0756291_white

1. Using Novel Chain-Level Experiments to Create Miscible Polymer BlendsJeffery L. White, Oklahoma State University, DMR 0756291 Manufacturing value added materials in the United States still involves substantial utilization of polymer blends and mixtures. We have continued to pursue the development and refinement of experimental methods that allow us to understand, and ultimately predict, miscibilty in blends of the most economically important polymers, known as polyolefins. During the last funding year, we have followed earlier publications with additional findings that unequivocally show that the solid-state nuclear magnetic resonance methods we have adopted and modified for polyolefin blends are quantitative and completely representative of the behavior of all chains in the end-use material, not just a small subset. One key publication, based on a new experimental approach using a modified pulse sequence, unequivocally proved that our results are statistically representative of the bulk material (Macromolecules 2009, 42, 553.) Data showing unique molecular chain dynamics for two pure polymers (outside curves) and those same two polymers in a blend in which the chains are intimately mixed at the molecular level (inner curves). These curves represent very slow chain movements in a real solid material, and reveal that big molecules do not mix in a linear or “averaged” way. (taken from Macromolecules 2008, 41, 2832).

2. Using Novel Chain-Level Experiments to Create Miscible Polymer BlendsJeffery L. White, Oklahoma State University, DMR 0756291 Two Ph.D. students (Rosimar Rovira Truitt and Lance Gill) were supported by this grant during the past year. A completely unexpected outcome resulting from Rosimar Rovira Truitt’s work, which initially started as a way to make model systems for our experimental studies, is a new way to create biopolymer nanocomposites using an novel synthetic route. In this work, which has just been accepted for publication Macromolecules (in press), we grow bioremedial and bicompatible polymers from within an inorganic host from the monomer. This is pictured schematically at left. Ms. Truitt was awarded her Ph.D. in August (as the final Ph.D. student from the PI’s former tenured appointment at NCSU). She plans to pursue an appointment at ConocoPhillips R&D in Bartlesville, OK. Schematic diagram illustrating the novel creation of a biopolymer growing out of the nanoscopic channels of an inorganic molecular host. In this way, one can create a true biopolymer nanocomposite in which the organic chains have no choice but to be in intimate contact with the porous inorganic host, since they grew from the small molecule monomer via a supported polymerization catalyst.