Highly Thermostable Dynamic Structures of Polyaramid Two-Dimensional Polymers

Abstract

This is the first comparative study of a chemically homologous series of linear and two-dimensional polyaramids at high temperatures. Detailed comparisons are made in the bulk and at free surface environments of the dynamical structures including ordered phases and hydrogen bonding statistics as functions of temperature. First-principles density functional theory molecular mechanics and dynamics methods agree quantitatively with the known behavior of linear poly(p-phenylene terephthalamide), more commonly known as Kevlar. The 2D polymer topology offers potential to design higher thermal resilience compared to legacy linear polymer topologies. At sufficient reticulation density, the hydrogen bonding in two-dimensional polymers significantly enhances aramid bond stability. Hydrogen-bonded 2D polymers, such as graphamid, are a unique material architecture for providing enhanced structural and thermomechanical stability. These results suggest that hydrogen-bonded 2D polymers offer significant advantages for combined light weight, high strength, and high temperature applications.

Catechol Sensing Performance of Pd-Functionalized Two-Dimensional Polyaramid: A DFT Investigation

“…These distinctive attributes collectively position 2DPA as highly promising candidates for diverse applications, specifically emphasizing their potential as sensors. 27 Recent advancements have highlighted 2DPA as a suitable material for hydrogen storage applications, as demonstrated by the first-principles studies. 28,29 The novelty of this material is underscored by its recent synthesis, with no prior reports on its applications.…”

“…The selection of 2DPA for detecting Cc in this study is driven by their inherent characteristics, such as a substantial surface-to-volume ratio, a sizable band gap, tunable chemical structures, and flexibility. These distinctive attributes collectively position 2DPA as highly promising candidates for diverse applications, specifically emphasizing their potential as sensors . Recent advancements have highlighted 2DPA as a suitable material for hydrogen storage applications, as demonstrated by the first-principles studies. , The novelty of this material is underscored by its recent synthesis, with no prior reports on its applications.…”

Highly Flexible Dielectric Films from Solution Processable Covalent Organic Frameworks**

“…Hydrazone-linked 2D COFs are chemically stable, [31] highly crystalline [32] materials reinforced with interlayer and intralayer hydrogen bonding [33,34] that originate from the NÀ H groups in their linkages. Previous reports have shown that hydrogen bonding in 2D COFs can have a positive effect on their surface area, bulk crystallinity, [35] thermal stability, [36] resistance to hydrolysis, [37] and mechanical strength. [18,38,39] Due to these factors, hydrazone-linked COFs and β-ketoenamine linked COFs that generate from tautamarization of hydrazone linkages [40,41] are excellent candidates for lightweight and strong materials that can be tuned for various types of applications.…”

Highly Flexible Dielectric Films from Solution Processable Covalent Organic Frameworks**

“…Hydrazone‐linked 2D COFs are chemically stable, [31] highly crystalline [32] materials reinforced with interlayer and intralayer hydrogen bonding [33,34] that originate from the N−H groups in their linkages. Previous reports have shown that hydrogen bonding in 2D COFs can have a positive effect on their surface area, bulk crystallinity, [35] thermal stability, [36] resistance to hydrolysis, [37] and mechanical strength [18,38,39] . Due to these factors, hydrazone‐linked COFs and β‐ketoenamine linked COFs that generate from tautamarization of hydrazone linkages [40,41] are excellent candidates for lightweight and strong materials that can be tuned for various types of applications.…”