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The mass loss mechanisms of polymers in a radio frequency induced atomic oxygen environment
Author(s) -
Whitaker A. F.,
Jang B. Z.
Publication year - 1993
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1993.070480804
Subject(s) - polymer , activation energy , oxygen , polymer degradation , atomic oxygen , analytical chemistry (journal) , degradation (telecommunications) , atomic mass , chemistry , materials science , polymer chemistry , composite material , organic chemistry , atomic physics , telecommunications , physics , computer science
The effects of atomic oxygen on several classes of polymers were investigated. Particular attention was directed to the determination of erosion or mass loss mechanisms in relation to the physical and chemical structures of polymers. Nineteen polymeric materials were exposed to a thermal atomic oxygen environment at fluxes of 10 22 atoms/m 2 −sec. Bulk material temperatures were maintained at 10, 45, and 75°C During exposure. Mass loss rate, which was characteristic of the type of polymer, was proportional to the exposure area and was linear in time for most polymers except for Mylar, which produced a shielding high temperature ash. The mass loss rate for the atomic oxygen degradation of polymers was related to the bond strength of the polymer structure and to the shielding effect of pendant structures. This degradation process was strongly dependent on polymer temperature. Activation energies ranged from 1 to 48 KJ / mole and were found to be related to gaseous diffusion in polymers. Frequency factors were proportional to activation energies. Activation energies were found to increase with increased mol wt and crosslinking. An equation was developed relating exposure area, atomic oxygen flux, frequency factor, and activation energy to the rate of polymer mass loss. © 1993 John Wiley & Sons, Inc.