Abstract:A high-barrier polyimide (2,7-CPI) was synthesized through the polymerization of pyromellitic dianhydride (PMDA) and a novel diamine (2,7-CDA) containing carbazole moiety. The synthesized diamine and polyimide were fully characterized by elemental analyses, FTIR and NMR. The 2,7-CPI displays very attractive barrier performances, with oxygen transmission rate (OTR) and water vapor transmission rate (WVTR) low to 0.14 cm3·m−2·day−1 and 0.05 g·m−2·day−1, respectively. Meanwhile, 2,7-CPI also exhibits exceptional … Show more
“… a Units of (cm 3 (STP)·cm −3 ·cm Hg −1 ); b (10 −8 ·cm 2 ·s −1 ); c (10 −8 cm 3 (STP)·cm·cm −2 ·s −1 ·cm Hg −1 ); d Data comes from Ref. [ 56 ]. …”
Section: Resultsmentioning
confidence: 99%
“…Solubility coefficients, diffusion coefficients and permeability coefficients for H 2 O and O 2 in NAPPI and Kapton. Units of (cm 3 (STP)•cm −3 •cm Hg −1 ); b (10 −8 •cm 2 •s −1 ); c (10 −8 cm 3 (STP)•cm•cm −2 •s −1 •cm Hg −1 ); d Data comes from Ref [56]…”
In order to meet the increasingly stringent requirements for heat resistance and barrier properties in the packaging and electronic device encapsulation field. A high-barrier polyimide (NAPPI) contains naphthalene ring and amide group was prepared by polymerization of a novel diamine (NAPDA) and pyromellitic dianhydride. The structure and properties of diamine monomers and polymers were characterized. Results show that the NAPPI exhibits superior barrier properties with extremely low water vapor and oxygen transmission rate values of 0.14 g·m−2·day−1 and 0.04 cm3·m−2·day−1, respectively. In addition, the NAPPI presents outstanding mechanical properties and thermal stability as well. This article attempts to explore the relationship between NAPPI structure and barrier properties by combining experiment and simulation. Studies on positron annihilation lifetime spectroscopy, Wide angle X-ray diffractograms and molecular dynamics simulations prove that the NAPPI has smaller interplanar spacing and higher chain regularity. In addition, the strong chain rigidity and interchain cohesion of NAPPI due to the presence of the rigid naphthalene ring and a large number of hydrogen bond interactions formed by amide groups result in compact chain packing and smaller free volume, which reduces the solubility and diffusibility of small molecules in the matrix. In general, the simulation results are consistent with the experimental results, which are important for understanding the barrier mechanism of NAPPI.
“… a Units of (cm 3 (STP)·cm −3 ·cm Hg −1 ); b (10 −8 ·cm 2 ·s −1 ); c (10 −8 cm 3 (STP)·cm·cm −2 ·s −1 ·cm Hg −1 ); d Data comes from Ref. [ 56 ]. …”
Section: Resultsmentioning
confidence: 99%
“…Solubility coefficients, diffusion coefficients and permeability coefficients for H 2 O and O 2 in NAPPI and Kapton. Units of (cm 3 (STP)•cm −3 •cm Hg −1 ); b (10 −8 •cm 2 •s −1 ); c (10 −8 cm 3 (STP)•cm•cm −2 •s −1 •cm Hg −1 ); d Data comes from Ref [56]…”
In order to meet the increasingly stringent requirements for heat resistance and barrier properties in the packaging and electronic device encapsulation field. A high-barrier polyimide (NAPPI) contains naphthalene ring and amide group was prepared by polymerization of a novel diamine (NAPDA) and pyromellitic dianhydride. The structure and properties of diamine monomers and polymers were characterized. Results show that the NAPPI exhibits superior barrier properties with extremely low water vapor and oxygen transmission rate values of 0.14 g·m−2·day−1 and 0.04 cm3·m−2·day−1, respectively. In addition, the NAPPI presents outstanding mechanical properties and thermal stability as well. This article attempts to explore the relationship between NAPPI structure and barrier properties by combining experiment and simulation. Studies on positron annihilation lifetime spectroscopy, Wide angle X-ray diffractograms and molecular dynamics simulations prove that the NAPPI has smaller interplanar spacing and higher chain regularity. In addition, the strong chain rigidity and interchain cohesion of NAPPI due to the presence of the rigid naphthalene ring and a large number of hydrogen bond interactions formed by amide groups result in compact chain packing and smaller free volume, which reduces the solubility and diffusibility of small molecules in the matrix. In general, the simulation results are consistent with the experimental results, which are important for understanding the barrier mechanism of NAPPI.
“…Unfortunately, the performance of commercial PI films, such as Kapton H® and Upilex S®, cannot meet the abovementioned requirement for flexible OLED substrates. Therefore, further improvement of T g and reduction of CTE have become hot research topics in the field of PI film materials 13–22 . Previous studies have shown that the intrinsic method, i.e., designing the molecular chain structure of PI, has the most obvious effect on the increase of T g and reduction of CTE 23–25 .…”
Section: Introductionmentioning
confidence: 99%
“…Therefore, further improvement of T g and reduction of CTE have become hot research topics in the field of PI film materials. [13][14][15][16][17][18][19][20][21][22] Previous studies have shown that the intrinsic method, i.e., designing the molecular chain structure of PI, has the most obvious effect on the increase of T g and reduction of CTE. [23][24][25] Yang et al prepared a series of PI films with pyridine and pyrimidine structures.…”
To tolerate high processing temperature during the fabrication of low-temperature polycrystalline silicon thin-film transistors (LTPS-TFT) in flexible OLED devices, the polyimide (PI) films, which are used as substrate, should have ultra-high glass transition temperature (T g > 450 C) and ultra-low coefficient of thermal expansion (CTE at 0-5 ppm K À1 ). In this paper, two novel heterocyclic monomers, namely, N,N'-(xanthone-2,7-diyl)bis(4-aminobenzamide) (p-DAXBA) and N,N'-(xanthone-2,7-diyl)bis(3-aminobenzamide) (m-DAXBA), which contain a xanthone moiety, are prepared and polycondensed with pyromellitic dianhydride (PMDA), respectively. PI films (PIa and PIb) with intrinsic high T g and low CTE are designed from the perspective of rigid conjugate xanthone structure and hydrogen bonding interaction. It is found that the PIa films prepared by p-DAXBA have better linear structure of molecular chains and show relatively higher T g and lower CTE. The T g of PIa-40 is greater than 450 C, and CTE can reach as low as 2.7 ppm K À1 , tensile strength of 179 MPa, modulus of 5.67 GPa, indicating potential application prospect as a flexible OLED substrate.
“…Morpholinyl, hexafluoroisopropyl (C[CF 3 ] 2 ), pyridine heterocyclic and fluorene “cardo” pendant non coplanar structures were introduced into the main chain of polyimide to investigate the influence of chemical structure under nitrogen atmosphere, physical properties and gas transport properties tested by various characterization methods. In addition, molecular dynamics simulation has emerged as an important theoretical tool to characterize the structural characteristics and gas permeation performances of polyimides at the atomic level, which is difficult to achieve by experimental means 34,40 . And a detailed molecular simulation study was carried out by Materials Studio 9 to comprehensively explore the relationship between chemical structures, free volume and gas transport properties of polymers.…”
Through one-step copolymerization of 4-(4-[1-morpholinyl]phenyl)-2,6-bis (4-aminophenyl)pyridine (MPAP), 9,9-bis(4-aminophenyl)fluorene (BAFL), and (4,4 0 -hexafluoroisopropylidene)diphthalic anhydride (6FDA), a series of polyimides containing morpholine group, pyridine ring, fluorene "cardo" pendant and hexafluoroisopropyl group are obtained. The synthesized polyimides have good thermal stability, high transparency, outstanding hydrophobicity and excellent solubility in not only high-boiling solvents but also low boilingpoint solvents. Furthermore, polyimide films have large molecular chain spacing, which is consistent with the free volume calculated by molecular simulation. Consequently, polyimide membranes display better gas permeability values of CO 2 (up to 24.47 Barrer) and He (up to 45.04 Barrer), and good ideal gas selectivity values of CO 2 /N 2 (up to 15.33 Barrer) and He/N 2 (up to 23.89 Barrer), which also shows potential application of polyimide matrix materials in gas separation.
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