Abstract: A charge transport polymer including repeat units selected from mers of the formulas ##STR1## and copolymers, and mixtures thereof.

Abstract: Woven or laid structures comprising at least two systems of parallel threads, at least one of these thread systems having more than 10 threads per centimeter and comprising at least 10%, based on the thread system, of hybrid yarns comprising reinforcing filaments and lower melting matrix filaments composed of thermoplastic polymers. In such woven or laid structures, the matrix component can be melted to form textile sheet materials of adjustable gas and/or liquid permeability, which are especially useful for manufacturing airbags.

Abstract: Liquid crystalline polymers that are made from 4-hydroxybenzoic acid, 2,6-naphthalenedicarboxylic acid, terephthalic acid, hydroquinone, and N-acetyl-4-aminophenol by heating the monomers in the presence of acetic anhydride are more easily synthesized in high molecular weight if isophthalic acid is also included as a monomer at a level of about 0.5 mole % to about 10 mole %.

Abstract: Materials of formula (I) are provided, wherein X.sub.1 -X.sub.5 are independently selected from H, F, Cl, NO.sub.2, CF.sub.3, OR, R, SR, .paren open-st.CO-- or .paren open-st.CO-- where R is C.sub.1-15 branched or straight chain alkyl; provided that one of X.sub.1 -X.sub.5 is selected from .paren open-st.CO-- or .paren open-st.OC--; p is at least 2; W=single bond, phenyl, fluorinated phenyl, .dbd., .tbd., cyclohexyl, thiophene, CO, OC; T.sub.1, T.sub.2, T.sub.3, T.sub.4 are independently selected from H, F, Cl, NO.sub.2, CF.sub.3, OR, R, SR, where R is C.sub.1-15 branched or straight chain alkyl; g=0 or 1; X is selected from CO.sub.2 and OOC; n is selected from 1-5; m is selected from 1-20, Y is selected from O, S, CH.sub.2, CO.sub.2, OOC; Q is CH.sub.2 and when m is greater than 1 then non-adjacent CH.sub.

Abstract: Disclosed is a process which comprises reacting a haloalkylated aromatic polymer with a material selected from the group consisting of unsaturated ester salts, alkoxide salts, alkylcarboxylate salts, and mixtures thereof, thereby forming a curable polymer having functional groups corresponding to the selected salt. Another embodiment of the present invention is directed to a process for preparing an ink jet printhead with the curable polymer thus prepared.

Abstract: Disclosed is a process which comprises reacting a polymer of the general formula ##STR1## wherein x is an integer of 0 or 1, A is one of several specified groups, such as ##STR2## B is one of several specified groups, such as ##STR3## or mixtures thereof, and n is an integer representing the number of repeating monomer units, with an acetyl halide and dimethoxymethane in the presence of a halogen-containing Lewis acid catalyst and methanol, thereby forming a haloalkylated polymer. In a specific embodiment, the haloalkylated polymer is then reacted further to replace at least some of the haloalkyl groups with photosensitivity-imparting groups. Also disclosed is a process for preparing a thermal ink jet printhead with the aforementioned polymer.

Abstract: Papermaking machine fabrics, filters and reinforcing layers for elastomers, comprise monofilaments of copolymers containing 85 to 99 mol % of the structural repeat unit of the formula I ##STR1## 1 to 15 mol % of the structural repeat unit of the formula II--OC--R.sup.2 --CO--O--R.sup.3 --O-- (II),whereR.sup.1 is a radical of a dihydric aliphatic or cycloaliphatic alcohol or is derived from mixtures of such alcohols,R.sup.2 is a radical of an aliphatic, cycloaliphatic or monocyclic aromatic dicarboxylic acid or is derived from mixtures of such dicarboxylic acids,R.sup.3 assumes one of the definitions for R.sup.1, and the quantitative data are based on the total amount of the polymer.

Abstract: This invention relates to block copolycarbonates made from polycarbonate blocks and polyisobutylene-.alpha.-haloketocarboxylic acid blocks (abbreviation: PIB blocks), wherein the PIB blocks may, for example, be obtained by ozonolysis of halogenated butyl rubber, and to blends of these block copolycarbonates with elastomers.

Abstract: A process for the production of a terminal-blocked aromatic polycarbonate by melt-polycondensing an aromatic dihydroxy compound and diphenylcarbonate, the process comprising adding a specific carbonate or carboxylic ester after a polycarbonate formed has an intrinsic viscosity of at least 0.3 dl/g, to form a terminal-blocked polycarbonate having an intrinsic viscosity which is greater than, or smaller than, the intrinsic viscosity of the polycarbonate formed before the addition by 0.1 dl/g at the most; and a process for the production of a polycarbonate having an increased intrinsic viscosity by melt-polycondensing an aromatic dihydroxy compound and diphenylcarbonate, the process comprising adding a specific diaryl carbonate or dicarboxylic diaryl ester after a polycarbonate formed has an intrinsic viscosity of at least 0.3 dl/g, to form a polycarbonate having an intrinsic viscosity greater than the intrinsic viscosity of the polycarbonate formed before the addition by more than 0.1 dl/g.

Abstract: For the preparation of polyesters and copolyesters, titanium dioxide/silicon dioxide coprecipitates having a composition of TiO.sub.2 :SiO.sub.2 =90:10 to 20:80 mol/mol and/or titanium dioxide/zirconium dioxide coprecipitates having a composition of TiO.sub.2 : ZrO.sub.2 =95:5 to 70:30 mol/mol are proposed as polycondensation catalysts. They have a higher catalytic activity than Sb.sub.2 O.sub.3, so that the preferred amount used is only 10 to 100 ppm, based on the esters or oligoesters to be subjected to polycondensation.

Abstract: There are disclosed a wholly aromatic polyester represented by formula I with enhanced flame retardance and chemical stability, and a method for the preparing the same. The polymer is prepared in interface polymerization wherein an alkali aqueous phase containing cyclotriphosphagene-containing bisphenols is in contact with an organic phase containing aromatic dicarboxylic acid chlorides in the presence of a phase transfer catalyst. ##STR1## wherein m and n each are an integer which satisfies the following conditions: 0<m/(m+n)<1 and 0<n/(m+n)<1; X represents --O--, --S--, --SO.sub.2 --, --SO--, --CO--, an alkylene group of C.sub.1-4, or an alkylidene group of C.sub.1-4 ; and R.sub.1, R.sub.2, R.sub.3, R.sub.1 ', R.sub.2 ', R.sub.3 ' and R.sub.4 ' are the same or different, and represent a hydrogen atom, a halogen atom, or an alkyl group of C.sub.1-4 or the derivatives thereof, respectively.

Abstract: This invention relates to polymers having non-linear optical properties which polymers include fluorene moieties having at least one electron accepting group and at least one electon donating group substituted to different phenyl rings of the fluorene moiety.

Abstract: A new class of polymers include repeating units comprising one or more arylene units substituted with heterocyclic side groups. The heterocyclic substituted arylene repeat units have the general structural formula: ##STR1## wherein Het is a heterocyclic group, R is an optional substituent, x is 1 or 2, and y is less than or equal to 4-x.

Abstract: The present invention relates to a random copolyester containing naphthalene ring structure, in particular to a random copolyester containing a first repeating unit which is the same as that of polyalkylene naphthalate, such as polyethylene naphthalate (PEN) and polybutylene naphthalate (PBN), and a second repeating unit which is similar to the first repeating unit except that an aryl ether linkage is incorporated thereto. The present copolyester can be prepared from a dihydroxyethoxy compound and bis(hydroxyalkyl)naphthalate via a direct melt polycondensation in the presence of a metallic catalyst.

Abstract: An improved process for preparing high molecular weight polyester polymers, such as poly(butylene terephthalate), an alkylene glycol and a di- or tricarboxylic acid by first preparing a pre-polymer in the form of uniform solid particles having an intrinsic viscosity of from 0.1 to about 0.3 dL/gm and a chemical composition which contains greater than a 1% stoichiometric excess of the alkylene glycol above the amount required to produce a high molecular weight polymer, and polymerizing the pre-polymer in the solid state.

Abstract: A process for producing fibers or films by the steps of:a) preparing an aromatic polyamide by polycondensation of dicarbonyl dihalides or mixtures thereof with at least two diamines in N-alkyllactams as a solvent, the polycondensation being of at least 90 mol %, based on the total amount of dicarbonyl dihalides in the reaction mixture, of compounds of the formula I or mixtures of such compoundsHal--OC--Ar.sup.1 --CO--Hal (I)with at least 90 mol%, based on the total amount of diamines in the reaction mixture, of compounds of the formula II and optionally III or mixtures of such compoundsH.sub.2 N--Ar.sup.2 --NH.sub.2 (II), H.sub.2 N--Ar.sup.3 --NH.sub.2 (III)where Ar.sup.1, Ar.sup.2 and Ar.sup.

Abstract: The yield of fully substituted, multidimensional aromatic hubs in the condensation of hydroxyl and acid halide functionalities is improved by adding a thallium catalyst, such as thallium ethoxide (T1-OC.sub.2 H.sub.5), in the solvent.

Abstract: Aromatic copolyamides, production thereof, formed structures and production thereofDescribed are aromatic copolyamides comprising the structural repeat units of the formulae I, II and III ##STR1## where Ar.sup.1, Ar.sup.2, Ar.sup.3 and Ar.sup.

Abstract: Crosslinkable, polyaromatic, polyether or polyester oligomers can have glass transition temperatures above 900.degree. F. while exhibiting desirable toughness for aerospace applications and ease of processing. A plurality (i.e. three or more) of generally linear aryl arms extend outwardly like spokes from a central aromatic hub through ether or ester linkages. Each spoke usually includes electronegative linkages, and is capped with one or two crosslinking functionalities (i.e. unsaturated hydrocarbon sites) which may be thermally or chemically activated to complete the advanced composite during curing. Among other methods, linear and multidimensional polyether oligomers are synthesized using nitrophthalic anhydride or halophthalic anhydride, dialcohols, or polyols, diamines, and suitable end caps.

Abstract: A copolymer consisting essentially of a repeating sequence represented by the formula ##STR1## where Ar.sub.1, Ar.sub.2, and Ar.sub.3, are each independently chosen from the group consisting of ##STR2## which are either unsubstituted or are substituted with one or more substituents chosen from the group consisting of alkyl groups having 1-6 carbon atoms, halogen (F, Cl or Br), and phenyl; Z, Y.sub.1 and Y.sub.2 are each independently O, NH, or S; n and m are positive integers; and X is a covalent bond, O, S, SO.sub.2, CO, C(C.sub.6 H.sub.5).sub.2, C(C.sub.6 H.sub.5)H, C(C.sub.6 H.sub.5)(CH.sub.3), C(CH.sub.3).sub.2, C(CH.sub.3)H, CH.sub.2, C(CF.sub.3).sub.2, or 3,3,5-trimethyl cyclohexyl. The polymers of this invention are derived from a minimum of three different monomers.

Abstract: This invention concerns positive-working photodefinable polyimide precursors which make use of chemical amplification based on photoacid catalyzed cleavage of acid labile-poly(amic acetal esters).

Abstract: The present invention relates to a process for the preparation of polycarbonates in which an oil-in-water emulsion is maintained throughout by employing special reaction conditions.

Abstract: The present invention relates to a polymerization method for preparing non-halogenated aromatic polyesters by a standard interfacial polymerization except the addition of a phase-transfer catalyst to the organic phase. More specifically, the present invention offers a method for substantially reducing the polymerization time and improving the reaction yield, by introducing a specific phase transfer catalyst, tetrabutyl ammonium bromide, to the organic phase.

Abstract: Crosslinkable, polyaromatic, polyether or polyester oligomers can have glass transition temperatures above 900.degree. F. while exhibiting desirable toughness for aerospace applications and ease of processing. A plurality (i.e. three or more) of generally linear aryl arms extend outwardly like spokes from a central aromatic hub through ether or ester linkages. Each spoke usually includes electronegative linkages, and is capped with one or two crosslinking functionalities (i.e. unsaturated hydrocarbon sites) which may be thermally or chemically activated to complete the advanced composite during curing. Among other methods, linear and multidimensional polyether oligomers are synthesized using nitrophthalic anhydride or halophthalic anhydride, dialcohols, or polyols, diamines, and suitable end caps.

Abstract: Fluorinated thermoplastic elastomers having a block structure:--[--R.sub.f --H.sub.1 --H.sub.2 --H.sub.1 --]--where --R.sub.f -- is a perfluoropolyoxyalkylene sequence of formula:--CF.sub.2 O--(CF.sub.2 CF.sub.2 O).sub.m --(CF.sub.2 O).sub.n --CF.sub.2 --with m/n=0.2.div.5, H.sub.1 and H.sub.2, equal or different from each other, are bivalent radicals having arylene, alkylarylene, alkylene or cycloalkylene structure, optionally containing fluorine and/or other heteroatoms selected among oxygen, sulphur, nitrogen. Such products are obtainable by utilizing a perfluoropolyoxyalkylene diol having a functionality at least equal to 1.97, preferably at least equal to 1.99, and are characterized by a tensile strength at 23.degree. C. at least 50% higher than that of the corresponding polyesters obtained starting from perfluoropolyoxyalkylene diols having a functionality not higher than 1.96.

Abstract: The present invention provides novel substituted biphenyl pyrazines or pyrazine derivatives ("BPD") which are functional and have useful application as a monomer for a variety of high performance polymers such as polyester, polyarylate, polycarbonate, polyetherketones, epoxides, polyimides, polyamides, and polyamides-imides; and as pigments for coating compositions such as paints. These BPD have the general formula: ##STR1## wherein R.sub.1 -R.sub.8 and n are defined herein.

Abstract: A method for preparation of a polyether-ester elastomer. The method comprises admixturing dibasic acid with short chain diol for the formation of a short chain ester monomer represented :into general formula (I) and with polyglycol for the formation of a long chain ether moromet represented into general formula (II), adding the alkali salt of dialkylsufoisophthalate to the admixture to react the admixture until the discharge of methanol is tip to above 70%, adding stabilizing agent to perform the polymerization reaction, and then, blending phenolic alkali metal salt. ##STR1## wherein R is a biradical obtained by removing carboxyl group from a dicarboxylic acid having a molecular weight not more than 400,D is a biradical obtained by removing hydroxyl group from a short chain diol having a molecular weight not more than 250, andG is a biradical obtained by removing hydroxyl group from a long chain ether glycol having a molecular weight of a range of about 400 to 4,000.

Abstract: This invention concerns positive-working photodefinable polyimide precursors which make use of chemical amplification based on photoacid catalyzed cleavage of acid labile-poly(amic acetal esters).

Abstract: It is intended to provide a liquid crystalline polyester whose orientation in the state of liquid crystal can be easily immobilized as glass phase and which is suitable for application to optical elements.A liquid crystalline polyester comprising repeating units a, b, c and d represented by the following general formulae: ##STR1## where X and Y are each independently a hydrogen atom, Cl, Br or an alkyl group having 1 to 4 carbon atoms, the repeating units a, b, c and d being in mole ratios such that (a+b)/(c+d) is approximately 1, a/b is in the range from 98/2 to 50/50 and c/d is in the range from 70/30 to 10/90.

Abstract: Polyetherimides, polyesterimides, poly(ester etherimides) and poly(carbonate imides) which are thermoplastic, polymeric materials contain divalent bisimides of formula ##STR1## wherein R is independently in each occurrence hydrogen, alkyl of from 1 to 20 carbons, aryl or aralkyl of from 1 to 20 carbons, halogen or NO.sub.2. Novel monomeric bisimides corresponding to the above formula are also disclosed.

Abstract: A poromeric material for maintaining an electrostatic charge is provided, the material including a matrix of fibers, a polymeric binder for binding the matrix, and electrets present substantially uniformly throughout the poromeric material. Also provided are methods for making the poromeric material. In one embodiment, a polymeric binder mixture having electrets substantially uniformly contained therein is formed. The matrix of fibers is impregnated with the mixture and cured, whereby the electrets are substantially uniformly distributed throughout the matrix to produce the electrostatic poromeric material. In an alternative embodiment, the electrets are contained in the fibers of the matrix. The poromeric material may be used to encase a core to form a roller, for example, a hickey-removing roller.

Abstract: Thermoplastic polyester-imides having improved mechanical properties, characterized in that they consist of recurring units of the formula I ##STR1## in which R denotes an 2,4-tolylene, 2,6-tolylene, 2,5-bis(4-phenylenethio) thiadiazole,or a 1,4-bis(phenylenethio)diphenyl sulfone radical, a process for their preparation and their use for the production of industrial components of plastic.

Abstract: Diarylacetylenes and diarylenamines are synthesized from a Schiff's base and an N-arylmethylheterocycle; these compounds are useful as intermediates for a variety of polymers; in particular an efficient process is provided for producing diaryl acetylenes useful in the efficient production of acetylene group-containing polymers which can be cross-linked to produce high strength polymers free of structural defects such as conventionally arise as a result of liberation of volatiles during the cross-linking.

Abstract: Composite printed circuit board substrates having fiber reinforcement in a polymer matrix are disclosed. The fibers may be thermotropic melt processable liquid crystal polymer fibers.

Abstract: Aromatic copolyamides are described which are soluble in organic polyamide solvents and which comprise the recurring structural units of the formulae Ia, Ib, Ic and Id[--OC--R.sup.1 --CO--NH--R.sup.2 --NH--] (Ia),[--OC--R.sup.1 --CO--NH--R.sup.3 --NH--] (Ib),[--OC--R.sup.1 --CO--NH--R.sup.4 --NH--] (Ic),[--OC--R.sup.1 --CO--NH--R.sup.5 --NH--] (Id)in whichR.sup.1 and R.sup.2 are mainly unsubstituted divalent aromatic radicals, the valency bonds of which are in the para-position or in a comparable coaxial or parallel position with respect to one another,R.sup.3 is a radical of the formula II ##STR1## R.sup.4 is a radical of the formula III--Ar.sup.1 --O--Ar.sup.1 --O--Ar.sup.1 -- (III), andR.sup.5 is a radical of the formula IV and/or V ##STR2## in which Ar.sup.1 has one of the meanings defined for R.sup.

Abstract: Polyimide compositions, films, and electronic devices using polyimides, based on 9-aryl-9(perfluoroalkyl)xanthene-2,3,6,7-dianhydride or 9,9'-bis(perfluoroalkyl)xanthene-2,3,6,7-dianhydride and benzidine derivatives. These polyimides offer a combination of low linear coefficient of thermal expansion, low dielectric constant, and low water absorption.

Abstract: This invention concerns novel fluorine-containing diamines, polyamides and polyimides. The compounds are useful in the formation of moisture resistant films, fibers and shaped articles.

Abstract: Thermotropic liquid crystalline poly(ester-amide) compositions are disclosed which comprise a bis(4-carbonyl phenylene) terephthalate unit and a unit derived from an N-substituted hydrocarbylenediamine (e.g., one derived from an N,N-dialkylalkylene).

Abstract: Di(hydroxyphenyl)benzimidazole monomers were prepared from phenyl-4-hydroxybenzoate and aromatic bis(o-diamine)s. These monomers were used in the synthesis of soluble polybenzimidazoles. The reaction involved the aromatic nucleophilic displacement of various di(hydroxyphenyl)benzimidazole monomers with activated aromatic dihalides or activated aromatic dinitro compounds in the presence of an alkali metal base. These polymers exhibited lower glass transition temperatures, improved solubility, and better compression moldability over their commercial counterparts.

Abstract: There are described aromatic copolyamides which are soluble in organic polyamide solvents and which consist essentially of recurring structural units of the formulae Ia, Ib and Ic on the one hand and Ia, Ib and Ie on the other[--OC--R.sup.1 --CO--NH--R.sup.2 --NH--] (Ia), [--OC--R.sup.1 --CO--NH--R.sup.3 --NH--] (Ib),[--OC--R.sup.1 --CO--NH--R.sup.4 --NH--] (Ic), [--OC--R.sup.1 --CO--NH--R.sup.7 --NH--] (Ie),where R.sup.1 and R.sup.7 are divalent aromatic radicals whose valence bonds are in the para or a comparable coaxial or parallel position relative to one another, R.sup.2 is a radical of the formula III ##STR1## and R.sup.3 and R.sup.4 are radicals of the formula IV ##STR2## where Z is --O--, --S--, --CO--, --SO.sub.2 --, C.sub.1 -C.sub.10 -alkylene or --O--R.sup.1 --O-- and R.sup.6 is in each case hydrogen or an inert substituent.The mole fractions of the individual structural features in the copolyamides are defined within selected limits.

Abstract: A ferroelectric, liquid-crystalline polymer is composed of repeating units of the formula (I) ##STR1## in which Y.sup.1 =H, CH.sub.3 or FY.sup.2 =H or FR.sup.1 = ##STR2## or an achiral alkyl having 2 to 16 carbon atoms, and R.sup.3 =H or CH.sub.3R.sup.2 =CH.sub.3, Cl or CNg and h=an integer from 0 to 10a=2 to 20, preferably 6 to 12b,c,d,e and f=0 or 1, where d+e+f=2 or 3A.sup.1,A.sup.2 and A.sup.3 =for example, 1,4-phenylene in which one or two hydrogen atoms may be substituted by F, Cl and/or CN, 1,4-cyclohexylene andM.sup.1,M.sup.2 and M.sup.3 =for example, CO--O or O--CO.These liquid-crystalline polymers have short response times and high resistance to mechanical stresses. They can be prepared by free-radical polymerization.

Abstract: A process for producing a branched polycarbonate comprising reacting a dihydric phenol, such as 2,2-bis(4-hydroxyphenyl) propane, a polyfunctional organic compound, such as 1,1,1-tris-(4-hydroxyphenyl)ethane, and phosgene to produce a polycarbonate oligomer, and then polycondensing with stirring the polycarbonate oligomer with a dihydric phenol, such as 2,2-bis(4-hydroxyphenyl) propane, and a monohydric phenol, such as p-tert butylphenol, whereby the interfacial area of the resultant emulsion is not less than 40 m.sup.2 /L.

Abstract: The invention relates to a class of copolymers capable of forming an optically anisotropic melt comprising recurring structural units (a) independently each occurrence selected from the group consisting of Formula I; recurring structural units (b) independently each occurrence selected from the group consisting of Formulas II and III; and optionally recurring structural units (c) independently each occurrence selected from the group consisting of Formula IV: ##STR1## wherein R independently each occurrence is a chemically inert substituent.

Abstract: Aromatic copolyamides are described which are soluble in organic polyamide solvents and which essentially consist of the recurring structural units of the formulae Ia, Ib and Ic ##STR1## wherein R.sup.1 and R.sup.4 are divalent aromatic radicals, the valency bonds of which are in the para position or in a comparable coaxial or parallel position relative to one another, R.sup.2 is a radical of the formula III ##STR2## and R.sup.3 is a radical of the formula IV ##STR3## The mole fractions of the individual structural features in the copolyamides are fixed within selected limits. Fibers composed of the copolyamides claimed are distinguished by a high stretchability.

Abstract: The invention comprises liquid crystalline polyesters suited to be used as a medium for optical data storage, especially reversible (or erasable) optical data storage. The polyesters comprise the polycondensation product of an aliphatic dicarboxylic acid or a derivative thereof and propane diol which on its center carbon bears a mesogenic substituent comprising two rings, either alicyclic or aromatic. Preferably also the dicarboxylic acid or derivative thereof is mesogenically substituted. The invention further comprises a medium for optical data storage containing polyesters of the above type.

Abstract: Polyimide compositions, films, and electronic devices using polyimides, based on 9,9-bis(perfluoroalkyl)xanthene-2,3,6,7-tetracarboxylic dianhydride or 9-aryl-9(perfluoroalkyl)xanthene-2,3,6,7-tetracarboxylic dianhydride and 3,3',4,4'-biphenyl tetracarboxylic dianhydride or 2,2-bis(3,4-carboxyphenyl)hexafluoropropane dianhydride and benzidine derivatives which offer a combination of desirable properties including, low linear coefficient of thermal expansion, low moisture absorption, high glass transition temperature, low dielectric constant, and improved tensile elongation.

Abstract: A halogenated copolycarbonate, including a poly(ester/carbonate), which contains reduced levels of phenolic end groups and end groups which result from side reactions of process chemicals with the copolycarbonate chain, has improved resistance to the degradation-inducing effects of such end groups and has improved washability.

Abstract: Polymers and copolymers having high glass transition temperature and which are soluble in organic solvents are produced from highly hindered biphenols, in particular polyetherketones, polyethersulfones, polyesters and polyetherimides, as well as copolymers based on these polymers may be produced for a variety of applications.

Abstract: The new polyphosphonates, which are highly branched through polyfunctional phosphorus compounds, are suitable for use as moldings, fibers or films and as flameproofing agents and stabilizers in plastics. The new highly branched polyphosphonates show high resistance to thermal ageing and ensure good processability coupled with high migration resistance at elevated in-use temperatures.

Abstract: Rigid fluorine-containing compounds, monomers, and polymers based on pentacyclic core systems, such as 12H,14H-5, 7-dioxapentacene with perfluoroalkyl and/or aryl groups in the 12, 14 positions, and 5H,12H-7, 14-dioxapentacene, with perfluoroalkyl and/or aryl groups in the 5,12 positions. These monomers have utility in the preparation of advanced high-performance polymers, particularly polyimides. The rigid pentacyclic core decreases the coefficient of thermal expansion of the polymers, while the fluorinated substituents improve the dielectric constant and water absorption properties. Each monomer unit contains within its pentacyclic core two-O-bridges, and two --CRR.sub.f bridges (where R is aryl, substituted aryl or perfluoroalkyl, and R.sub.f is perfluoroalkyl).