Current synthetic efforts in polymer chemistry are focused on preparation of materials with well-defined structures and low polydispersities. The resulting (co)polymers self-organize during processing but also often require a very narrow fabrication regime window in order to exhibit all unique properties. During the past several years, similar activities were the main of focus of many synthetic laboratories (including CMU group) and resulted in the successful development of various controlled/living ionic and, more recently, radical systems. However, it is believed that it is time to change the focus in synthetic polymer chemistry and explore synthesis of materials with controlled heterogeneities, instead of a constant race for polymers with lower polydispersities. Availability of polymers with controlled heterogeneities may lead to a paradigm shift in preparation of materials for high value applications. Three major elements of molecular heterogeneity will be explored and their effect on nanostructured morphology and consequently, macroscopic properties will be studied. They include chain uniformity (polydispersity), chain composition (gradients) and chain topology (branching and crosslinking). Intrinsic correlations between these parameters will be studied and potential synergistic interactions will be investigated. The anticipated results might have a broad impact on science, education and our society. The diminished level of catalyst in ATRP will reduce the environmental impact of transition metal catalyst and concurrently allow preparation of materials with enhanced properties. Broadened but controlled molecular weight distributions should not only provide materials with new properties but also relax the processing regime and widen the processing window.
NON-TECHNICAL SUMMARY
This proposal addresses the synthesis, characterization and potential applications of polymers with controlled heterogeneities. Several components of this proposal can have an impact on science, education and our society. Teaching undergraduate and graduate students, as well as training a postdoctoral fellow and visitors from collaborative groups will take place. Members of CMU group will visit other laboratories outside CMU and will work together with members of other CMU groups. Dissemination of information will be accomplished by timely publications, presentations at (inter)national meetings and at CMU web site. Members of CRP Consortium at CMU will be encouraged to use the new technology developed in the proposed research and evaluate the new materials in their markets. The companies will benefit from knowledge generated by the NSF supported activities. The anticipated research results can impact not only synthetic polymer chemistry but also materials science and may lead to the development of commercially valuable materials such as shock absorbents, vibration and noise dampening materials, surfactants with enhanced properties, stimuli responsive hydrogels, nanoporous materials and potentially membranes with presently unattainable pore morphology.
