1. Restriction of Spin Probe Motions in Polymer Composites Due to Chemical Factors
- Author
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J. Tino, Ivan Chodák, Pavel Mach, and Z. Hloušková
- Subjects
chemistry.chemical_classification ,Base (chemistry) ,Polymers and Plastics ,Hydrogen bond ,Nitroxyl ,General Chemistry ,Polyethylene ,Spin probe ,chemistry.chemical_compound ,chemistry ,Polyamide ,Polymer chemistry ,Materials Chemistry ,Ceramics and Composites ,Physical chemistry ,Molecule ,Hyperfine structure - Abstract
Hyperfine splitting constants of the nitroxyl radical, with and without hydrogen bonds to the surrounding molecules, have been calculated using the UHF method on a 6-31G * base. In polyethylene filled with silica, hydrogen bonds are formed between nitroxyl radicals and -OH groups of the filler. The formation of hydrogen bonds leads to a change in the A ZZ value from 3.33 mT for an isolated nitroxyl radical to 3.83 mT for a radical with a hydrogen bond. The relevant values as measured experimentally are 3.4 and 4.0 mT, respectively. The same procedure was used to calculate the theoretical A ZZ value for a nitroxyl radical interacting with polyamide via a hydrogen bond. The value was found to be 3.63 mT (experimental value= 3.6 mT)
- Published
- 1994
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