IDENTIFICATION OF KEY PARAMETERS IN DYNAMIC WETTING AND DEWETTING PHENOMENA WITH MOLTEN POLYMERS FOR COMPOSITE PROCESSING

• Published in: Integrating Materials and Manufacturing Innovation
• Main Authors: Pucci, M, F, Duchemin, Benoît, Gomina, M., Breard, J.
• Other Authors: Centre d'études spatiales de la biosphère (CESBIO), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Laboratoire d'Ingénierie des Matériaux de Bretagne (LIMATB), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Brestois du Numérique et des Mathématiques (IBNM), Université de Brest (UBO)-Université de Brest (UBO)
• Format: Conference Object
• Language: English
• Published: HAL CCSD 2019
• Subjects: dynamic wetting; capillary effects; molten polymers; [CHIM.MATE]Chemical Sciences/Material chemistry; Luleå
• Online Access: https://hal.science/hal-02394157; https://hal.science/hal-02394157/document; https://hal.science/hal-02394157/file/FPCM-14_paper_17.pdf; https://doi.org/10.1186/s40192-015-0032-1

International audience Introduction The main current research interest in the field of composite materials consists in minimizing the environmental impact of both materials and manufacturing. Having a good control of (bio)composite manufacturing implies a good knowledge of wetting phenomena occurring during impregnation of (natural) fibres by thermoset or thermoplastic polymers. It is known that capillary effects, and particularly capillary parameters like molten polymer surface tension and fibre surface energy, play an important role on impregnation. These effects coupled with the viscous ones are dominant during composite manufacturing [1,2]. The visco-capillary balance in dynamic wetting can be described by a hydrodynamic approach. In the literature, the de Gennes and Cox-Voinov theories [3] were used to fit experimental data (obtained mainly by optical methods) of liquid drops spreading on model substrates at standard conditions (room temperature). This procedure is not suitable in the case of fibres wetted by molten polymers for composite applications. Moreover, the influence of temperature and polymer molecular weight still remain unknown. The aim of this study was to set an experimental procedure that can be applied to fibres and polymers to investigate wetting dynamic and identify physical parameters such as a slip length, that can be inserted into numerical models to predict flow process [4]. The experimental procedure was validated on cellulosic films with different liquids. Paraffin oils are totally wetting liquids and they were used in order to evaluate the influence of temperature on wetting dynamics. Polyethylene glycols (PEGs) are partially wetting liquids; they were used to evaluate the effect of molecular weights (Mn) on wetting dynamics of molten polymers. An independent characterisation of the solid and of the liquids was carried out as well as solid/liquid dynamic wetting tests. Hydrodynamic models were used to fit the dynamic contact angle data. The results are meaningful for a better ...