Abstract: Polyethylene glycol for use in fields with application to a living body wherein the sum of the contents of ethylene glycol and diethylene glycol in the polyethylene glycol is less than or equal to that expressed in the following formula [I]: Sum ⁢   ⁢ of ⁢   ⁢ ethylene ⁢   ⁢ glycol ⁢   ⁢ and ⁢   ⁢ diethylene ⁢   ⁢ glycol ⁢   ⁢ contents ⁢  

Abstract: In multimetal cyanide complexes, more than 30% by weight of the primary particles have a platelet-like habit, i.e. the length and width of the primary particles is at least three times the thickness of the particles.

Abstract: The present invention relates to a process for the production of flexible polyurethane foams by reaction of a) at least one compound having at least two isocyanate-reactive hydrogen atoms, with b) polyisocyanates, wherein the compund used as said compound having at least two isocyanate-reactive hydrogen atoms a) comprises at least one block polyoxypropylene/polyoxyethylene/polyol having a hydroxyl value of from 25 to 45 mg KOH/g and a content of terminally bound ethylene oxide units of from 15 to 17 wt %, based on the total amount of the alkylene oxide, obtained by attachment of ethylene oxide and propylene oxide to an initiator having an average functionality of 3.

Abstract: A process for the purification or fractionation of aqueous soluble polymers using an aqueous two-phase system is described. The concentrations of the polymer to be fractionated and of an aqueous soluble salt, and the temperature of the aqueous fractionation medium are adjusted so that two phases form, the lower molecular weight polymer molecules partition into the high salt concentration phase, and the higher molecular weight polymer molecules partition into the low salt concentration phase. The resulting high molecular weight polymers are characterized by a higher average molecular weight and a narrower molecular weight distribution and decreased unsaturation than the unfractionated polymers. After being subjected to the fractionation process, polyol polymers that form hydrogels in aqueous solution exhibited higher viscosities and a liquid to gel transition over a narrower temperature range than the unfractionated polyol polymers.

Abstract: Polyester-polyether block copolymers can be prepared by catalytic addition of alkylene oxides onto H-functional initiator substances, using polyester alcohols as H-functional initiator substances and multimetal cyanide compounds as catalysts.

Abstract: The present invention comprises novel preparations of polyoxypropylene/polyoxyethylene copolymers which retain the therapeutic activity of the commercial preparations, but are substantially free from the undesirable effects which are inherent in the prior art preparations. Because the preparations of polyoxypropylene/polyoxyethylene copolymers which comprise the present invention are a less polydisperse population of molecules than the prior art polyoxypropylene/polyoxyethylene copolymers, the biological activity of the copolymers is better defined and more predictable.

Abstract: The present invention pertains to glycidyl ether-capped acetylenic diol ethoxylates having a structure according to the formula: wherein R1 is hydrogen or a linear, branched, or cyclic alkyl group having from 1 to about 6 carbon atoms; R2 is a linear, branched, or cyclic alkyl group having from 1 to about 12 carbon atoms; R3=—CH2OR4; R4 is a linear, branched, or cyclic alkyl, alkenyl, aryl, or aralkyl group having from 2 to about 30 carbon atoms; (n+m) is from 1 to about 100; and (p+q) is from 0.5 to about 5 and its use to reduce equilibrium and dynamic surface tension in water-based compositions containing an organic or inorganic compound, particularly aqueous organic coating, ink, acid gas scrubbing and agricultural compositions.

Abstract: A process for the preparation of polyetherpolyols by reacting diols or polyols with ethylene oxide, propylene oxide, butylene oxide or a mixture thereof in the presence of a multimetal cyanide complex catalyst is proposed, the reaction being carried out in a stirred kettle reactor and the reaction mixture being circulated via an external heat exchanger by means of a pump.

Abstract: In a process for preparing polyether alcohols by catalytic addition of at least two alkylene oxides onto H-functional initiator substances, at least one multimetal cyanide compound is used as catalyst and the addition of the alkylene oxides onto the initiator substance includes incorporation of at least one oxyalkylene block during whose formation at least two alkylene oxides are metered in together and the ratio of the alkylene oxides to one another in the mixture is changed during the joint introduction.

Abstract: The invention relates to novel double metal cyanide (DMC) catalysts for the preparation of polyether polyols by polyaddition of alkylene oxides to starter compounds containing active hydrogen atoms, wherein the catalyst contains a) double metal cyanide compounds, b) organic complex ligands other than c), and c) carboxylic acid ester of polyhydric alcohols. The catalysts according to the invention have greatly increased activity in the preparation of polyether polyols.

Abstract: The invention relates to double-metal cyanide (DMC) catalysts for preparing polyether polyols by the polyaddition of alkylene oxides on to starter compounds containing active hydrogen atoms, wherein the DMC catalysts are composed of: a) at least one DMC compound; b) at least one organic complexing ligand which is not a coronand; and c) at least one coronand. The DMC catalysts of the present invention have increased activity compared to known catalysts.

Abstract: Nonaqueous compositions comprising at least one product of the reaction between A) a linking agent of formula I R4(Y)3  (I) Wherein each Y group is a halogen atom or one Y group is a halogen atom and two Y groups represent an epoxy oxygen atom, which is attached to two adjacent carbon atoms in the R4 group to form an epoxy group, and R4 is an alkanetriyl group containing from 3 to 10 carbon atoms; and B) a compound of formula II R3(EO)n(PO)m(BO)pX  (II) Wherein R3 is substituted or unsubstituted, saturated or unsaturated, organic oxy or thio group having from 1 to 36 carbon atoms or a primary or secondary amino group having from 1 to 36 carbon atoms; n is a number of from 0 to 50; m is a number of from 0 to 50; p is a number of from 0 to 50; and X is hydrogen, or X can be a mercapto group, an amino group, or a C1-C6 alkylamino group in place of a terminal —OH group, provided that when X is mercapto, amino or a C1-C6 alkylamino, the sum of n, m, and p must be at least 1; and the

Abstract: A method of recovering a decomposition product from a polyurethane, the method comprising the steps of thermally decomposing a polyurethane into a liquid containing a polyol and a urea compound which is soluble in the polyol, and solids containing a urea compound which is insoluble in the liquid in the presence of a polyamine compound at a temperature of 120 to 250° C.; removing the solids; hydrolyzing the residue with water retained at a high temperature of 200 to 320° C. and a high pressure; and recovering the resulting polyamine and/or polyol.

Abstract: Polymeric compounds useful as low foaming surfactants and defoaming and stabilizing agents for aqueous-and nonaqueous-based compositions, and to processes for the preparation of the polymeric compounds, wherein the polymeric compounds are the reaction products of reactants comprising A) at least one linking compound of formula I R1(X)3  (I) wherein each X group is a halogen atom or one X group is a halogen atom and two X groups represent an epoxy oxygen atom, which is attached to two adjacent carbon atoms in the R1 group to form an epoxy group, and R1 is an alkanetriyl group containing from 3 to 10 carbon atoms; and B) compounds of formula 11 R2(OA)nX  (II) wherein R2 is an organic group containing from 4 to 36 carbon atoms, n is a number of from 0 to 200, X is —OH, —NHR′, or —SH and each OA group is independently an ethyleneoxy, 1,2-propyleneoxy, or 1,2-butyleneoxy group.

Abstract: The present invention relates to a process for the preparation of polyether polyols by catalytic reaction of H-functional initiators with lower alkylene oxides, wherein the catalysts used are multimetal cyanide compounds and the H-functional initiators used are butane-1,4-diol, &agr;-hydroxy-&ohgr;-hydroxypoly(oxybutane-1,4-diyl), pentane-1,5-diol, decane-1,10-diol or mixtures of at least two of these compounds.

Abstract: Disclosed are a process for producing a poly(alkylene ether) glycol which comprises polymerizing a cyclic ether in the presence of at least a catalyst and a carboxylic acid anhydride, wherein the carboxylic acid anhydride has a ketene dimer content of 50 ppm or lower, and a process for producing a poly(alkylene ether) glycol which comprises polymerizing a cyclic ether in the presence of at least a catalyst and acetic anhydride, wherein the acetic anhydride is purified acetic anhydride obtained by treating acetic anhydride by contacting with at least one of a metal oxide and a mixed oxide, and optionally, distilling the acetic anhydride simultaneously with or after the contact treatment.

Abstract: The present invention comprises preparations of polyoxypropylene/polyoxyethylene copolymers which retain the therapeutic activity of the commercial preparations, but are substantially free from the undesirable effects which are inherent in the prior art preparations. Because the preparations of polyoxypropylene/polyoxyethylene copolymers which comprise the present invention are a less polydisperse population of molecules than the prior art polyoxypropylene/polyoxyethylene copolymers, the biological activity of the copolymers is better defined and more predictable.

Abstract: Polyether polyols can be prepared by reacting polyols with epoxides in the presence of basic catalysts, by treating the polyether polyols containing the basic catalysts with OH-functional solid compounds of metals of groups III to VIII of the periodic system of the elements (Mendeleyev), the compounds being insoluble in the polyether polyols and having BET surface areas of from 10 to 1000 m2/g, isolating the solid inorganic compounds laden with the basic catalysts from the polyether polyol and using them in the reaction of polyols with epoxides, or bringing the isolated inorganic compounds laden with the basic catalysts into contact with the polyols that are to be used in the reaction with epoxides, separating those polyols from the inorganic compounds and delivering them to the reaction with epoxides.

Abstract: The present invention provides a production method of a 5-phthalancarbonitrile compound, which comprises the use of a novel compound of the formula [I] 1

Abstract: The present invention relates to highly active, substantially crystalline double metal cyanide (DMC) catalysts, a process for the preparation of these double metal cyanide catalysts, a process for producing polyether polyols by the polyaddition of alcohol ethers onto starter compounds containing active hydrogen atoms from these DMC catalysts, and to the polyether polyols produced by this process. The DMC catalysts of the invention comprise a) double metal cyanide compounds, b) organic complexing ligands, and c) functionalized polymers. These catalysts exhibit increased activity in the process for the production of polyether polyols.

Abstract: A resilient polyurethane foam produced by using a polyether polyol produced by reacting alkylene oxides with a polyhydroxy compound having at least 2 hydroxyl groups as an initiator in the presence of the catalyst for alkylene oxide ring-opening polymerization of the present invention, which is excellent in foam physical properties, vibration characteristics and molding properties.

Abstract: A crystalline multimetal cyanide complex of the formula (I) M1a[M2(CN)bL1c]d*e(M1fXg)*hL2′iH2O  (I) where M1 is at least one element from the group consisting of Zn(II), Fe(II), Co(III), Ni(II), Mn(II), Co(II), Sn(II).

Abstract: There is provided a process for preparing a poly(alkylene oxide) by using a polymerization initiator which does not cause any problem on preparing and handling in the preparation of the polyalkylene oxide by polymerizing an alkylene oxide compound and does not require a special treatment before the initiation of the polymerization. That is, it is a process of polymerizing the alkylene oxide compound in the presence of a phosphine oxide compound represented by the formula (1): wherein R is the same or different and each represents a hydrocarbon group having 1 to 10 carbon atoms, and x represents an amount of water molecules contained in terms of a molar ratio and is within a range from 0 to 5.0, or in the presence of said phosphine oxide compound and an active hydrogen compound selected from water or an organic compound having a partial structural formula —OH or —NH—.

Abstract: The invention is directed to new double metal cyanide (DMC) catalysts, a process for the preparation of these catalysts, and to a process for the preparation of polyetherpolyols by the polyaddition of alkylene oxides to starter compounds which contain active hydrogen atoms, wherein the catalyst comprises the novel double metal cyanide (DMC) catalyst of the present invention. These new double metal cyanide (DMC) catalysts comprise a) one or more double metal cyanide compounds, b) one or more organic complex ligands, and c) one or more cyclodextrins, with the proviso that b) and c) are different compounds. The catalysts of this invention exhibit greatly increased activity during preparation of a polyetherpolyol.

Abstract: Most generally, the invention provides a method for making a neutralized polyether polyol, comprising the steps of a) Polymerizing one or more alkylene oxides in the presence of an alkaline catalyst to form a polyalkylene oxide intermediate; and b) Neutralizing the intermediate, after the polymerization step a) is complete, with an organic acid of general formula where R1 is hydrogen, methyl, or ethyl; R2 is methyl or ethyl; and R3 is an alkyl, aryl, or aralkyl group containing one to twelve carbon atoms. The invention also comprises the novel compositions made by the above process.

Abstract: The present invention includes novel polyoxyethylene/polyoxypropylene block copolymers as well as methods for making the block copolymers. The block copolymers are high molecular weight molecules and are useful as general surfactants and display enhanced biological efficacy as vaccine adjuvants.

Abstract: Block copolyethers having general formula (I):RX--(CH.sub.2 --CHR.sub.1 --O--).sub.x --(--CH.sub.2 CHR.sub.2 --O--).sub.y --(--CH.sub.2 --CHR.sub.3 --O--).sub.z --R.sub.4wherein:R is selected from H, alkyl, alkylaryl;X is selected from O, S and N;R.sub.1, R.sub.2 and R.sub.3 are selected from H, CH.sub.3, and C.sub.2 -C.sub.10 alkyl radicals;R.sub.4 is selected from H, alkyl, acyl;x,y,z represent the number of ether units and are integers which have such values that the molecular weight of the compound having general formula (I) is between 600 and 4000, and in addition (x+z)/y is between 1.5 and 5.0; with the proviso that:a) either R.sub.1 and R.sub.3 are selected from H and CH.sub.3, in which case R.sub.2 is selected from C.sub.2 to C.sub.10 alkyl radicals,b) or R.sub.1 and R.sub.3 are selected from C.sub.2 -C.sub.10 alkyl radicals, in which case R.sub.2 is selected from H and CH.sub.3.

Abstract: There is provided an sealant made with an isocyanate or hydroxyl terminated prepolymer made by reacting a stoichiometric excess of an organic polyisocyanate with polyols made of at least a polyoxyalkylene polyether triol or a mixture thereof with a polyoxyalkylene polyether diol. The triol or diol has within its structure the nucleus of an initiator compound, an internal blocks of oxypropylene groups, and external blocks of oxyalkylene groups, wherein the internal blocks of oxypropylene are between said nucleus and said external blocks, said external blocks are made of oxyalkylene groups derived from a C.sub.4 or higher alkylene oxide. The amount of the internal blocks of oxypropylene groups is from 25 weight percent to 80 weight percent based on the weight of all oxyalkylene groups and initiator in the prepolymer The triol or diol has a compatibility index of 25.degree. C. or less, and may be part of a two component or a one component moisture cured sealant.

Abstract: During polyoxyalkylation in the presence of certain double metal cyanide catalysts, a very high molecular weight hydrophobic fraction, i.e. a "tail", is produced during preparation of high secondary hydroxyl polyols which is believed to contribute to foam collapse in polyurethane foam formulations. The processing latitude of such foams may be improved by altering the hydrophile/lipophile balance of the high molecular weight tail by oxyalkylating with a mixture of ethylene oxide and higher alkylene oxide during the greatest portion of total oxyalkylation such that essentially pure higher alkylene oxide is present in a terminal portion of oxyalkylation not exceeding 15 weight percent of total polyol weight.

Abstract: Copolymer DMC-catalyzed polyoxypropylene polyols which exhibit processing latitude similar to base-catalyzed copolymer analogs and base-catalyzed homopolyoxypropylene analogs may be prepared by oxyalkylation with a mixture of propylene oxide and ethylene oxide such that a finite ethylene oxide content is maintained in the oxyalkylation reactor for the most substantial part of the oxyalkylation, the polyoxypropylene polyol having randomly distributed oxyethylene moieties which constitute 1.5 weight percent or more of the polyol product.

Abstract: Copolymer DMC-catalyzed polyoxypropylene polyols which exhibit processing latitude similar to base-catalyzed copolymer analogs and homopolyoxypropylene analogs may be prepared by oxyalkylation with a mixture of propylene oxide and ethylene oxide such that a finite ethylene oxide content is maintained in the oxyalkylation reactor for the most substantial part of the oxyalkylation, the polyoxypropylene polyol having randomly distributed oxyethylene moieties which constitute 1.5 weight percent or more of the polyol product. Block copolymer polyols having external blocks containing lesser oxyethylene content than internal blocks and bicompositional compositions containing discrete multimodal and dissimilar and optionally multimodal polyols produced by a continuous addition of starter process are useful as polyols exhibiting greater processing latitude.

Abstract: The present invention comprises novel preparations of polyoxypropylene/polyoxyethylene copolymers which retain the therapeutic activity of the commercial preparations, but are substantially free from the undesirable effects which are inherent in the prior art preparations. Because the preparations of polyoxypropylene/polyoxyethylene copolymers which comprise the present invention are a less polydisperse population of molecules than the prior art polyoxypropylene/polyoxyethylene copolymers, the biological activity of the copolymers is better defined and more predictable.

Abstract: Elastomers exhibiting decreased demold times and improved green strength are prepared by reacting a di- or polyisocyanate with a monodisperse polyoxypropylene diol having ultra-low unsaturation, and preferably prepared by the double metal cyanide.t-butyl alcohol catalyzed polymerization of propylene oxide. Further improved demold times and elevated elastomer physical properties are made possible by the use of multidisperse polyoxyalkylene polyether polyol blends having an overall unsaturation of less than 0.010 meq/g and a polydispersity of about 1.4 or greater.

Abstract: This invention relates to a process for the purification of polyether polyols. This process enables the removal of residual alkaline metal catalyst from produced polyether polyol. It comprises a) adding glycerine to a polyether polyol that contains Group IA alkaline metal catalyst to form a precipitate, and b) separating the precipitate formed in a) to provide a purified polyether polyol. The present invention also relates to the purified polyether polyol produced by this process, the precipitate produced by this process, and the use of the precipitate as an alkaline metal catalyst in a process for the production of polyether polyols.

Abstract: A process for the continuous and discontinuous production of tetrahydrofuran polymers by homopolymerizing tetrahydrofuran or copolymerizing tetrahydrofuran with 1,2-alkylene oxides in the presence of compounds with reactive hydrogen or carboxylic acid anhydrides on an acid-treated, calcined and granulated aluminium silicate catalyst which may consist of amorphous aluminium silicate, a zeolite or kaolin. By keeping the concentration of carboxylic acid anhydride or alkylene oxide constant below 1 wt. % in the polymerization recipe throughout the polymerization it is possible to largely prevent the formation of cyclic ethers and to obtain a polymer with a very narrow molecular weight distribution. In granular form, the catalysts exhibit a hitherto unknown activity and form polymers with a very narrow molecular weight distribution and low color and acid numbers.

Abstract: The reaction product ofA) a linking compound of formula IR.sup.1 (X).sub.3 (I)wherein each X group is a halogen or one X group is a halogen and two X groups with 2 carbon atoms from the R.sup.1 group and an oxygen atom form an epoxy group, and R.sup.1 is an alkanetriyl group containing from 3 to 10 carbon atoms;B) a compound of formula IIR.sup.2 (OA).sub.n --OH (II)wherein R.sup.2 is an aliphatic group containing from 4 to 36 carbon atoms, n is a number of from 1 to 200, and each OA group is independently an ethyleneoxy, 1,2-propyleneoxy, or 1,2-butyleneoxy group; andC) a compound of formula IIIH--(OA).sub.m --OH (III)wherein OA is as defined above, and m is a number of from 1 to 500;processes for its preparation; and methods for its use as a thickener in aqueous compositions.

Abstract: The present invention includes compositions and methods using biologically active nonionic reverse block copolymers. The reverse copolymers have an inner core of polyoxypropylene (POP) that is flanked on either end by polyoxyethylene (POE). The reverse block copolymers have the following formula: ##STR1## wherein "b" represents a number such that the molecular weight of the hydrophobe (C.sub.3 H.sub.6 O).sub.b is between approximately 2,000 and 10,000, and "a" represents a number such that the percentage of hydrophile (C.sub.2 H.sub.4 O).sub.a is between approximately 5% and 30%. The reverse block copolymers stimulate the immune response, can suppress immune responses such as those in autoimmune diseases, promote the growth of animals, and stimulate hormone production.

Abstract: A process for the fractionation of polyoxyalkylene block copolymers wherein the polydispersity of the polyether is reduced. The fractionation process, which removes lower molecular weight species such as polyoxyalkylene homopolymer, truncated polyoxyalkylene diblock polymers, or other reaction byproducts, comprises salt extraction and liquid phase separation to provide a product with a narrower molecular weight distribution, lower degree of unsaturation, and distinctly different physical characteristics compared to the starting material.

Abstract: Polyurethane elastomers exhibiting improved green strength while maintaining short demold times are prepared from ultra-low unsaturation polyoxypropylene polyols containing up to 20 weight percent internal random oxyethylene moieties. The elastomers adsorb less than 10 weight percent water at 0.degree. C. The internal polyoxyethylene moiety-containing polyoxypropylene polyols may be used to prepare ultra-low unsaturation polyoxyethylene capped polyols which are haze-free and which may be used to prepare haze-free 4,4'-MDI prepolymers. Multidisperse blends of monodisperse internal oxyethylene moiety-containing polyoxypropylene polyols of ultra-low unsaturation provide yet further improvements in elastomer processing.

Abstract: Branched, dendrimeric-type macromolecules composed essentially of a central nucleus and of a series of polyoxaalkyl chains that depart from said nucleus and spread into the surrounding space branching in a cascade fashion useful as carriers of drugs, contrast agents, etc.

Abstract: The present invention concerns the use of dendrimeric-type branched macromolecules, comprising polyoxaalkylene chains, as catalysts or coadjuvants of phase transfer catalysis reactions.

Abstract: Polyether polyols having reduced terminal unsaturation are prepared in a process comprising a first step of contacting a polyether having allyl terminal unsaturation with an isomerization catalyst whereby the allyl terminal unsaturation of the polyether is reduced by at least 90% conversion to propenyl terminal unsaturation in one step and, in a final step, the resulting polyether product of the first step is contacted with an acid catalyst whereby a substantial amount of the propenyl terminal unsaturation of the polyether is removed and the corresponding polyether having an additional hydroxyl group is obtained.

Abstract: The present invention comprises novel preparations of polyoxypropylene/polyoxyethylene copolymers which retain the therapeutic activity of the commercial preparations, but are substantially free from the undesirable effects which are inherent in the prior art preparations. Because the preparations of polyoxypropylene/polyoxyethylene copolymers which comprise the present invention are a less polydisperse population of molecules than the prior art polyoxypropylene/polyoxyethylene copolymers, the biological activity of the copolymers is better defined and more predictable.

Abstract: The present invention comprises novel preparations of polyoxypropylene/polyoxyethylene copolymers which retain the therapeutic activity of the commercial preparations, but substantially reduce the undesirable effects which are inherent in the prior art preparations. Because the preparations of polyoxypropylene/polyoxyethylene copolymers which comprise the present invention are a less polydisperse population of molecules than the prior art polyoxypropylene/polyoxyethylene copolymers, the biological activity of the copolymers is better defined and more predictable and the cardiotoxicity inherent in the native copolymers is substantially reduced.

Abstract: Low-odor, higher molecular weight polyether polyols are produced by purifying the polyether polyols at temperatures of 110.degree. to 150.degree. C. and pressures of 10 to 70 hPa with the addition of 5 to 30% by weight of water, wherein the water is passed in finely divided form, with a droplet diameter of about 5 to 100.mu., through the polyether polyols to be purified for a time of metered addition of 1 to 5 hours.

Abstract: Active esters of PEG acids and related polymers are provided that have a single propionic or butanoic acid moiety and no other ester linkages. These polymer acids have a half life in water of from about 10 to 25 minutes. For example, alpha-methoxy, omega-propionic acid succinimidyl ester of PEG ("methoxy-PEG-SPA") has a nearly ideal reactivity with amino groups on proteins and other biologically active substances. The half life of methoxy-PEG-SPA is about 16.5 minutes in water. The invention also provides conjugates with proteins, enzymes, polypeptides, drugs, dyes, nucleosides, oligonucleotides, lipids, phospholipids, liposomes, and surfaces of solid materials that are compatible with living organisms, tissue, or fluid.

Abstract: High resilience polyurethane foams exhibiting little or no shrinkage may be prepared from low unsaturation double metal cyanide catalyzed polyoxyalkylene polyols in amounts greater than 20 weight percent of the total polyol component, when low unsaturation poly(oxypropylene/oxyethylene) random polyols having less than 35 weight percent of an all polyoxypropylene block catalyzed by double metal cyanide catalysts and one or more external random polyoxypropylene/polyoxyethylene blocks each containing 2 weight percent or more oxyethylene moieties, and an unsaturation of less than 0.02 meq/g are employed.

Abstract: A process for polymerizing oxepanes, dioxolanes, trioxanes, and tetrahydrofurans to their respective polymers by contacting them with a selected metal compound and an accelerator which is a selected vinyl ester or a selected phosphorous compound.

Abstract: The present invention comprises novel preparations of polyoxypropylene/polyoxyethylene copolymers which retain the therapeutic activity of the commercial preparations, but are substantially free from the undesirable effects which are inherent in the prior art preparations. Because the preparations of polyoxypropylene/polyoxyethylene copolymers which comprise the present invention are a less polydisperse population of molecules than the prior art polyoxypropylene/polyoxyethylene copolymers, the biological activity of the copolymers is better defined and more predictable.

Abstract: The present invention comprises novel preparations of polyoxypropylene/polyoxyethylene copolymers which retain the therapeutic activity of the commercial preparations, but are substantially free from the undesirable effects which are inherent in the prior art preparations. Because the preparations of polyoxypropylene/polyoxyethylene copolymers which comprise the present invention are a less polydisperse population of molecules than the prior art polyoxypropylene/polyoxyethylene copolymers, the biological activity of the copolymers is better defined and more predictable.