Confinement Effects on Polymer Degradation in Nanocomposites
Abstract
While thermal stability is crucial to manufacturing reliable aerospace composite materials, the mechanism is highly complex and often intrinsic to the combinations of polymers and fillers. A recent report demonstrated that nanocomposite with extremely high loading of silica nanoparticles significantly slowed down the degradation kinetics of commodity polymer, polystyrene (PS). However, the underlying mechanism is unclear due to a lack of systematic study of other polymers-fillers which would alter interfacial interactions, and a lack of fundamental study on degradation driving forces under confinement, so-called nanoconfinement effect. To this end, this proposal aims to uncover the effects of nanoconfinement on thermal degradation of polymers in nanocomposites, focusing on thermodynamics and kinetics contributions. To establish a platform to obtain thermophysical insights for the thermal stability of polymer nanocomposites, our objectives are to study 1) thermodynamics of degradation via isothermal tests; 2) decomposition kinetics by varying heating rates; and apply 3) beyond model systems. This study leverages the PI’s unique instrumentations of flash differential scanning calorimetry (DSC) and mass spectrometry-equipped rapid thermal processor to elucidate the confinement effect on polymer degradation from thermodynamics and kinetics perspectives, which will be applied to other nanocomposite systems. A model system is carefully chosen to deconvolute the effects of interfacial interaction and geometric confinement by using spherical silica nanoparticles with diameters of 5- 100 nm. The surface chemistry of the silica can be easily tuned from hydrophilic to hydrophobic by using the hydroxyl group as a reaction handle. Such systematic investigation will inform the future design of nanocomposite materials that can be stable at elevated temperatures.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 29, 2024
- Source ID
- FA95502310201
Entities
People
- Reika Katsumata
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of Massachusetts