TY - JOUR
T1 - Pure Hydrolysis of Polyamides: A Comparative Study
AU - Brette, Mathis Mortensen
AU - Holm, Allan Hjarbæk
AU - Drozdov, Aleksey D.
AU - Christiansen, Jesper de Claville
PY - 2024/2
Y1 - 2024/2
N2 - Polyamides (PAs) undergo local environmental degradation, leading to a decline in their mechanical properties over time. PAs can experience various forms of degradation, such as thermal degradation, oxidation, hydrothermal oxidation, UV oxidation, and hydrolysis. In order to better comprehend the degradation process of PAs, it is crucial to understand each of these degradation mechanisms individually. While this review focuses on hydrolysis, the data from degrading similar PAs under pure thermal oxidation and/or hydrothermal oxidation are also collected to grasp more perspective. This review analyzes the available characterization data and evaluates the changes in molecular weight, crystallinity, chemical structure, and mechanical properties of PAs that have aged in oxygen-free water at high temperatures. The molecular weight and mechanical strength decrease as the crystallinity ratio rises over aging time. This development is occurring at a slower rate than degradation in pure thermal oxidation. By combining the data for the changes in mechanical properties with the ones for molecular weight and crystallinity, the point of embrittlement can be not only predicted, but also modeled. This prediction is also shown to be dependent on the fibers, additives, types of PA, pH, and more.
AB - Polyamides (PAs) undergo local environmental degradation, leading to a decline in their mechanical properties over time. PAs can experience various forms of degradation, such as thermal degradation, oxidation, hydrothermal oxidation, UV oxidation, and hydrolysis. In order to better comprehend the degradation process of PAs, it is crucial to understand each of these degradation mechanisms individually. While this review focuses on hydrolysis, the data from degrading similar PAs under pure thermal oxidation and/or hydrothermal oxidation are also collected to grasp more perspective. This review analyzes the available characterization data and evaluates the changes in molecular weight, crystallinity, chemical structure, and mechanical properties of PAs that have aged in oxygen-free water at high temperatures. The molecular weight and mechanical strength decrease as the crystallinity ratio rises over aging time. This development is occurring at a slower rate than degradation in pure thermal oxidation. By combining the data for the changes in mechanical properties with the ones for molecular weight and crystallinity, the point of embrittlement can be not only predicted, but also modeled. This prediction is also shown to be dependent on the fibers, additives, types of PA, pH, and more.
KW - aging
KW - crystallization
KW - degradation
KW - embrittlement
KW - hydrolysis
KW - polyamide
UR - http://www.scopus.com/inward/record.url?scp=85187270770&partnerID=8YFLogxK
U2 - 10.3390/chemistry6010002
DO - 10.3390/chemistry6010002
M3 - Review article
SN - 2624-8549
VL - 6
SP - 13
EP - 50
JO - Chemistry
JF - Chemistry
IS - 1
ER -