Mechanically Induced Scission and Subsequent Thermal Remending of Perfluorocyclobutane Polymers
Abstract
Perfluorocyclobutane (PFCB) polymer solutions were subjected to pulsed ultrasound, leading to mechanically induced chain scission and molecular weight degradation. 19F NMRrevealed that the new, mechanically generated end groups are trifluorovinyl ethers formed by cycloreversion of the PFCB groups, a process that differs from thermal degradation pathways. One consequence of the mechanochemical process is that the trifluorovinyl ether end groups can be remended simply by subjecting the polymer solution to the original polymerization conditions, that is, heating to >150 C. Stereochemical changes in the PFCBs, in combination with radical trapping experiments, indicate that PFCB scission proceeds via a stepwise mechanismwith a 1,4-diradical intermediate, offering a potential mechanismfor localized functionalization and cross-linking in regions of high stress.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 03, 2011
- Accession Number
- ADA587221
Entities
People
- Hope M. Klukovich
- Scott T Iacono
- Stephen L Craig
- Zachary S. Kean
Organizations
- University of Illinois Urbana–Champaign