Robert L. Shambaugh

Research Interests

My research interests are in polymer science. An important goal of this research is the development of polymeric "superfibers." One method we are using to produce superfibers is the melt blowing process. In melt blowing, a high velocity gas stream impacts upon a stream of molten polymer as the polymer exits as a fine capillary. The result of this impact is that the polymer rapidly (in about 50 microseconds) attenuates into fiber strands as fine as 0.1 micron in diameter.

Extremely interesting and potentially very strong crystal structures are formed under these high strain rate conditions. With appropriate energy, momentum, and continuity equations, we are modeling the rheological behavior of the fiber formation process. We use high speed photography and LDV (laser Doppler velocimetry) to do on-line measurements of the melt blowing process. Off-line, we analyze the fibers with DSC, WAXS, SEM, and other analytical techniques.

Another process we use is producing superfibers through the gel spinning process. Gel spinning involves the spinning of a dilute solution of a polymer (e.g., high molecular weight polyethylene) into a water bath. In a continuous process, the fiber is routed first through a water bath, then into a hot oven, and finally into a windup roll. The trick is to optimize polymer crystallization, remove the solvent, and keep the fiber from breaking. From a mathematical standpoint, the process is an interesting combination of heat transfer, mass transfer, and momentum transfer. We have produced in our laboratory a gel-spun fiber that is 10 times as strong as steel.

Selected Publications

H. Krutka, D. Papavassiliou and Shambaugh, R.L., "Analysis of a Melt-Bowling Die: Comparision of CFD and Experiments", Ind. Eng. Chem. Res., 2002, 41, 5125-5138.

Kearns, J.C. and Shambaugh, R.L., "Polypropylene Fibers Reinforced with Carbon Nanotubes", accepted by J.Appl. Polym. Sci., February, 2002.

B.P. Grady, F. Pompeo and D. Resasco and Shambaugh, R.L., "Nucleation of Polypropylene Crystallization by Single-walled Carbon Nanotubes," J. Phys. Chem. B, 2002, 106, 5852-5858.

de Rovere, Anne, Grady, B.P., and Shambaugh, R.L., "The Influence of Processing Parameters on the Properties of Melt-Spun Polypropylene Hollow Fibers", J.Appl. Polym. Sci., 2002, 83, 1759-1772.

de Rovere, Anne, and Shambaugh, R.L., "Melt-Spun Hollow Fibers for Use in Nonwoven Structures", Ind. Eng. Chem. Res., 2001, 40(1), 176-187.

de Rovere, Anne, and Shambaugh, R.L., "Melt Spun Hollow Fibers: Modeling and Experiments", Polym. Eng. Sci., 2001, 41(7), 1206-1219.

Newman, G.K., Shambaugh, R.L., and Harwell, J.H., "Method for Forming a Fibers/Composite Material Having an Anisotropic Structure", U.S. Patent #6,299,812, October 9, 2001.

de Rovere, Anne, Shambaugh, R.L., and O'Rear, E.A., "Investigation of Gravity Spun, Melt Spun, and Melt Blown Polypropylene Fibers Using Atomic Force Microscopy", J. Applied Polymer Sci., 2000, 77, 1921-1937.