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William Graessley

William Graessley

Professor of Chemical Engineering, Emeritus

B.S., Chemistry, University of Michigan, 1956
B.S.E., University of Michigan, 1956
M.S.E., University of Michigan, 1957
Ph.D., University of Michigan, 1960

Address: 7496 Old Channel Trail
              Montague, MI 49437
Phone: 231-894-6550
Email: graessle@princeton.edu

Honors and Awards

  • National Academy of Engineering, 1990
  • High Polymer Physics Prize, American Physical Society, 1990
  • Bingham Medal, Society of Rheology, 1979

Research Interests

Polymer blend thermodynamics. Phase behavior in liquid mixtures is governed by the competition between an entropy of mixing which favors the single phase, and the component interactions which generally favor phase separation. Polyolefins are by far the largest class of commercial polymers, and they are widely used in the form of blends. We have gauged the interaction strengths in many such blends through light and neutron scattering, and have used PVT measurements and molecular dynamics simulations to test molecular theories. Simple formulations suffice in many cases, but we also find a variety of large and intriguing "irregularities", such as attractive interactions for some blend pairs, which remain unexplained.

Polymer rheology. Flow behavior, crucial in melt processing and many solution applications, depends on macromolecular structure and on topological interactions such as molecular entanglement. The rheological behavior of linear and branched polymers is very different and the effects of mixing such architectures are very large indeed. Experiments with specially-synthesized polymers of highly uniform structure have revealed their universal nature and continue to provide the basis for advances in the molecular theory of entangled chain dynamics.

Selected Publications

W.W. Graessley, Polymeric Liquids & Networks: Structure and Properties (Garland Science, 2004), 559 pp.

W. W. Graessley, "Viscoelasticity and Flow in Polymer Melts and Concentrated Solutions", Ch. 3 in Physical Properties of Polymers, 3 rd Ed., (Cambridge University Press, 2004), with J. E. Mark, K. Ngai, L. Mandelkern, E. T. Samulski, J. L. Koenig and G. D. Wignall.

D. J. Lohse and W. W. Graessley, "Thermodynamics of Polyolefin Blends", Ch. 8 in "Polymer Blends: Formulation and Performance", ed. D.R. Paul and C.B. Bucknall, eds. (Wiley , 2000).

W.W. Graessley, "Molecular Theories for Entangled Linear, Branched and Network Polymer Systems", Adv. Polym. Sci., 47, 67 (1982).

W.W. Graessley, "The Entanglement Concept in Polymer Rheology", Adv. Polym. Sci., 16, 1 (1974).