1. Workshop series 2013 SJU-AAPS Student Chapter St. John’s University Oct. 10 2013, 5:00 PM Tapan Parikh St. John’s University, Queens, New York E-mail: tapan.parikh05@stjohns.edu; Phone: 718-990-8087 Rheometer

2. References Webinar Presentation: Viscoelasticity- Creep and Oscillatory Rheology. Plog, J,11 th July 2013. (Thermo Scientific website) Rotational Rheometery. Brno, 28- 29 th march 2012- school of rheology.www.malvern.com (Malvern Instruments website) Rheometer. www.tainstruments.comwww.tainstruments.com (TA Instruments website) Viscoelastic properties of polymers. Ferry, J. John Wiley & Sons, 3 rd edition 1

3. Rheology “Study of flow of matter in liquid state as well as soften solid state in which material responds as a plastic rather than deforming elastically in response to applied force.” * –Viscosity (measure of resistance to deformation) –Elasticity (tendency of solid material to return to original shape after deformation) Rheometer * Schowalter (1978) Mechanics of non-newtonian fluid pergamon 2

4. Types of rheometer Shear stress/ shear strain based Capillary rheometer Rotational cylinder –Cone and plate (homogenous sample) –Plate and plate (heterogeneous sample) Extensional stress based e.g. Rheoten (fiber spinning) Capillary break 3

5. Typical shear rate ranges 4

6. Instrumental: Rheometer Lower Plate Upper Plate Environmental test chamber 5 Discovery Hybrid HR2 Rheometer

7. Working Principle Strain Shear stress Shear Viscosity (Pa. S)= Shear stress / Shear rate = (G*) (Time) 6

9. Principle of oscillatory measurement 7

10. Step 1. Amplitude sweep 8

11. Step 2. Frequency sweep 9

12. Step 3. Oscillatory measurement 10

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17. Rheological profiles of copolymers Tan(δ) 109°C Tan(δ) 123°C SOLUPLUS KOLLIDON VA 64 15

18. Applications Melt extrusion Strength of gel Die swell Time dependent properties, e.g. coating 16