Atmospheric gas concentrations in polymers
Authors
Centanni, Michael Anthony
Issue Date
1977-05
Type
Electronic thesis
Thesis
Thesis
Language
ENG
Keywords
Solid state physics
Alternative Title
Abstract
Paramagnetic oxygen molecules, present as impurities, have been detected by pulsed nuclear magnetic resonance techniques, magnetic susceptibility measurements, and mass measurements in polystyrene, linear polyethylene, and branched polyethylene. The spin-lattice relaxation time (T₁) of the protons in the polymers changes from about one second to hundreds of seconds when oxygen is removed from the samples by gentle baking in a vacuum. The baked samples are subsequently exposed to air for certain intervals of time, and then T₁ is again determined. This technique has yielded information concerning the relative-rates at which molecular oxygen diffuses into the three polymers. In fact, molecular oxygen is seen to diffuse much more rapidly into the two polyethylene samples than into the polystyrene sample.
Description
May 1977
School of Science
School of Science
Full Citation
Publisher
Rensselaer Polytechnic Institute, Troy, NY