Abstract: Disclosed is a shaped article comprising a composition comprising polyamide and ionomer wherein the ionomer comprises a mixture of Zn and alkali metal (M2) cations wherein the Zn/M2 equivalent ratio is from about 0.6 to about 6. The articles prepared from the compositions with mixed ion ionomers exhibit high stiffness, hardness and toughness, good scratch resistance, desirable low melt viscosity and high processability.

Abstract: Films for inflatable cushions are disclosed. Generally, each of the disclosed films includes a pair of web layers that are aligned to be generally coextensive and that are sealed together by longitudinal and/or transverse seals that cooperatively define the boundaries of inflatable chambers.

Abstract: A polyolefin composition comprising: A) from 85.0 wt % to 99.5 wt %; A terpolymer containing propylene, ethylene and 1-hexene wherein: (i) the content of 1-hexene derived units ranges from 1.0 wt % to 5.0%; (ii) the content of ethylene derived units is comprised between 0.5 wt % and 10.0 wt % (iii) the melting temperature ranges from 130° C. to 145° C.; B) from 0.5 wt % to 10.0 wt %; of a propylene, ethylene copolymer composition comprising: b1) from 12 wt % to 52 wt %; of a propylene homopolymer or a propylene/ethylene copolymer having a content of ethylene derived units ranging from 0.1 wt % to 4.5 wt %; and having a xylene soluble content measured at 25° C. lower than 10 wt %; b2) from 48 wt % to 88 wt % of a propylene ethylene copolymer having a content of ethylene derived units ranging from 15.0 wt % to wt % to 42.0 wt %; wherein the resulting polyolefin composition has an melt flow rate (230° C./5 kg. ISO 1133) ranging from 0.2 g/10 min to 4.0 g/10 min; the sum A+B being 100 and the sum b1+b2 being 100.

Abstract: Disclosed is an m-xylene group-containing polyamide resin composition having excellent gas barrier properties and heat aging resistance, which contains (A) a polyamide composed of a diamine unit containing 30% by mole or more of an m-xylylenediamine unit and a dicarboxylic acid unit and (B) an aromatic secondary amine based compound and has an oxygen permeability coefficient of not more than 1 cc·mm/m2·day·atm at 23° C. and 75% RH.

Abstract: Disclosed is a polyamide resin composition having excellent gas barrier properties and heat aging resistance, which contains (A) a polyamide composed of a diamine unit containing a 1,3-bis(aminomethyl)cyclohexane unit and a dicarboxylic unit and at least either of (B) an aromatic secondary amine based compound and (D) a phenol based antioxidant and has an oxygen permeability coefficient of not more than 1.5 cc·mm/m2·day·atm at 23° C. and 75% RH.

Abstract: The present invention relates to a crosslinked rubber composition based on at least one elastomer of ethylene-propylene-diene terpolymer type (EPDM) and on at least one phase-change material (PCM), to a process for preparing this composition and to a multilayer pipe incorporating it. This composition includes at least 100 phr (phr: parts by weight per one hundred parts of elastomer(s)) of at least one phase-change material (PCM), and it is such that said at least one PCM is dispersed in the crosslinked composition and is provided with protection means that are capable of preventing its dispersion therein at a temperature above its melting point, which composition has a breaking strength of greater than 3 MPa and/or an elongation at break of greater than 100%, these properties being measured at 23° C. according to standard ASTM D 412.

Abstract: Thermoplastic polyurethane (TPU) made using low free isocyanate monomer (LF) prepolymer, for example a prepolymer based on p-phenylene diisocyanate (PPDI) with low free isocyanate content, possess unique performance features including exceptional tear strength, low compression set, and an exceptional overall balance of physical properties including high temperature mechanical strength.

Abstract: The present invention is concerned with the process for preparing a cross-linked stabilized polymer composition using at least one graftable polymer stabilizer, and the subsequent use of that composition for forming pipes, for example PEX pipes. The graftable stabilizer becomes anchored to the polymer such that stabilizer activity is retained in the cross-linked product. Cross-linking can be achieved by conventional processes such as PEXa, PEXb and PEXc. Embodiments demonstrate excellent levels of antioxidant retention (as measured by oxidative induction retention after exhaustive solvent extraction) and the cross-linked product are suitable for portable water applications, including hot water applications.

Abstract: Fluid-assisted injection molding articles and processes for producing the articles are described. In one embodiment, a fluid-assisted injection molded article is formed from a polymeric composition containing a polyethylene terephthalate homopolymer in combination with a polyethylene terephthalate copolymer. The polyethylene terephthalate copolymer may comprise a copolymer of polyethylene terephthalate with isophthalic acid. The polymeric composition can also contain a reinforcing agent, such as glass fibers. Products made in accordance with the present disclosure have shown dramatically improved surface characteristics. In particular, pitting on the surface of the molded article is minimized.

Abstract: A formulation includes a polymeric material, a nucleating agent, a blowing agent, and a surface active agent. The formulation can be used to form a container.

Abstract: The present disclosure describes a strategy to create self-healing, slippery liquid-infused porous surfaces (SLIPS) that can be modified as desired. Roughened (e.g., porous) surfaces can be utilized to lock in place a lubricating fluid, referred to herein as Liquid B to repel a wide range of objects, referred to herein as Object A (Solid A or Liquid A). Use of an external stimuli or degradation of the Liquid B can be utilized to change the characteristics of SLIPS structures reversibly or irreversibly that may be desired in a number of different applications. Numerous characteristics, such as adhesion, optical, mechanical, and the like, can be dynamically changed.

Abstract: The development described provides methods of producing functionalized cellulose in a one-step acid treatment process and of using the cellulose so derived to make composite polymer materials. The composite materials may include mixtures of the acid treated cellulose, functionalized cellulose polymers, including but not limited to cellulose acetate, cellulose butyrate, cellulose propionate, methyl cellulose, and ethyl cellulose, biobased and/or biodegradable polymers, impact modifying agents, and other components such as nucleating agents and pigments. The composite materials formed possess thermomechanical properties that differ from those of similar polymer composites made using prior art. In particular, the composite and nanocomposite materials are characterized by increased heat distortion temperatures and improved impact strengths.

Abstract: This invention relates to a pipe for fluid transport that is comprised of a hollow cylinder having an outer wall and an aperture extending longitudinally through the cylinder, wherein the outer wall is comprised of (a) from about 60 weight percent to about 95 weight percent of a polyarylene sulfide resin, (b) from about 5 weight percent to about 40 weight percent of a thermoplastic vulcanizate, and (c) from about 3 weight percent to about 15 weight percent of a compatibilizer. The present invention also relates to an impact resistant polyarylene sulfide composition which is comprised of (a) from about 60 weight percent to about 95 weight percent of a polyarylene sulfide resin, (b) from about 5 weight percent to about 40 weight percent of a thermoplastic vulcanizate, and (c) from about 3 weight percent to about 15 weight percent of a compatibilizer.

Abstract: The present invention relates to the thermal stabilization of halogen containing polymer compositions. More particularly the invention relates to a tin stabilizer composition for chlorine containing polymers, and more specifically a composition comprising a mono alkyltin compound as major compound of the tin stabilizer composition and a co-stabilizer. The present invention relates as well to the use of a mono alkyl tin compound as major compound of the tin stabilizer and a co-stabilizer as heat stabilizers for processing chlorine containing polymer composition.

Abstract: The polymeric material having oxygen barrier properties and low light transmission characteristics, in particular within the UV and visible light wavelengths and comprises (A) a polyester, (B) mineral particles, (C) a polyamide, and (D) at least one transition metal catalyst. Preferably the amount of mineral particles is not more than 26 wt % of the total weight of the material, and is not less than 20 wt % of the total weight of the material.

Abstract: A polyolefin composition having an increased modulus of elasticity as well as increased heat resistance, wherein the polymer composition has high melt viscosity, and wherein the composition contains a carbon material as a filler, wherein the filler is present in the form of a carbon nanofiber.

Abstract: It is an object to provide a tubular body made from a novel fiber-reinforced epoxy resin material having improved strength. A tubular body made of a fiber-reinforced epoxy resin material according to the present invention is a tubular body made of a fiber-reinforced epoxy resin material comprising a cured product of an epoxy resin composition and a reinforcing fiber. The cured product of the epoxy resin composition has a swelling ratio of 20% by mass to 42.5% by mass in methyl ethyl ketone.

Abstract: The present invention relates to a pipe comprising a polyolefin composition with low migration of the used additives and its decomposition products, especially phenolics, out of the composition, at the same time showing good pressure testing performance.

Abstract: A sulfur-containing cycloaliphatic compound, useful as a crosslinker for filled sulfur-vulcanizable elastomer compositions, is represented by the general formula: G[-CaH2a—S[C(?O)]bR]n wherein G is selected from the group consisting of: saturated, monocyclic aliphatic group of valence n containing from 5 to 12 carbon atoms and optionally containing at least one halogen, and saturated monocyclic silicone [RSiO—]n[R2SiO—]p group of valence n; wherein each R independently is a hydrogen or monovalent hydrocarbon of up to 20 carbon atoms; each occurrence of subscripts a and b independently is an integer wherein a is 2 to 6 and b is 0 or 1; p is an integer of from 0 to 3; and, n is an integer of from 3 to 6, with the provisos that when b is 0, R is a hydrogen atom, and when G is a non-halogenated, saturated monocyclic aliphatic group of 6 carbon atoms, n cannot be 3.

Abstract: An encapsulating film system comprises (a) a flexible barrier film, (b) an adhesive on at least a portion of the flexible barrier film, and (c) a desiccant on at least a portion of the flexible barrier film or the adhesive.

Abstract: The invention provides a composition comprising the following: A) an ethylene/?-olefin/diene interpolymer; B) an ethylene/?-olefin copolymer with a Mooney Viscosity [ML(1+4) at 125° C.] greater than 40; and C) a peroxide; and wherein the ?-olefin of the ethylene/?-olefin copolymer of component B comprises at least four carbon atoms; and wherein component A is present in an amount from 50 to 95 weight percent, based on the sum weight of components A and B.

Abstract: Provided is a large-size injection molded article which is obtained by injection molding a composition containing a heat-meltable fluoropolymer. Specifically, provided is a large-size injection molded article, which can be molded at a lower injection pressure as compared with a conventional PFA and obtained by molding a composition superior in mold release characteristics from a metal mold. This large-size injection molded article is superior in, particularly, heat resistance and chemical resistance, as well as dimensional accuracy, for a substrate processing apparatus. Provided is an injection molded article, having a projection area in an injection direction of 1100 cm2 or more, obtained by injection molding a composition containing a heat-meltable fluoropolymer. It is a preferable aspect that the composition including a heat-meltable fluoropolymer is a composition containing a melt moldable tetrafluoroethylene/fluoroalkoxytrifluoroethylene copolymer having an MFR over 60 g/10 minutes.

Abstract: A casing member for forming a connection between two tubular sections, said casing member having a first, cross-linked, heat shrinkable plastic layer, and a second, inner, non-crosslinked (or less cross-linked) layer. The casing member also has an electrically heatable member spaced inwardly from the first layer, for fusion bonding the second layer to the tubular sections.

Abstract: The invention refers to a tubular film with one or more layers, wherein at least one of the two external sides of the tubular film has a coating at least in sections with at least one polysiloxane and/or a coating and/or covering with at least one migrating compound.

Abstract: A biocomposite material (1) and methods of production thereof are described. The biocomposite material (1) exhibits a physical stiffness, strength and toughness comparable to known glass fiber composites while its composition makes it inherently impermeable to water. A general formulation for the biocomposite material (1) is given by the expression: Cel(1-x-y) HPIx HPOy where “Cel” represents cellulose fragments (2), “HPI” represents hydrophilic binders (4), “HPO” represents hydrophobic binders (5) and (x) and (y) quantify the percentage by weight of the hydrophilic (4) and hydrophobic binders (5) present within a material, respectively. The described properties of the biocomposite material (1) are achieved when (x) is within the range of from 0.05 to 0.55 and (y) is within the range of from 0.05 to 0.65.

Abstract: The instant invention is a chlorinated polyethylene composition, method of producing the same, and articles made therefrom. The chlorinated polyethylene composition according to the present invention comprises: (a) a chlorinated polyethylene; (b) less than 10 phr by weight of one or more curing agents; (c) from 50 to 150 phr by weight of one or more fillers; (d) from 1 to 8 phr by weight of one or more processing oil; (e) from less than 10 phr by weight of one or more stabilizing agents comprising an acid scavenger; (f) from less than 2 phr by weight of one or more antioxidants; and (g) from 3 to less than 15 phr by weight of an additive polymer comprising the reaction product of an olefin, an acrylate, and a maleic anhydride.

Abstract: A method for manufacturing tubular bodies (1) exhibiting an inner circumferential surface (8) and outer circumferential surface (7) for packaging tubes out of a strip-shaped film substrate (2), which exhibits at least one weldable plastic layer (3) or consists of the latter, and which encompasses a first edge face (5) extending in the longitudinal direction of the film substrate (2) or a second edge face (6) spaced apart from the first edge face (5) by the width of the film substrate (2), wherein the first edge face (5) runs at a first angle (?) relative to a first thickness extension direction on a first radially innermost border (9) of the first edge face (5), and the second edge face (6) runs at a second angle (?) relative to a second thickness extension direction on a second radially outermost border of the second edge face (6), and wherein the first and second edge faces (6) are placed opposite each other and joined together during exposure to heat, wherein the first angle (?) and second angle (?) differ

Abstract: An energy absorbing system has an inner tube and an outer tube that are stitched together. The inner tube contains a set of fibers oriented in a first direction and the outer tube has a second set of fibers oriented in a direction different from the first direction. Preferably these orientations are equal and opposite to each other. The inner tube may be hollow, but preferably has a cellular core. The outer tube may be spaced apart from the inner tube to create an annular cavity that is filled with a cellular material.

Abstract: Provided are a fluororesin tube that has substantially no scratches formed during manufacturing, and a rotary member for a fixing device, the rotary member obtained by using the fluororesin tube. The fluororesin tube is a heat-shrinkable fluororesin tube that covers a rotary member for a fixing device, such as a fixing roller or a pressure roller, to form an outermost layer of the rotary member, wherein a maximum depth of a linear scratch on a surface of the fluororesin tube is 0.8 ?m or less. In one embodiment, the length of the linear scratch is 1 mm or less, and the thickness of the fluororesin tube is 100 ?m or less.

Abstract: A package with self-forming insulating walls includes a tray for supporting a food item, a flap joined to the tray along a fold line, and an insulating microwave material overlying at least a portion of the tray and at least a portion of the flap. The insulating microwave material may be joined to the flap. The insulating microwave material may include a microwave energy interactive material supported on a first polymer film layer, a moisture-containing layer joined to the microwave energy interactive material, and a second polymer film layer joined to the moisture-containing layer in a predetermined pattern, thereby defining a plurality of expandable cells between the moisture-containing layer and the second polymer film layer.

Abstract: A layer for directing a hydraulic fluid includes a first fluoropolymer, a first crosslinker, and an anti-static additive. The first fluoropolymer is present in an amount greater than 60 parts by weight, the first crosslinker is present in an amount of from about 1 to about 10 parts by weight, and the anti-static additive is present in an amount of from about 0.4 to about 4 parts by weight, each based on 100 parts by weight of the layer. The layer may be included in a layered tube. In addition to the layer, the layered tube also includes an outer layer. The outer layer includes a second fluoropolymer, which is the same as or different than the first fluoropolymer. The second fluoropolymer is present in an amount greater than 60 parts by weight based on 100 parts by weight of the outer layer.

Abstract: A polyamide resin composition comprising a PA 6/12 (component A), a plasticizer (component B), and a modified polyolefin (component C), the component A comprising units a derived from ?-caprolactam or ?-aminocaproic acid and units b derived from aminododecanoic acid or ?-laurolactam, wherein the content of the units a in the units constituting the component A is 60 to 98% by weight and the content of the units b in the units constituting the component A is 40 to 2% by weight, wherein the content of the component A in the polyamide resin composition is 50 to 98% by weight, the content of the component B in the polyamide resin composition is 20 to 1% by weight, and the content of the component C in the polyamide resin composition is 30 to 1% by weight. The composition can provide various characteristics which are at least equivalent to those of PA 12.

Abstract: An object of the present invention is to provide a fluorine-containing elastomer composition being flexible and having excellent fuel barrier property, heat resistance, chemical resistance and oil resistance. Another object of the present invention is to provide a sealing material, a molded article and a fuel hose obtained by crosslinking the fluorine-containing elastomer composition. The composition is a fluorine-containing elastomer composition comprising a polyol-crosslinkable fluorine-containing elastomer, a polyol crosslinking agent and a hydrotalcite, wherein an acid acceptor comprising only an oxide or hydroxide of a divalent metal is contained in an amount of not more than 2 parts by weight based on 100 parts by weight of the fluorine-containing elastomer.

Abstract: A metallocene-catalyzed polymer comprising (i) a higher molecular weight component and (ii) a lower molecular weight component wherein the polymer has a polydispersity index of from about 10 to about 26; a zero shear viscosity of from about 5×105 Pa·s to about 2×1014 Pa·s and a smooth-to-matte transition critical stress of from about 20 kPa to about 85 kPa at a shear rate of from about 1.5 s?1 to about 17 s?1. A dual metallocene catalyzed polyethylene comprising (i) a higher molecular weight component and (ii) a lower molecular weight component wherein the polymer has a polydispersity index of from about 10 to about 26; a zero shear viscosity of from about 5×105 Pa·s to about 2×1014 Pa·s and a smooth-to-matte transition stress of from about 20 kPa to about 85 kPa at a shear rate of from about 1.5 s?1 to about 17 s?1.

Abstract: Disclosed is a multilayer structure useful for preparing highly abrasion-resistant protective liners, including tubular articles such as multilayer tubes or pipes.

Abstract: By using an oxidative process, it is possible to apply an adhesive material to silicone. The process is controlled, allowing selective oxidative treatment to a silicone structure, thus enabling treatment to the inside of a tubular structure.

Abstract: The method for making a reinforced balloon for a balloon catheter involves blending a polymer with a nano composite to form a composite matrix, extruding a parison from the composite matrix, blow molding the parison into a balloon and orienting the nano composite generally axially with respect to the balloon. The balloon formed has a high strength for resisting bursting. The nano composite may be carbon nanotubes, nano-ceramic fibers or a nano clay.

Abstract: A process for producing a heat- and pressure-resistant polyester bottle, comprising a primary blow-molding step of obtaining a primary molded article by biaxially stretch-blow-molding a preform of a polyester resin, a heat-treating step of obtaining a secondary molded article that is heat-shrunk by heat-treating the primary molded article, and a secondary blow-molding step of obtaining a finally molded article by biaxially stretch-blow-molding the secondary molded article, wherein the primary blow-molding step biaxially stretches the neck portion of the primary molded article to a size nearly the same as the neck portion of the finally molded article, and the heat-treating step does not cause the neck portion of the secondary molded article to be heat-shrunk.

Abstract: A metallocene-catalyzed polymer comprising (i) a higher molecular weight component and (ii) a lower molecular weight component wherein the polymer has a polydispersity index of from about 10 to about 26; a zero shear viscosity of from about 5×105 Pa·s to about 2×1014 Pa·s and a smooth-to-matte transition critical stress of from about 20 kPa to about 85 kPa at a shear rate of from about 1.5 s?1 to about 17 s?1. A dual metallocene catalyzed polyethylene comprising (i) a higher molecular weight component and (ii) a lower molecular weight component wherein the polymer has a polydispersity index of from about 10 to about 26; a zero shear viscosity of from about 5×105 Pa·s to about 2×1014 Pa·s and a smooth-to-matte transition stress of from about 20 kPa to about 85 kPa at a shear rate of from about 1.5 s?1 to about 17 s?1.

Abstract: Provided are a chloroprene rubber, a chloroprene rubber composition and the vulcanizate and formed body thereof superior in low-temperature properties. A chloroprene rubber is obtained by emulsion polymerization of raw monomers containing antiperiplanar trans-1-chlorobuta-1,3-diene and cis-1-chlorobuta-1,3-diene in a total amount of 0.5 mass % or more, 2,3-dichlorobuta-1,3-diene in an amount of 2.0 mass % or more, and the rest being chloroprene. A composition containing the chloroprene is vulcanized into a formed body.

Abstract: A tubular member formed of a polyamide resin layer includes carbon black and a semi-aromatic polyamide resin having at least a repeating unit structure derived from an aromatic dicarboxylic compound and an aliphatic diamine compound with the alkyl carbon number in the range of from 9 to 13.

Abstract: An elongate tube formed from a composite material comprising a polymer and a photoluminescent material has a cylindrical wall that defines an arc of between about 180 degrees and 360 degrees or greater. An elongate opening is defined in the wall along the length of the tube. The wall of the tube is flexible which permits the opening to be manually enlarged to enable the tube to be mounted over an electric light source. The wall is configured to approximate the outer dimensions of the light source which retains the tube on the light source. The photoluminescent material in the tube wall is energized by the light source and emits sufficient light for a period of time if the electricity to the light source is temporarily interrupted.

Abstract: The invention relates to A process for the polymerisation of ethylene to produce a polyethylene resin in at least two slurry loop reactors connected to each other in series, the resin having a bimodal molecular weight distribution, a molecular weight distribution MWD of at least 7.0, an HLMI of from 1 to 100 g/10 min, and a density of from 0.935 to 0.960 g/cm3, wherein in one reactor 30 to 47 wt % based on the total weight of the polyethylene resin of a high molecular weight (HMW) polyethylene fraction is produced having an HL275 of from 0.05 to 1.8 g/10 min (the equivalent of HLMI of from 0.01 to 1.56 g/10 min), a density of from 0.925 to 0.942 g/cm3 and an MWD of at least 5.0, and in the other reactor a low molecular weight (LMW) polyethylene fraction is produced having an HLMI of from 10 to 1500 g/10 min and a density of from 0.960 to 0.975 g/cm3, in the presence of a Ziegler-Natta catalyst system.

Abstract: Food packaging inserts comprising a myoglobin blooming agent that promote or preserve the desirable appearance of food products, food packages, and methods of food packing comprising the same, are provided.

Abstract: The present disclosure relates to a process for recycling of plastic waste comprising: segregating plastic waste collected from various sources followed by cleaning of the segregated plastic waste to obtain segregated cleaned waste; grinding of the segregated cleaned waste to obtain grinded waste; introducing the grinded waste into an extrusion line having a venting extruder component as part of the extrusion line, to obtain molten plastic; and removing the impurities by vacuum venting of the molten plastic to obtained recycled plastic free from impurities. The present disclosure further relates to various articles like Industrial Post Recycled (IPR) plastic tubes, blow moulded bottles, pallates, manufactured from the recycled plastic waste.

Abstract: In the tube manufacturing industry, five general methodologies for manufacturing tubes are known at this time. The first is under an extrusion of molten metal by means of a press. The second is by means of a rotary lamination system known as “Piercing” or “Mannesmann”. The third is the welded pre-tube that is obtained from a laminated strip. The fourth, known as the “Cast & Roll” system, whereby a pre-tube, obtained directly from the melting, is laminated by a triple roller system. Finally, the innovative manner whereby a continuous vertical casting manufactures pre-tubes continuously, directly from the melt. The four first systems are widely used in the industry to manufacture what is known as a “pre-tube” that usually has a diameter of 60 mm or higher, which we shall name “old pre-tube”. Different processes are applied to that old pre-tube to bring it to smaller diameters and thicknesses finally required by the market.

Abstract: A tubular structure which includes a plurality of axial sites in circular relation to one another and a plurality of bias sites that interconnect the axial sites to form the tubular structure. The tubular structure's axial sites have a greater diameter than the structure's bias sites.

Abstract: Polyimide resin compositions that contain an aromatic polyimide, graphite, and acicular titanium dioxide are found to exhibit high thermal oxidative stability. Such compositions are especially useful in molded articles that are exposed to high temperatures, such as bushings, bearings, and seal rings that are used in aerospace, transportation, and materials handling applications.

Abstract: Ultra high molecular weight polyethylene (UHMWPE) polymers that have an average molecular weight of at least 500,000 g/mol and an enthalpy of at least 190 J/g is provided. The UHMWPE polymer may include at least one comonomer. The UHMWPE polymer is used to form a membrane, that, when expanded, has a node and fibril structure. The UHMWPE membrane has an endotherm of about 150° C. associated with the fibrils in the membrane. The membrane has a percent porosity of at least 25%, and in exemplary embodiments, the percent porosity is at least 60%. Additionally, the UHMWPE membrane has a thickness less than 1 mm. An UHMWPE membrane may be formed by lubricating the UHMWPE polymer, subjecting the lubricated polymer to pressure at a temperature below the melting point of the UHMWPE polymer to form a tape, and expanding the tape at a temperature below the melting temperature of the UHMWPE polymer.

Abstract: The invention relates to a copolyamide comprising at least two different units corresponding to the following general formulation: A/X.T A is chosen from a unit obtained from an amino acid, a unit obtained from a lactam and a unit corresponding to the formula (Ca diamine).(Cb diacid), with a representing the number of carbon atoms of the diamine and b representing the number of carbon atoms of the diacid, a and b each being between 4 and 36, advantageously between 9 and 18, X.