Coupled aging effects in nanofiber-reinforced siloxane foams

Journal Article · Thu Jan 11 00:00:00 EST 2018 · Polymer Degradation and Stability

DOI:https://doi.org/10.1016/j.polymdegradstab.2018.01.010· OSTI ID:1417828

Labouriau, Andrea ^[1]; Robison, Tom ^[2]; Geller, Drew Adam ^[1]; Cady, Carl Mcelhinney ^[1]; Pacheco, Adam Nicholas ^[1]; Stull, Jamie Ann ^[1]; Dumont, Joseph Henry ^[1]

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1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2. Kansas City National Security Campus, Kansas City, MO (United States)

Here, this study investigates the combined effects of ionizing radiation and thermal treatments on the aging of siloxane foams containing small amounts of carbon nanofibers. Our siloxane foams were exposed to accelerated aging conditions for more than two years, resulting in very low dose rates. In addition, foams were aged under compressive load to evaluate the strength of the porous microstructure. Samples were characterized by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), Mössbauer, mass spectroscopy, electron paramagnetic resonance spectroscopy (EPR), solvent swelling, imaging techniques, uniaxial compressive load testing and tear testing. No significant changes in thermal stability or chemistry of the accelerated aged foam were observed, although gas evolution was detected. Changes in crystallization levels at low temperatures, microstructure, and mechanical properties were observed for foams with and without carbon nanofibers. In particular, foams aged under compressive load showed irreversible deformation of the porous microstructure. This study demonstrates that aging effects were enhanced when thermal and radiolysis were coupled together and that the addition of carbon nanofibers did not improve aging effects.

• Research Organization: Los Alamos National Laboratory (LANL)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC52-06NA25396
• OSTI ID: 1417828
• Report Number(s): LA-UR-17-30401
• Journal Information: Polymer Degradation and Stability, Journal Name: Polymer Degradation and Stability Vol. 149; ISSN 0141-3910
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
Accelerated aging
Carbon nanofibers
Polysiloxanes
RTV foams
Radiolysis