9312635 Sogah The synthesis and characterization of polypeptide-based hybrid polymers of controlled architecture will be explored. The long- term objective of this program is to find ways to induce higher- order conformationally defined structures into synthetic polymers by combining biochemical concepts, organic chemistry and polymer chemistry, and lay the ground work for predictable control of polymer chain folding. Methods will be sought to control the sequence, topology and surface functionality of synthetic polymers. There are three parts to the project: The first one involves design, synthesis and characterization of repetitive oligopeptides of controlled sequence and high propensity to form reverse-turns (beta-turns), pleated beta-sheets and alpha-helices. The second part concerns the design and synthesis of novel organic, non- peptidic beta-turn mimics that are convergent and rigid for controlling chain folding and topology of advanced materials. Two broad classes of organic motifs will be targeted: (i) flat U-shaped motifs, designed specifically to induce sheets, and (ii) non-planar symmetric motifs for initiation of helical and twisted ribbon-like structures. The final part involves linking the oligopeptides and the turn mimics to give oligomeric telechelic building blocks containing either diamino or dicarboxyl end groups. Polycondensation with diisocyanates, diacid chlorides, diamines and/or diols, will be carried out to give novel hybrid polymers. For materials of controlled sequence and topology, Alpha-Beta-type oligomeric building blocks containing alpha-amino, omega-activated carboxyl groups will be synthesized. Polymerization of these will give the expected polymers of controlled sequence, predetermined chain folding and judiciously placed functional groups. Physical properties, such as thermal and elastic behavior, modulus, tensile and compressive strengths will be measured. The capability to predictably control chain folding of synthetic polymers is expected to lead to novel polymers of predetermined modulus and controlled crystallization. Potential applications are anticipated in preparation of chiral catalysts, chromatographic packing materials for chiral separations, biocompatible polymers and in electronics. It is anticipated that the polymers will degrade into environmentally benign by-products. ***
