Radical Cage Effects in the Photochemical Degradation of Polymers:  In-Cage Trapping of Photochemically Generated Radical Cage Pairs in Polymer Model Compounds

1999 ◽  
Vol 32 (12) ◽  
pp. 3898-3906 ◽  
Author(s):  
Jonathan L. Male ◽  
Myungok Yoon ◽  
Anne G. Glenn ◽  
T. J. R. Weakley ◽  
David R. Tyler
Keyword(s):  
Photochemical Degradation ◽  
Polymer Model ◽  
Model Compounds ◽  
Cage Effects

The relative thermal stability of polymer model compounds

1962 ◽  
Vol 6 (19) ◽  
pp. 47-56 ◽  
Author(s):  
Desmond Sheehan ◽  
Alan P. Bentz ◽  
John C. Petropoulos
Keyword(s):  
Thermal Stability ◽  
Polymer Model ◽  
Model Compounds ◽  
Relative Thermal Stability ◽  
Thermal Stability Of

scholarly journals Photochemical Degradation of Short-Chain Chlorinated Paraffins in Aqueous Solution by Hydrated Electrons and Hydroxyl Radicals

2022 ◽  
Author(s):  
Brian DiMento ◽  
Cristina Tusei ◽  
Christoph Aeppli
Keyword(s):  
Organic Pollutants ◽  
Hydroxyl Radicals ◽  
Surface Waters ◽  
Rate Constants ◽  
Degradation Rate ◽  
Chlorine Content ◽  
Photochemical Degradation ◽  
Model Compounds ◽  
Chlorinated Paraffins ◽  
Hydrated Electrons

Short-chain chlorinated paraffins (SCCPs) are a complex mixture of polychlorinated alkanes (C10-C13, chlorine content 40-70%), and have been categorized as persistent organic pollutants. However, there are knowledge gaps about their environmental degradation, particularly the effectiveness and mechanism of photochemical degradation in surface waters. Photochemically-produced hydrated electrons (e-(aq)) have been shown to degrade highly chlorinated compounds in environmentally-relevant conditions more effectively than hydroxyl radicals (·OH), which can degrade a wide range of organic pollutants. This study aimed to evaluate the potential for e-(aq) and ·OH to degrade SCCPs. To this end, the degradation of SCCP model compounds was investigated under laboratory conditions that photochemically produced e-(aq) or ·OH. Resulting SCCP degradation rate constants for e-(aq) were on the same order of magnitude as well-known chlorinated pesticides. Experiments in the presence of ·OH yielded similar or higher second-order rate constants. Trends in e-(aq) and ·OH SCCP model compounds degradation rate constants of the investigated SCCPs were consistent with that of other chlorinated compounds, with higher chlorine content producing in higher rate constants for e-(aq) and lower for ·OH. Above a chlorine:carbon ratio of approximately 0.6, the e-(aq) second-order rate constants were higher than rate constants for ·OH reactions. Results of this study furthermore suggest that SCCPs are likely susceptible to photochemical degradation in sunlit surface waters, facilitated by dissolved organic matter that can produce e-(aq) and ·OH when irradiated.

Chemical Degradation of Membrane Polymer Model Compounds under Simulated Fuel Cell Conditions

2019 ◽  
Vol 33 (1) ◽  
pp. 883-888 ◽  
Author(s):  
David A. Schiraldi ◽  
Deepa Savant ◽  
Chun Zhou
Keyword(s):  
Fuel Cell ◽  
Chemical Degradation ◽  
Polymer Model ◽  
Model Compounds ◽  
Simulated Fuel

Cage Effects in the Photochemical Degradation of Polymers. Studies of Model Complexes with Different Chain Lengths

1997 ◽  
Vol 30 (20) ◽  
pp. 6404-6406 ◽  
Author(s):  
Jonathan L. Male ◽  
Britt E. Lindfors ◽  
Katharine J. Covert ◽  
David R. Tyler
Keyword(s):  
Photochemical Degradation ◽  
Model Complexes ◽  
Chain Lengths ◽  
Cage Effects

Irradiation effects on polymer-model compounds

1991 ◽  
Vol 37 (1) ◽  
pp. 29-35 ◽  
Author(s):  
Tadao Seguchi ◽  
Yosuke Katsumura ◽  
Nariyuki Hayashi ◽  
Naohiro Hayakawa ◽  
Naoyuki Tamura ◽  
...  
Keyword(s):  
Polymer Model ◽  
Irradiation Effects ◽  
Model Compounds
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