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Preparation and properties of polyimide films codoped with barium and titanium oxides
Author(s) -
Tong Yuejin,
Li Yuesheng,
Liu Jieping,
Ding Mengxian
Publication year - 2001
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.10118
Subject(s) - materials science , polyimide , dielectric , thermal stability , barium , titanium , barium titanate , chemical engineering , x ray photoelectron spectroscopy , thermal treatment , curing (chemistry) , polymer chemistry , composite material , layer (electronics) , metallurgy , optoelectronics , engineering
Polyimide hybrid films containing bimetalic compounds were obtained by codoping poly(amic acid) with a barium and titanium precursor prepared from BaCO 3 , Ti(OBu) 4 , and lactic acid followed by casting and thermal curing. FTIR, WAXD, and XPS measurements showed that barium and titanium precursor could be transformed to BaTiO 3 at a temperature above 650°C, while the mixed oxides were only found in hybrid films. The measurements of TEM and AFM indicated a homogeneous distribution of inorganic phase with particle sizes less than 50 nm. The hybrid films exhibited fairly high thermal stability, good optical transparency, and promising mechanical properties. The incorporation of 10 wt % barium and titanium oxide lowered surface and volume electrical resistivity by 2 and 5 orders, respectively, increasing dielectric constant from 3.5 to 4.2 and piezoelectric constant from 3.8 to 5.2 × 10 −12 c/N, relative to the nondoped polyimide film. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1810–1816, 2002