Abstract: A method for synthesizing 1,4-bis(4-aminophenoxy)naphthalene and a series of polyamides, polyimides and copoly(amide-imide)s derived from the said compound is disclosed. These polymers possess excellent thermal stability and mechanical strength.

Abstract: The present invention is a molding compound comprising an unsaturated polyester resin, a filler, a reinforcement material, a crosslinking monomer, a catalyst, and a mold release agent. The compound also may include a thickener and a low profile thermoplastic additive. The mold release agent is a liquid at room temperature and is selected from the group consisting of tertiary alkyl primary amine carboxylates. The present invention further includes a method of manufacturing a molded plastic component using said molding compound.

Abstract: The invention relates to an integrated circuit device comprising (i) a substrate, (ii) metallic circuit lines positioned on the substrate, and (iii) a porous dielectric material positioned on the circuit lines. The dielectric material comprises the reaction product of an organic polysilica and polyamic ester preferably terminated with an alkoxysilyl alkyl group.

Abstract: Pyrrolidonyl-containing polyesters and polyamides I to III ##STR1## where R, X, A and Z are defined herein, are suitable as film formers and conditioners in hair-cosmetic formulations, for stabilizing hydrogen-peroxide in aqueous solution, for complexing iodine, as tablet binders and as a constituent of film coatings in pharmaceutical preparations, for enzyme and bleach stabilization in detergent formulations, as an auxiliary in the production and finishing of textiles, as a solubilizer and protective colloid in the preparation and stabilization of polymer dispersions, and as an adhesive raw material.

Abstract: A water solvent extraction degreasing method capable of reducing degreasing time without consideration of abrupt decomposition/vaporization and swelling caused by heat. An organic binder is removed from a molded product that is produced by a powder material mixed with the organic binder and this organic binder contains at least one water-soluble organic compound and at least one water-insoluble thermoplastic resin. The degreasing step of this method includes a water solvent extraction step for extracting the water-soluble organic compound from the organic binder contained in the molded product, using water as a solvent.

Abstract: A biodegradable anti-scalant for steam generators, boilers and other heat transfer equipment is provided. Anti-scalants prepared in accordance with the present invention include aspartic acid, poly(aspartic acid) and copolymers of aspartic acid and functionalized aspartic acid. Anti-scalants provided in accordance with the present invention are biodegradable and therefore more environmentally friendly than currently available anti-scalant for use with hard water. Methods and use of making anti-scalants are also provided.

Abstract: An epoxy-modified polyamide resin obtained by reacting a diisocyanate(A) with at least one member selected from the group consisting of a dicarboxylic acid and a tricarboxylic acid anhydride (B) in a nitrogen-containing aprotic solvent to form a polyamide resin intermediate and reacting this polyamide resin intermediate with an epoxy resin (C) in the nitrogen-containing aprotic solvent. This epoxy-modified polyamide resin has a high molecular weight and can provide a film with excellent heat resistance and flexibility, and its composition can be used as a coating material, adhesive or such in the form as it is.

Abstract: Disclosed are novel crosslinked polymeric ammonium salts wherein in said polymeric salt: about 25% or more of the segments which link ammonium nitrogen atoms are group Y wherein Y is an n-alkylene group or alkyl substituted n-alkylene group, wherein said n-alkylene group has 7 to about 20 carbon atoms; zero to about 75% of segments which link ammonium nitrogen atoms are group Z wherein Z is a hydrocarbylene radical containing 2 or more carbon atoms, said hydrocarbylene radical optionally containing one or more hydroxyl, ether, amino, thioether, keto, or silyl groups or heterocyclic rings; and about 25% or more of the ammonium atoms are secondary ammonium atoms.

Abstract: There are disclosed a para-aramid shaped article having a density of 1.390-1.470/cm.sup.3. The para-aramid has an inherent viscosity .eta.inh of at least 3.5 and contains metal ions of 500 ppm or less, the metal ions being combined with acid end groups linked with the para-aramid molecules. The invention also relates to a process for preparing the same. Due to a reduced rate of moisture sorption, a reduced hygroscopic expansion coefficient and excellent mechanical properties, the para-aramid of the present shaped article is suitable for use for reinforcing fiber materials for a composite material and for a magnetic recording medium.

Abstract: This invention relates to a nonwoven web and fibers comprising a water soluble polyamide and articles constructed therefrom. The water soluble polyamide may be used alone or in combination with conventional thermoplastic web and fiber forming materials such as water insoluble polyethylene, polypropylene, polyester and polyamide. The water soluble polyamide may also be combined with biodegradable or selectively dispersible material to form nonwoven webs and fibers having various combinations of properties. Such water soluble webs and fibers have utility in the manufacture of disposable absorbent articles such as disposable diapers, feminine napkins, incontinent products and cellulosic articles such as tissues and towels, as well as for water soluble heat fusible webs for the textile industry.

Abstract: A method of providing for manufacturing a colored polymer resin having the steps of:(a) blending a disazo colorant into a mixture of monomers, the colorant having a poly(oxyalkylene) substituent comprising from 2 to 200 alkylene oxide residues, bonded to each end of the disazo chromophore, the poly(oxyalkylene) substituent having a nucleophilic terminal group which is capable of reacting with at least a portion of the monomers;(b) providing conditions under which the monomers and disazo colorant polymerize to form a colored polymer resin.

Abstract: Disclosed is a polyamide resin composition comprising a melt-kneaded product of (A) a polyamide; (B) a polyphenylene ether; (C) a styrene polymer; and (D) a compound having in a molecule thereof a carbon-to-carbon double bond and at least one functional group selected from a carboxylic acid group, an acid anhydride group, an epoxy group, an amino group and a hydroxyl group, wherein the polyamide (A) is present as a continuous phase in which the polyphenylene ether (B) and the styrene polymer (C) are dispersed individually, independently or in mixture thereof to form a dispersion phase having an average particle diameter of 5 .mu.m or less, and wherein the (B)/(C) weight ratio is from 20/80 to 70/30, and the styrene polymer (C) in the melt-kneaded product has a reduced viscosity of 0.70 dl/g or more.

Abstract: Ethylenically unsaturated compounds are provided having Structure I and from which polymers with a plurality of groups of Structure II are derived. ##STR1## In Structures I and II, R.sub.1 is hydrogen or methyl, and R.sub.3 is hydrogen or lower alkyl having 1 to 4 carbon atoms, and when R.sub.3 is hydrogen and R.sub.2 has two carbon atoms R.sub.2 is methyl methylene. In Structure I, R.sub.2 and in Structure II R'.sub.2 is a divalent linking group having 2 to 20 carbon atoms. When R.sub.3 is hydrogen and R'.sub.2 has two carbon atoms, R'.sub.2 is methyl methylene. The compounds of Structure I may be used as monomers and reacted with other ethylenically unsaturated monomers via addition polymerization to arrive at the polymer with groups of Structure II.

Abstract: The process for single-stage postcondensation of a polycondensate in a fluidized bed reactor (1) includes feeding the polycondensate through the fluidized bed reactor (1); circulating a main stream of nitrogen carrier gas through the fluidized bed reactor; withdrawing a fractional stream at a temperature of from 20.degree. to 230.degree. C. from the main stream of the nitrogen carrier gas; passing the fractional stream through a water-filled gas scrubber column (15) so as to form a conditioned stream of the nitrogen carrier gas with a predetermined dew point between 10.degree. to 80.degree. C.; and returning the conditioned stream to the main stream. In preferred embodiments the polycondensate is allowed to cool during a cool-down stage at an end of the postcondensation and the withdrawal of the fractional stream from the main stream is halted, but the circulating of the main stream through the fluidized bed reactor is continued during the cool-down stage.

Abstract: Process for the solid state polycondensation of polyamide resins by the use in the polycondensation reactor of a quantity of an inert gas such that the ratio by weight between the solid capacity/h at the reactor outlet and that one of gas fed into the reactor is lower than 0.5.

Abstract: Process for the preparation of polyether-amide solutions, steam-sterilizable dialysis membranes obtainable using the polyether-amide solutions, and a process for the production of these membranes.Polycondensation of one or more dicarboxylic acid derivatives of the formula I ##STR1## with one or more aromatic diamines of the formula II ##STR2## and, if appropriate, m-phenylenediamine, in aprotic polar solvents is known.As a result of passing ammonia, in an amount sufficient to neutralize the HCl formed, into the polymer solution obtained after the end of the polycondensation and filtering off the ammonium chloride formed, it is possible to prepare neutral, salt-free and particularly storage-stable polyether-amide solutions which can be further processed to membranes without isolation of the polymer. The resulting membranes are steam-sterilizable, chemically and thermally stable and show efficiency data in the region of that of good high-flux dialysis membranes.

Abstract: A para-oriented polyamide porous film comprising a fibril having a diameter of not more than 1.mu., with fibrils planarly arranged as a network or nonwoven fabric and laminated in a layer, the thermal linear expansion coefficient at 200.degree.-300.degree. C. within .+-.50.times.10.sup.-6 /.degree.C. and 30-95% vacant spaces. Also, a battery separator using the porous film. Also, a production process of: (a) forming a film-like material from a solution containing 1-10% of a para-oriented aromatic polyamide having an inherent viscosity of 1.0-2.8 dl/g and 1-10% of a chloride of an alkali metal or an alkali earth metal in a polar amide or polar urea solvent; (b) maintaining the film-like material at not less than 20.degree. C. and not more than -5.degree. C.

Abstract: An aromatic polyamide resin composition composed of two types of aromatic polyamide (A) and (B), where (A) is an aromatic polyamide wherein the molar ratio of aromatic polyamide with respect to the monomer components that constitute the polyamide is 0.4 or greater, and (B) is an aromatic polyamide containing an aromatic monomer as the monomer component that constitutes the polyamide and has a recrystallization temperature that is lower than that of the aromatic polyamide (A), where said aromatic polyamide resin composition has a recrystallization temperature that is 10.degree. C. or more lower than the recrystallization temperature of the aromatic polyamide (A).Merit:The aromatic polyamide composition of the present invention has the high heat resistance characteristic of aromatic polyamides, superior dimensional stability with respect to water absorption, and maintenance of physical stability and chemical resistance, while providing improved molding characteristics.

Abstract: Amide-containing polymers characterized by the presence of piperazine amide and/or substituted piperazine amide in the polymer chain are used as adsorbents to remove polyphenolic compounds from liquids. The compositions are especially useful in combination with protein removal agents such as silica gel or tannin. The amide-containing polymer compositions (alone or in combination with protein removal agents) are especially useful in the stabilization and/or chillproofing of plant derived liquids or beverages such as beer, wine, fruit juice and vegetable juice.

Abstract: A composition of an aliphatic ester-amide copolymer which is soluble in an organic solvent with an LD.sub.50 value (orally administered to a rat) of about 2,000 mg/kg or more.

Abstract: Disclosed are polyesteramide resin compositions having amide units of formula (I): ##STR1## and the units of the formula (II): ##STR2## wherein the polyesteramide is substantially devoid of units derived from butane diol. The ratio of (I) to (II) in the polyesteramide is preferably less than 1:3. Preferred polyesteramides have at least 80% of units of formula (I) separated by at least one of the units of formula (II).

Abstract: A crystalline terpolymer polyamide produced from: (a) an equimolar salt of hexamethylenediamine with adipic acid, (b) an equimolar salt of hexamethylenediamine with terephthalic acid, and (c) 12-aminododecanoic acid or .omega.-laurolactam; a polyamide resin composition comprising (A) the terpolymer polyamide and (B) a modified polyolefin; a polyamide resin composition comprising (A) the terpolymer polyamide, (B) the modified polyolefin, and (C) polyamide 12; a polyamide resin composition comprising (A) the terpolymer polyamide and (D) an inorganic filler and/or a flame retardant; and an automotive part comprising a molding one of these terpolymer polyamide and polyamide resin compositions.

Abstract: A new diamine, 2,2'-dimethyl-4,4'-bis(4-aminophenoxy)-biphenyl was synthesized and used to prepare high performance engineering plastics by polycondensation. The new diamine as shown in the following formula has a noncoplanar 2,2'-disubstituted biphenylene and a flexible aryl units: ##STR1## The engineering plastics disclosed in the present invention includes polyamides, polyimides and poly(amide-imide)s.

Abstract: A method of producing a polyamide resin by reacting 1 mol of linear polyester resin (as calculated in repeating unit of the linear polyester resin) consisting of at least one dicarboxylic acid component and at least one diol component and having an intrinsic viscosity of not less than 0.2 dl/g with 0.5-1.5 mol of at least one diamine compound in a reaction medium comprising at least one solvent which is selected from the group consisting of hydrocarbons, halogenated hydrocarbons, ethers and acetals, so that the diol component of the linear polyester resin is substituted by the diamine compound to provide the polyamide resin as a reaction product.

Abstract: The present invention relates to a fast setting water sensitive polyamide composition which is the reaction product of at least one reactant which is a dicarboxylic acid, ester or anhydride thereof and at least one reactant is a diamine wherein at least one of said diamines is polyoxyalkylene diamine and at least one of said other reactants is aromatic and said polyamide composition has a T.sub.g of greater than about 15.degree. C. and a .DELTA.H greater than 0 Joules/gram.

Abstract: A process for making polyimide-polyamic ester copolymer composition comprisingreacting at least one diamine, a pyromellitic diacid diester compound; at least one other tetracarboxylic diacid diester compound and a selected phosphoramide in the presence of a base catalyst to form a polyimide-polyamic acid ester copolymer.

Abstract: An amino-acrylate polymer is prepared by the reaction of an aliphatic hydroxyl polyacrylate monomer, like pentaerythritol triacrylate, with a polyamine like a hexyldiamine to provide a rigid fast gelling and curing polymer, which polymer may be modified with resin modifiers. The amino-acrylate polymer may be used in the preparation of composite structures with fibers and filler materials.

Abstract: The invention relates to a mixture in powder form and comprising (i) at least one polyamide and (ii) at least one polymer (A) containing hydroxyl functional groups and compatible with the polyamide. The polymer (A) may be an ethylene/vinyl alcohol copolymer. The mixture may be used to coat metal substrates.

Abstract: Methods are provided for the synthesis of poly(ethylene oxide) ("PEO") star macromolecules including functionalizable groups. In one embodiment, a core molecule including a plurality of dendritic branches or having a comb structure, and including a plurality of accessible reactive groups is reacted with functionalizable poly(ethylene oxide) ("PEO") molecules. The functionalizable poly(ethylene oxide) molecules include a reactive group capable of reacting with the reactive group on the core molecule, and a functionalizable group capable of being chemically modified, which optionally is protected. In the reaction, the PEO molecules are covalently attached to the core molecule, to form a PEO star macromolecule with terminal functionalizable groups. Preferably, the functionalizable PEO is a heterofunctional linear PEO which includes the reactive group at one terminus and the functionalizable group at the other terminus.

Abstract: A process is disclosed for preparing a polyamide by polymerizing a diacid and a diamine, aminocarboxylic acid or lactam in the presence of excess of either acid or amine such that the ratio of acid to amine end groups or the ratio of amine end groups to acidend groups in the polymer is at least 2.0:1.0.

Abstract: 18.4 grams of 4,4'-(hexafluoroisopropyridine)diphthalic acid dianhydride and 7.5 grams of 1,4-phenylenediamine dihydrochloride are mixed in a solvent consisting of 80 ml of N-methyl-2-pyrrolidone and 20 ml of dichlorobenzene and are heated at an argon atmosphere to raise its temperature from a room temperature to 170.degree. C. slowly and to be reacted for five hours while an azeotropic dihydration of water which is generated at 170.degree. C. is conducted. After the reaction is completed, a reaction product is precipitated in methanol, the precipitate is washed with methanol and dried at 80.degree. C. FIG. 1 shows the infrared spectra of the reaction product.

Abstract: The present invention relates to a new process for preparing mono and polyaspartates from primary mono and polyamines and maleates in presence of five-membered aromatic ring compounds containing nitrogen atoms in the ring structure as catalysts and use of these mono and polyaspartates as reactive components for polyisocyanates in two-component polyurethane coating compositions and for preparing polyurethane prepolymers.

Abstract: Polymer-based polyvalent malonic acid derivatives having anti-adhesive properties are described. The compounds comprise a polyamino acid linked to a group of formula (I). In formula (I), R.sup.1 and R.sup.2 together form a six-membered carbocylic or heterocyclic ring, containing at least one substituent selected from R.sup.4, R.sup.5, and R.sup.6. R.sup.3 is H, (CH.sub.2) .sub.m X or CH.sub.2 O(CH.sub.2).sup.m X.sup.1. The polyamino acid and the group of formula II are linked via R.sup.4, R.sup.5, or R.sup.6, or optionally via a spacer of formula --?Q.sup.1 --(CH.sub.2).sub.p --Q.sup.2 --!.sub.r. A and B independently are O, S, NH, HN--CO, OC--NH, O--CO, OC--O, NH--CO--O, --O--CO--NH, S--CO, SC--O, O--CS--S, S--CS--OS, NH--CS--S, S--CS--NH, or CH.sub.2. Z is a pyranose, furanose, open-chain polyalcohol or Y--X.sup.6. Y is --O--(CX.sup.2,X.sup.3).sub.n, -(CX.sup.2,X.sup.3).sub.n, --CH.sub.2 --(CX.sup.2,X.sup.3).sub.

Abstract: A diamine which is useful in preparing a new flexible polyamide and polyimide with an aromatic dicarboxylic acid and a tetracarboxylic dianhydrides, respectively, has a general formula as follows: ##STR1## wherein R.sub.1 is a proton (--H) or methyl (--CH.sub.3) and n is an integer ranging from 1 to 4. These polyamide and polyimide exhibit good mechanical performance and processability.

Abstract: Methods for purifying an oligomer by normal phase column chromatography on a support selected from polyhydroxyethyl aspartamide, hydrophilic silica and silica from an oligomer impurity having a different nucleoside sequence are described. These methods are based upon the different retention times of the oligomer and the impurity on the column.

Abstract: In a process for the preparation of poly-o-hydroxyamides and poly-o-mercaptoamides, a bis-o-aminophenol or a bis-o-aminothiophenol is reacted with a dicarboxylic acid derivative with the following structure:M--CO--R*--CO--Mwhere M stands for the residue of an (optionally substituted) 2-hydroxybenzoxazole, 2-hydroxybenzothiazole, or 1-hydroxybenzotriazole or of corresponding mercapto compounds and R* is the parent body of the dicarboxylic acid.

Abstract: A polyamide resin comprising the reaction product obtained by the reaction of an acid component comprised of a major concentration of a dimer acid and minor concentration of a monobasic acid and an amine component comprised of a major concentration of a short-chain alkylenediamine, a first minor concentration of a medium-chain alkylenediamine and second minor concentration of a polyoxyalkylene diamine having a molecular weight greater than about 500 is provided. The polyamide resin is used to form a blend of containing the polyamide in a major amount by weight and a first minor amount by weight of a polar wax and a second minor amount by weight of a polyolefin elastomer. The composition is used to reinforce a footwear upper, e.g. as a print on box toe material.

Abstract: A new class of branched dendrimeric macromolecules, is described essentially consisting of a polyvalent central nucleus and a series of polyoxaalkylene "dendra". Such molecules are characterized by the presense of at least one branch, attached either directly to the "core" or to a "dendron", which does not participate in the growth and which therefor differs from all the other functions of the macromolecule.

Abstract: The invention provides a process for directly manufacturing a diamine/dicarboxylic acid salt with a low water content. The process includes reacting a diamine with a dicarboxylic acid to form a diamine/dicarboxylic acid salt. The reaction of the diamine and the dicarboxylic acid is carried out in the presence of about 0.5% to about 25% by weight water, based on the weight of the reaction mixture, while providing conditions in the reaction mixture such that the reaction mixture is in substantially solid particulate form.

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: The present invention relates to addition products ofA) oligomers having at least two acrylic ester and/or methacrylic ester groups per molecule andB) diamines having a primary and a tertiary amino group,the ratio of primary amino groups of B) to the (meth)acrylic double bonds of A) being 0.01:1 to 0.2:1, preferably 0.03:1 to 0.1:1.The invention also relates to processes for the preparation of the addition products, to radiation-curable surface coating compositions based on the addition products and to the use of the surface coating compositions for woodcoating and papercoating.

Abstract: A process for making polyimide composition comprising reacting at least one diamine, at least one tetracarboxylic diacid diester, selected phosphoramide and at least one base catalyst to form at least one polyimide compound, said reaction carried out at a temperature from about 20.degree. C. to about 60.degree. C. and wherein the molar ratio of diamine:tetracarboxylic diacid diester:phosphoramide:base catalyst is in the range of 0.8-1.2:1:2.5-4.0:2.5-4.0.

Abstract: A process for producing a polyimide composition by reacting at least one polyamic acid or at least one polyamic ester or a mixture of at least one polyamic acid and at least one polyamic ester with a selected phosphoramide in the presence of at least one base catalyst to from a polyimide composition.

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: The purification process comprises removing carboxylic acids and/or carboxylic acid salts contained as impurities in a fluorinated polyether having at at least one end thereof a terminal vinyl group linked thereto through an amide group-containing linkage by heating, in the presence of an amine compound such as triethylamine and dimethylaminotrimethylsilane, the fluorinated polyether containing said impurities or a reaction mixture obtained after the completion of reaction in a process of producing said fluorinated polyether. According to the purification process, the impurities can be easily removed from said fluorinated polyether. When the thus purified fluorinated polyether is used as a starting material for an addition type curable composition together with a SiH group-containing organosilicon compound, a liquid rubber material excellent in curability and storage stability can be obtained.

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: There are provided a polyamic acid obtainable by reacting a diamine compound of the formula (1) ##STR1## wherein R.sup.1 is an alkyl group having 1 to 12 carbon atoms, a haloalkyl group having 1 to 12 carbon atoms or a halogen atom, each of X and Y is independently a divalent linking group,with a tetracarboxylic acid dianhydride; a polyimide obtainable by dehydrating and ring-closing the above polyamic acid; and a liquid crystal aligning agent containing the above polyamic acid and/or the above polyimide.

Abstract: A process for the preparation of aromatic polyamide pulp having both excellent physical properties and a high degree of polymerization by continuous polymerization and orientation by using of mixed solutions. The solutions are prepared by reacting diamine with aromatic diacid dichloride in an amide and/or urea-based polymerization solvent containing inorganic salts, or a mixture of inorganic salts and a Lewis acid compound. The process can be practiced by polymerization-orientation apparatus located on the continuous transferable polymerization-orientation means comprised of a belt and one or more stirring bars.

Abstract: In a process for the preparation of poly-o-hydroxyamides and poly-o-mercaptoamides, a bis-o-aminophenol or a bis-o-aminothiophenol is reacted with a dicarboxylic acid ester with the following structure:G--O--CO--R*--CO--O--G,where G is an (optionally substituted) succinimide or maleinimide group and R* is the parent body of the dicarboxylic acid.

Abstract: The present invention relates to a method for the preparation of polyamino acids, with controlled molecular weights, by polymerization of N-carboxyanhydrides (NCAs) of at least one amino acid, using at least one initiator of the strong base type and in liquid medium, characterized in that it consists in including, in the liquid reaction medium, given amounts of water and/or of alcohol. Application: synthesis of polyamino acids with mechanical and rheological characteristics adapted to applications as biomaterials.