Related Experiment Video
Updated: Jan 5, 2026

Disentangling High Strength Copolymer Aramid Fibers to Enable the Determination of Their Mechanical Properties
Published on: September 1, 2018
Hydrogen Bond Preserving Stress Release Mechanism Is Key to the Resilience of Aramid Fibers
Subodh C Tiwari1, Kohei Shimamura2, Ankit Mishra1
1Collaboratory for Advanced Computing and Simulations, Department of Physics & Astronomy, Department of Computer Science, Department of Chemical Engineering & Materials Science, and Department of Biological Sciences , University of Southern California , Los Angeles , California 90089-0242 , United States.
Abstract:
Ab initio molecular dynamics simulations of shock loading on poly(p-phenylene terephthalamide) (PPTA) reveal stress release mechanisms based on hydrogen bond preserving structural phase transformation (SPT) and planar amorphization. The SPT is triggered by [100] shock-induced coplanarity of phenylene groups and rearrangement of sheet stacking leading to a novel monoclinic phase. Planar amorphization is generated by [010] shock-induced scission of hydrogen bonds leading to disruption of polymer sheets, and trans-to-cis conformational change of polymer chains. In contrast to the latter, the former mechanism preserves the hydrogen bonding and cohesiveness of polymer chains in the identified novel crystalline phase preserving the strength of PPTA. The interplay between hydrogen bond preserving (SPT) and nonpreserving (planar amorphization) shock release mechanisms is critical to understanding the shock performance of aramid fibers.
More Related Videos
07:15A Testing Platform for Durability Studies of Polymers and Fiber-reinforced Polymer Composites under Concurrent Hygrothermo-mechanical Stimuli
Published on: December 11, 2014
10:01In Situ High Pressure Hydrogen Tribological Testing of Common Polymer Materials Used in the Hydrogen Delivery Infrastructure
Published on: March 31, 2018
Related Concept Videos
Residual Stresses
Hooke's Law
Plastic Behavior
Hydrogen Bonds
Hydrogen Bonds
Hydrogen Bonds Control the World!
Because hydrogen has very weak electronegativity when it binds with a strongly electronegative atom, such as oxygen or nitrogen, electrons in the bond are unequally shared....
Stress-Strain Diagram - Ductile Materials