Coupling effects of gamma irradiation and absorbed moisture on silicone foam

Polymer Degradation through Chemical Change: A Quantum-based Test of Inferred Reactions in Irradiated Polydimethylsiloxane

“…Despite these characteristics, PDMS is not impervious to chemical damage and it can interact with other materials. Common vectors for degradation arise from the ready uptake of environmental water [4][5][6][7] or absorption of radiation. [7][8][9][10][11][12] Understanding the degradation responses of PDMS has enormous practical applications, ranging from assessing environmental ima Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, United States; E-mail: kroonblawd1@llnl.gov pacts [13][14][15] to establishing models for the aging and lifetime prediction of silicone components.…”

“…Common vectors for degradation arise from the ready uptake of environmental water [4][5][6][7] or absorption of radiation. [7][8][9][10][11][12] Understanding the degradation responses of PDMS has enormous practical applications, ranging from assessing environmental ima Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, United States; E-mail: kroonblawd1@llnl.gov pacts [13][14][15] to establishing models for the aging and lifetime prediction of silicone components. [4][5][6][7][8][9][10][11][12]16,17 Ionizing radiation is a common cause for polymer degradation that can arise during component sterilization, 1,18,19 as a consequence of planned operation conditions, and as a driver in accelerated aging studies.…”

“…[7][8][9][10][11][12] Understanding the degradation responses of PDMS has enormous practical applications, ranging from assessing environmental ima Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, United States; E-mail: kroonblawd1@llnl.gov pacts [13][14][15] to establishing models for the aging and lifetime prediction of silicone components. [4][5][6][7][8][9][10][11][12]16,17 Ionizing radiation is a common cause for polymer degradation that can arise during component sterilization, 1,18,19 as a consequence of planned operation conditions, and as a driver in accelerated aging studies. [7][8][9][10][11][12] In 1955, Charlesby proposed 20 a set of reaction schemes for crosslinking in irradiated PDMS that were quickly refined by others 21,22 and were based on IR vibrational spectroscopy, titration, mass spectra of off-gassing species, and chromatography (see Figure 1).…”

“…[4][5][6][7][8][9][10][11][12]16,17 Ionizing radiation is a common cause for polymer degradation that can arise during component sterilization, 1,18,19 as a consequence of planned operation conditions, and as a driver in accelerated aging studies. [7][8][9][10][11][12] In 1955, Charlesby proposed 20 a set of reaction schemes for crosslinking in irradiated PDMS that were quickly refined by others 21,22 and were based on IR vibrational spectroscopy, titration, mass spectra of off-gassing species, and chromatography (see Figure 1). These reactions respectively connect the evolution of hydrogen (H 2 ), methane (CH 4 ), and ethane (C 2 H 6 ) with the formation of silethylene (Si-C-C-Si), silmethylene (Si-C-Si), and silicon-silicon (Si-Si) crosslinks.…”

A Quantum-Based Approach to Predict Primary Radiation Damage in Polymeric Networks

“…915 Nuclear magnetic and electron paramagnetic resonance experiments provide some of the most direct measures of time-and dose-dependent chemistry and network changes in irradiated polymers. 12,13,1619 Atomistic modeling techniques such as reactive molecular dynamics (MD) can provide insight into underlying network-altering chemistry in polymers, 15,2028 but upscaling these insights to inform models for macroscale responses is challenging. A desirable foundation for multiscale modeling of radiation damage in polymers would incorporate accurate high throughput sampling of atomic-scale chemistry and an automated scheme for extracting statistics on changes to the network.…”