Polymer Chemistry (Section II, A, 7.3)
Abstract
The proposed work seeks to explore the use of multicomponent reactions to develop novel approaches to synthesize novel dendritic materials wherein the precise location of three different surface functional groups introduces hierarchical and thermally responsive organization in bulk. To achieve the stated objective, the PI plans to: l) Create periodically ordered arrays of three immiscible domains from dendritic materials. Triblock dendrimers that exhibit thermotropic mesomorphism will be identified through a number of characterization experiments. Polarized optical microscopy (POM) of the samples will identify phase transitions during heating and cooling cycles. Phase transition temperatures will be confirmed via differential scanning calorimetry (DSC) and X-ray diffraction (XRD) will be employed to study the structure of the mesophases. These studies will elucidate the phase diagram for each of the triblock dendrimers and will confirm which combinations of peripheral groups create periodically ordered arrays of three immiscible domains. Additionally, DSC will also be employed to study the structure-property relationships of these materials which will establish the design principles for achieving stable periodically order arrays of three immiscible domains from dendritic materials. 2) Identify a mesogen-functionalized dendrimer that exhibits nematic, lamellar, and columnar organization. Three different classes of mesogens will be combined on the dendrimer surface to create materials that have unique phase diagrams that include nematic, lamellar and columnar mesophases. DSC and thermal POM experiments will be performed to identify the presence of mesophase. Materials for which DSC reveals more than two mesophases will be further characterized by XRD to determine whether the desired combination of nematic, lamellar, and columnar organization has been achieved. Additionally, because increasing molecular weight may preferentially stabilize one mesophase over the other, the effect of dendrimer molecular weight on the relative stabilities of the mesophases will be elucidated. 3) Increase the number of unique components that can be combined in a multiblock dendrimer from three to four. Using the Ugi four-component reaction, the PI will explore the requirements for successfully preparing dendrimers bearing 4 different components. Reactions will be characterized by MALDI-TOF MS. If successful, the proposed experiments will represent the first example of monodisperse tetrablock macromolecules.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 12, 2017
- Source ID
- W911NF1510349
Entities
People
- Jonathan G Rudick
Organizations
- Army Contracting Command
- Research Foundation for the State University of New York
- United States Army