High-permeability fluorinated polyimide microcapsules by vapor deposition polymerization

• Published in: Polymer (Guilford) Vol. 44; no. 4; pp. 995 - 1001
• Main Authors: Tsai, F.Y, Harding, D.R, Chen, S.H, Blanton, T.N
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-02-2003; Elsevier
• Subjects: Applied sciences; Exact sciences and technology; Fluorinated polyimide; Forms of application and semi-finished materials; Inertial confinement fusion; Miscellaneous; Polymer industry, paints, wood; Technology of polymers; Vapor deposited polyimide; Vapor deposited polyimide; Fluorinated polyimide; Inertial confinement fusion; Polyimide; Transport properties; Fluorine containing polymer; Microcapsule; Aromatic polymer; Temperature effect; Mechanical properties; Condensation polymerization; Experimental study; Cryogenic temperature; Gas permeability; Target; Vapor deposition; Manufacturing process; Amorphous state structure
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/S0032-3861(02)00787-5

Spherical microcapsules (∼1
mm in diameter and ∼1
μm in wall thickness) to be used as inertial confinement fusion targets were prepared from 6FDA–ODA polyimide by vapor deposition polymerization. Compared with the previously developed PMDA–ODA polyimide microcapsules, the 6FDA–ODA microcapsules were ∼50-fold more permeable to gases including He, D
2, O
2, N
2, Ar, and Ne, considerably more transparent in the UV–visible spectrum, and of marginally lower Young's modulus, tensile strength, and elongation at break. The microcapsules possessed amorphous morphology with an amorphous
d-spacing of 5.8
Å as determined by wide-angle X-ray diffraction. The cryogenic permeability of helium was measured between 133 and 295
K, and the activation energy for permeation was determined to be 12.3
kJ/mol.