021001 nanoscience & nanotechnology ,Flax fibre ,0104 chemical sciences ,[CHIM.POLY]Chemical Sciences/Polymers ,SEM ,Degradation (geology) ,PLA ,AFM ,0210 nano-technology - Abstract
International audience; PLA-flax non-woven composites are promising materials, coupling high performance and possible degradation at their end of life. To explore their ageing mechanisms during garden composting, microstructural investigations were carried out through scanning electron microscopy (SEM) and atomic force microscopy (AFM). We observe that flax fibres preferentially degrade ‘inwards’ from the edge to the core of the composite. In addition, progressive erosion of the cell walls occurs within the fibres themselves, ‘outwards’ from the central lumen to the periphery primary wall. This preferential degradation is reflected in the decrease in indentation modulus from around 23 GPa for fibres located in the preserved core of the composite to 3–4 GPa for the remaining outer-most cell wall crowns located at the edge of the sample that is in contact with the compost. Ageing of the PLA matrix is less drastic with a relatively stable indentation modulus. Nevertheless, a change in the PLA morphology, a significant decrease in its roughness and increase of porosity, can be observed towards the edge of the sample, in comparison to the core. This work highlights the important role of intrinsic fibre porosity, called lumen, which is suspected to be a major variable of the compost ageing process, providing pathways of entry for moisture and microorganisms that are involved in cell wall degradation.
- Published
- 2021
- Full Text
- View/download PDF