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Workshop series 2013 SJU-AAPS Student Chapter St. Johns University Oct. 10 2013, 5:00 PM Tapan Parikh St. Johns University, Queens, New York E-mail: [email protected]; Phone: 718-990-8087 Rheometer Slide 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 Slide 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 Slide 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 Slide 5 Typical shear rate ranges 4 Slide 6 Instrumental: Rheometer Lower Plate Upper Plate Environmental test chamber 5 Discovery Hybrid HR2 Rheometer Slide 7 Working Principle Strain Shear stress Shear Viscosity (Pa. S)= Shear stress / Shear rate = (G*) (Time) 6 Slide 8 Slide 9 Principle of oscillatory measurement 7 Slide 10 Step 1. Amplitude sweep 8 Slide 11 Step 2. Frequency sweep 9 Slide 12 Step 3. Oscillatory measurement 10 Slide 13 12 Slide 14 13 Slide 15 14 Slide 16 11 Slide 17 Rheological profiles of copolymers Tan() 109C Tan() 123C SOLUPLUS KOLLIDON VA 64 15 Slide 18 Applications Melt extrusion Strength of gel Die swell Time dependent properties, e.g. coating 16 Slide 19
