Polysulfone Modified Thermoplastic Polyimide Segmented Copolymer Matrix Resin Systems

Wilkens, D.L.; Arnold, C.; Jurek, M. J.; Rogers, Martin E.; McGrath, James E.

doi:10.1177/089270579000300101

Cited by 7 publications

(2 citation statements)

References 4 publications

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“…Figure22. 'H NMR spectra from the imidization of 15K 4,4'-ODA/ODPA poly(amic acid): (A) poly(amic acid); (B) fully cyclized polyimide after 11-h reaction at 180 °C.…”

mentioning

confidence: 99%

Kinetic and mechanistic investigations of the formation of polyimides under homogeneous conditions

Kim¹,

Glass²,

Lyle³

et al. 1993

Macromolecules

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This paper describes kinetic and mechanistic studies of the homogeneous formation of highperformance polyimides. Controlled molecular weights and nonreactive phthalimide end groups were emphasized. NMR spectroscopy, nonaqueous titration, and solution viscosity measurements were the principal techniques utilized. The disappearance of the amic acid groups was followed to quantitative conversion via nonaqueous titration with tetramethylammonium hydroxide. The homogeneous solution imidization processes were well described by auto-acid-catalyzed second-order kinetics. The effects of heteroatom electron-donating and -withdrawing bridging groups (0 and SOz) in the diamines and dianhydrides on imidization rates were investigated, and a possible reaction mechanism for the solution imidization processes was proposed. Imidization of 4,4'-oxydianiline/4,4'-oxydiphthalic anhydride poly(amic acid) was investigated at three different temperatures (140,150, and 180 O C ) . Two-dimensional 'H-lH correlation spectroscopy and intrinsic viscosity measurements provided direct evidence for partial degradation of the poly(amic acid) backbone structures. Complete imidization, including rehealing of the broken chains, was achieved under proper reaction conditions, and the implication of these findings was considered to be very significant for the synthesis of thermally stable high-performance polyimides. For polyimide systems containing benzophenonetetracarboxylic dianhydride (BTDA), direct evidence for network formation involving imine branching and cross-linking was observed by high-field lH NMR spectroscopy and the formation of gels was discussed as a function of reaction conditions. One might anticipate that all ketone-containing polyimides could, to varying degrees, display this behavior.

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“…Figure22. 'H NMR spectra from the imidization of 15K 4,4'-ODA/ODPA poly(amic acid): (A) poly(amic acid); (B) fully cyclized polyimide after 11-h reaction at 180 °C.…”

mentioning

confidence: 99%

Kinetic and mechanistic investigations of the formation of polyimides under homogeneous conditions

Kim¹,

Glass²,

Lyle³

et al. 1993

Macromolecules

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“…21,22 These demerits could be overcome by blending certain additives, which possessed excellent thermal capacity as well as mitigating fouling behavior in polysulfone matrix. [23][24][25][26] Various nanomaterials such as bentonite, 27 SiO 2 , 28,29 and TiO 2 , [30][31][32][33] with certain modifications have been incorporated in the polymeric membrane for imparting the thermo-responsive behavior of the membrane. With the recent advancement in nanotechnology, a new family of 2-D nanomaterials named "boron nitride (BN)" has gained a lot of attention in recent years in the field of membrane-based separation applications.…”

Section: Introductionmentioning

confidence: 99%

A novel temperature-responsive mixed matrix ultrafiltration membrane based on boron nitride nanomaterial

Srivastava

Raviya

Raval

2022

Journal of Thermoplastic Composite Materials

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A novel mixed matrix membrane was prepared by blending polysulfone with two-dimensional boron nitride followed by its hydroxyl functionalization. Prepared nanocomposite membranes were characterized for the surface morphology, surface roughness, zeta potential and hydrophilicity. Uniform dispersion of boron nitride nanoparticles in polysulfone matrix and consequent changes in membrane properties were confirmed by scanning electron microscope images, atomic force microscope images, zeta potential, contact angle analysis, and X-Ray photoelectron spectroscopy. Differential scanning calorimetry (DSC) technique was used to determine the glass transition temperature (Tg) of the modified membrane and the results revealed the presence of BN in the membrane matrix. The highest water flux of 329.52 Liters per sqm per hour (LMH) was obtained in case of PS/BN (1%) as compared to 151.87 LMH of virgin membrane and Albumin rejection also increased by nanocomposites membranes up to certain concentration of Boron nitride. A unique behavior of temperature responsiveness of nanocomposite membrane was observed, where a steep increment in permeate flux by 205% at higher temperature was noted as compared to the virgin Polysulfone membrane where only 103% increase was recorded for the same temperature range. Moreover, the water uptake capacity of nanocomposite membranes were measured to understand the changes with nanomaterial incorporation. The membrane showed a good promise for high-temperature separation applications.

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Synthesis and blend behavior of high performance homo‐ and segmented thermoplastic polyimides

McGrath

Rogers

Arnold

et al. 1991

Makromolekulare Chemie. Macromolecular Symposia

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New synthetic methodology was developed as part of an effort to increase the processibility of high Tg polyimide homo− and copolymers, suitable as matrix resins and structural adhesives. Molecular weight and end group control together with solution imidization techniques were successfully employed to convert a variety of poly(amic acid) intermediates to fully cyclized polyimides. The solution imidization was conducted in N‐methylpyrrolidone (NMP) with o‐dichlorobenzene used as the azeotroping agent at 165–190°C. This technique has produced products which are more soluble than polyimides prepared previously by bulk thermal cyclization of poly(amic acids) at temperature of 300°C. They are also more stable than “chemically” imidized materials. In addition, incorporation of the monofunctional reagent phthalic anhydride provides nonreactive phthalimide end groups and controlled molecular weight. This latter feature significantly further improved the melt and solution processibility of the resulting polyimides. In this study thermoplastic, fully cyclized polyimides of 10 000, 20 000, and 30 000 M̄n were prepared which displayed glass transition temperatures ranging from 260–353°C, with the highest Tg observed with phthalimide capped polyimide systems derived from 6F‐dianhydride and p‐phenylene diamine. Tough, transparent films were prepared from polymers of 20 000 and 30 000 g/mol by casting from NMP solution or by compression molding at 50–70°C above the glass transition temperature. For purposes of molecular weight assessment, t‐butyl phthalic anhydride was used as the end blocker. This permitted 400 M‐Hertz proton NMR to be used for assessing the concentration of end groups. Comparison of the 18 aliphatic protons at the end of the chain allowed M̄n values to be determined, which agreed well with theory. A series of poly(arylene ether ketone)/aromatic polyimide blends were investigated to determine the influence of structural variation and composition on miscibility. As an extension to the PEEKTM/UltemTM blend system, which has been reported to be miscible over all proportions, this study examined how structural variations in both the poly(arylene ether ether ketone) and the polyimide portions affect miscibility. In particular, replacement of the hydroquinone fraction in PEEKTM with bisphenol A or sulfonyl diphenol produced an amorphous polymer which was no longer miscible with UltemTM. Polyimide structures modified by employing 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride (BTDA) and 4,4′‐[1,4‐phenylene‐bis‐(1‐methyl ethylidene)] bisaniline (Bis P) diamine to obtain higher glass transition temperatures were also investigated. This system afforded homogeneous blends with PEEKTM when the (Bis P) diamine was utilized in the synthesis of the polyimide. Furthermore, up to 50 mole percent of hexafluoro‐bis‐dianhydride (6FDA) could be substituted for BTDA without loss of miscibility. However, when the more polar 3,3′‐diaminodiphenylsulfone diamine was employed, immiscible blends resulted. An additional importa...

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Polysulfone Modified Thermoplastic Polyimide Segmented Copolymer Matrix Resin Systems

Cited by 7 publications

References 4 publications

Kinetic and mechanistic investigations of the formation of polyimides under homogeneous conditions

Kinetic and mechanistic investigations of the formation of polyimides under homogeneous conditions

A novel temperature-responsive mixed matrix ultrafiltration membrane based on boron nitride nanomaterial

Synthesis and blend behavior of high performance homo‐ and segmented thermoplastic polyimides

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