Abstract: Crosslinked polymer compositions comprise a first synthetic polymer containing multiple nucleophilic groups covalently bound to a second synthetic polymer containing multiple electrophilic groups. The first synthetic polymer is preferably a synthetic polypeptide or a polyethylene glycol that has been modified to contain multiple nucleophilic groups, such as primary amino (--NH.sub.2) or thiol (--SH) groups. The second synthetic polymer may be a hydrophilic or hydrophobic synthetic polymer which contains, or has been derivatized to contain, two or more electrophilic groups, such as succinimidyl groups. The compositions may further comprise other components, such as naturally occurring polysaccharides or proteins (such as glycosaminoglycans or collagen) and/or biologically active agents.

Abstract: This invention relates to a process for the production of masterbatches which contain short fibres or pulps and which may be used for the production of polymer compositions or rubber compositions.

Abstract: A highly polymerizable N-vinylcarboxylic acid amide having an N-1,3-butadienylcarboxylic acid amide content of 30 ppm or less, a process for producing the same, and a process for producing a homopolymer of N-vinylcarboxylic acid amide or a copolymer thereof with another copolymerizable monomer using the same. Also, a highly polymerizable N-vinyl-carboxylic acid amide is produced by thermal cracking or catalytic cracking of N-(1-alkoxyethyl)carboxylic acid amide or ethylidenebiscarboxylic acid amide, wherein the N-vinyl-carboxylic acid amide content of the N-(1-alkoxyethyl)-carboxylic acid amide or ethylenebiscarboxylic acid amide is 10 wt % or less.

Abstract: A heat resistant positive-working photosensitive composition that has a polybenzoxazole precursor bearing acid labile functional groups, a photoacid generator, a photosensitizer, and a solvent. The polybenzoxazole precursor bearing acid labile functional groups, has the structure: ##STR1## wherein k.sub.1 is an integer of 1 or 2, k.sub.2 is an interger of 0 or 1, and the sum of k.sub.1 and k.sub.2 is 2; Ar.sub.1 is a tetravalent aromatic, aliphatic, or heterocyclic group, or mixtures thereof; Ar.sub.2 is a divalent aromatic, aliphatic, or heterocyclic group or siloxane group; D is a monovalent acid labile group; and n is an integer from 20 to 200. A portion of Ar.sub.1 can be a divalent aromatic, aliphatic, or heterocyclic diamine moiety such that the fraction of diamine compound is 0-60 mole percent and the sum of diamine and diamino dihydroxy compound is 100%.

Abstract: A method of producing an injection moldable polyimide resin composition, which is characterized by the fact that at least one aromatic acid anhydride and at least one aromatic diamine are directly combined with at least one polymer that can be melt molded at a temperature lower than 400.degree. C. Furthermore, the resulting product can be heat treated.

Abstract: A fiber-forming polyamide composition contains a fiber forming polyamide and a sulfonated polyester concentrate, the concentrate disabling and dye sites in the polyamide so that fibers formed from the composition will have enhanced stain and soil resistance. The sulfonated polyester concentrate contains a reagent, preferably an alkali metal salt of 5-sulfoisophthalic acid, and thermoplastic polyester, preferably one or more of PET, PTT, PBT, PETG and poly(ethylene terephthalate-co-isophthalate).

Abstract: A polyamide resin composition comprising 100 parts by weight of a polyamide resin, from 0.01 to 100 parts by weight of a liquid-crystalline resin, and from 0.01 to 5 parts by weight of an acid anhydride all the time has good fluidity even when it is left for a relatively long period of residence time in a cylinder of a molding machine while it is molded, and has good moldability. The amount of cushion resin needed for molding the composition fluctuates little, and the failure such as cobwebbing in molding the composition is reduced. The moldings of the composition have good impact resistance and good outward appearance. The composition is most suitable to producing box-type moldings with thin-wall parts.

Abstract: A thermoplastic resin composition comprising an aromatic polyester and an amorphous polyimide. There is provided, for example, a polyalkylene naphthalate resin composition having greatly improved moldability and enhanced crystallinity, and being free from troubles such as bleeding out after molded. The resin composition further exhibits reduced emission of fluorescence and excellent weatherability and delamination resistance.

Abstract: Novel powder coating compositions containing reactive hyperbranched polymers are disclosed and claimed. Preferred embodiments include powder coating compositions formed from hyperbranched polyesters having terminal hydroxy, carboxy, epoxy, and isocyanate groups. Preferred hyperbranched polyesters are formed from .alpha.,.alpha.-bis-(hydroxymethyl)-propionic acid, which act either as crosslinkers, adhesion promotors, or flow and leveling agents.

Abstract: Method for the preparation of a polymeric mixture for cable insulators and coatings and sheaths for optic fiber cables; polymeric mixture thus produced and the cables containing it.The method is characterized in that one completely mixes, up to the obtainment of a homogeneous composition, (i) from 50 to 80 parts (w/w) of a first thermoplastic polymer which is amorphous, highly resistant to flames and combustion, and consists of an aromatic polyester of isophthalic and terephthalic acid with bisphenol A, and (ii) from 20 to 50 parts (w/w) of at least a second thermoplastic polymer consisting of an elastomeric polyether-ester block copolymer, having a Shore D hardness greater than 50 and a Vicat softening point greater than 170.degree. C., for a mixing time less than 10 minutes.

Abstract: The present invention relates to a thermoplastic composition comprising at least one crystalline water sensitive polymer and at least one amorphous water sensitive polymer. The thermoplastic composition may optionally further comprise additional ingredients such as other polymers, tackifying resins, plasticizers, waxes, and mixtures thereof. The thermoplastic compositions are useful in a variety of applications wherein water or moisture sensitive thermoplastic materials are employed such as various packaging adhesive applications including case and carton sealing, remoistenable adhesives, repulpable/recyclable adhesives and multiwall bag applications. The present invention is also useful for moisture activatable reinforcement strings and opening tapes for corrugated containers, as well as for a variety of nonwoven applications such as body fluid impermeable barriers, core stabilization adhesives, and construction adhesives.

Abstract: A partially or fully cured thermosetting product which includes a cured and molded product of a thermosetting composition. The composition includes 70% to 99% by weight of at least one thermosetting resin or compound and 1% to 30% by weight of at least one toughening agent. The toughening agent is at least one hyperbranched dendritic macromolecule formed of ester units, optionally in combination with ether units.

Abstract: A thermoplastic resin composition containing a polyetherimide resin, a siloxane-polyetherimide copolymer and a branched polycarbonate resin exhibits exhibit high heat distortion temperature, improved room temperature impact properties and improved impact strength and ductility at low temperatures.

Abstract: Crosslinked polymer compositions comprise a first synthetic polymer containing multiple nucleophilic groups covalently bound to a second synthetic polymer containing multiple electrophilic groups. The first synthetic polymer is preferably a synthetic polypeptide or a polyethylene glycol that has been modified to contain multiple nucleophilic groups, such as primary amino (--NH.sub.2) or thiol (--SH) groups. The second synthetic polymer may be a hydrophilic or hydrophobic synthetic polymer which contains, or has been derivatized to contain, two or more electrophilic groups, such as succinimidyl groups. The compositions may further comprise other components, such as naturally occurring polysaccharides or proteins (such as glycosaminoglycans or collagen) and/or biologically active agents.

Abstract: There is a provided a method to produce a polymer composite material in which the rigid polymer (R.sub.m).sup.n is dispersed uniformly at the molecular level in the flexible polymer (M), preferably by both polymerization with no solvent in the molten and mixed state and subsequent polymerization in the solid state. According to the preferred embodiment of the present invention, the polymer composite material is produced by polymerization with no solvent in the molten and mixed state. In the case that the rigid polymer is polymerized from the monomer having a slow polymerization rate, in order to prevent roughness of the rigid polymer during polymerization, the polymerization in the molten state is stopped at the polymerization degree equal to that of an oligomer and the resulting composite is subsequently polymerized in the solid state to increase the polymerization degree of the rigid polymer.

Abstract: The present invention relates to a process for minimizing the formation of undesirable byproducts in ozonated liquids comprising the steps of:providing a container comprising a polyester comprising repeat units from a dicarboxylic acid component comprising at least about 85 mole percent terephthalic acid, 2,6-naphthalenedicarboxylic acid or a mixture thereof and at least about 85 mole percent ethylene glycol; and from about--to about--weight % of at least one polyamide which displays a melting point below that of said polyester, andfilling said container with an ozonated liquid.

Abstract: The polymer composite material is produced using no solvent and includes a rigid polymer (B) dispersed uniformly into a matrix (A) at the molecular level in a state of a copolymer (A/B and/or A'/B) thereby enhancing the interface bonding of the rigid polymer (B) to the matrix (A). The non-solvent method includes a step of polymerizing a thermoplastic polymer (A) and a monomer to form a rigid polymer (B) with no solvent in the molten and kneaded state to provide a copolymer (A/B and/or A'/B) in which the flexible molecular chains (A and/or A') are made up of the thermoplastic polymer to the rigid polymer (B) to reduce the stress concentrating sources of the rigid polymer dispersed microscopically at the molecular level in the thermoplastic polymer matrix and enhance the interface bonding between the rigid polymer (B) and the matrix (A).

Abstract: Disclosed are aromatic brominated polycarbonate/polyester carbonate/silicone polyimide compositions having improved flame resistance and reduced drippage and heat release rate, comprising by weight:(A) from about 20 to about 77 parts of an aromatic brominated polycarbonate resin;(B) from about 20 to about 77 parts of a polyester carbonate resin;(C) from about 0.5 to about 10 parts of a silicone-polyimide resin;(D) from about 0 to about 25 parts of an aromatic polycarbonate having a molecular weight of from about 40,000 to about 90,000; the sum of (A)-(D) being 100 parts by weight;(E) from about 0.05 to about 2.0 parts of a metal salt of a halogenated monomeric or polymeric aromatic sulfonic acid or mixtures thereof, wherein the metal salt is selected from the group consisting of alkali metal salts, alkaline earth metal salts, and mixtures of the metal salts; and(F) from about 0.1 to about 5.0 parts by weight of filler or a pigment.

Abstract: A thermoplastic resin composition containing a polyetherimide resin, a siloxane-polyetherimide copolymer and a branched polycarbonate resin exhibits exhibit high heat distortion temperature, improved room temperature impact properties and improved impact strength and ductility at low temperatures.

Abstract: A thermoplastic resin composition comprising a thermoplastic resin (A) not forming an anisotropic melt phase and a liquid crystal polymer (B) capable of forming an anisotropic melt phase, an injection molding method thereof and an injection molded article capable of providing a thin molded article having excellent mechanical strength. A thermoplastic resin composition (C) comprises 99 to 50 wt. % of the thermoplastic resin (A) and 1 to 50 wt. % of the liquid crystal polymer (B). The liquid crystal polymer (B) is microscopically dispersed in an island form in the matrix phase of the thermoplastic resin (A) so that when the composition (C) is heat-treated at a temperature not lower than the melting point of the liquid crystal polymer (B) under a non-load state and is then cooled, the liquid crystal polymer (B) has a weight average particle diameter within the range of 10 to 40 micrometers and at least 80 wt. % thereof has a particle diameter within the range of 0.5 to 60 micrometers.

Abstract: The present invention relates to a golf ball, comprising a cover, a core and optional intermediate layers, wherein the various ball components are formed from compositions comprising a polyamide, in the form of a homopolymer, a copolymer or mixtures thereof. The compositions include a blend of about 1 wt. % to about 99 wt. % of at least one sulfonated and/or phosphonated polymer and about 99 wt. % to about 1 wt. % of at least one polyamide polymer. The polyamides of the present invention comprise polyamides and polyamide copolymers, such as polyamide block copolymers. The sulfonated and/or phosphonated polymer preferably comprises sulfonated thermoplastic elastomers, sulfonated thermoplastic polymers, and mixtures thereof.

Abstract: A low molecular weight, ester-terminated polyamide may be blended with a liquid hydrocarbon to form a transparent composition having gel consistency. The ester-terminated polyamide is prepared by reacting "x" equivalents of dicarboxylic acid wherein at least 50% of those equivalents are from polymerized fatty acid, "y" equivalents of diamine such as ethylene diamine, and "z" equivalents of monoalcohol having at least 4 carbon atoms. The stoichiometry of the reaction mixture is such that 0.9.ltoreq.{x/(y+z)}.ltoreq.1.1 and 0.1.ltoreq.{z/(y+z)}.ltoreq.0.7. The reactants are heated until they reach reaction equilibrium. The gel contains about 5-50% ester-terminated polyamide with the remainder preferably being pure hydrocarbon. The gels are useful in formulating personal care products and other articles wherein some degree of gel-like or self-supporting consistency is desired.

Abstract: A crosslinked nylon block copolymer comprising a copolymer containing a polyamide block and an elastomeric block, irradiation crosslinked, including a compound which promotes crosslinking therein. In process form, the present invention comprises supplying a nylon block copolymer, containing a polyamide block and an elastomeric block, along with crosslinking promotor and exposing the block copolymer to irradiation, sufficient to crosslink the copolymer and improve mechanical properties therein. The crosslinked nylon block copolymers here have particular utility in both the medical and wire and cable industries.

Abstract: The thermosetting composition of the present invention includes an unsaturated polyester, an addition polymerizable monomer, a low shrink agent other than an aliphatic polyester, and an aliphatic polyester decomposed in a decomposing solution containing a base and at least one solvent selected from the group consisting of water, methanol, ethanol, and ethylene glycol at a temperature lower than a boiling point of the decomposing solution after being cured.

Abstract: The present invention is a compositional blend having a polyester, an acetaldehyde reduction compound and less than 50 ppm of an optical brightener. The blend has utility for food and beverage molded containers where improved clarity and flavor retention are important without producing a haze. The acetaldehyde reduction compound can be a low molecular weight partially aromatic polyamide, a low molecular weight aliphatic polyamides or polyesteramide. The optical brightener preferably is a bis(benzoxazolyl) stilbene. Articles, and especially beverage containers, produced from the blend have a yellowness, b*, less than about 2.5.

Abstract: The present invention relates to a golf ball, comprising a cover, a core and optional intermediate layers, wherein the various ball components are formed from compositions comprising a polyamide, in the form of a homopolymer, a copolymer or mixtures thereof. The compositions include a substantially optical brightener-free blend of about 1 wt. % to about 99 wt. % of at least one nonionomer polymer and about 99 wt. % to about 1 wt. % of at least one polyamide polymer. The polyamides of the present invention comprise polyamides and polyamide copolymers, such as nylons, nylon copolymers and nylon block copolymers. The nonionomer polymer comprises a nonionomer thermoplastic elastomer or a nonionomer thermoplastic. The present invention also relates to a golf ball comprising a cover layer, a core and at least one intermediate layer interposed between the cover layer and the core, wherein one of said layers comprises a substantially optical brightener-free composition comprising from about 1 wt. % to about 99 wt.

Abstract: The present invention relates to articles of manfacture, such as films, tubes, and coatings, comprising a multiaxially oriented film having a planar morphology, wherein the article of manfacture comprises at least one thermoplastic flexible polymer, at least one thermotropic liquid crystalline polymer, or a blend thereof. Recyclable articles of manufacture having improved barrier properties are also provided.

Abstract: A liquid crystalline resin which comprises at least one kind of liquid crystalline polymer selected from liquid crystalline polyester and liquid crystalline polyester amide, both forming an anisotropic molten phase, and an inorganic phosphorus compound, said liquid crystalline resin having an absorbance of 0.5 or less at 380 nm when measured over an optical path length of 10 mm in a 0.5 wt % solution in a 1:1 mixed solvent of pentafluorophenol and chloroform (by weight). It is useful as engineering plastics because of improved color, heat resistance, and hydrolytic resistance.

Abstract: A liquid crystal alignment agent containing at least two kinds of polymers selected from the group consisting of polyamic acids and imidized polymers and having a structure obtained by dehydration and ring closure of polyamic acid. In the at least two kinds of polymers contained in the liquid crystal alignment agent, the polymer of higher imidization degree has a smaller surface free energy. The liquid crystal alignment agent gives a liquid crystal display device having less stuck image and high pretilt angle.

Abstract: A colored polyester copolymer comprising the reaction product of at least one linear thermoplastic polyester precursor and at least ten parts per million by weight of a residue of at least one 1,4-bis (2,6-dialkylanilino)-9,10-anthraquinone colorant. A composition may be formed comprising the copolymer in admixture with at least one thermoplastic polymer. The copolymer may be formed by reacting at least one thermoplastic polyester precursor with a 1,4-bis (2,6-dialkylanilino)-9,10-anthraquinone colorant which has a polyester reactive group.

Abstract: Two-component curable adhesive for blocking automotive wiring bundles, the respective components preferably amine-terminated polyamide Part A, and acrylate, anhydride or epoxy Part B, being contained in separate sheets which are inter-leaved with one another. The concentration of the reactive components in the sheets is chosen to cause the adhesive to flow on initial heating and then to cure to resist further flow at elevated temperatures in service. Apparatus, kits and method for blocking cables or wire bundles using the adhesive are also claimed.

Abstract: Novel golf ball compositions which contain liquid crystalline polymers and liquid crystalline polymer blends. These compositions can be foamed or unfoamed. Golf balls that employ at least one layer of these blends in any of the golf ball cover, core, or a mantle situated between the cover and the core provide ball properties and performance similar to and in some cases better than the state of the art ionomer based golf balls.

Abstract: A composition comprising a polyamide, a polyolefinic modifier, and an ethylene/acrylic acid copolymer.

Abstract: Visually clear thermoplastic resin compositions include a polyetherimide resin, a first polyester resin and a second polyester resin, wherein from 50 to 100 mole percent of the structural units of the first polyester resin include an alicyclic hydrocarbon radical as the diol residue of the structural unit, and wherein less than 50 mole percent of the structural units of the second polyester include an alicyclic hydrocarbon radical as the diol residue of the structural unit, exhibit resistance to elevated temperature and improved impact properties.

Abstract: A block copolymer containing one or more polyoxyethylene blocks and one or more polyoxy(higher alkylene) blocks, wherein at least some of the blocks are linked together by an oxymethylene group, can be prepared by reacting one or more dihydroxy terminated polymers selected from poly(ethylene glycol), poly(higher alkylene glycol), and block copolymers thereof in solution with a dihalomethane in the presence of a base. Such copolymers can be used as surfactants and surface modifiers. The reaction can be conducted at ambient temperature, and does not require the addition of heat.

Abstract: This invention relates to adhesion agents and compatibility agents, respectively, on the basis of partially crystalline, high-molecular block (co)polyester amides, produced by direct esterification of carboxyl-terminated or hydroxycarboxyl-terminated polyamide precondensates and hydroxyl-terminated or hydroxycarboxyl-terminated polyester segments, characterized in that the block (co)polyester amides form two crystalline phases and comprise as segments(A) at least one polyamide or copolyamide block having a uniform number average molar mass of at least 1000 g/mole,(B) at least one aromatic polyester and/or copolyester block having a uniform number average molar mass of at least 1000 g/mole, and(C) at least one further diol component of the general structureHO--R--OH,wherein R is selected from the group consisting of aliphatic or partially aromatic (co)polyesters, aliphatic polyethers, aliphatic (co)polyester amides, polycarbonates or aliphatic or aromatic hydrocarbons.

Abstract: Graft copolymers are obtainable by reactingA) polyarylene ethers,B) polyamides andC) copolymers which contain cyclic, .alpha.,.beta.-unsaturated dicarboxylic anhydridesand are used for the preparation of thermoplastic molding materials or as compatibilizers for polymer blends based on polyarylene ethers and polyamides.

Abstract: Blends containing a polyetherimide and from about 8 to about 20 wt. % of a modifier formulation comprising an acrylate rubber and a polycarbonate, and a method for improving the ESCR properties of polyetherimides.

Abstract: Conventional hot-melt adhesive compositions for the coating of textile sheet structures exhibit problems in respect of resistance to washing and cleaning. The presence of an epoxide in hot-melt adhesive composition enables the production of cleaning-resistant laminated materials having a particularly high level of wash resistance.

Abstract: A composition which is a blend of at least two different polyetheramide copolymers, one having predominantly hard polyamide segments and one having predominantly soft polyether segments. When formed into a film and attached to a textile fabric, forms a laminate which is suitable for the production of surgical gowns, and the like. Such films are strong, have good moisture barrier properties while allowing the transmission of air therethrough and have a softness to which provides a clothlike feel.

Abstract: The invention relates to a packaging comprising a thermoplastic film based on a polymer containing polyamide blocks and polyether blocks, said polymer being permeable to water vapor, to ethylene, to CO.sub.2 and to oxygen, such that the permeability to CO.sub.2 is very much greater than the permeability to oxygen. The invention is particularly useful for making sachets in order to conserve fresh fruit, vegetables or meat.

Abstract: Crosslinked polymer compositions comprise a first synthetic polymer containing multiple nucleophilic groups covalently bound to a second synthetic polymer containing multiple electrophilic groups. The first synthetic polymer is preferably a synthetic polypeptide or a polyethylene glycol that has been modified to contain multiple nucleophilic groups, such as primary amino (--NH.sub.2) or thiol (--SH) groups. The second synthetic polymer may be a hydrophilic or hydrophobic synthetic polymer which contains, or has been derivatized to contain, two or more electrophilic groups, such as succinimidyl groups. The compositions may further comprise other components, such as naturally occurring polysaccharides or proteins (such as glycosaminoglycans or collagen) and/or biologically active agents.

Abstract: The present invention relates to a method for forming the LCP composite having LCP fibers dispersed in the matrix resin even if the LCP content may be smaller than the lower limit of the fiber formable range.The method is characterized in that a resin composite reinforced by the LCP fiber in a mixture ratio beyond the fiber formable range or the preferred fiber formable range by means of an extrusion or injection molding of a resin mixture containing a liquid crystal resin composite extruded in the fiber formable range or the preferred fiber formable range.

Abstract: The present invention relates generally to aqueous coating compositions comprising a resin component including a functional group-containing crosslinkable resin and, optionally, a curing/crosslinking agent for functional groups of the crosslinkable resin. More specifically, the resin component includes, at least in part, a special anionically or anionically/non-ionically stabilized functional group-containing crosslinkable resin which can function as either the primary crosslinkable resin (self-emulsifying system) or as a reactive emulsifier for other lipophilic crosslinkable resins (stabilized system).

Abstract: A process for the preparation of polymeric alloys from polyester resins and polymers containing groups capable of giving addition reaction with functional compounds containing at least two reactive groups comprising the melt state mixture stage of polyester resin, reactive polymer and functional compound of mixture pelletizing and following polyaddition reaction in the solid state at temperatures between 150.degree. and 220.degree. C. to obtain an increase of the polymer intrinsic viscosity of 0.1 dl/g in comparison with the starting polyester resin.

Abstract: Disclosed are transparent blends of a polyetherimide, at least one resin selected from the group consisting of polycarbonate resins, poly(ester-carbonate) resins, and polyarylate resins, and an effective amount of a catalyst to provide transparency to the blends. In addition to being transparent, the blends have good ductility as well as high flexural and tensile properties. The yellowness index of the compositions can be improved with the addition of a phosphite.

Abstract: The present invention is directed to in situ reinforced thermoplastic fibers having improved mechanical properties and a method of making same. These composites have improved tensile strength and tensile moduli that exceed that predicted by composite theory under the rule of mixtures. The in situ composites can be used in woven preforms.

Abstract: The thermosetting composition of the present invention includes an unsaturated polyester, an addition polymerizable monomer, a low shrink agent other than an aliphatic polyester, and an aliphatic polyester decomposed in a decomposing solution containing from about 0.1 to about 50% by weight of at least one base selected from the group consisting of alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal oxides, alkaline earth metal oxides, alkali metal alkoxides and alkaline earth metal alkoxides, and at least one solvent selected from the group consisting of water, methanol, ethanol, and ethylene glycol at a temperature lower than a boiling point of the decomposing solution after being cured.

Abstract: A polyamide resin composition comprising: (A) 100 parts by weight of at least one member selected from a polyamide-11 resin and a polyamide-12 resin; optionally (B) from 3 to 30 parts by weight of a modified polyolefin resin; and (C) from 3 to 25 parts by weight of a plasticizer mixture comprising a plasticizer (C1) and a plasticizer (C2). The modified polyolefin resin (B) is either a modified polyolefin (B1) which is a copolymer of an olefin comprising at least one of ethylene and propylene, with an .alpha.,.beta.-unsaturated carboxylic acid or a derivative thereof, or a modified polyolefin (B2) which is a graft polymer obtained by grafting an .alpha.,.beta.-unsaturated carboxylic acid or a derivative thereof onto a copolymer of an olefin comprising at least one of ethylene and propylene. The plasticizer (C1) has a solidifying point of -40.degree. C.

Abstract: An ester-amide block copolymer of the formula (1): ##STR1## wherein R is an aromatic hydrocarbon group with 6-20 carbon atoms and G is a residue of an aliphatic polyester, an aliphatic polycarbonate, an aliphatic polyethercarbonate or a polyorganosiloxane, and having a weight average molecular weight of 30,000-1,000,000. This copolymer is advantageously prepared by polycondensing an activated acyl lactam-terminated aromatic amide of the formula (2) with a diol of the formula (3) by bulk polymerization in a molten state: ##STR2## wherein R and G are the same as defined above.