Chain-End Reactivity and Anisotropic Electronic Softening Define Candidate Design Targets in BPDA/4,4′-ODA Polyimide Insulation
- 1, Xi’an 710077, China;
- 2China State Key Laboratory of Electric Insulation and Power Equipment, , Xi’an 710049, China
Abstract
Identifying the molecular origins of thermal and electric-field response can guide polyimide insulation design. We combined an 18-film aromatic imide oligomer ensemble, reactive molecular dynamics, and signed finite-field r2SCAN-3c calculations to separate packing, chain-end chemistry, and directional electronic response. Independently initialized films exhibited a fivefold variation in probe-accessible volume, with distinct connected void geometries at similar accessible fractions. Across sixteen 5 ps thermal trajectories, terminal imide N–H sites accounted for 20 of 21 persistent reference-bond losses; the nonterminal inventory contained 14 new C–O connectivities and one C–N loss. In six matched film pairs, nonterminal records increased from 2 to 5 at 1600 K and from 12 to 19 at 1800 K between 5 and 10 ps, revealing the growing contribution of nonterminal rearrangement. Trajectories extending to 20 ps also resolved the onset of increased mass escape. At ±2 V nm−1, the isolated ether-linked bis-imide fragment showed 0.342–0.841 eV frontier-gap narrowing across six directions, compared with at most 0.049 eV for the imide fragment, despite overlapping size-normalized induced responses. Together, these results identify chain termination and segment orientation as candidate design variables and provide quantitative descriptors for morphology-matched thermal comparisons and orientation-resolved electronic screening.
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BibTeX
@article{bai2026chainend,
title = {{Chain-End Reactivity and Anisotropic Electronic Softening Define Candidate Design Targets in BPDA/4,4′-ODA Polyimide Insulation}},
author = {Dongqiao Bai and Tianyu Lin},
journal = {Nanomaterials (Basel, Switzerland)},
year = {2026},
month = sep,
doi = {10.3390/nano16191236},
url = {https://europepmc.org/article/PMC/PMC13666579},
note = {CC BY},
}
RIS
TY - JOUR
TI - Chain-End Reactivity and Anisotropic Electronic Softening Define Candidate Design Targets in BPDA/4,4′-ODA Polyimide Insulation
AU - Dongqiao Bai
AU - Tianyu Lin
PY - 2026
DA - 2026/09/30
JO - Nanomaterials (Basel, Switzerland)
DO - 10.3390/nano16191236
UR - https://europepmc.org/article/PMC/PMC13666579
AB - Identifying the molecular origins of thermal and electric-field response can guide polyimide insulation design. We combined an 18-film aromatic imide oligomer ensemble, reactive molecular dynamics, and signed finite-field r2SCAN-3c calculations to separate packing, chain-end chemistry, and directional electronic response. Independently initialized films exhibited a fivefold variation in probe-accessible volume, with distinct connected void geometries at similar accessible fractions. Across sixteen 5 ps thermal trajectories, terminal imide N–H sites accounted for 20 of 21 persistent reference-bond losses; the nonterminal inventory contained 14 new C–O connectivities and one C–N loss. In six matched film pairs, nonterminal records increased from 2 to 5 at 1600 K and from 12 to 19 at 1800 K between 5 and 10 ps, revealing the growing contribution of nonterminal rearrangement. Trajectories extending to 20 ps also resolved the onset of increased mass escape. At ±2 V nm−1, the isolated ether-linked bis-imide fragment showed 0.342–0.841 eV frontier-gap narrowing across six directions, compared with at most 0.049 eV for the imide fragment, despite overlapping size-normalized induced responses. Together, these results identify chain termination and segment orientation as candidate design variables and provide quantitative descriptors for morphology-matched thermal comparisons and orientation-resolved electronic screening.
SN - 2079-4991
ER -