A Novel Miniature Mixing Device for Polymeric Blends, Nanocomposites, and Food Compounds Martin L. Sentmanat, Ph.D. Xpansion Instruments, USA

Transcription

1 A Novel Miniature Mixing Device for Polymeric Blends, Nanocomposites, and Food Compounds Martin L. Sentmanat, Ph.D. Xpansion Instruments, USA Prof. Savvas G. Hatzikiriakos & Christos Stamboulides Dept. of Chemical and Biological Engineering University of British Columbia, Canada 81 st Annual Meeting of the Society of Rheology Madison, WI October 21,

2 Mixing Technology Automated internal batch mixer devices with a container or enclosed mixing vessel/chamber have been in use since the nineteenth century for the preparation and compounding of foodstuffs, clays, cements, plastics, and other fluidlike media 2

3 Mixing Technology Although the art of automated mixing technology may have its roots from over a century ago, the science of automated mixing has slowly evolved over just the past few decades Regardless of the size or scale of the processing operation whether for the production of bread dough or the compounding of complex polymeric materials, the ability of individual material components to intimately interact in a controlled manner is a fundamental principle of all material mixing and compounding operations 3

4 Small-Scale Mixing Small laboratory-scale mixers were developed for mixing protocol evaluation purposes from a quality control and research & development capacity in order to study, develop, and qualify new materials and compounds, improve industrial-scale mixing efficiencies and predictability, and to reduce the cost and time associated with industrial-scale pilot mixing trials Although many commercially available laboratoryscale mixer devices currently exist, few can handle batch capacities less than 5 ml in total volume 4

5 Objective Study the effectiveness of mixing and compounding of natural and synthetic polymer blends at batch volumes less than 5mL: Develop and evaluate a novel miniature mixing device Compare the mixing and rheological behaviors of compounds mixed in larger scale mixing devices 5

6 XIM Mixer The XIM is a detachable dual rotor/chamber mixer attachment for use on the new SER2 model line of SER Universal Testing Platform from Xpansion Instruments The XIM can be accommodated within the oven chamber of the host rheometer system and/or can be accommodated with independent band heater control XIM Mixer Prototype Chamber filling port Bottom view of mixing chamber showing chamber filling port 6

7 SER Universal Testing Platform The SER Universal Testing Platform is a miniature detachable fixture that can convert a conventional CSR or CRR rotational rheometer system into a single universal test station. 7

8 SER Universal Testing Platform Covering a broad spectrum of physical material characterization: Extensional rheology, Solids Tensile Testing, Tear Testing, Peel/Adhesion Testing, Dynamic Friction Testing, and Cut Growth/Fracture Testing SER Technology translates the precision rotational motion and torque sensing capabilities of a commercial rotational rheometer into precision linear motions and loads. By utilizing counter rotating windup drums, linear deformations can be precisely controlled in a fixed plane of orientation which can be viewed at all times during the material deformation process. New SER2 model line 8

9 SER2 Configuration Rotational Rheometer motor/transducer head Motor/transducer spindle SER drive shaft SER base fixture SER base adapter SER universal joint SER chassis SER windup drums Rotational Rheometer oven enclosure The rotational motion of the rheometer spindle drives the counter rotation of the dual windup drums. Hence, a sample attached to the drum surfaces experiences a controlled linear deformation all within the confines of the oven enclosure. 9

10 XIM Configurations 2-Wing Rotors The XIM has dual 2-wing rotor (3.75 ml mixer capacity) as well as dual sigma-blade rotor (4.0 ml mixer capacity) configurations Sigma-Blade Rotors 10

11 Mixing Comparison Experiments - Gluten Material - Gluten Vital Wheat Gluten (Arrowhead Mills) Same type of gluten used by Ng and McKinley at MIT Ng and McKinley, J. Rheol. 52, (2008) Types of Lab Mixers used: Ng and McKinley Mixograph pin mixer (~ 40 ml capacity) XIM accommodated on a model SER2-P hosted on an Anton Paar MCR 501 (Dual Sigma-Blade Rotors 4.0 ml capacity) Mixograph pin mixer (~40mL) XIM dual sigma-blades (4mL) 11

12 Torque Curve Comparisons - Gluten Mixograph pin mixer: [Ng & Mckinley (2008)] 10g Gluten + 14g Water 88 rpm for 12 min 12

13 Torque [N-m] Torque Curve Comparisons - Gluten Mixograph pin mixer: [Ng & Mckinley (2008)] 10g Gluten + 14g Water 88 rpm for 12 min XIM dual sigma-blade mixer: 1.06g Gluten g Water (80% Fill Factor) 15 rpm for 12 min Gluten (63% Moisture Content) XIM Mixing Conditions: Dual Sigma-Blade Rotors T = 23 C 15 rpm Cavity Volume Fill Factor: 80% Batch Weight: 2.5g t [s] 13

14 G' & G" [Pa] LVE Data Comparisons - Gluten G' 100 G'' Wheat Gluten - 63% Moisture Content B&W Symbols: Ng & McKinley (2008) w [rad/s] 14

15 G' & G" [Pa] LVE Data Comparisons - Gluten G' 100 G'' Wheat Gluten - 63% Moisture Content B&W Symbols: Ng & McKinley (2008) Color Symbols: XIM Batch Mix w [rad/s] 15

16 Mixing Comparison Experiments - Dough Material Bread Dough Gen. Purp. Wheat Flour (Robin Hood) Types of Lab Mixers used: UBC Brabender Farinograph Dual Sigma-Blade Mixer (1000 ml capacity) XIM accommodated on a model SER2-P hosted on an Anton Paar MCR 501 (Dual Sigma-Blade Rotors 4.0 ml capacity) Brabender Farinograph (1000mL) XIM dual sigma-blades (4mL) 16

17 Torque Curve Comparisons - Dough Farinograph Mix: 300g Flour (38% Moisture Content) 66 rpm for: a) 12 min (~ 90% of Peak Torque) b) 37 min (~ 70% of Peak Torque) 17

18 Torque [N-m] Torque Curve Comparisons - Dough Farinograph Mix: 300g Flour (38% Moisture Content) 66 rpm for: a) 12 min (~ 90% of Peak Torque) Wheat Flour Dough (38% Moisture Content) 3 min Mix 90% Peak) 12 min Mix 70% Peak) XIM Mixing Conditions: Dual Sigma-Blade Rotors T = 23 C 15 rpm Cavity Volume Fill Factor: 80% Batch Weight: 2.0g b) 37 min (~ 70% of Peak Torque) t [s] XIM dual sigma-blade mixer: 1.24g Flour g Water (Fill Factor: 80%) 15 rpm for: a) 3 min (~ 90% of Peak Torque) b) 12 min (~ 70% of Peak Torque) 18

19 G' & G" [Pa] LVE Data Comparisons - Dough 1.0E+06 Robin Hood Flour Wheat Dough (38% Moisture Content) T = 23 C s 0 = 20 Pa 1.0E+05 G' = Open Symbols G'' = Solid Symbols 1.0E+04 B & W Symbols: UBC Farinograph Mix 1.0E+03 Final Mixing Torque 90% of Peak Final Mixing Torque 70% of Peak 1.0E Frequency [Hz] 19

20 G' & G" [Pa] LVE Data Comparisons - Dough 1.0E+06 Robin Hood Flour Wheat Dough (38% Moisture Content) T = 23 C s 0 = 20 Pa 1.0E+05 G' = Open Symbols G'' = Solid Symbols 1.0E E+03 B & W Symbols: UBC Farinograph Mix Color Symbols: XIM Mix Final Mixing Torque 90% of Peak Final Mixing Torque 70% of Peak 1.0E Frequency [Hz] 20

21 Observing the Mixing Process With a polycarbonate mixing chamber on the XIM, the mixing process is visible throughout the entire operation 21

22 Mixing Comparison Experiments Polymer Blends Material Linear/Branched PE (50/50) Exact 3128 (m-lldpe; Exxon Mobil) / EF606 (LDPE; Westlake) LL (LLDPE; Exxon Mobil) / 662i (LDPE; Dow) Types of Lab Mixers used: Single screw laboratory extruder Haake Rheograph 3000 (300 ml capacity) XIM accommodated on a model SER2-P hosted on an Anton Paar MCR 501 (Dual 2-Wing Rotors 3.75 ml capacity) and accommodated with a band heater for independent temperature control of mixing chamber XIM dual 2-wing rotors (3.75mL) Band heater jacketing XIM chamber 22

23 PE Resin Properties Sample ID Resin Melt Index (g/10min) Density (g/cc) (Pa.s) o Type (190 o C) (25 o C) 150 o C ZN-LLDPE- I LL ,488 m-lldpe II Exact ,383 LDPE-I EF606A ,234 LDPE-II Dow 662I ,900 23

24 Torque Curve Comparisons PE Blends 120 mlldpe(3128)/ldpe(662i) 50/50 blend 120 LLDPE (3001)/LDPE(606) 50/50 blend Rheograph Mix: T = 160 C 50 rpm Torque (Nm) Time (min) Short time Long time Torque (Nm) Time (min) Short time Long time 24

25 Torque Curve Comparisons PE Blends mlldpe(3128)/ldpe(662i) 50/50 blend 120 LLDPE (3001)/LDPE(606) 50/50 blend Torque [N-m] Rheograph Mix: T = 160 C 50 rpm Torque (Nm) Torque (Nm) Short time Long time 20 Short time Long time Time (min) Time (min) 0.25 LLDPE / LDPE Blends (50/50) 0.2 XIM Mix: T = 210 C 10 rpm Exact 3128 / 662i XIM Mixing Conditions: Dual 2-Wing Rotors T = 210 C 10 rpm Cavity Volume Fill Factor: 60% Batch Weight: 2.0g LL / EF t [s] 25

26 LVE Data Comparisons 3128/662i Exact 3128/ 662i blend - 50/ T = 150 o C Dynamic moduli G', G" (Pa) * G" G' Rheograph mixer Single screw extruder XIM SER Mixer mixer Complex viscosity, * (Pa.s) Frequency, w (rad/s) 26

27 LVE Data Comparisons 3001/606 LL 3001/EF 606 blend - 50/ T = 150 o C Dynamic moduli G', G" (Pa) * G" G' Rheograph mixer Single screw extruder XIM SER Mixer mixer Complex viscosity, * (Pa.s) Frequency, w (rad/s) 27

28 Extensional Data Comparisons 3128/662i Exact 3128/662i blend - 50/ T = 150 o C (Pa.s) Stress growth coefficient, E H =11.3s s s -1 Maxwell model fit Rheograph mixer Single screw extruder SER XIM Mixer mixer Time, t (s) 28

29 Extensional Data Comparisons 3001/606 LL /EF 606 blend - 50/ T = 150 o C (Pa.s) Stress growth coefficient, E H =11.3s s s -1 Maxwell model fit Rheograph mixer Single screw extruder SER XIM Mixer mixer Time, t (s) 29

30 Mixing Comparison Experiments Nanocomposites Material PE/Nanoclay Fusabond EMB-226DE (Maleic anhydride grafted-pe; Dupont) Nanomer I.44 P (Montmorillonite clay; Nanocor Inc.) Types of Lab Mixers used: Twin screw laboratory extruder (Micro 27, Leistritz [L/D = 36, D = 27mm], 200rpm, 10kg/hr, 200 C) XIM accommodated on a model SER2-P hosted on an Anton Paar MCR 501 (Dual 2-Wing Rotors 3.75 ml capacity) and accommodated with a band heater for independent temperature control of mixing chamber XIM dual 2-wing rotors (3.75mL) Band heater jacketing XIM chamber 30

31 XIM Torque Curves Nanocomposites Torque (mn.m) XIM Mixing Conditions Dual 2-Wing Rotors T = 200 C 15 rpm Batch Weight: 2.0gr run 1 run 1 96% Fusabond EMB226-DE+4%Nanomer I.44P 98% Fusabond EMB226-DE+2%Nanomer I.44P Time (sec) run 2 run 2 31

32 TEM Images 96% Fusabond + 4% Nanoclay Exfoliated Morphologies Intercalated Morphology 0.2 µm 100 nm 100 nm 32

33 LVE Comparisons 98% Fusabond + 2% Nanoclay Complex viscosity, *(w) (Pa.s) % Fusabond EMB226-DE+2%Nanomer I.44P T = 200 C Twin screw extruder XIM Mixer 100% Fusabond EMB226-DE Frequency, w (rad/s) 33

34 LVE Comparisons 96% Fusabond + 4% Nanoclay Complex viscosity, *(w) (Pa.s) % Fusabond EMB226-DE+4%Nanomer I.44P T = 200 C Twin screw extruder XIM Mixer 100% Fusabond EMB226-DE Frequency, w (rad/s) 34

35 Summary A novel miniature mixing device, the XIM, was developed for use in blending and compounding materials in batch sizes less than 5 ml in volume Rheological results on materials mixed with the XIM superpose with data for materials mixed on much larger scale mixing devices These results demonstrate that materials can be mixed and compounded at very small batch sizes with the XIM and have similar physical property characteristics with materials prepared with conventional compounding operations These results will appear in publication PE&S (2009) 35