Abstract
This effort provides a multifaceted analysis of the structural changes and material dynamics of thermally driven softening and curing of three distinct phthalonitrile (PN) resins that cross-link into thermally stable and oxidation-resistant thermosets. Although this material system has yielded a large subset of fire-retardant composites that require facile processing and low-temperature curing, to date, insufficient information had been available on the fundamental processes that drive their softening and curing stages. Our approach conducted a complementary analysis the chemistry, monomer mobility, and rheology of three PN polymers in order to correlate the curing processes with corresponding structural and behavioral transformations of thermosets. We focused on PNs with a bisphenol S backbone, a bisphenol A (PEEKTM-like) backbone, and a resveratrol backbone. We relied on quasi-elastic neutron scattering (QENS) in order to analyze the in situ dynamics and self-diffusion properties of PN monomers, and to track changes in their mobilities during cross-linking and staging. Our analysis facilitates proper control over the staging and final curing of these resins and enables more efficient processing of these thermosets.
Original language | English |
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Pages (from-to) | 3419-3431 |
Number of pages | 13 |
Journal | Journal of Polymer Science |
Volume | 58 |
Issue number | 24 |
DOIs | |
State | Published - Dec 15 2020 |
Funding
National Science Foundation, Grant/Award Number: DMR‐1508249; Laboratory Directed Research and Development; U.S. Department of Energy, Office of Basic Energy Sciences; National Academy of Sciences; Naval Innovative Science & Engineering (NISE); U.S. Naval Research Laboratory (NRL) Funding information This effort was partially funded by the U.S. Naval Research Laboratory (NRL) and its Naval Innovative Science & Engineering (NISE) workforce development program. Boris Dyatkin and Tristan Butler received funding from the National Academy of Sciences Research Associateship Program. Boris Dyatkin was also supported by the Karles Fellowship (NISE workforce development program). Naresh C. Osti was supported by the U.S. Department of Energy, Office of Basic Energy Sciences. Oak Ridge National Laboratory is managed by UT-Battelle, LLC, for U.S. DOE under Contract No. DE-AC05-00OR22725. QClimax is a part of the Integrated Computational Environment Modeling and Analysis of Neutron Data (ICE-MAN) (LDRD 8237) project, funded by the Laboratory Directed Research and Development program at ORNL. Experiments on HFBS at NIST Center for Neutron Research (NCNR) were supported in part by the National Science Foundation under Agreement No. DMR-1508249. Certain commercial material suppliers are identified in this article to foster understanding. Such identification does not imply recommendation or endorsement by the National Institute of Standards and Technology, nor does it imply that the materials or equipment identified are necessarily the best available for the purpose. This effort was partially funded by the U.S. Naval Research Laboratory (NRL) and its Naval Innovative Science & Engineering (NISE) workforce development program. Boris Dyatkin and Tristan Butler received funding from the National Academy of Sciences Research Associateship Program. Boris Dyatkin was also supported by the Karles Fellowship (NISE workforce development program). Naresh C. Osti was supported by the U.S. Department of Energy, Office of Basic Energy Sciences. Oak Ridge National Laboratory is managed by UT‐Battelle, LLC, for U.S. DOE under Contract No. DE‐AC05‐00OR22725. QClimax is a part of the Integrated Computational Environment Modeling and Analysis of Neutron Data (ICE‐MAN) (LDRD 8237) project, funded by the Laboratory Directed Research and Development program at ORNL. Experiments on HFBS at NIST Center for Neutron Research (NCNR) were supported in part by the National Science Foundation under Agreement No. DMR‐1508249. Certain commercial material suppliers are identified in this article to foster understanding. Such identification does not imply recommendation or endorsement by the National Institute of Standards and Technology, nor does it imply that the materials or equipment identified are necessarily the best available for the purpose.
Keywords
- cross-linking
- neutron scattering
- polymer dynamics
- resin
- rheometry
- self-diffusion
- thermoset