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Hydrothermal aging mechanisms of aramid fibers via synchrotron small‐angle X‐ray scattering and dynamic thermal mechanical analysis
Author(s) -
Li ChangSheng,
Zhan MaoSheng,
Huang XianCong,
Zhou Hong,
Li Yan
Publication year - 2012
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.38419
Subject(s) - small angle x ray scattering , dynamic mechanical analysis , materials science , composite material , thermal analysis , scattering , ultimate tensile strength , synchrotron , aramid , glass transition , thermal , polymer , fiber , optics , thermodynamics , physics
In this study, synchrotron small‐angle X‐ray scattering (SAXS) and dynamic mechanical thermal analysis (DMTA) were used to evaluate the aging behavior of microfibrils and nanovoids. The effects of such structures on the tensile strength were also investigated. We investigated the correlation length of the fibril interface by fitting the SAXS intensity using the Debye–Bueche method. The orientation and size of the voids were determined with Ruland's streak method. The results show that the correlation length decreased with aging time at 90°C. Voids formed after aging at high temperatures for prolonged periods. In addition, the orientation of the 10 Å voids changed with the degree of degradation. DMTA results revealed a new transition temperature for the aged fibers. A model based on the SAXS and DMTA results is proposed to illustrate the hydrothermal aging mechanism. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013