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Aging and Degradation of LDPE by Compact NMR
Author(s) -
Teymouri Yadollah,
Kwamen Rance,
Blümich Bernhard
Publication year - 2015
Publication title -
macromolecular materials and engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.913
H-Index - 96
eISSN - 1439-2054
pISSN - 1438-7492
DOI - 10.1002/mame.201500156
Subject(s) - low density polyethylene , materials science , fourier transform infrared spectroscopy , crystallization , polyethylene , degradation (telecommunications) , relaxation (psychology) , wax , phase (matter) , accelerated aging , polymer chemistry , chemical engineering , composite material , organic chemistry , chemistry , psychology , telecommunications , social psychology , computer science , engineering
Morphological and structural changes of commercial‐brand low‐density polyethylene induced by thermal aging for different times at different temperatures are studied by compact 1 H NMR relaxation, FTIR spectroscopy, and SEC including the impact of wax content. Two regimes were observed. The changes in phase composition and relaxation time suggest that thermally induced crystallization is predominant during aging and oxidation of LDPE below 100 °C while, after 28 d aging at 100 °C, oxidative degradation is predominant. This is in good agreement with carbonyl index and molecular weight variations evaluated by FTIR and SEC, respectively, which indicate multi‐stage oxidation during aging.