Abstract: An ionically conductive polymer has the chemical structure 1 as shown herein. Examples of the polymer include 4,4?-(4-(1H-benzo[d]imidazol-2-yl)butane-2,2-diyl)diphenol, sulfonated poly(aryl ether sulfone) containing benzimidazole backbone, sulfonated poly(aryl ether sulfone) containing carboxylic acid backbone, and sulfonated poly(aryl ether sulfone) containing benzimidazole backbone from carboxylic acid containing sulfonated poly(aryl ether sulfone). The polymer has intrinsic ion conducting properties so that it is effectively conductive even under low water conditions. In one embodiment, the polymer has an ionic conductivity of at least 1×10?5 S/cm at a temperature of 120° C. when the polymer is substantially anhydrous.

Abstract: Novel polyethersulfone compositions have been discovered which incorporate structural subunits derived from sulfonated bis(halophenyl)sulfones, dihydroxy terphenyls, and/or bis(hydroxyphenyl)pyridines. The sulfonated polyethersulfones show promise as materials for use in polymer electrolyte membranes (PEMs) in fuel cells owing to their high proton conductivities (0.02-0.07 S/cm at 20° C. and 100 percent humidity). In addition, a novel unsulfonated thermoplastic polyethersulfone comprising structural subunits derived from a non-sulfonated bis(halophenyl)sulfone bis4-fluorophenyl)sulfone and 4,4?-dihydroxyphenyl-2,6-pyridine (CAS No. 171820-16-9) is disclosed.

Abstract: Membranes comprising functional polyarylether having structural units of formula I are useful for hemodialysis and hemofiltration: wherein X is selected from Br, NR4R5, OOCR6, OR7, NR4CONR5R6, NR4COOR5R6 and combinations thereof; R1, R2 and R3 are independently at each occurrence CH2X, H, halo, cyano, nitro, a C1-C12aliphatic radical, a C3-C12cycloaliphatic radical, a C3-C12aromatic radical or a combination thereof; R4 and R5 are independently H, a C1-10 aliphatic radical, a C3-C12cycloaliphatic radical, a C3-C12 aromatic radical, or a combination thereof; R6 is H, a C2-10 aliphatic radical, a C3-C12 cycloaliphatic radical, a C3-C12 aromatic radical or a combination thereof; R7 is OCH2CH2(OCH2CH2)nOH or OOCCH2(OCH2CH2)nCH3; Z is a direct bond, O, S, SO, SO2, CO, phenylphospinyl oxide, alkenyl, alkynyl, a C1-C12aliphatic radical, a C3-C12cycloaliphatic radical, a C3-C12 aromatic radical or a combination thereof; a, b, and c are independently 1 or 2; and m, n and p are independently 0 or 1.

Abstract: Provided is a fluorine substituted oligomeric or polymeric ester including the reaction product of a fluorine substituted acrylate or a fluorine substituted methacrylate; an unsaturated anhydride; and an alkyl acrylate or an alkyl methacrylate. Also provided is a method of making the composition.

Abstract: High heat polyethersulfone compositions are provided which possess unexpectedly high glass transition temperatures. The polyethersulfone compositions comprise structural units derived from phthalimide bisphenols such as 3,3-bis(4 -hydroxyphenyl)-N-phenylphthalimide, and structural units derived from at least one biphenyl-bissulfone such as 4,4?-bis((4-chlorophenyl)sulfonyl)-1,1?-biphenyl. The novel polyethersulfone compositions may further comprise structural units derived from one or more biphenols such as 4,4?-biphenol, bisphenols such as BPA, or other electrophilic sulfone monomers, such as bis(4-chlorophenyl)sulfone. In one embodiment, the polyethersulfone composition of the present invention comprises structural groups derived exclusively from 3,3-bis(4-hydroxyphenyl)-N-phenylphthalimide, and 4,4?-bis((4-chlorophenyl)sulfonyl)-1,1?-biphenyl and exhibits a single glass transition of greater than 300° C.

Abstract: Branched polyarylene polymers are provided comprising monovalent endcappers, divalent linear units, and polyvalent branching units. The composition of the polymers is controlled by adjusting the ratio of the three types of monomers.

Abstract: A new family of high temperature thermoset resins having high glass transition temperatures and enhanced hygrothermal stability that are synthesized using inexpensive starting materials in essentially a single step process. A trifunctional aromatic, wherein at least one of the three functional groups comprises a halogen and the balance thereof comprises OH groups and wherein said aromatic has electron withdrawing properties, is polymerized using an excess of a diol.

Abstract: A branched (co)polyformal is disclosed. The (co)polyformal contains structural units conforming to at least one the general formulae (1a) and (1b) wherein each of -E- and -D- independently of one another denote an aromatic radical having 6 to 40 C atoms, k is 1 to 4,000, o is 1 to 4,000, m is z/o and n is (o-z)/o, where z is 0 to o. The branched (co)polyformal is characterized by its reduced water uptake and improved hydrolytic stability. Also disclosed are processes for its preparation and use in the production of molded articles.

Abstract: Disclosed is a fluorine compound having perfluorostyrene introduced at a terminal thereof, as represented in the following Formula 1, and a coating solution and an optical waveguide device using the same, characterized in that the introduction of perfluorostyrene results in a facile fabrication of thin films by a UV curing or a thermal curing, high thermal stability and chemical resistance, and low optical propagation loss and birefringence: Wherein Z is O or S; RF is an aliphatic or aromatic group; y is a natural number of 1–10; y? is an integer of 0–1; x is an integer of 0–200; and Wherein B is a single bond or selected from the group consisting of —CO—, —SO2—, —S— and —O—, and Hal is selected from the group consisting of F, Cl, Br and I.

Abstract: A thermoplastic molding composition comprising a linear (co)polyformal is disclosed. The (co)polyformal corresponds to formulae (Ia) or (Ib), in which A independently denotes hydrogen or phenyl, —O-D-O— and —O-E-O— independently denote a diphenolate residue, in which -E- and -D- independently denote an aromatic radical having 6 to 40 C atoms, wherein at least one of —O-D-O— and —O-E-O— denotes 1,1-bis(4-hydroxyphenyl)cyclohexane residue. The composition is characterized in its restricted water absorption. Also disclosed is a process for the preparation of the composition.

Abstract: A material for dielectric films is a polymerizable composition containing an organic solvent, and an adamantanepolycarboxylic acid derivative represented by following Formula (1): wherein X is hydrogen atom, a hydrocarbon group or R4; R1, R2, R3 and R4 and are each independently a protected or unprotected carboxyl group, etc.; and Y1, Y2, Y3 and Y4 are each independently a single bond or a bivalent aromatic cyclic group; and an aromatic polyamine derivative represented by following Formula (2): wherein Ring Z is a monocyclic or polycyclic aromatic ring; and R5, R6, R7 and R8 are each a substituent bound to Ring Z and are each independently a protected or unprotected amino group, etc., dissolved in the organic solvent.

Abstract: A diamine compound represented by the formula (1): wherein R1 is a trivalent organic group, each of X1 and X2 is a bivalent organic group, X3 is an alkyl or fluoroalkyl group having from 1 to 22 carbon atoms, or a cyclic substituent selected from aromatic rings, aliphatic rings, heterocyclic rings and their substituted groups, and n is an integer of from 2 to 5. And, a polyimide precursor and a polyimide synthesized by using the diamine compound; and a treating agent for liquid crystal alignment containing the polyimide precursor and/or the polyimide.

Abstract: A method of preparing an ion-conducting polymeric material, for example, for a fuel cell, in a desired form (hereinafter “said formed polymeric material”), comprises: (i) selecting a first ion-conducting polymeric material; (ii) selecting a solvent formulation which can dissolve said first ion-conducting polymeric material, wherein said formulation includes a first solvent part which is water; (iii) preparing a composite formulation in a process which includes dissolving first ion-conducting polymeric material in said solvent formulation; (iv) forming said composite formulation into a desired form; (v) providing conditions for removal of said solvent formulation from said form described in (iv) thereby to prepare said formed polymeric material. The first ion-conducting polymeric material preferably includes polyaryletherketone units. Said solvent formulation preferably includes a second solvent part selected from acetone, tetrahydrofuran and acetone.

Abstract: Provided are a sulfonated polymer capable of high hot water resistance even if it has an increased amount of the sulfonic groups introduced therein, and a solid polymer electrolyte containing the sulfonated polymer that has high proton conductivity and excellent generating performance. The sulfonated polymer has repeating units represented by the formula (1?): wherein B's are each independently an oxygen or a sulfur atom, R1 to R3 may be the same or different and are selected from a hydrogen atom, a fluorine atom, a nitrile group and an alkyl group, n is an integer of 2 or greater, and Q is a structure represented by the formula (q): wherein A is independently a divalent atom or organic group or a direct bond, and R4 to R11 may be the same or different and are selected from a hydrogen atom, a fluorine atom, an alkyl group and an aromatic group.

Abstract: The present invention provides a polyimide resin for an electrical insulating material which comprises a polyimide resin having a repeating unit represented by general formula (I): wherein R1 represents a bivalent organic group.

Abstract: A preparation process of polyimide aerogels that composed of aromatic dianhydrides and aromatic diamines or a combined aromatic and aliphatic diamines is described. Also descried is a process to produce carbon aerogels derived from polyimide aerogel composed of a rigid aromatic diamine and an aromatic dianhydride. Finally, the processes to produce carbon aerogels or xerogel-aerogel hybrid, both of which impregnated with highly dispersed transition metal clusters, and metal carbide aerogels, deriving from the polyimide aerogels composed of a rigid aromatic diamine and an aromatic dianhydride, are described. The polyimide aerogels and the polyimide aerogel derivatives consist of interconnecting mesopores with average pore size at 10 to 30 nm and a mono-dispersed pore size distribution. The gel density could be as low as 0.008 g/cc and accessible surface area as high as 1300 m2/g.

Abstract: Disclosed herein are polyetherimide compositions comprising structural units of the formula: derived from at least one benzimidazole diamine, wherein R1 and R2 are independently selected from hydrogen and C1–C6 alkyl groups; “A” comprises structural units of the formulae: or mixtures of the foregoing structural units; wherein “D” is a divalent aromatic group, R3 and R10–R12 are independently selected from hydrogen, halogen, and C1–C6 alkyl groups; “q” is an integer having a value of 1 up to the number of positions available on the aromatic ring for substitution; and “W” is a linking group; and “B” comprises substituted and unsubstituted arylene groups having from about 6 to about 25 carbon atoms. Methods for producing the polyetherimide compositions are also disclosed herein.

Abstract: A method for preparing a polyimide includes introducing a mixture of an oligomer and a solvent to an extruder, removing solvent via at least one extruder vent, and melt kneading the oligomer to form a polyimide. The polyimide has a low residual solvent content. The method is faster than solution polymerization of polyimides, and it avoids the stoichiometric inaccuracies associated with reactive extrusion processes that use monomers as starting materials.

Abstract: A novel polyimide resin consisting essentially of 3,3?,4,4?-benzophenonetetracarboxylic dianhydride (BTDA), 3,4,3?,4?-biphenyltetracarboxylic dianhydride (BPDA), 2,2 bis (3?,4?-dicarboxy phenyl) hexafluoro propane dianhydride (6FDA), 2-(3,4-dicarboxyphenyl)-1-phenylacetylene anhydride (4-PEPA) and an aromatic diamine.

Abstract: Polyimide sulfone resins are provided with a glass transition temperature of from 200–350° C., residual volatile species concentration of less than 500 ppm and a total reactive end group concentration of less than about 120 milliequivalents/kilogram resin. The resins have high heat capability and good melt stability. Methods to prepare the said resins and articles made from the resins are also provided.

Abstract: The present invention relates to novel polyimides derived from 6FDA and from 3,3-dihydroxy-4,4?-diaminobiphenyl and novel polyimides derived from PMDA and from Bis-AP-AF, having alkyl, arylalkyl, heteroarylalkyl, (cycloalkyl)alkyl, fluoroalkyl or siloxane side groups. The present invention also relates to a method of producing nematic liquid-crystal devices, which comprises the steps consisting in: depositing one of the polyimides according to the invention on a substrate; annealing the polyimide in one or more steps; and defining an azimuthal orientation of the polyimide coating.

Abstract: A new class of hybrid organic-inorganic materials, and methods of synthesis, that can be used as a proton exchange membrane in a direct methanol fuel cell. In contrast with Nafion® PEM materials, which have random sulfonation, the new class of materials have ordered sulfonation achieved through self-assembly of alternating polyimide segments of different molecular weights comprising, for example, highly sulfonated hydrophilic PDA-DASA polyimide segment alternating with an unsulfonated hydrophobic 6FDA-DAS polyimide segment. An inorganic phase, e.g., 0.5–5 wt % TEOS, can be incorporated in the sulfonated polyimide copolymer to further improve its properties. The new materials exhibit reduced swelling when exposed to water, increased thermal stability, and decreased O2 and H2 gas permeability, while retaining proton conductivities similar to Nafion®. These improved properties may allow direct methanol fuel cells to operate at higher temperatures and with higher efficiencies due to reduced methanol crossover.

Abstract: The invention relates to a modified polybenzimidazole (PBI), membranes that are fabricated from these polymers, and their use in electrochemical applications. These membranes have high ionic conductivity and are suitable for solid polymer electrolytes in electrochemical applications, especially for high temperature polymer electrolyte membrane (PEM) fuel cells.

Abstract: This invention relates to polyimides having improved thermal-oxidative stability, to the process of preparing said polyimides, and the use of polyimide prepolymers in the preparation of prepregs and composites. The polyimides are particularly useful in the preparation of fiber-reinforced, high-temperature composites for use in various engine parts including inlets, fan ducts, exit flaps and other parts of high speed aircraft.

Abstract: Ion-Exchange polymers for a polymer electrolyte membrane include a moiety of formula (I), and/or a moiety of formula (II), and/or a moiety of formula (III) wherein at least some of the units I, II and/or III are sulphonated; wherein the phenyl moieties in units I, II, and III are independently optionally substituted and optionally cross-linked; and wherein m, r, s, t, v, w and z independently represent zero or a positive integer, E and E? independently represent an oxygen or a sulphur atom or a direct link, G represents an oxygen or sulphur atom, a direct link or a —O—Ph—O— moiety where Ph represents a phenyl group and Ar is selected from one of the above moieties (i) to (x) which is bonded via one or more of its phenyl moieties to adjacent moieties

Abstract: Provided are polyimide and a thin film thereof which have a three-dimensional structure and therefore are excellent in a mechanical strength and a heat resistance as compared with those of conventional linear polyimide. The polyimide is obtained from a salt of multifunctional amine represented by Formula (1): (wherein A represents a tetravalent organic group, and n represents an integer of 0 to 3) and tetracarboxylic diester represented by Formula (2): (wherein B represents a tetravalent organic group having 1 to 20 carbon atoms, and R1 and R2 each represent independently an alkyl group having 1 to 5 carbon atoms).

Abstract: A polyimide excelling in heat resistance, chemical resistance, water repellency, dielectric characteristics, electrical characteristics, and optical characteristics and a polyamide acid useful as the raw material therefor are provided. Specifically, a polyamide acid containing a chlorine atom and a fluorine atom and comprising a repeating unit represented by the following formula (1): (wherein X and X? independently denote a divalent organic group; Y and Y? independently denote a chlorine, bromine, or iodine atom; p and p? denote independently denote the number of fluorine atom {F in the formula (1)} bonded to the relevant benzene ring, representing an integer of 0-3; q and q? independently denote an integer of 0-3; and p+q total 3, and p?+q? total 3).

Abstract: Methods of reducing the amount of undesirable cyclic oligomer by-products in the production of polyetherimides are disclosed. The resulting polyetherimides have enhanced thermomechanical properties.

Abstract: A polyimide composition and a process to prepare polyimide resins with reduced plate out and mold deposits is described. During resin molding operations the low plate out resins show a longer period of operation between cleaning of equipment leading to more efficient operation.

Abstract: A process of preparing a polyimide of the present invention comprises effecting an imidization reaction of a diamine and a tetracarboxylic dianhydride in a solvent containing 50 to 100% by weight of an equimolar composition of a nitrogen-containing cyclic compound indicated by chemical formula (1) below and a phenol indicated by chemical formula (2) below: in formula (1), X represents —CH2— or —N(CH3)—, and in formula (2), R1 and R2 may be the same as, or different from, each other and represent each any one of —H, —OH, —CH3, —C2H5, —C3H7, —C4H9, —C5H11, —C6H13, —C7H15, —C8H17, —C9H19, —C10H21, —OCH3, —O(C6H5), —NO2, —Cl, —Br and —F.

Abstract: The present invention provides an optical polyimide precursor for use in making a polyimide. The precursor is defined by the following formula: wherein X is Cl, Br, oxo-halide, or fully halogenated alkyl, and A is a divalent aromatic or halogenated aromatic moiety. The present invention provides a method of preparing a diamine compound for use as an optical polyimide precursor. The method includes the steps of dissolving 2-chloro-5-nitrobenzotrifluoride and a diol in N,N-dimethylacetamide to form a solution, adding potassium carbonate, tert-butylammonium chloride and copper powder to said solution and heating the resulting mixture, removing the copper, precipitating and recrystallizing a dinitro-compound resulting from heating the mixture, and dissolving the dinitro-compound and reducing the dinitro-compound to yield a diamine compound.

Abstract: A method for the synthesis of poly(etherimide)s comprises the reaction of 4-halotetrahydrophthalic anhydride with an activating primary amine to yield an activated 4-halotetrahydrophthalimide. Activated 4-halotetrahydrophthalimide may then be aromatized and treated with the disodium salt of a bis(phenol) to yield an activated bisimide. The activated bisimide may then be directly treated with a diamine to yield poly(etherimide)s.

Abstract: A polyimide is disclosed of the formula: CG1 and CG2 are independently electron-accepting and/or electron-donating groups; x is an integer from about 3 to about 3000; ODAH is any of a number of known dianhydride residues; ODAM is any of a number of known diamine residues; and m, n, o, and p cumulatively add to 1.0, with the sum of m and n ranging from about 0.05 to about 1.0, the sum of o and p ranging from about 0 to about 0.95, the sum of m and o being about 0.5 and the sum of n and p being about 0.5. In addition, a film structure comprising the polyimide and devices utilizing the film structure are disclosed.

Abstract: Copolyetherimides comprise phthalimide structural units comprising both 3- and 4-linkages, wherein the designations 3-linkage and 4-linkage refer to the isomeric positions on the phthalimide ring in the totality of phthalimide-comprising structural units in the copolymer. The products have excellent properties, including high glass transition and heat distortion temperatures, high ductility and good melt flow properties, and low polydispersity.

Abstract: Ion-Exchange polymers for a polymer electrolyte membrane include a moiety of formula (I), and/or a moiety of formula (II), and/or a moiety of formula (III) wherein at least some of the units I, II and/or III are sulphonated. The phenyl moieties in units I, II, and III are independently optionally substituted and optionally cross-linked; m, r; s, t, v, w and z independently represent zero or a positive integer, E and E′ independently represent an oxygen or a sulphur atom or a direct link, G represents an oxygen or sulphur atom, a direct link or a —O—Ph—O— moiety where Ph represents a phenyl group and Ar is selected from one of the moieties (i) to (x) as set forth herein which is bonded via one or more of its phenyl moieties to adjacent moieties.

Abstract: The present invention provides a method for easily producing a high-molecular weight polyimide resin at high yield by drying and heating a mixture mixed by material monomers of polyimide.

Abstract: Polyimides having a desired combination of high thermo-oxidative stability, low moisture absorption and excellent chemical and corrosion resistance are prepared by reacting a mixture of compounds including (a) 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA), (b) 3,4′-oxydianiline (3,4′-ODA), and (c) 5-norbornene-2,3-dicarboxylic anhydride (NA) in a high boiling, aprotic solvent to give 5 to 35% by weight of polyamic acid solution. The ratio of (a), (b), and (c) is selected to afford a family of polyimides having different molecular weights and properties. The mixture first forms a polyamic acid precursor. Upon heating at or above 300° C., the polyamic acids form polyimides, which are particularly suitable for use as a high temperature coating, adhesive, thin film, or composite matrix resin.

Abstract: Polyhydroxyamides are polymerized to form highly-crosslinked, temperature-stable polymers. The polyhydroxyamides include as their central, parent structure a benzenetricarboxylic acid to which side chains containing a terminal reactive group are attached by an amide bond. By way of this reactive group, highly crosslinked polymers can be formed. In addition, the polyhydroxyamide can be added as an additive to polymers in order to bring about three-dimensional crosslinking.

Abstract: The present invention relates to methods for the preparation of polyesters, poly(ester amide)s and poly(ester imide)s. The materials obtained by the methods of present invention are useful as fluid separation membranes and as high performance materials.

Abstract: An alkyldiamine having excellent polymerization reactivity, a polyimide comprising it as a constituting element, and a liquid crystal alignment film excellent in uniformity of liquid crystal alignment, are presented. Namely, the present invention relates to a diaminobenzene derivative represented by the following general formula (1) and to a polyimide obtained by reacting a diamine containing at least 1 mol % of the diaminobenzene derivative represented by the general formula (1), with at least one compound selected from a tetracarboxylic. dianhydride and its derivatives, to obtain a polyimide. precursor having a reduced viscosity of from 0.05 to 5.0 dl/g (in N-methylpyrrolidone at a temperature of 30° C., concentration: 0.5 g/dl) and ring-closing it, and having a repeating unit represented by the general formula (2). Further, the present invention relates to a liquid crystal alignment film containing at least 1 mol % of the above repeating unit.

Abstract: The aromatic diamine compound of the present invention is represented by the following formula (1), and from the aromatic diamine compound a polyimide having a repeating unit represented by the following formula (4), which has low-temperature adherability, can be obtained. In the formulas (1) and (4), n is an integer of 3 to 7, each R is independently an atom or a group selected from the group consisting of a hydrogen atom, a halogen atom and a hydrocarbon group, the same or different two hetero atoms selected from nitrogen atoms and oxygen atoms bonded to each benzene ring are at the ortho- or meta-positions to each other on at least one benzene ring, and when n is 3, the hetero atoms are at the ortho- or meta-positions to each other on all the benzene rings. In the formula (4), Y is a tetravalent organic group.

Abstract: A solvent-free, catalyst-free and contamination-free method of synthesis of polyimides is disclosed. The method includes polymerizing a diamine with 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) at a pressure of 0.1-760 mm Hg, preferably a reduced pressure at about 36 mm Hg, and a temperature of 90-400° C., preferably 10-240° C.

Abstract: An acid dianhydride, together with a diamine, is heated in an organic polar solvent in the presence of &ggr;-caprolactone or &bgr;-butyrolactone as an acid catalyst to prepare a polyimide having an average molecular weight of 10,000 to 300,000. This production process can realize the production of a polyimide which is soluble in a solvent and has high processability and stability.

Abstract: A polyimide film that exhibits improved peel strength when clad with a metal layer is prepared by reacting a polyamic acid polymer and an esterified polyamic acid oligomer. The esterified oligomer has from two to twenty repeating units and at least two crosslinkable groups selected from the group consisting of carbonyl, cyano, hydroxy, alkyne, maleimide, norbornene and sulfonyl groups. The polyamic acid is dissolved in a solvent to form a polyamic acid solution, which has a minimum gel-film forming temperature, or a minimum green film forming temperature, associated therewith. The esterified polyamic acid oligomer has an imidization temperature, which is higher than the minimum gel-film forming temperature, or the minimum green film forming temperature, of the polyamic acid solution.

Abstract: The present invention provides PMR-type polyimides that exhibit lower melt viscosities than PMR-type polyimides of the prior art. These PMR-type polyimides are created by incorporating flexible linkages, such as kinked structures and twisted or non-coplanar moietes into the backbone structure of the PMR. Specifically, the present invention provides for the production of PMR-type polyimides having 2,2′-disubstituted biaryls in the polymer backbone.

Abstract: New hyperbranched polymers having repeating units of the formula The polymer is prepared by the polymerization of the AB2 monomer N-{3,5-bis(4-hydroxybenzoyl)benzene}-4-fluoroisophthalimide.

Abstract: Disclosed is a polyamide ester which comprises a plurality of specific amide ester recurring units including, in a specific ratio, recurring units containing a tetravalent benzene group and recurring units containing a tetravalent diphenyl ether group, and which is adapted to be converted to a polyimide in a coating form by heat-curing, wherein the polyimide coating exhibits a residual stress of 33 MPa or less as measured with respect to a 10 &mgr;m-thick polyimide coating formed on a silicon substrate. Also disclosed is a polyamide ester composition comprising a plurality of different polyamide esters, wherein the plurality of different polyamide esters collectively contain, in a specific ratio, the recurring units containing a tetravalent benzene group and the recurring units containing a tetravalent diphenyl ether group.

Abstract: A polyamic ester prepared by partially substituting hydrogen atoms of carboxylic groups of a polyamic acid with acid labile groups, the polyamic ester comprising one or more repeating units represented by Formula 1, and each of at least one terminal of the polyamic ester molecule terminates with the same or different reactive end-capping monomer: wherein in Formula 1, R1 and R2 are independently a hydrogen atom, or an acid labile group; X is a tetravalent, an aromatic or an aliphatic organic group; Y is a divalent, an aromatic or an aliphatic organic group; and m is an integer equal to or greater than 1.

Abstract: The invention relates to a semi-permeable membrane separation process and device in which the said membranes comprise sulphonated polyimides. The present invention also relates to the use of sulphonated polyimide membranes in separation processes and devices using semi-permeable membranes.

Abstract: Sulfonated polyimide polymers incorporating bulky monomers are disclosed. The polymers have a liquid crystalline structure and exhibit high conductivity, high water uptake and water stability over a range of relative humidities and temperatures. The polymers are particularly adapted for use as a polymer electrolyte membrane in fuel cells.