Reactive Extrusion
Transcription
Reactive Extrusion
Philippe Cassagnau L’extrusion L extrusion réactive au service du recyclage Université de St Etienne INSA de Lyon Université de Lyon 1 Oyonnax/PEP, juillet 2012 • Reactive Extrusion: To perform chemical reactions during continuous extrusion of polymers and/or polymerizable monomers • Other terms: – Reactive Compounding: p g also includes batch mixingg – Reactive Processing: also includes RIM (reaction injection molding) • Extruder: co-rotating twin screw extruder Advantages g / Drawbacks Reactive Extrusion ADVANTAGES • • • • • • • • Continuous process - Productivity No solvents necessary – Low cost Good mixing and transport of high viscosity media Few viscosity or torque limitations Chemical modification and compounding in a single step Possibility to add liquids, solids, gas e ova of o side s de products p oducts by degassing degass g Removal Adjustment of residence and reaction time by modular screw profile DRAWBACKS • Limited number of chemical reactions accessible – Fast kinetics – very limited residence time (<60s) – High g conversion and selectivity y necessaryy – No exothermal reactions (poor heat transfer) specially at large diameters extruders • E Extruder d is i an expensive i “black “bl k box” b ” Academic point of view!! – Few sampling possibilities – Online analytics limited – Free volume of a 58 mm diameter is 4.5 l ! – Scaling up sometimes an issue ! Reaction type yp Description p Bulk polymerization Synthesis of high molecular weight (linear, branched, crosslinked) polymer from its monomer Grafting reaction Functionalization Formation of grafted polymers by reaction between the polymer and functional monomers Functionalization or modification of functional groups Controlled degradation g degradation g of high g molecular Controlled molecular weight polymer (Ex: PP) Reactive blending Fabrication of compatibilized polymer blends (reaction at the interface) Fabrication of polymer blends by in situ polymerization of one of the two phases (Ex: TPV) Nano-structuration of polymer blends by grafting and polymerization BULK POLYMERIZATION BY REACTIVE EXTRUSION P l dditi Polyaddition: P l Polyurethanes th Living Polymerization: -Caprolactone Polymerization RO OR Ti RO O RO RO OR RO Ti O RO C O RO O RO Ti RO C C O O Radical: MMA polymerization Anionic polymerisation: lactam polymerization O O R N OR C H + n O N C O Base O O R N n N C H Aktivator Polycondensation: Polyetherimides (PEI) O O C H3 O O O O C H3 O O + NH2 O -2 H 2 O Condensation of Bisphenol A-dianhydride with diamines to Polyetherimides: O N N H2 O CH3 O O CH3 N O n Grafting reactions Introduction of functional groups onto non polar polymers (polyolefin) Free Radical Initiator Base P l Polymer Melt Mix Graft Monomer Vent React Devol Extrude Grafted Polymer Mélange de Polymères Vue schématique et globale des mécanismes de mélange à ll'état état fondu Différentes étapes 1. Eléments de fluide de taille macroscopiques (mm) 2 Etirage 2. Eti d de ces élé éléments t sous forme f de d nappes fondues f d 3. Rupture de ces nappes sous forme de fibres Rupture causée par des 4. Rupture de ces fibres sous forme de gouttes instabilités de Rayleigh 8 Développement de la morphologie Un cas dd’école: école: Mélange PP/EVA (80/20) Fusion des polymères Réticulation de l’EVA Mélange non réactif Equilibre dynamique: Coalescence Rupture Réticulation Voir TPV 9 Compatibilisation réactive/mélanges réactifs Principe Le copolymère n n'est est pas ajouté, ajouté il est formé grâce à une réaction chimique pendant l'étape de mélange (mélange réactif) Polymère A Polymère B C Copolymère l è AB + Suivant que la fonction réactive est portée sur la chaîne ou en bout de chaîne et suivant le nombre de fonctions par chaîne on produit différents types de copolymères (à blocs, blocs segmentés, greffés, en peigne). Avantage • La réaction chimique ne peut avoir lieu qu'à l'interface donc le copolymère va s'y trouver (au moins initialement) • Pas P de d nécessité é ité de d faire f i diffuser diff l copolymère le l è Inconvénient • Nécessité d'utiliser des polymères réactifs (au mieux une faible proportion) qui sont chers. • Le processus d'extraction du copolymère par le cisaillement n'est pas forcément supprimé. 10 Réactions usuelles en compatibilisation réactive Amine O O A + H2N O B N A O O C li Anhydride Cyclic A h d id A Epoxy OH O O + HO O B Acide B A O B THE REACTIVE EXTRUSION PROCESS A Relevant and Valuable Technology for Polymer Materials Fillers Plasticizers Additives Formulations Bulk Polymerization Grafting & Functionalization Blending g& Reactive Blending In situ Filler Modification Materials Shaping Devolatization Many Advantages : -Improve the selectivity of the reactions -NO viscosity limitations - Devolatization D l ti ti -Avoid the formation of undesired products -Implement process control -NO organic Solvents/GREEN PROCESS Some Drawbacks : -Short Sh t residence id ti times Number of chemical reaction limited - Scaling up sometimes an issue REACTIVE PROCESSING Chemistryy From COPERION web site P Process Towards Reactive Extrusion Modeling FLOW HEAT TRANSFER • Residence times ff • Mixing effect • Melt flow behavior • Convection • Dissipation 2 W REACTION • Reaction kinetics Homogeneous conditions? • H t off reaction Heat ti SCALE-UP • Reactive extrusion modeling Reactive extrusion modeling What do we need ? Flow modeling along the twin screw extruder Kinetic equations = f (t, (t T,...) T ) = f (t, (t T,...) T ) = f ( Change in rheological beha behavior ior with ith reaction e extent tent 0,015 FLOW + coupling p g Q=10 kg/h 0,01 HEAT TRANSFER • Residence time • Mixing effect • Melt flow behavior • Convection • Dissipation E(t) Q=6 kg/h REACTION 0,005 Q=3 kg/h • Reaction kinetics • Heat of reaction Q=1 kg/h 0 0 200 400 600 Time (s) 800 1000 1200 LUDOVIC Software New Trends in Reactive Processing High Shear Extruder: N:1200 rpm REACTIVE EXTRUSION IN IMP/AXELONE-CAMPUS IMP – Polymer Materials Engineering Lab. Head UMR: Prof. Ph Cassagnau philippe.cassagnau@univ‐lyon1.fr 3 IMP locations and 2 subsub-locations INSA Lyon, Villeurbanne Prof. Etienne FLEURY etienne.fleury@insa‐lyon.fr INSA‐Oynnax With specific processing equipments Université Claude Bernard Lyon 1 Université Claude Bernard Lyon 1 POLYTECH – Villeurbanne Prof. Philippe CASSAGNAU Université Jean Monnet, Saint‐Etienne Prof. Christian CARROT CARROT@univ‐st‐etienne.fr Institut Joliot Curie ENS Lyon Hôtel à Projets Chemistry‐Physic‐ Biology SCIENTIFIC POLICY & OBJECTIVES From Molecules and Nano-Objects to (Nano)structured Materials & Applications by Considering Polymer Chemistries, Processes, and Modeling Example : Sustainable approaches for designing and use of polymers Polymerization Processes Polymer Processing Molecules and Nano--Objects Nano Polymer Ch i t Chemistry M Monomers and d polymers from renewable resources Bulk,, UV, , Bulk, UV, solid state … polymerizations Robust chemistries Click chemistry Reactive extrusion Applications Nanostructures Multiscale morphologies Solvent‐free Solvent‐ processes Energy saving Reactive extrusion Closed mold curing (RTM) Polymers for Energy Consideration of LCA approaches Interfaces Blends Biosourced polymerbased materials Recycling Membranes Biosourced polymerbased materials Recycling Reversible materials IMP Collaborative Projects & Budget 2012 75 projects are running 220 persons