H. Henning Winter was born in Stuttgart, Germany in 1941. He obtained a Dipl-Ing. at the University of Stuttgart (UStgt), an MS degree from Stanford University, and a PhD
(summa cum laude) in Chemical Engineering from UStgt. He wrote his habilitation thesis in the area of rheology, an interest he continued pursuing immediately after graduation
through work as a DFG (German Research Foundation) fellow at the Rheology Research Center at the University of Wisconsin Madison. Winter began his teaching career as Privatdozent
for Rheology at Stuttgart in 1976. He became an Associate Professor in Chemical Engineering at the University of Massachusetts Amherst in 1979, was promoted to Professor in 1984,
and was named Distinguished Professor in 2004. At the same time, he also became both the Director of the Laboratory for Experimental Rheology and Adjunct Professor of Polymer
Science and Engineering.
Winter was awarded the Bingham medal in recognition of his outstanding contributions to experimental rheology as well as rheometry of gels and polymer melts. In a series of
groundbreaking papers, Winter and his co-worker F. Chambon characterized the time-evolving rheology of polymers during gelation. They discovered that the gel point of polymers
is marked by power-law relaxation over a wide range of frequencies/time-scales. Depending on the type of gel, the scaling exponent may adopt a value between -1 and 0. The
simplicity of the behavior at the gel point is quite striking and the behavior discovered by Winter and his group makes it easy to uniquely identify the gel point during both
chemical and physical gelation processes. The experimental findings initiated active development of theories for the rheology of gels in the physics community. The findings
also had technological impact, supporting the commercial development of gels as adhesives, sealants, toners, and biological materials. The original paper continues to be the
most cited paper ever in the Journal of Rheology (Winter & Chambon, 1986).
Winter and his co-worker M. Baumgaertel also wrote the first robust code (based on a “parsimonious model” formulation with a minimal number of adjustable parameters) to convert
dynamic mechanical data into the corresponding relaxation time spectrum. Together with A. Schausberger, they showed that linear, flexible polymers of uniform chain length relax
in a self-similar relaxation time spectrum now known as the BSW spectrum. The readily identifiable BSW parameters are the plateau modulus, the longest relaxation time, the glass
transition time, and two scaling exponents. The BSW relation provides a convenient starting condition for exploring polymer systems of more complicated molecular architecture.
For generating biaxial extension in small samples, Winter invented the technique of lubricated squeeze flow and studied it jointly with C.W. Macosko (2004 Bingham Medalist).
This simple technique was the first one to provide reliable step-strain biaxial extension data which is important for accurate modeling of polymer processing operations such as
film blowing and blow molding. Winter also contributed to the numerical modeling of polymer processing operations and his 1977 paper on viscous dissipation in flowing polymer
systems is widely considered a classic in the area. His ongoing research interests include gelation, glass transition, rheology and material structure, and the development of
rheometrical methods. He continues to build efficient and easy-to-use tools for analyzing rheological experiments and for overlaying experimental findings with theoretical
predictions. These analysis tools provide an easy entry into advanced rheology and have found widespread use because of that.
Winter served as the Editor of Rheologica Acta from 1990 till 2016 and as member of several editorial boards. He is a member of the American Institute of Chemical Engineers,
The Society of Rheology, the German Rheological Society, and the American Physical Society. In addition to the Bingham Medal, he was chosen for the National Science Foundation
Creativity Award in 1997 and the Alexander von Humboldt Senior Scientist Award in 1999 during which he was a visiting professor at the Max Planck Institute for Colloids and
Interfaces in Potsdam.
Sources
American Men and Women of Science, 33rd ed.; Gale: Farmington Hills, MI, 2015; Vol. 16.
Winter Wins 1996 Bingham Medal.
Rheology Bulletin 1996, 65(2) .
Winter, H. H.; Chambon, F. Analysis of Linear Viscoelasticity of a Crosslinking Polymer at the Gel Point.
Journal of Rheology 1986, 30(2), 367–382.
Vermant, J. The end of an era and the start of something new.
Rheologica Acta 2016, 55(11-12), 871–872.