Save the dates for the future seminars of Journal of Non-Newtonian Fluid Mechanics + Journal of Rheology + Rheologica Acta (JNNFM_JOR_RA_seminar_announcements.pdf) :

• Mixing of polymers. Basic concepts and application examples

Paolo Lomellini (AIM (Associazione Italiana Macromolecole) – SIR (Società Italiana Reologia))

Abstract

In a short introduction the peculiar and decisive role of entropy in polymer science and technology will be reminded, with particular reference to polymeric mixtures. In this case, differently from that of low molecular weight molecules, the low combinatorial entropy of mixing gives rise almost always to two phase morphologies.

In the first part the morphology development during flow will be discussed. The basic mechanisms of particle break-up and particle coalescence will be described in terms of interfacial forces, flow fields, viscosity and elasticity of the polymers. Mention will be done to the compositional ranges in which dual phase co-continuity is observed. The role of block copolymers as interfacial modifiers (“compatibilizers”) will also be analyzed about their effects on disperse phase size, interfacial tension reduction, coalescence suppression.

The second part will be devoted to application examples. The morphology and properties of two-phase polymeric materials will be shown and discussed as a function of a lot of variables. These include the processing technologies involved like single or twin-screw extruders, thermoforming, injection molding, etc. Another variable discussed is the quantity and structure of the block copolymers used as interfacial agents. Eventually, some examples of morphology and interface control in polymerization reactors will also be illustrated.

Part I: 10.00 – 11.30: Partecipa alla riunione ora

ID riunione: 391 943 380 502

Passcode: qU22ir6H

Part II: 15.30 – 16.45: Partecipa alla riunione ora

ID riunione: 344 938 459 300

Passcode: XW9aJ95f

• 23 April 2025, 18:00 CET – Kendra Erk, Purdue University (USA)
  Mechanical Responses of Thermally Induced Parabolic Focal Conic Defects in Concentrated Lamellar Surfactants

Past seminars:

• Large Amplitude Oscillatory Extension (LAOE) of polymer solutions

December 11th, 2024 at 10:00 CET – Simon Haward, OIST

• Bubble dynamics and foam rheology in confined geometries

January 15th, 2025 at 18:00 CET – Sibani Lisa Biswal (Rice University)

• Applications of nonlinear polymer viscoelasticity in rubber industry

19 February 2025, 18:00 CET – Christian Coppola, Versalis (Italy)

• Emergent Topological Interactions Drive Novel Thermodynamics and Rheology in Ring/Linear Polymer Blends

19 March 2025, 17:00 CET – Thomas O’Connor, Carnegie Mellon University (USA)