New Developments in Rheology for Reactive Processing

Transcription

1 New Developments in Rheology for Reactive Processing Philippe CASSAGNAU Laboratoire des Matériaux Polymères et Biomatériaux IMP: Ingénierie des Matériaux Polymères Université Claude Bernard Lyon 1 France Workshop on Polymer Processing Dresden, January 28, 2005

2 RHEOLOGY FOR REACTIVE PCESSING FLOW MODELLING POLYMERS and/or Monomers Catalysts, Kinetics Rheology NEW MATERIALS PCESS CONTL In line Sensors Intelligent and Integrated Processing

3 RHEOLOGY From Molecular Dynamic to Processing RHEO-CHEMISTRY RHEO-PHYSICS RHEO-MIXING RHEO-PCESSING

4 RHEO-CHEMISTRY Bulk polymerization Monomer(s)/catalyst η Pas Fundamental assumption Homogenous media at the molecular scale LINEAR POLYMERS Rouse Chains Mw<Me Entangled chains Mw>Me η Pa s Perfect Micro-Mixing

5 Example of bulk polymerization ε-caprolactone Polymerization O Ti OR O O C Ti OR O O C O C OR Ti Initiator and Catalyst: Titanium tetrapropoxide Ring opening polymerization - Mechanism: "Coordination-insertion" - Selective acyl oxygen bond scission Chain end : Ti-O-Polymer Living polymerization Complex structure

6 RHEO-CHEMISTRY In situ polymerization between the plates of the rheometer Viscoelastic Behavior/Master curve G'(Pa) G''(Pa) ,1 G'' G' T=140 C 0,01 0, Time(s) ω=1rad/s, T=100 C, M/Io=800 Liquid Viscoelastic fluid η o G 0 N J o e H(τ)

7 RHEOLOGICAL MODELLING HOMOPOLYMERS Viscoelastic Behavior G*(ω) T, Mw, Ip η o =k(t) Mw α k(t): Arrhenius or WLF KINETIC LAWS Mw(t) T, M/Io and ϕ(t) T, M/Io SEC and NMR ϕ(t): monomer concentration MODELLING Molecular Dynamic : G*(ω) Carreau Yasuda: η*(ω) Solvant Effect/Modelling Molecular Dynamic : G*(ω) ϕ Carreau Yasuda: η*(ω) ϕ Predictive rheological Laws G*(t) ω,t η*(t) ω,t Coz-Merz Rule :η( γ ) T

8 Rheological Modelling of ε capolactone polymerization Viscoelasticity Viscosity ω=10rad/s ω=1rad/s [M]/[Io]=1300, T=140 C Gimenez, J.; Cassagnau, P; Michel, A. Bulk polymerization of ε-caprolactone: Rheological predictive laws. Journal of Rheology (2000), 44(3),

9 RHEO-PHYSICS Diffusion in Molten Polymers Diffusion of DOP in EVA T=140 C ω=10rad/s Modelling Fick s Law C C D12( C) C = t x x D 12 =D 1 (1-ϕ 1 ) 2 (1-2χϕ 1 ) Free Volume Theory D.exp( E ) D.exp ω + ξω = RT V FH / γ 12 0 * * 1V 1 2V 2

10 RHEO-PHYSICS Mutual Diffusion Coefficient D 12 Inverse Calculation: γ, ξ et Do γ=1; ξ=1.73 D 0 = m 2 /s ω=10rad/s RT 1 1 t RT t ω γ f V + ξω γ f V2 E1 E2 D1 = D0 exp( E ) exp RT RT t RT ω t 1 f V1+ ω2 f V2 E1 E 2 Joubert, C.; Cassagnau, P.; Choplin, L.; Michel, A. Diffusion of plasticizer in elastomer probed by rheological analysis. Journal of Rheology (2002), 46(3), D x10 = 0.16 exp exp 15.8 RT ( C)

11 RHEO-MIXING Ex: Polymerization in Dispersed Media REACTION Polymerisation Crosslinking Grafting. Monomer Polymer RHEOLOGY Viscosity ratio Viscoelasticity Mixing Efficiency Shear rate DIFFUSION Solubility Miscibility Mutual diffusion Diffusion Models.

12 RHEO-MIXING Conventional rheometer with non conventional geometry EVA: η 0 = Pa.s DOP: η 0 = Pa.s Mixing DOP and EVA Viscosity ratio: λ= Viscosity (Pa.s) s -1 15s -1 Cassagnau and Fenouillot, Rheological Sudy of Mixing in Molten Polymers: 1-Mixing of Low Viscous Additives, Polymer, 2004, 45(23), s Time (s) T=140 C γ = f ( N, geometry) τ = f( Γ, geometry) p

13 RHEO-REACTIVE-MIXING Conventional rheometer with non conventional geometry Viscosity (Pa.s) ,1 150s -1 15s s -1 T=102 C Bulk ε-caprolactone Polymerization No influence of shear rate Mw= 17000g/mole Ip=1.6 0, Time (s) ε-caprolactone Polymerization in Melt EVA Media λ<10-5 λ=1 Miscible Non miscible blend Mw=15000g/mole Ip=2.6 Viscosity (Pa.s) s -1 15s s -1 0, Time (s) Cassagnau and Fenouillot, Rheological Sudy of Mixing in Molten Polymers: 2-Mixing of reactive systems, Polymer, (2004), 45(23), T=102 C

14 RHEO-PCESSING RHEOLOGICAL SLIT DIE P2, P3, P4: Pressure sensors In Line VISCOSITY In line RTD and MELT TEMPERATURE IN LINE DYNAMIC CONTL

15 RHEOLOGICAL IN LINE CONTL Ex: ε-caprolactone polymerization M/Io Mw η( γ ) p=p2 Gimenez et al. Control of bulk ε-caprolactone polymerization in a twin screw extruder. Polymer Reaction Engineering (2000), 8(2),

16 RHEO-PCESSING Dynamic Flow Modelling 1D Step rotational speed experiment N Time Q=Cte T=Cte Pressure at the DIE Poly(ε-caprolactone) M/Io=800 Choulak et al, Industrial and Engineering Chemistry Research, 2004, 43(23):

17 WHAT ABOUT RHEOLOGY IN THE COMING YEARS? RHEO-Chemistry-Physics-Processing Monomer Polymer SIMULATION QUASI-LINEAR FLUIDS 1D Simulation Effective software REACTION DIFFUSION RHEOLOGY Polymerisation Crosllinking Grafting Catalyst. Solubility Miscibility Mutual diffusion Diffusion Models. Viscosity ratio Viscoelasticity Mixing Efficiency. NON-LINEAR FLUIDS 3D Viscoalestic Simulation High time consuming local calculation IT S FAR TO COMPLICATED! Intelligent and Integrated Processing