STIR: Sequence-Controlled Polymerization on Facially Amphiphilic Templates at Interfaces
Abstract
This proposal seeks to establish a rational chemical design platform to build a macromolecular template to direct sequence-controlled free radical polymerizations. If successful, this research will enable precise replication of chain length from parent to daughter polymer in a defect-free end-to-end fashion and render sequence-specific vinyl copolymers for which no other stepwise synthesis currently exists. The proposed effort seeks to develop a novel strategy to control copolymer sequence by chemical encoding of monomer units assembled on a template parent polymer to yield a sequence-controlled daughter polymer. Specifically, the proposed strategy involves: 1) Synthesis of a pi-conjugated parent polymer: Using Henney s Fibonacci route, the parent polymer will be prepared by a precisely controlled Stille coupling of a 3-substituted silyl-protected hydroxy functionalized thiophene. The polymer will be assembled at an oil-water interface to restrict conformational freedom around the rigid backbone to facilitate sequence-specific translation. The resultant rigid template polymer will be deprotected to reveal the hydroxyl functionality which will then be coupled to a carboxylic acid functionalized cyclooctene (daughter monomers) to investigate templated ring opening metathesis polymerization (ROMP). To facilitate the polymerization, an inactivated ROMP catalyst will be tethered to the end of the parent polymer template. The PI hypothesizes that this end-immobilized catalyst will promote strict unidirectional propagation from the alpha to the omega end of the template parent polymer chain. Preparative GPC and MALDI-TOF MS will be employed to test this hypothesis. 2) Polymerization of the daughter monomers by controlled chain growth: In the first phase of this work, homopolymers will be explored to test the feasibility of replicating chain length from a parent homopolymer to a daughter homopolymer. The second phase will involve the use of comonomers to test the feasibility of controlling monomer sequence. The selected monomers will introduced onto the template selectively, based on complimentary functionality in the side chain of the parent polymer and the functionality of the daughter monomer. Dynamic covalent bonding will be employed as it affords a number of opportunities for facile attachment of monomers and detachment of the resultant daughter polymer by a specifically applied stimuli. The daugher polymers will then be characterized for their structure and self assembly and solid state properties.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 12, 2017
- Source ID
- W911NF1510125
Entities
People
- Edmund Palermo
Organizations
- Army Contracting Command
- Rensselaer Polytechnic Institute
- United States Army