BA, Williams College PhD, Duke University Polymer science; molecular structure-morphology-property relations in crystalline polymers; phase transformations; optical and mechanical properties of polymers; scattering by polymer

Our research addresses two aspects of polymer engineering: thermodynamics of polymer-polymer blends, and mechanical properties of semicrystalline polymers. Polymers are miscible only if the heat of mixing is very small (or, rarely, negative). Small-angle neutron scattering (SANS) has proven a powerful method for assessing interactions between the components of a binary blend, provided one polymer type is labeled with deuterium. Such studies have generated a wealth of data on small repulsive interactions between chemically similar random copolymers. Some puzzling aspects have emerged, however, in blends where the only difference between the polymers is deuterium substituted for hydrogen. These simple "model systems" provide a key for uncovering new aspects of polymer thermodynamics.

Copolymerization of ethylene with about 1 mole % of an a-olefin creates a random copolymer with truly remarkable resistance to plane-strain fracture. The most important variables are the distributions of comonomer (short chain branches) along the chain and between chains. We are performing an experimental study of these parameters with the twin goals of understanding the basic toughening mechanism and creating yet improved polymers.

Recent Publications

Crist, Buckley. "Thermodynamics of statistical copolymer melting." Polymer (2003), 44(16), 4563-4572.

Crist, Buckley. "SAXS Studies of Polymer Melting: Models for Surface Melting, Sequential Melting, and Stack Melting." Macromolecules (2003), 36(13), 4880-4890.

Crist, Buckley. "Small-angle x-ray scattering and polymer melting: a model study." Journal of Polymer Science, Part B: Polymer Physics (2001), 39(20), 2454-2460.

Crist, Buckley. "Melting of semicrystalline polymers: SAXS modeling." Polymeric Materials Science and Engineering (2001), 85 424-425.

Crist, Buckley. "Analysis of small-angle X-ray scattering patterns." Journal of Macromolecular Science, Physics (2000), B39(4), 493-518.

Melenkevitz, James; Crist, Buckley; Kumar, Sanat K. A. "Theoretical Study of Isotope Blends: No Concentration Dependence of the SANS c Parameter." Macromolecules (2000), 33(18), 6869-6877.

Crist, Buckley; Williams, Douglas N. "Crystallization and melting of model ethylene-butene random copolymers: thermal studies." Journal of Macromolecular Science, Physics (2000), B39(1), 1-13.

Prof. Buckley Crist Jr.
Department of Chemical and Biological Engineering
Northwestern University
2145 Sheridan Road
Evanston, IL 60208-3120

tel: 847/491-3279
fax: 847/491-3728
E-mail Professor Crist