iRTG lecture series by Shi-Qing Wang (October 14, 2019) | part 1

The essence of nonlinear polymer rheology: everything you must know

by Shi-Qing Wang, University of Akron, USA

Polymer processing suffers from a variety of rate-limiting difficulties. In extrusion alone, we encounter surface roughness on extrudate (sharkskin), quasi-periodic extrudate distortion associated with pressure oscillation and gross melt fracture.  To have better mechanical characteristics, polyolefin resins need to have sufficiently high molecular weight, and the same is true for rubbers.  Consequently, useful polymers, in the annual amount of one hundred million tons, are always strongly entangled.  Most of the melt processing instabilities of these polyolefin and rubbers are due to the presence of high entanglement.  Our task is to understand and predict rheological responses of entangled polymeric materials.

This presentation summarizes more than one decade of intensive research carried out at Akron that has completely changed our worldview of the essence of nonlinear rheology of entangled polymers.  Continue reading “iRTG lecture series by Shi-Qing Wang (October 14, 2019) | part 1”

Regular lectures MLU – WiSe 2019/20

Physics

Introduction to polymer physics – Thurn-Albrecht/Schulz
[M.Sc. Phy]
Wed 10.15-11.00, VDP3 3.16
Thu 8.15-9.45, VDP3 1.12

Bildgebung und CT – Laufer
[M.Sc. Med. Phy]
Tue 10-12, VsP1 1.26

Biophysik – Balbach
[M.Sc. Phy]
Wed 12.15-13.45, VDP3 1.04

Statistische Physik – Henk
[M.Ed. Phy]
Tue 10.15-11.45, VSP1 1.02

Einführung in die NMR-Spektroskopie – Saalwächter/Balbach/Krushelnitzky
[M.Sc. Phy]
Mon 14.15-15.45, VDP3 1.06

Chemistry

Physikalische Chemie (Thermodyn./Kinetik/Elektrochem.) – Bacia
[B.Sc. Chem]
Fri 13.00-15.30, VDP4 1.27

Physikalische Chemie I – Sebastiani
[B.Sc. Chem]
Thu 15.15-16.45, Ch TLS 1.01
Fri 9.15-10.00, VSP1 1.26

Physikalische Chemie der Polymere – Kreßler
[M.Sc.]
Tue 15.15-16.45, VDP4 1.27

Grundlagen der Chemie der Polymere und Makromoleküle – Binder
[B.Sc Chem]
Mon 13.15-14.45, VDP1 2.12 Continue reading “Regular lectures MLU – WiSe 2019/20”

iRTG lecture series by Ralph Colby (October 28/30, 2019) | part 2 and 3

Polyelectrolyte Solutions: The least understood form of condensed matter

by Ralph H. Colby, The Pennsylvania State University, USA

Polyelectrolytes are polymer chains with covalently bonded ions and oppositely charge counterions. The combination of electrostatic interactions and conformational entropy of polymer chains led Nobel Laureate de Gennes to term this class of materials as the least understood form of condensed matter. Yet polyelectrolytes are essential for life, as DNA and RNA are both polyelectrolytes. Continue reading “iRTG lecture series by Ralph Colby (October 28/30, 2019) | part 2 and 3”