Preparation and properties of polyimide films codoped with barium and titanium oxides

Abstract

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 ϫ 10 Ϫ12 c/N, relative to the nondoped polyimide film.

UV‐Curable Organic‐Inorganic Hybrid Film Coatings Based on Epoxidized Cyclohexene Derivatized Linseed Oil

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] However, most of these coatings were thermal cured and not photo-polymerized. As photopolymerization of the organic phase is much faster than the hydrolysis of TEOS, [25] to facilitate a rapid formation of the inorganic network and to avoid volatilization of the TEOS monomers, TEOS oligomers were used instead of monomer.…”

“…Increased tensile strength, hardness and adhesion to metal substrate have previously been reported in hybrid coatings. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]18] Increased tensile strength and hardness have been attributed to the increased crosslink density, which has in turn been attributed to the interaction between the organic and inorganic phase. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]18] Both the ring opening polymerization of epoxidized cyclohexene derivatized linseed oil (ECLO) and the sol-gel reactions of TEOS oligomers were acid catalyzed, resulting in cocomitant curing of both the organic and inorganic phases.…”

“…However, different systems have different optimum sol-gel precursor contents [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]18] which depend on the chemical structures of the organic and inorganic materials. To balance the tensile properties, fracture toughness, hardness, adhesion, impact and abrasion resistance, 15 wt.-% TEOS oligomer content is the optimum for this UV-curing TEOS/ECLO system.…”

“…To balance the tensile properties, fracture toughness, hardness, adhesion, impact and abrasion resistance, 15 wt.-% TEOS oligomer content is the optimum for this UV-curing TEOS/ECLO system. Compared to most previous reports, [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] oligomerized precursors instead of precursor monomers were used to facilitate the rapid formation of the inorganic network. Kinetic studies of the hybrid composite were conducted, which indicated that TEOS oligomer can increase the curing speed of the hybrid compound when it reaches a certain content (15 wt.-% in this case).…”

Corrosion Resistance Nano-hybrid Sol–Gel Coating on Steel Sheet

“…Various organo metal precursors based on silicone, titanium, aluminium, and zirconium have been used in sol-gel process for synthesis of the inorganic part. [1][2][3][4][5][6] The hybrid materials combine some advantages of organic polymers (easy processing with conventional techniques, elasticity and organic functionalities) with properties of inorganic oxides (hardness, thermal and chemical stability, and transparency. 7) Most of the organic-inorganic hybrid materials reported in literature is thermally cured.…”