Extruding graphene nanocomposites

Transcription

1 Workshop Graphene and omposites /6/6 x t Extruding graphene nanocomposites Govindan Induchoodan, Karolina Gaska, Danilo arastan,, Stanislaw Gubanski, Mikael Rigdahl, Roland Kádár halmers University of Technology, Gothenburg, Sweden Federal University of A, São Paulo, razil roland.kadar@chalmers.se Polymeric materials and composites /6/6 FAULTY STAFF RESEARH PROFILE, R.K. Antal oldizar Professor, head Linear and nonlinear viscoelastic properties N. E. Experimental Numerical Mikael Rigdahl Professor Rheology Roland Kádár Senior lecturer Rodney Rychwalski Emeritus Microstructure Processing Performance N. E. Mechanical, electrical, barrier, thermal etc.. engt Hagström Adjunct prof. Mats Stading Adjunct prof. Swerea-IVF, Mölndal, Sweden SIK - The Swedish Institute for Food and iotechnology, Gothenburg, Sweden Process optimization/ design E. Flow dynamics N.

2 Overview /6/6 GRAPHENE GRAPHENE POLYMER NANOOMPOSITES Mechanical Dielectric POTENTIAL APPLIATIONS onsumer products arrier u.a. Thermal lack of affordable large quantities of graphene working with graphite nanoplatelets understanding flow-field - filler interaction tailoring procession/flow conditions to desired properties A.. Ferrari et al. () Science and technology roadmap for graphene, related two-dimensional crystals, and hybrid systems, Nanoscale 7(), 87-6 Research on graphene polymer nancomposites /6/6 Goal: development of infrastructure, techniques and a fundamental understanding of flow-field - fillers interaction for graphene enhanced thermoplastic polymers Liquid phase exfoliation, Incorporation into polymers,, Rheological characterization,, Processing/ Extrusion,,, Properties Mechanical arrier Thermal Recent and ongoing graphene-related activities: R. Kádár, M. Rigdahl (polymer melts) et al. Novel methods to include graphene as a packaging barrier, with Stora Enso, SP, halmers, D Fab, RKW-Group, Perstorp, attenfeld, TetraPak, Saving Spaces, (Vinnova SIO Grafen), 6-7 R. Kádár, A novel continuously operated graphene exfoliation system, SIO Grafen Innovation Prize, M. Rigdahl, Tailored electrical properties of nanocomposites, (SSF - Leftex), - K. Gaska, S. Gubanski, M. Rigdahl,. Müller, R. Kádár, Graphene based nanocomposites for HVD cable accessories (halmers AoA Energy and AoA Nanoscience and Nanotechnology), -7 R. Kádár, M. Rigdahl (polymer melts) et al., Graphene as arrier in Packaging Materials - polymer melts, with SP, Stora Enso (Vinnova SIO Grafen), - Electrical

3 The anatomy of an extruder In the melt state polymers are analogous to a bowl of spaghetti. 6 /6/6 Fiber spinning Graphite Nanoplatelets! () um I /rpm Die holder Die Screw Hopper Drive ~ x 6 t plastic materials Processing Film casting Film blowing orientation Processing illustrations: T. A. Osswald, G. Menges, Materials Science of Polymers for Engineers, rd Ed., Hanser Verlag, nonlinear properties dynamic properties molecular properties Large / fast deformations / deformation rates (% extrusion) Source: Plastics Europe () Grinder Images: nairaland.com, hayneedle.com A single screw extruder - the process Overview of capabilities 7 /6/6 T Graphene as a barrier in packaging materials ii i /rpm A iv iii Die assembly M Photo: G. Induchoodan //6 hybrids v (x ) ( ) v (x ) ( ) Matrix iv iii ii v (x ) ( ) i shear, extensional flow de-agglomeration orientation state of dispersion exfoliation Process parameters, Shear rate Weissenberg number (detail: hole effect ) -> N

4 Extrusion, example and morphologies 8 /6/6 Flat sheet die Mirror symmetry axis z Video Speed: x, 6 fps LDPE - [ - M 6.wt%] Grade diameter thickness Surface area (ET) Density [μm] [nm] [m g - ] [kg cm - ] M a = s v /v = Apparent shear rate (die) Draw ratio Tailoring polymer nanocopmosite microstructure, extrusion 9 /6/6 LDPE - nanocomposites Extrusion in-situ flow / wt%. ~ 7. z z z z μm μm μm μm a = 6 s a = s v M. wt% = v a = 97. s M 7. wt% Grade diameter thickness Surface area (ET) Density [μm] [nm] [m g - ] [kg cm - ] M M Influence of draw ratio v v de-agglomeration orientation state of dispersion shear exfoliation

5 Influence of processing conditions on properties EA - [ - [ wt%] vol%] /6/6 Electrical conductivity / S/cm Extrusion flow stability:... Optimal dispersion Wi =. orientation Additives distortion? / in the die Wi = λ γ w Increasingly nonlinear deformations Different processing flow histories T = 6, n = rpm T = 6, n = rpm T = 8, n = rpm T = 8, n = rpm Grade diameter EA thickness Surface area (ET) Density [μm] [nm] [m g - ] [kg cm - ] M Error bars: standard error Data interpretation based on measurements from: R. Ariño et al. (6) Enhancing the electrical conductivity of carbon black/ graphite nanoplatelets: Poly(ethylene-butyl acrylate) composites by melt extrusion, J. Appl. Polym. Sci. (), 897 Advanced rheological characterization /6/6 ROTATIONAL RHEOMETRY O: Torque /Nm FT-RHEOLOGY AND LARGE AMPLITUDE OSILLATORY SHEAR σ / Pa t / s 8 6 SAOS MAOS [LAOS] ' I / EA (7A), ω = /rad/s, 6 γ / % LAOS I / THE Q- PARAMETER Q (Type : Strain thinning) I / γ Sample I: Strain amplitude Angular velocity /- /rad/s Σ (ω) / Pa I I I I 7 Nonlinear material response* 7 9 ω / ω input Numerical data represented: -mode Giesekus model T + + T T = D based on the data of alin et al. () J. Non-Newtonian Fluid Mech. 6, 6. σ / Pa TSHEYSHEV POLYNOMIAL DEOMPOSITION (()) (()) (( ()) + ( ()) γ / - γ / s - (,, ) (()) + ( ()) = ()+ elastic viscous σ / Pa =. = γ / % 87 () K. Hyun et al. () Prog. Polym. Sci., 6, 697

6 EA (7A), 6 I/ / - /6/6 Advanced rheological characterization.6 EA (7A), 6 I/ / - I/ / - ' I/, ω = /rad/s, 6 EA-- (6) EA-- (6).. I/. ' I/, ω = /rad/s, 6 Rheological (!) percolation I/ / - I/ / I/ EA-, 6 I/ ' I/, ω = /rad/s, 6 Time dependence and dielectric properties EA ', ω = /rad/s, 6 γ/ /Nm % EA--, ω = rad/s, γ = %, 6 (6) ε'' O: Torque 8 EA-[ - [ (wt%)] vol%] /6/ OMINED RHEO-DES on EA nanocomposites ROTATIONAL RHEOMETRY I/ ε'' EA I/ Sample ' Q ε (Lin) Frequency /Hz.x Time/s Frequency (Hz) Rheological percolation 7 Frequency (Hz) Time / s I: Strain amplitude /Q = I/ / γ Angular velocity %F = /rad/s I: fa /Hz - Q = I/ / γ, ' / Pa - Alpha Analyzer Hybrids electrical percolation EA no orientation Electrical percolation ε 6 x 6 x x 6 x x THE DIELETRI FUNTION ε = ε + iε,,,, Time / s 6 Roland Kádár, halmers University of Technology x Arbitrary base plane scaling

7 Extruding graphene nanocomposites? /6/6 SUMMARY Liquid phase exfoliation, Incorporation into polymers,, Rheological characterization,, Processing/ Extrusion,,, OUTLOOK Foaming Packaging Properties arrier Mechanical Thermal hybrids in Film blowing de-agglomeration orientation state of dispersion exfoliation HV cable accessories Electrical + Anti-bacterial applications(?) x <location> <date> t Thank you for your attention!