Abstract: This invention relates primarily to organofunctional monomers, predominantly dimethacrylates and/or diacrylates containing one or more (predominantly two carboxyl groups, with moieties that provide sufficient affinity with water to allow any desired amount of water and/or miscible fugitive solvents to be mixed homogeneously with these monomers and formulations containing them. The activity of water in the monomer formulations can be adjusted so that it is equal to the water activity in biological tissues. This promotes biocompatibility and enhances the adhesive characteristics of polymers prepared from these formulations. Probability statistics are disclosed that optimize the compositions of polymer reaction products.

Abstract: Aramids, which in the drawn state have high tensile strengths tensile elongations, and tensile moduli, are made from units derived from p-phenylenediamine, terephthalic acid, a substituted terephthalic acid, and 4,4'-bibenzoic acid or 2,6-naphthalene dicarboxylic acid. The aramids are useful for ropes and composites.

Abstract: The heat resistant adhesive of the invention comprises polyamic acid and/or polyimide which are prepared by using 1,3-bis(3-aminophenoxy)benzene as an aromatic diamine component and 3,3',4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride and/or 3,3',4,4'-diphenylethertetracarboxylic dianhydride as tetracarboxylic acid dianhydrides, and further by blocking the polymer chain end with dicarboxylic anhydride or a monoamine compound; or comprises a polyimide solution containing the polyimide in a good solvent.The adhesive of the invention is a heat-resistant adhesive capable of adhering under mild temperature/mild pressure conditions. The adhesive of polyimide solution can provide desired adhesion by simple procedures such as applying to the adherend and heating under pressure and exhibits excellent adhesive strength.

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: Fiber- or particulate-filled polyphthalamide molding compositions, wherein the polyphthalamide comprises recurring units obtainable from terephthalic acid, 2,6-naphthalene dicarboxylic acid, aliphatic diamine and, optionally, isophthalic acid, exhibit a desirable combination of thermal, mechanical and solvent resistance properties.

Abstract: Polyphthalamides having a useful combination of thermal and mechanical properties and excellent solvent resistance, particularly to alcohols, comprise recurring aliphatic terephthalamide and 2,6-naphthalene dicarboxylamide units and, optionally, isophthalamide units.

Abstract: This invention relates to cyclic diamides that are readily polymerized to form poly(terephthalamides). The resulting poly(terephthalamides) have high crystallinity, high temperature capabilities, dimensional stability, low moisture sensitivity, and solvent and chemical resistance.

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: Amorphous polyamide compositions are provided which are transparent and have improved glass transition and thermal decomposition temperatures. The polyamide compositions of the present invention can be prepared as the polymeric condensation product of a diamine component comprising neopentyldiamine, and a diacid component comprising an aromatic dicarboxylic acid.

Abstract: The heat resistant adhesive of the invention comprises polyamic acid and/or polyimide which are prepared by using 1,3-bis(3-aminophenoxy)benzene as an aromatic diamine component and 3,3', 4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride and/or 3,3',4,4'-diphenylethertetracarboxylic dianhydride as tetracarboxylic acid dianhydrides, and further by blocking the polymer chain end with dicarboxylic anhydride or a monoamine compound; or comprises a polyimide solution containing the polyimide in a good solvent.The adhesive of the invention is a heat-resistant adhesive capable of adhering under mild temperature/mild pressure conditions. The adhesive of polyimide solution can provide desired adhesion by simple procedures such as applying to the adherend and heating under pressure and exhibits excellent adhesive strength.

Abstract: A process is disclosed for the production of linear amorphous polyamides which results in polyamides having more amine endgroups than acid endgroups. It comprises condensing an aqueous solution of salts comprising at least one aromatic diacid containing from 7 to 20 carbon atoms and a greater than equimolar amount of at least one aliphatic diamine containing from 4 to 20 carbon atoms.

Abstract: There are described copolyamides which are soluble in organic polyamide solvents and contain recurring structural units of the formulae Ia, Ib, Ic and Id or Ia, Ib, Id and Ig or Ia, Ib, Ic, Id and Ig and optionally of the formulae Ie and/or If--OC--Ar.sup.1 --CO-- (Ia),--NH--Ar.sup.2 --NH-- (Ib),--NH--Ar.sup.3 --NH-- (Ic), ##STR1##--OC--R.sup.2 --CO-- (Ie),--NH--R.sup.3 --NH-- (If),--OC--Ar.sup.4 --CO-- (Ig),whereAr.sup.1 and Ar.sup.2 are each independently of the other divalent aromatic radicals whose valence bonds are in the para or a comparable coaxial or parallel position relative to one another,Ar.sup.3 and Ar.sup.4 are each independently of the other divalent radicals whose valence bonds are in the meta or a comparable kinked position relative to one another,R.sup.1 is lower alkyl, lower alkoxy or halogen, andR.sup.2 and R.sup.3 are each independently of the other divalent aliphatic, cycloaliphatic or araliphatic radicals.

Abstract: Linear aromatic copolyamides having good processability, superior thermal stability and excellent mechanical properties are provided. They comprise 55-90 mole % of a repearing unit of ##STR1## and 45-10 mole % of a repeating unit of ##STR2## wherein R.sub.1 and R.sub.2 each is a C.sub.4-12 aliphatic alkylene.

Abstract: Disclosed herein are chromium carbonyl complexes of polyamides containing units derived from aromatic diamines in which about 10 to about 90% of those units are complexed with a chromium carbonyl compound, and a process for making them. When aramids are used, the solubility of the polymer in organic solvents is enhanced, and in the case of certain aramids lyotropic solutions are formed. These solutions can be used to make anisotropic films and fibers.

Abstract: Azole rings, such as oxazole and thiazole rings, can activate an aromatic ring bonded to a leaving group such as a halogen atom so that the aromatic ring will undergo aromatic nucleophilic substitution. The reaction is useful for making ethers, thioethers and amines containing azole rings. In particular, monomers having azole rings, activated aromatic rings with leaving groups and nucleophilic moieties can react under conditions of aromatic nucleophilic displacement to form non-rigid rod PBZ polymers. The non-rigid rod PBZ polymers can be used to form molecular composites with rigid rod PBZ polymers which molecular composites are not substantially phase separated.

Abstract: A polyamide comprising a recurring unit of the formula (I), ##STR1## wherein each of R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7 and R.sup.8 is independently a hydrogen atom, a halogen atom, a hydroxyl group, or a group of a carbon skeleton which may contain a hetero atom or a halogen atom, and A.sup.1 is a divalent hydrocarbon group; and a process for the production of a polyamide comprising the recurring unit of the formula (I), which comprises subjecting to a polycondensation reaction a dicarboxylic acid comprising an alicyclic dicarboxylic acid of the formula (a)-1, ##STR2## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7 and R.sup.8 are as defined in the formula (I), and a diamine of the formula (b)-1,H.sub.2 N-A.sup.1 -NH.sub.2 (b)-1wherein A.sup.1 is as defined in the formula (I).

Abstract: Preparation of specially substituted aromatic polyamides containing structural units of the formula I mentioned and copolyamides containing at least 10 mol % of structural units of the formula I and structural units of the formula II mentioned and their use as orientation layer in liquid crystal display elements and/or liquid crystal switching elements.

Abstract: A thermoplastically processable aromatic polyamide is prepared by polycondensing diacid monomer A with diamine monomer B: (A) HOOC--Ar--COOH;(B) H.sub.2 N--Ar'--NH.sub.2 ; wherein Ar is 1,3-- or 1,4-phenylene; 1,4--, 1,5--, 2,6-- or 2,7-naphthylene, ##STR1## and Ar' is ##STR2## wherein X is --SO.sub.2 -- or --CO--; Y is --O-- or --S--; Z is --O--, --S--, --SO.sub.2 --, --CO-- or ##STR3## wherein R and R' each is --H or C.sub.1 -- to C.sub.4 -alkyl and n is 0 or 1 in the melt at a temperature in the range of from 200.degree. to 400.degree. C. in the presence of a catalyst selected from the group consisting of alkyl- or aryl-phosphonic acids, -phosphonous acids, -phosphinic acids, esters thereof, halides thereof and mixtures thereof, the catalyst content being 0.01 to 2.0 mol % relative to the total content of components A and B.

Abstract: Azole rings, such as oxazole and thiazole rings, can activate an aromatic ring bonded to a leaving group such as a halogen atom so that the aromatic ring will undergo aromatic nucleophilic substitution. The reaction is useful for making ethers, thioethers and amines containing azole rings. In particular, monomers having azole rings, activated aromatic rings with leaving groups and nucleophilic moieties can react under conditions of aromatic nucleophilic displacement to form non-rigid rob PBZ polymers. The non-rigid rod PBZ polymers can be used to form molecular composites with rigid rod PBZ polymers which molecular composites are not substantially phase separated.

Abstract: A wholly aromatic copolymer and a shaped article thereof having an excellent mechanical property, high resistances to heat and chemicals, and a satisfactory processability, is composed of (1) an aromatic dicarbonyl moiety consisting of recurring dicarbonyl units (A) and (B): ##STR1## and (2) an aromatic diamine moiety consisting of recurring diamine units (C) and (D): ##STR2## and the recurring dicarbonyl units (B) being in an amount of 0.01 molar % or more but less than 20 molar % based on the total molar amount of the dicarbonyl moiety (1), and the recurring diamine units (D) being in an amount of 60 molar % or less but more than 20 molar % based on the total molar amount of the diamine moiety (2).

Abstract: An improved stereolithography method for building a three-dimensional article including the steps of patternwise curing successive layers of a bath of curable liquid resin formulation until the article has been completely built up, removing the article from the liquid resin bath and then post-curing the article, wherein the liquid resin is a "thiol/nene" formulation including:(a) a first compound having a plurality of norbornene groups thereon;(b) a second compound having a plurality of thiol groups therein; and(c) a free radical photoinitiator,the total functionality of the formulation being greater than 4.

Abstract: The present invention comprises diamantane groups interspersed among benzothiazole groups, benzoxazole groups or benzimidazole groups. This constitutes a rigid-rod polymer with stable cycloaliphatic groups interspersed into the aromatic-heteroaromatic backbone of the rods. The presence of the aliphatic groups decreases crystallinity by adding disorder to the rods thus minimizing interactions between the heteroaromatic groups. The interspersed aliphatic groups act as insulators and thus permit greater relative protonation. Also, the reduced conjugation of the aromatic-heteroaromatic rings reduces the color of the polymers. The preferred method of manufacturing this improved rigid-rod polymer is by condensation of dimethyl diamantanecarboxylate with 2,5-diamino-1,4-benzenedithiol, 1,2,4,5-tetraaminobenzene, or 4,6-diamino-1,3-benzenediol.

Abstract: Diamines having a 1,1,3-trimethylphenylindane dicarboxylic moiety linked on both sides to phenylene diamine by an amide bond (PIDA diamines) are disclosed. By reacting these diamines with aromatic difunctional acid derivatives, amorphous polymers having high glass transition temperatures (Tg) can be prepared. If aliphatic diacid derivatives are used the resulting polymers have a lower Tg, but have the advantage of melt-processability. The PIDA-diamines can also be used in the preparation of polyimides, being reacted either with tri-or tetracarboxylic anhydrides or with imide group-containing acid derivatives.

Abstract: Provided is a para-ordered aromatic heterocyclic copolymer having repeating units of the formula --(--Q--Ar--).sub.m --(--Q--Ph--).sub.n -- wherein Q is ##STR1## wherein X is --O--, --NH-- or --S--, m is 0.05 to 0.50 and n is 1.

Abstract: Aromatic polyamides of the invention are polyamides comprising a recurring unit ##STR1## and a recurring unit [--NH--Ar.sub.1 --NH--] and copolyamides comprising a recurring unit ##STR2## and a recurring unit [--NH--Ar.sub.2 --NHCO--Ar.sub.3 --CO--] wherein Ar.sub.1 and Ar.sub.2 are, for example, phenylene group, naphthylene group, biphenylene group, and 4,4'-methylenediphenylene group and Ar.sub.3 is, for example, phenylene group, naphthylene group and biphenylene group in which both the bonding chains extend in the coaxial direction or in the parallel direction to axis.The aromatic polyamide of the invention has high glass transition temperature and has heat resistance, high strength, and high elasticity and besides is soluble in various solvents and is excellent in spinnability and film-formability. The aromatic polyamide is molded into fibers or films and can be utilized as electric insulating materials, laminates, varnishes, fabrics, synthetic papers, etc.

Abstract: Amorphous polyamide compositions are provided which are transparent and have improved glass transition and thermal decomposition temperatures. The polyamide compositions of the present invention can be prepared as the polymeric condensation product of a diamine component comprising neopentyldiamine, and a diacid component comprising an aromatic dicarboxylic acid.

Abstract: The present invention is an improved polyamide copolymer having monomer units including repeat units of the formula ##STR1## where n is from 10 to 14 and preferably is 12 (1,12-dodecanediamine), units derived from a symmetrical diacid or derivatives of said diacid, preferably a symmetrical aromatic dicarboxylic acid. The copolymer has minor amounts, preferably 3 to 30 and more preferably 5 to 10 mol percent, of units derived from an additional comonomer.

Abstract: New polybenzimidazolone polymers produced from the reaction of an aromatic tetraamine with a hexafluoro dianhydride. These hexafluoro polybenzimidazolone polymers based on an aromatic hexafluoro dianhydrides show improved solubility, easy processability, low moisture uptake, high thermal stability, resistance to solvent and other improvements over conventional polybenzimidazolone polymers.

Abstract: This invention discloses new polybenzimidazolone polymers produced by the reaction of a hexafluoro aromatic tetraamine with a dianhydride reactant. These hexafluoro polybenzimidazolone polymers based on an aromatic hexafluoro tetraamine show improved solubility, easy processability, low moisture uptake, high thermal stability, resistance to solvent and other improvements over conventional polybenzimidazolone polymers.

Abstract: Compounds are disclosed which are anhydrides containing additional carboxylic acid moieties and dianhydrides of disubstituted maleic anhydride compounds wherein the acid anhydrides and dianhydrides retain their alkene character. These compounds are useful as precursors for polyesters, thermally stable polyamide-imides and polyimides.

Abstract: There is provided a para-ordered, rigid-rod aromatic heterocyclic copolymer having repeating groups of the formula:--Ba--Ar).sub.x (Ba--Fl).sub.1.0-xwherein x has a value of 0.50 to 0.99, Fl is a 2,7-fluorene moiety, Ar is a para-ordered arylene group and Ba is a benzazole group of the formula: ##STR1## wherein Y is S or O.

Abstract: Diamine compounds having the structural formula: ##STR1## wherein R.sub.1 is a methyl or ethyl group, can be used in preparing various polymers which are useful components in gas separation membranes. The combined effect of specific substituents ortho to the amino groups and the fluorenylidene bridging group imparts useful properties to polymeric membranes formed with these monomers.

Abstract: A fiber product comprising one or more fibers of aromatic polyamide polymer having a microscopic structure of an extended molecular chain, free of crystal defect layers perpendicular to the fiber axis, a high inherent viscosity of at least 3.0 [dl/g], and a high tensile strength of at least 15 g/d, said inherent viscosity being determined at 30.degree. C. using a concentration of 0.5 grams of said polymer in 100 ml of concentration sulfuric acid.

Abstract: A novel class of cyano-, cyanoalkyl-, carboxy- or carboxyalkylaryl-substituted 1,6-diaza [4.4] spirodilactams, having a cyano-, cyanoalkyl-, carboxy- or carboxyalkylaryl substituent attached to each spiro ring nitrogen atom, are useful for the preparation of polyesters and polyamides.

Abstract: This invention relates to novel polyimides derived from alicyclic dianhydrides and a process for synthesizing the polyimides.

Abstract: Amorphous para-oriented aromatic homo- and co-polyamides are prepared from terephthaloyl chloride or 2,6-naphthoyl chloride and 2,2'-dibromo-5,5'-dimethoxy-[1,1'-biphenyl]-4,4'-diamine with up to 92.5 mol % of certain other diamines.

Abstract: Soluble, film-forming, polyamides, polyimides, and polyamide-imides and their copolymers made using 3,5-diamino-t-butylbenzene are described. These polymers have some solubility in organic solvents such as N-methylpyrrolidone, a high Tg, excellent thermal stability, lower density and lower moisture uptake and are useful in films, fibers and composites, and in the electronics industry as electrical component substrates, protective coatings, interlevel dielectrics and the like.

Abstract: High modulus, high tenacity fibers of poly-p-phenylene terephthalamide (PPD-T) are disclosed along with a fiber heat treating process for increasing the inherent viscosity and the crystallinity index of the PPD-T. Never-dried fibers swollen with water of controlled acidity are heated beyond dryness.

Abstract: Resinous condensation polymers of polycarboxylic acid compounds and aromatic diprimary amines comprising diamino-t-butylbenzenes are described. In particular, film-forming polyamides, polyimides and polyamide-imides and their copolymers made using diamino-t-butylbenzenes which have amino groups meta or para to each other on a benzene ring are described. These polymers have some solubility in organic solvents such as N-methylpyrrolidone, a high glass transition temperature, excellent thermal stability, and are useful in films, fibers and composites, and in the electronics industry as electrical component substrates, protective coatings, interlevel dielectrics and the like.

Abstract: A separation membrane consisting of a polyamide having a unit (I) or a mixing of polyamides having units (I) and (II) an (II') or a polyester having a unit (III) or (IV) and (IV') or a mixture of polyesters having units (III) and (IV) and (IV'):--HN--X--NH--Z.sub.1 -- (I)--(HN--X--NH--Z.sub.1).sub.l -- (II)--HN--X--NH--Z.sub.1 ').sub.n -- (II')--O--X--O--Z.sub.2 -- (III)--(O--X--O--Z.sub.2).sub.r -- (IV)--O--X--O--Z.sub.2 ').sub.s -- (IV')wherein X represents ##STR1## where R represents H, CH.sub.3, or C.sub.2 H.sub.5 ; Z.sub.1 and Z.sub.2 represent ##STR2## Z.sub.1 ' represents --CO--(CH.sub.2).sub.p --CO--, Z.sub.2 ' represents --CO--CH.dbd.CH--CO--, p is an integer of 4 to 8, n/l is 1.0 to 20, and r/s is 0.5 to 100.

Abstract: Resinous condensation polymers of polycarboxylic acid compounds and aromatic diprimary amines comprising diamino-t-butylbenzenes are described. In particular, film-forming polyamides, polyimides and polyamide-imides and their copolymers made using diamono-t-butylbenzenes which have amino groups meta or para to each other on a benzene ring are described. These polymers have some solubility in organic solvents such as N-methylpyrrolidone, a high glass transition temperature, excellent thermal stability, and are useful in films, fibers and composites, and in the electronics industry as electrical component substrates, protective coatings, interlevel dielectrics and the like.

Abstract: Resinous condensation polymers of polycarboxylic acid compounds and aromatic diprimary amines comprising diamino-t-butyltoluene are described. In particular, film-forming polyamides, polyimides and polyamide-imides and their copolymers made using diamino-t-butyltoluene which have amino groups meta or para to each other on a benzene ring are described. These polymers have some solubility in organic solvents such as N-methylpyrrolidone, a high glass transition temperature, excellent thermal stability, and are useful in films, fibers and composites, and in the electronics industry as electrical component substrates, protective coatings, interlevel dielectrics and the like.

Abstract: Soluble, film-forming, polyamides, polyimides, and polyamide-imides and their copolymers made using 3,5-diamino-t-butylbenzene are described. These polymers have some solubility in organic solvents such as N-methylpyrrolidone, a high Tg, excellent thermal stability, lower density and lower moisture uptake and are useful in films, fibers and composites, and in the electronics industry as electrical component substrates, protective coatings, interlevel dielectrics and the like.

Abstract: Polyamides having improved solubility and processing characteristics are provided having incorporated into the polymeric chain a novel aromatic diamine compound, 2-(3-aminophenyl)-2-(4-aminophenyl) hexafluoropropane (3-4'-6F Diamine). The polyamides are prepared by reacting the 3,4'-6F Diamine with an aliphatic or aromatic di-acid or acid halide. It has been found that the polyamides of this invention have improved solubility characteristics, low dielectric constants and improved thermal flow properties as a consequence of the meta/para positioning of the amino groups on the daimine, which renders these polymers more readily melt spinnable for the production of fibers. The polymers may also be compression molded and fabricated into composites at moderate temperatures and pressures.

Abstract: Copolyamides are prepared by the reaction of monocyclic spiro(bis)indane polyamide oligomers with lactams in the presence of basic reagents.

Abstract: Novel hydroxyethylnorbornene esters are disclosed which are prepared by reacting cyclopentadienylethanol with an acrylate ester. Novel polyesters are disclosed which are prepared by the self-polymerization of the hydroxyethylnorborane (HEN) esters. Novel polyesters are also obtained by reacting HEN compounds and a diol or other polyol in the presence of diacids or their esters or anhydrides. The polyesters of the present invention are useful as tackifying agents, adhesives, coatings, and for other purposes.

Abstract: A soluble heat-resistant aromatic polyamide having amide bonds at the terminal ends thereof represented by the formula (I):R.sup.1 CO--NH--Y--NH--X).sub.n NH--Y--NHCOR.sup.1 (I)wherein R.sup.1 represents an alkyl group or aromatic group,Y represents ##STR1## wherein R.sup.2 represents hydrogen, methyl, or ethyl, X represents ##STR2## wherein Z represents an aromatic ring which may be substituted with an alkyl group, andn is a recurring unit number; said polyamide having an inherent viscosity (.eta..sub.inh) of at least 0.30 dl/g as measured in a solution of 0.5 g of the polyamide in 100 ml of dimethylacetamide at 30.degree. C.

Abstract: Cyclic polyamide oligomers are prepared by the reaction of various spirobiindane diamines, including spirobiindane bisphenol bis-aminophenoxy ethers, with dicarboxylic acid chloride such as isophthaloyl chloride. The oligomer compositions may be converted to copolyamides by reaction with lactams in the presence of basic reagents.

Abstract: A curable thiol-ene formulation comprising(a) a polythiol(b) a 'ene compound having a plurality of groups of the formula: ##STR1## where Q is CH.sub.2, CHCH.sub.3, C(Ch.sub.3).sub.2, O, S, NR.sup.1 or SO.sub.2 R.sup.1 is H or alkyl, and m is 0-10, and(c) an effective amount of a free radical initiator.

Abstract: A heat-resistant polyamide having a repeating unit represented by the formula (I):--X--NH--Y--NH--(I)wherein X represents the structure (A): ##STR1## or the structure (A) and the structure (B) --C.sub.m H.sub.2m -- wherein R represents hydrogen, methyl, or ethyl and m is an integer of 2 to 8; and Y represents the structure (C) ##STR2## and the structure (D) --CO--C.sub.n H.sub.2n --CO-- wherein n is 2 to 6, provided that Y may be the structure (C) when X is the structures (A) and (B), said polyamide having an inherent viscosity (.eta..sub.inh) of at least 0.25 dl/g as determined at a temperature of 30.degree. C. in a solution of 0.5 g of the polyamide in 100 ml of dimethylacetamide.