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Aging of polyamide 11. Part 1: Evaluating degradation by thermal, mechanical, and viscometric analysis
Author(s) -
Mazan Tobiasz,
Berggren Randi,
Jørgensen Jens Kjær,
Echtermeyer Andreas
Publication year - 2015
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.41971
Subject(s) - thermogravimetric analysis , differential scanning calorimetry , viscometer , crystallinity , glass transition , materials science , ultimate tensile strength , polyamide , dynamic mechanical analysis , composite material , plasticizer , thermomechanical analysis , thermal analysis , degradation (telecommunications) , polymer , viscosity , thermal , chemistry , thermodynamics , organic chemistry , thermal expansion , physics , telecommunications , computer science
Hydrolytic degradation at elevated temperatures is a key reason for failure in offshore flexible risers. In this article, the aging of polyamide 11 in deoxygenated water at 90°C and 120°C was studied. Tensile and dynamic mechanical thermal analysis tests were performed to measure changes in mechanical properties. Viscometry, gravimetric measurements, differential scanning calorimetry, and thermogravimetric analysis were used to link these properties with morphological changes. General trends are increased stiffness, tensile strength, and glass transition temperature as well as decreased glassy state damping efficiency with increased aging times. Changes can be initially ascribed to plasticizer depletion and then to interplay between molecular weight decrease and crystallinity increase. Viscosity at hydrolysis equilibrium indicates that brittle failure typically involves oxidation or UV exposure. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 41971.