Abstract: A curable fluorine-containing polyimide of the formula: ##STR1## wherein R.sup.1 is a group derived from an aromatic tetracarboxylic acid dianhydride by the removal of two acid anhydride groups,R.sup.2 is a group derived from an aromatic diamine by the removal of two amino groups,A.sup.1 is a residue of the formula: ##STR2## (wherein R.sup.2 is the same as defined above, and Z is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms),A.sup.2 is a residue of the formula: ##STR3## (wherein R.sup.1 and Z are the same as defined above), and n is a number of 0 to 90, and at least one of the groups R.sup.1 and R.sup.

Abstract: A terminal-modified imide oligomer composition, comprising(A) 100 parts by weight of a terminal-modified imide oligomer obtained by a reaction in a solvent of a biphenyltetracarboxylic acid compound with an aromatic diamine compound and a monoamine compound containing a carbon-carbon triple bond, and having an unsaturated terminal group at the terminal of the oligomer and an imide bond in the oligomer, and having a logarithmic viscosity number at 30.degree. C., as determined at a concentration of 0.5 g/100 ml of N-methyl-2-pyrrolidone as a solvent, of from 0.1 to 1 and;(B) 5 to 180 parts by weight of an unsaturated imide compound obtained by a reaction in a solvent of a substituent-containing nadic anhydride with a monoamine compound having a carbon-carbon triple bond in an equimolar ratio, and having an unsaturated terminal group at the terminal thereof and an imide bond therein.

Abstract: A method for the preparation of a polyimide containing reversible crosslinks comprising the step of curing a monomer having the formula ##STR1## wherein R and R' may be the same or different and each is H or lower alkyl having 1-5 carbon atoms under conditions conducive to the formation of a polyimide and thereby forming a polyimide having the formula ##STR2## R and R' are as defined above and n is an integer from 10 to 100. The polyimide may be converted to a soluble polymer by cleaving the disulfide bond in the presence of a solvent and a reducing agent. The reduced polymer may be reformed into the polymer in an oxidation step or into a modified polyimide in other reaction steps. Copolymerization processes are also disclosed.

Abstract: Polyetherketoneimides and copolymers thereof having an imide repeat unit of formula ##STR1## wherein Ri is ##STR2## in which A is a direct bond or --O--or another substantially non-electron-withdrawing group, and/or Ra is an at least partly arylene moiety other than m- or P-phonylene.These polymers tend to have improved melt stability and other properties, especially when made from a pre-existing imide monomer, instead of by the known amic acid route which results in uncyclised amic acid residues in the polymer.

Abstract: Curing of phthalonitrile monomers and prepolymers is accelerated by inclusion of an acid curing agent. Cured phthalonitrile polymers have high thermal oxidative stability and are useful as resins in various compositions and as adhesives.

Abstract: Improved imide-containing copolymers comprising, in the aromatic diamine component, p-phenylene diamine and at least one additional aromatic diamine have increased rigidity and useful processability. The copolymers of this invention also may exhibit improved resistance to the detrimental effects of humid environments and retain mechanical properties at elevated temperatures after exposure to humid environments.

Abstract: Poly(dianhydride) compounds having formulae (I) and (II): ##STR1## where m is 0 to 50. ##STR2## wherein n is 0 to 20 and X is bond junction, oxygen atom, sulfur atom, SO.sub.2, C(CF.sub.3), CO, C(CH.sub.3).sub.2, CF.sub.2 --O--CF.sub.2, CH.sub.2, and CHOH.

Abstract: Polymerization or cure of di-phthalonitrile monomers or prepolymers by a curing agent selected from (a) an acid and an amine, (b) a salt of an acid and an amine, and (c) mixtures of (a) and (b). In a preferred embodiment, the curing agents are amine salts which are reaction products of an aromatic amine and an aromatic sulfonic acid. The use of the novel curing agents enhances curing rates and results in polymers which have high Tg.

Abstract: A perfluorinated polyimide comprising a repeating unit represented by general formula (1): ##STR1## and a perfluorinated poly(amic acid) comprising a repeating unit represented by general formula (6): ##STR2## wherein R.sub.1 is a tetravalent organic group; and R.sub.2 is a divalent organic group, provided that chemical bonds between carbon atoms and monovalent elements contained in R.sub.1 and R.sub.2 are exclusively carbon-to-fluorine bonds; methods for preparing them; and optical material including the perfluorinated polyimide. 1,4-Bis(3,4-dicarboxytrifluorophenoxy)tetrafluorobenzene dianhydride, 1,4-difluoropyromellitic anhydride, 1,4-bis(3,4-dicarboxytrifluorophenoxy)tetrafluorobenzene, 1,4-difluoropyromellitic acid, and 1,4-bis(3,4-dicyanotrifluorophenoxy)tetrafluorobenzene as well as methods preparing them. The perfluorinated polyimide has a thermal stability and has a low optical loss in an optical communication wavelength region (0.8 to 1.7 .mu.m).

Abstract: A novel aromatic diamine; a polyimide comprising 1,3-bis(3-aminobenzoyl)benzene or 4,4'-bis(3-aminobenzoyl)biphenyl as a diamine component and having recurring structural units represented by the formula (III): ##STR1## wherein R is a tetravalent radical selected from the group consisting of an aliphatic radical having from 2 to 27 carbon atoms, alicyclic radical, monoaromatic radical, condensed polyaromatic radical, and noncondensed aromatic radical connected each other with a direct bond or a bridge member, and X is a divalent radical of ##STR2## and a polyimide having a terminal aromatic group which is essentially unsubstituted or substituted with a radical having no reactivity with amines or dicarboxylic acid anhydrides or a composition comprising said polyimide.

Abstract: The invention relates to soluble homo- or copolyimides of formula I ##STR1## wherein Y is hydrogen or the substituents Y, together with the linking N atom, are a divalent radical of of formulae IIa to IIc ##STR2## and X is the radical of of an aromatic amine after removal of the amino end groups, and n is an integer from 5 to 150.The compounds of the invention are readily soluble in organic solvents and are suitable tougheners for epoxy, bismaleimide and triazine resin systems.

Abstract: A high-temperature stable, highly optically transparent-to-colorless, low dielectric linear aromatic polyimide is prepared by reacting an aromatic diamine with 3,3'bis(3,4-dicarboxyphenoxy)diphenylmethane dianhydride in an amide solvent to form a linear aromatic polyamic acid. This polyamic acid is then cyclized to form the corresponding polyimide, which has the following general structural formula: ##STR1## wherein Ar is any aromatic or substituted aromatic group, and n is 10-100.

Abstract: The present invention relates to new polyetherimideimides having imideimide group with the following structural formula(I) and inherent viscosity of 0.27.about.0.71 dl/g, which can be made by effecting reaction between an aromatic bis(ether anhydride) and an organic diamine or an aromatic bis(nitro imideimide) and a metal salt of diol.

Abstract: A hot-melt adhesive comprising a special polyamideimide or polyamide is excellent in heat resistance and adhesive strength and usable for providing substrates for printed circuit boards.

Abstract: In a process for the preparation of polyimide by reacting a diamine compound with tetracarboxylic dianhydride in a phenol based solvent, an improved process for reacting the diamine compound with tetracarboxylic dianhydride in a solution by forming separate solutions of the tetracarboxylic dianhydride and the diamine compound and mixing the solutions and/or by dissolving tetracarboxylic dianhydride in the phenol-based solvent containing an organic base.

Abstract: A polyimide having a high heat-resistance good processability and recurring structural units of the formula (I): ##STR1## wherein R is a tetravalent radical selected from the group consisting of an aliphatic radical having at least two carbon atoms, alicyclic radical, monocyclic aromatic radical, fused polycyclic aromatic radical and polycyclic aromatic radical bonded through a direct bond or a bridge member.

Abstract: It is advantageous to prepare oligomers of polybenzazole polymers by reaction of AA-PBZ monomer with an excess of BB-PBZ monomer. The resulting oligomer dopes may be stored at a temperature at which they remain pumpable until such time as the dope can be advanced to higher molecular weight by adding additional AA-PBZ monomer. The molecular weight of the polymer may be adjusted by controlling the amount of chain extender and/or chain terminator added to oligomer mixtures as they are advanced to final molecular weight.

Abstract: A method for preparing high molecular weight polyethermide polymers in a dual solvent system is disclosed. The inventive method provides for polymerizing a diamine monomer and a dianhydride monomer in a solvent system comprised of at least two solvents, a first solvent is selected for its solubility characteristics such that the polyethermide polymer is highly soluble therein and a second solvent is selected for its relatively high boiling point characteristics such that when the second solvent and first solvent are mixed together, the boiling point of the dual solvent system is at least as high as the temperature at which polymerization of said monomers occurs. In one embodiment, a diamine monomer of 4,4'-sulfonyl dianiline (SDAN) is reacted with a dianhydride monomer of bisphenol A dianhydride (BPADA) in the presence of a catalyst and a chain stopper in a dual solvent system comprised of chloroform and ortho-dichlorobenzene. The resulting polyethermide has an intrinsic viscosity exceeding 0.

Abstract: Polyimide oligomers include (1) linear, monofunctional crosslinking oligomers prepared by condensing a monoanhydride end cap with a diamine that includes alternating ether and "Sulfone" (--SO.sub.2 --, --S--, --CO--, --(CF.sub.3).sub.2 C--, or --(CH.sub.3).sub.2 C--) linkages connecting alternating aromatic radicals and with a dianhydride (or dianhydride mixture), particularly the unsaturated, aliphatic dianhydride commonly known as MCTC; (2) linear, mono- or difunctional crosslinking oligomers prepared by condensing an amine end cap with a diamine and a dianhydride; and (3) multidimensional, crosslinking oligomers having an aromatic hub and at least three radiating arms connected to the hub, each arm including a crosslinking end cap at its distal end and at least one imide linkage.Blends, prepregs, and composites can be prepared from the oligomers.

Abstract: Polyimide resins, which have reduced anhydride content when molded, are prepared by a novel reaction process that includes reacting an esterified aromatic tetracarboxylic acid or anhydride monomer with a primary aromatic diamine until substantially no free monomer remains to form a polyamide-acid (the molar ratio of esterified monomer to diamine ranging from 1:1 to 1:2); reacting the polyamide-acid with a low molecular weight end-capping agent to form an end-capped polyamide-acid; and heating the end-capped polyamide-acid to form the polyimide.

Abstract: A copolymeric amphiphilic polyimide precursor having the recurring unit of the formula (1): ##STR1## wherein R.sup.1 is a tetravalent group having at least 2 carbon atoms, R.sup.2 is a bivalent group having at least 2 carbon atoms, and R.sup.3, R.sup.4, R.sup.5 and R.sup.6 are hydrogen atom or a monovalent group having 1 to 30 carbon atoms selected from the group consisting of an aliphatic group, an alicyclic group, an aromatic group, a group in which an aliphatic group is combined with an aromatic group, or an alicyclic group, and their groups substituted by a halogen atom, nitro group, amino group, cyano group, methoxy group or acetoxyl group, provided that at least one of R.sup.3, R.sup.4, R.sup.5 and R.sup.6 is neither hydrogen atom nor the above-mentioned group which has 1 to 11 carbon atoms; a part of at least one of said R.sup.1 and said R.sup.2 being substituted with a group having a valence different therefrom.

Abstract: Soluble and/or fusible polyimides or polyamidoimides of the general formula I ##STR1## in which R denotes a divalent radical of the formula II ##STR2## Ar denotes trivalent or tetravalent aromatic radicals or mixtures thereof, X denotes the amide radical, if Ar is trivalent, and if Ar is tetravalent denotes the imide radical and R.sub.1 denotes divalent aromatic radicals, and a process for their preparation.

Abstract: Fully cyclized polyimides based on aromatic tetracarboxylic acid dianhydrides with substitution in the positions ortho to the bridging moiety and aromatic diamines, exhibiting solubility in organic solvents, increased glass transition temperatures, low coefficients of thermal expansion and photoimagability; said polyimides being suitable for the production of films, protective coatings and photolithographic relief images.

Abstract: Polyimides having a high thermal and oxidative stability are prepared by reacting a mixture of monomers comprising (a) a dialkyl, trialkyl, or tetraalkylester of an aromatic tetracarboxylic acid, (b) an aromatic diamine, and (c) an end cap compound. The ratio of (a), (b), and (c) is chosen so that upon heating the mixtures, low molecular weight prepolymers are formed, the prepolymers having only one end cap radical and being suitable for chain extension and crosslinking to form high molecular weight, thermally stable polyimides. Upon heating, the prepolymers form polyimide resins, which can have T.sub.g in excess of 600.degree. F. and superior physical properties.

Abstract: Polyimides having a high thermal and oxidative stability are prepared by reacting a mixture of monomers comprising (a) a dialkyl, trialkyl, or tetraalkylester of an aromatic tetracarboxylic acid, (b) an aromatic diamine, and (c) an end cap compound. The ratio of (a), (b), and (c) is chosen so that upon heating the mixtures, low molecular weight prepolymers are formed, the prepolymers having only one end cap radical and being suitable for chain extension and crosslinking to form high molecular weight, thermally stable polyimides. Upon heating, the prepolymers form polyimide resins, which can have T.sub.g in excess of 600.degree. F. and superior physical properties.

Abstract: New polyimides have been prepared from the reaction of aromatic dianhydrides with novel aromatic diamines containing carbonyl and ether connecting groups between the aromatic rings. Several of these polyimides were shown to be semi-crystalline as evidenced by wide angle x-ray diffraction and differential scanning calorimetry. Most of the polyimides form tough solvent resistant films with high tensile properties. Several of these materials can be thermally processed to form solvent and base resistant moldings.

Abstract: Novel polyimides have been prepared from the reaction of aromatic diahydrides with novel aromatic diamines having carbonyl and ether groups connecting aromatic rings containing pendant methyl groups. The methyl substituent polyimides exhibit good solubility and form tough, strong films. Upon exposure to ultraviolet irradiation and/or heat, the methyl substituted polyimides crosslink to become insoluble.

Abstract: Polyimides having a high thermal and oxidative stability are prepared by reacting a mixture of monomers comprising (a) a dialkyl, trialkyl, or teThis invention was made with Government support under F33615-88-C-5409 awarded by the Department of the Air force. The Government has certain rights in this invention.

Abstract: A thermosetting resin composition, a solution composition of the resin and a thermosetting dry film formed out of the resin are disclosed. The thermosetting resin composition contains a specific resin component as the main component. The resin component consists of (A) 100 weight parts of an aromatic polyimide; and (B) 5 to 2,000 weight parts of (a) a terminal-modified imide oligomer or (b) an unsaturated imide compound. The aromatic polyimide (A) is formed from a tetracarboxylic acid ingredient which contains 2,3,3',4'-biphenyltetracarboxylic acid or its derivative in an amount of at least 60 mole % and an aromatic diamine ingredient. The polyimide has such a high molecular weight that the logarithmic viscosity (concentration: 0.5 g/100 ml of solvent; solvent: N-methyl-2-pyrrolidone; and temperature of measurement: 30.degree. C.) is not less than 0.2. The polyimide is soluble in an organic polar solvent.

Abstract: Aromatic tetracarboxylic acids or derivatives thereof of the general formula I ##STR1## in which R denotes a divalent radical of the formula II ##STR2## Ar denotes tri- or tetravalent aromatic radicals or mixtures thereof, X, if Ar is trivalent, denotes an amide radical, and if Ar is tetravalent denotes an imide radical, and Y and Z either together denote the anhydride radical --CO--O--CO-- or by themselves and independently of one another denote the radicals --COOH, --COCL or --COOR.sub.1, and a process for their preparation.

Abstract: The present invention provides for a novel heat stable class of polyamide-imide polymers having excellent flow properties and hydrolytic stability which are prepared by forming the polycondensation product of one or more aromatic or aliphatic diamines and a comonomer comprising a tri- or hexafluoro-substituted tricarboxylic acid anhydride (or acid derivative thereof) having the structure: ##STR1## wherein R is CF.sub.3 or a phenyl radical. In addition to improved flow properties, the polyamide-imide polymers of this invention also exhibit improved solubility properties in most organic solvents, good resistance to attack by chlorinated solvents such as trichloroethylene as compared with polyimides, improved hydrophobic properties as well as good thermal properties, including resistance to thermooxidative degradation.

Abstract: A process for preparing polyimides having enhanced melt flow properties is described. The process consists of heating a mixture of a high molecular weight poly(amic acid) or polyimide with a low molecular weight amic acid or imide additive in the range of 0.05 to 15% by weight of additive. The polyimide powders so obtained show improved processability, as evidenced by lower melt viscosity by capillary rheometry. Likewise, films prepared from mixtures of polymers with additives show improved processability with earlier onset of stretching by TMA.

Abstract: A preferred class of polyimide oligomers include (1) linear, difunctional crosslinking oligomers prepared by condensing an imidophenylamine end cap with a lower alkylene diamine or a polyaryldiamine such as 3,3'-phenoxyphenylsulfone diamine and with a dianhydride, particularly 4,4'-phenoxyphenylsulfone dianhydride; and (2) multidimensional, crosslinking, polyimide oligomers having an aromatic hub and at least two radiating arms connected to the hub, each arm including a crosslinking imidophenylamine end cap at its distal end and at least two imide linkages.Blends, prepregs, and composites can be prepared from the oligomers.

Abstract: Disclosed herein are processes for the preparation of polyimide-isoindroquinazolinediones and precursor thereof. These polymers are useful as heat-resistant electric insulation materials, surface coating films for electronic instrument parts and especially suitable for manufacturing a photoresist. The above precursor is produced by reacting a an alkylenebistrimellitate dianhydride, a diaminoamide compound and the other amine. The precursor is readily dehydrated and ring-closed to produce polyimide-isoindroquinazolinedione, which is often conveniently conducted by producing a varnish of the precursor, applying it onto adequate substrates such as silicon wafers, glass plates, metal plates, etc. and then subjecting the coated film to dehydration. The resulting films have excellent physical properties such as good adherence, high tensile strength, low elasticity, etc.

Abstract: Copolyimides and their precursors are disclosed comprising units represented by the formula ##STR1## where R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are the same or different and are hydrogen or C.sub.1 to C.sub.6 linear or branched alkyl, with the proviso that R.sub.1, R.sub.2, R.sub.3 and R.sub.4 cannot simultaneously be hydrogen and where Z is a chemical bond, ##STR2## Ar is the tetravalent residue of a tetracarboxylic acid or acid dianhydride or di- or tetraester thereof, where x and y are integers from about 100 to about 1,000, and the ratio of x to y is from about 1:99 to about 49:51, and z is 0-5.These copolymers have improved resistance to stress cracking. They may also be used in applications such as coatings, or adhesives.

Abstract: A process for the synthesis of derivatives of materials containing an imide group conjugated to an aromatic moiety to form an ester, a thioester, an amide, a ketone, and silylesters. Electrons are supplied to redox sites to form a reduced imide material. The reduced imide material is contacted with a nucleophile which opens the imide ring of the reduced imide and chemically combines with a carbonyl carbon atom of the open imide ring to form an imide derivative.

Abstract: The present invention provides cross-linkable polyimide polymers having at least one repeating unit of the sturcture of: ##STR1## wherein n is the number of repeating groups and A is a tetravalent aromatic organic radical wherein each pair of carbonyl groups are attached to adjacent carbons in the ring moiety A.It has been found that polyimides having the structure of formula I may be crosslinked at surprisingly low temperatures when heated from about 75 to about 110.degree. C. to form infusible and solvent resistant shapes, thereby rendering them useful in the preparation of films, laminates and composites where inertness to solvents is a prerequisite.

Abstract: A high-temperature stable, optically transparent, low dielectric aromatic polyimide is prepared by chemically combining equimolar quantities of an aromatic dianhydride reactant and an aromatic diamine reactant, which are selected so that one reactant contains at least one Si(CH.sub.3).sub.2 group in its molecular structure, and the other reactant contains at least one --CH.sub.3 group in its molecular structure. The reactants are chemically combined in a solvent medium to form a solution of a high molecular weight polyamic acid, which is then converted to the corresponding polyimide.

Abstract: Polyimides having a high thermal and oxidative stability are prepared by reacting a mixture of monomers comprising (a) a dialkyl, trialkyl, or tetraalkylester of an aromatic tetracarboxylic acid, (b) an aromatic diamine, and (c) an end cap compound. The ratio of (a), (b), and (c) is chosen so that upon heating the mixtures, low molecular weight prepolymers are formed, the prepolymers having only one end cap radical and being suitable for chain extension and crosslinking to form high molecular weight, thermally stable polyimides. Upon heating, the prepolymers form polyimide resins, which can have T.sub.g in excess of 600.degree. F. and superior physical properties.

Abstract: Disclosed is a film of polyimide having repeating units of formula (1) and a birefringence (.DELTA.n) of at least 0.13: ##STR1## wherein R.sup.1 is an aromatic group having a valency of 4, at carbon atoms constituting the aromatic ring, and R.sup.2 is an aromatic group having a valency of 2, at carbon atoms constituting the aromatic ring. This polyimide film exhibits good thermal dimensional stability.

Abstract: A polyimide resin having a repeating unit of the formula: ##STR1## wherein R.sub.1 is a tetravalent organic group constituting a tetracarboxylic acid or its derivative, wherein four atoms directly bonded to the four carbonyl groups are carbon atoms having no unsaturated bond, and R.sub.2 is a bivalent organic group constituting a diamine.

Abstract: A polyimide thin film is formed on a substrate by imparting energy under vacuum, by means of heating, ultraviolet light or electron beam irradiation, or a combination thereof, to a polyimide having in the polymer main chain imide bonds and decomposable bonds such as carbon-carbon single bond differing from the imide bonds so as to break the decomposable bonds.

Abstract: This invention relates to new fluorine-containing polyimides, polyamide-acids/esters, polyamides, addition polyimides and imide oligomers which exhibit low melting points, better solubilities, low dielectric constants, superior thermal and thermal oxidative stability, and improved processing characteristics.The products of this invention are characterized by the fact that they are derived from 4,4'-bis[2-(3,4-(dicarboxyphenyl)hexafluoroisopropyl]diphenyl ether dianhydride.

Abstract: Production of polyenaminonitriles including those which can be cyclized to very stable poly(aminoquinolines) without the evolution of any small molecules and thus in a manner free of volatiles. The polyenaminonitriles are polymers which have desirable dielectric properties, and include those which can be cyclized to poly(aminoquinolines) without the evolution of volatiles to make defect-free films and composites of similar dielectric properties because of this characteristic.

Abstract: A polyimide resin composed essentially of repeating units represented by the general formula: ##STR1## where R is a divalent aromatic hydrocarbon radical.

Abstract: A method is provided for stabilizing polyamide acids of pyromellitic dianhydride and pyromellitic dianhydride copolymers utilizing certain silicon nitrogen compounds such as hexamethyldisilazane.

Abstract: This invention relates to new fluorine-containing polyimides, polyamide-acids/esters, polyamides, addition polyimides and imide oligomers which exhibit low melting points, better solubilities, low dielectric constants, superior thermal and thermal oxidative stability, and improved processing characteristics.The products of this invention are characterized by the fact that they are derived from 4,4'-bis[2-(amino(halo)phenoxyphenyl)hexafluoroisopropyl]diphenyl ether.

Abstract: The present invention here disclosed is directed to a photosensitive polymer having an inherent viscosity of 0.1 to 5 dl/g and represented by the general formula ##STR1## wherein R.sup.1 is independently a trivalent or tetravalent carbon cyclic aromatic group or heterocyclic group; R.sub.2 is independently an aliphatic group having at least 2 carbon atoms, an alicyclic group, an aromatic aliphatic group, a carbon cyclic aromatic group, a heterocyclic group or a polysiloxane group; R.sub.3 and R.sub.4 are CH.sub.2 --CH.dbd.CH.sub.2 ; m is 1 or 2; n is 0 or 1; and m and n satisfy 1.ltoreq.m+n.ltoreq.2.The photosensitive polymer of the present invention is applicable as electronic materials such as passivation films of semiconductors and print circuits.

Abstract: Copolyimides derived from the reaction product of 3,3'-6 F diamine or 4,4'-6 F diamine, at least one other diamine, and pyromellitic dianhydride can be rendered solvent soluble while at the same time exhibiting an improvement in both mechanical and electrical properties by the inclusion of at least one other dianhydride having a diaryl nucleus in the reaction media. Suitable such dianhydrides include bis (3,4 dicarboxy phenyl) ether dianhydride, 3,3'4,4' benzophenone tetracarboxylic dianhydride, 3,3',4,4' diphenyl tetracarboxylic acid dianhydride and 2,2 bis(3,4 dicarboxyphenyl) hexafluoropropane dianhydride (6F-DA). Such polyimides are soluble in common organic solvents such as methyl ethyl ketone or N-methyl pyrrolidone, and exhibit excellent film forming properties with improved mechanical and electrical properties as compared to the corresponding homopolyimides. They possess excellent heat stability (Tg's in excess of about 350.degree. C.

Abstract: Macrocyclic oligomers, including polycarbonates, polyesters, polyamides, polyimides, polyetherketones and polyethersulfones, are conveniently prepared from various spiro(bis)indane compounds, especially the 6,6'-difunctional 3,3',3'-tetramethylspiro(bis)indanes. The macrocyclic oligomers may be conveniently converted to linear polymers.