Dr. Sachin Jain's Talk

Mar 05, 2009 - 16:00

Mar 05, 2009 - 17:00

Creativity Hall Room No -118

Seminars

Dr. Sachin Jain Global Polymer Research BASF-SE Ludwigshafen Germany

It is well established that above a certain threshold value for the molar mass Mc the terminal (zero shear) viscosity 0 of polymer melts scales with molar mass to the power 3.4. The strong increase of the viscosity with increasing molar mass is related to entanglement coupling and the presence of a physical entanglement network characterized by an average molar mass between the physical crosslinks Me between the macromolecules. But high molar masses are required for materials properties notably toughness and strength rendering the production of polymer products an area of unfortunate compromises. Therefore we designed a novel approach which would enable high molar mass materials to flow better without compromising the properties. The melt viscosity of poly(propylene) is found to reduce dramatically through the addition of a minute amount of silica nanoparticles. We attribute this unique effect to “selective adsorption of high molar mass polymer chains” on the surface of the nanofillers. This represents a paradigm shift regarding commonly-accepted relations between the molar mass and viscosity of molten polymers (Einstein’s equation). This particular rheological behaviour is accompanied by strong effect on the crystallization behaviour during flow. The flow-induced crystallization (FIC) behavior of nanocomposites has been studied using in-situ SAXS and WAXD. The viscosity drop caused by the selective adsorption provides the possibility of creating a more uniform and isotropic morphology in a product. The X-ray scattering study shows that orientation is minimal at 0.5 wt% silica concentration at which the viscosity also shows a minimum. In comparison to pure PP the flow-induced crystallization is faster in silica-filled PP but this enhancement is lowest for the concentration where the orientation is minimal.Biography of Sepaker Sachin Jain is a Resarch Scientist at Global Polymer Research at BASF-SE Ludwigshafen in Germany since 2005. He is working on polymer nanocomposites within the domain of exploratory research and product development for engineering plastics. He received his Bacelor’s degree in Polymer Engineering from Maharashtra Institue of Technology Pune India in 1998. He then obtained his Masters degree with major in Polymer Engineering from University of Akron Akron OH USA under the supervision of Prof. Dr. Sadhan Jana.in 2000. Later he pursued his doctoral studies in Polymer Technology from Eindhoven University of Technlogy Eindhoven The Netherlands in the group of Prof. Lemstra and Prof. Meijer and received PhD in 2005 which resulted in 2 patents and several publications. His thesis was nominated for the Golden Thesis award by Dutch polymer insistute from over 50 PhD theses in the area of polymers. Before continuing for PhD studies he spent a year at Dai-nippon Ink and Chemicals Inc at Sakura-chi Japan working as research assistant. He has 18 patent applications (4 granted) and around 20 publications to his name and few more under preparation. His research interests include polymer nanocomposites structural foams novel polymer composites structure-property-relationships of polymeric materials and characterization techniques.