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The effect of γ radiation on the physical structure and mechanical properties of ultrahigh molecular weight polyethylene
Author(s) -
Birkinshaw C.,
Buggy M.,
Daly S.,
O'neill M.
Publication year - 1989
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.1989.070381101
Subject(s) - crystallinity , materials science , irradiation , differential scanning calorimetry , ultimate tensile strength , amorphous solid , polyethylene , composite material , chemistry , crystallography , thermodynamics , physics , nuclear physics
Ultrahigh molecular weight polyethylene has been irradiated using a cobalt 60 source to give received dose between zeor and 50 Mrad. Irradiacted specimens were subjected to tensile characterization, dynamic mechanical analysis, and differential scanning calorimetry. Changes in tensile and dynamic mechnaical properties following irradiation arise from both molecular rearrangement and from increased crystallinity following scissionof long interlamella tie chains. The effects of post‐irradiation aging on mechanical properties are associated with increasing crystallinity resulting from decomposition of metastable groups formed in the amorphous region during irradiation. Irradiated materials have been subject to sinusoidal stressing between 0.275 and 0.55 of yield stress for 100,000 cycies, and changes in mechnaical and physical properties measured. Increased resistance to creep during stressing was observed with the irradiated materials, behavior which is consistent with previsouly observed changes in crystallinity and crosslink density. Overall property changes measured following stressing were small compared with those induced by the initial irradiation.