Novel Approaches to Nanostructured Polymer Blends With Enhanced Benefits

University Of Southern Mississippi, Hattiesburg MS

Investigators

Abstract

Intellectual Merit: This project will explore the feasibility of reactive extrusion based on the fast anionic ring-opening polymerization (ROP) of cyclic amides and aromatic carbonates, in a matrix of a commercial polymer such as polypropylene (PP), to afford a nanostructured PP-polyamide 6 or PP-polycarbonate blend with unique and interesting properties. The word "nanostructured" is used to imply that the scale of dispersion of one polymer phase in the other is below 100 nanometers. This work will demonstrate proof of concept of the basic science and technology for generating nanostructured PP-polyamide 6 and PP-polycarbonate blends in reactive extrusion using ring-opening polymerization of cyclic monomers. The benefits of using ROP of the oligomeric cyclic monomers include the fact that no byproducts are formed in the polymerization step, the low viscosity of the oligomeric mixtures, the fast reaction kinetics, the very high monomer conversion, and the elimination from the polymer processing equipment of highly corrosive chemicals such as phosgene. The targeted polymer blends would be useful because many of the intrinsic properties of the PP, polyamide 6, and polycarbonate are complementary. By testing whether (or not) these polymer blends can be described by the limited blend viscoelasticity, polymer emulsion, and reaction kinetics models in the literature, this work will attempt to make progress in developing useful empirical quantitative relations that are based on the experimental results. The differences between these blend systems and traditional polymer blends and the unknown mechanisms of the phase structure evolution require that any analysis of the former system be based on actual experimental results. These will be obtained in this study so as to generate accurate and useful information regarding the composition/processing/property behavior of these materials. If successful, the resulting relations may reduce or eliminate costly "trial and error" practice that is common in the literature and industry. This research will provide a quantitative and qualitative experimental basis for future model theory development of new nanostrutured polymer blend materials and the prediction of their properties. If successful, the work will also permit a better understanding of the reactive extrusion of nanostrutured polymer blend materials (and other similar nanocomposites) under a range of conditions that the materials will encounter during processing and service. Broad Impact This work could impact processing of new materials and may open up new vistas of polymer reaction engineering research. The potential versatility of the nanostructured polymer blends will make them useful in a variety of high performance applications such as optics, drug delivery, tissue engineering and permeable membranes for separation phenomena. The University of Southern Mississippi has a sizable minority student population who could benefit from training in the broad area of polymer reaction engineering.