Abstract: Disclosed is a novel air drying polymer, such as an alkyd, built up from alternating air drying units and spacer units and having a general structure of R1—R3—(R2—R3); —R1 wherein each R1 and R2 independently is an air drying ester or polyester unit, each R3 independently is an ester, polyester, ether, polyether, urethane or polyurethane spacer unit which by ester and/or urethane bonding links said air drying units, n is an integer and at least 1 and wherein each R1 and R2 independently may be the same or different units.

Abstract: The present invention provides polyols which can be obtained by a simple process. These polyols, unless explicitly specified, are to be understood to encompass both polyether polyols and polyether ester polyols. The invention further provides the simple process for the production of the polyols, and also, the production of polyurethanes comprising reacting a polyol according to the invention with a polyisocyanate.

Abstract: A polymer with a backbone having at least one structural unit represented by formula (I): Wherein R1, R2, R3, R4, and R5 independently denote one of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, or a substituted or unsubstituted alkenyl group, and n preferably denotes an integer from 1 to 10.

Abstract: The present invention relates to novel diepoxides having the formulas I. and II. R*SO2N(A)RN(A)SO2R* where A=2,3-epoxypropyl, R* is a monovalent hydrocarbon radical or an inertly substituted hydrocarbon radical and R is a divalent hydrocarbon radical or an inertly substituted divalent hydrocarbon radical. The epoxies are useful in preparing novel epoxide resins.

Abstract: Various non-limiting embodiments disclosed herein related to photochromic materials comprising the reaction product of (a) at least one ring-opening cyclic monomer, and (b) a photochromic initiator. Other non-limiting embodiments related to photochromic materials represented by: wherein S? comprises the at least one ring-opened cyclic monomer as set forth herein. Other non-limiting embodiments related to photochromic compositions, optical elements, and methods of inhibiting migration of a photochromic material in a polymeric material using the photochromic materials disclosed herein. Methods of making such photochromic materials, compositions, and optical elements are also disclosed.

Abstract: The present invention relates to a hardener for epoxy resins, which on the one hand contains a Michael adduct of a bifunctional amine and of an acrylic acid derivative and also an adduct from a epoxy and the bifunctional amine. The invention likewise relates to a method for hardening an epoxy resin by mixing of a not yet hardened epoxy resin with a Michael adduct of a bifunctional amine and of an acrylic acid derivative. Furthermore, purposes of use of the hardener according to the invention are provided.

Abstract: Hydroxyl polyester compounds or compositions which are useful as oilfield demulsifiers are prepared through esterifying carboxylic compounds and epoxide compounds under controlled molar ratios. The hydroxyl polyesters are useful as biodegradable demulsifiers on oil productions.

Abstract: Disclosed are copolymers made of alkylene oxides and glycidyl ethers according to formula (I) in which R1 is hydrogen or a C1-C4-alkyl radical, R2 and R4 are an alkyl or aryl radical having 1 to 30 carbon atoms, and R3 is an alkyl or aryl radical having 1 to 50 carbon atoms, which may also contain heteroatoms. A is an alkylene unit having 2 to 6 carbon atoms. In formula (1), x is a number from 0 to 10, y is a number from 0 to 10, n is a number from 0 to 100, k is a number from 1 to 100, C is an acid group or hydrogen, and m is a number from 1 to 500, with the proviso that (y+n) must be at least 1.

Abstract: The present invention relates to a manufacturing process for producing a polyol from a fatty acid ester in-situ. The process does not use any added organic or inorganic acid catalyst. The polyol produced by the process is essentially free of any cation or anion. The fatty acid ester oil epoxidation and hydroxylation reactions can occur progressively in the same reactor for essentially a one-pot reaction. The polyol produced by the process is essentially free of any cation or anion. The polyol can be used to produce polyurethanes having improved properties.

Abstract: The present invention relates to a class of conducting oligomers and polymers and to a method for the preparation of the same. The conducting oligomers and polymers contain an end-capping group, which is non-electrically conductive and contains at least one branch point. The branched end-capping groups are made by a method that first substitutes the branched group on the heteroaromatic monomer, particularly at the “2” position on these monomers. In a second step, the end-capping intermediate is co-polymerized with one or more additional heteroaromatic monomers to form capped conducting oligomers and polymers.

Abstract: A photosensitive resin which exhibits excellent storage stability, affinity, miscibility, or solubility with respect to a variety of compounds, and high sensitivity can be solidified even under hydrous conditions as well as exhibiting high cure-related sensitivity and high flexibility and being uniformly solidified even under highly hydrous conditions, a photosensitive resin composition containing the resin, and a novel compound. The photosensitive resin is a saponified poly(vinyl acetate)-based photosensitive resin having a structural unit represented by formula (1): (wherein R1 represents H or Me; R2 represents a linear or branched C2-C10 alkylene group; n is an integer of 1 to 3; X represents m is an integer of 0 to 6; and Y represents an aromatic ring or a single bond).

Abstract: An acrylic composition, or star acrylic polymer, includes the reaction product of an initiator, a first compound, and a highly-branched, polyfunctional core molecule. The initiator has a radical-forming portion and a functional group. The first compound, which includes a vinyl functional group, is reactive with the initiator to form a functionalized intermediate. The core molecule is reactive with the functionalized intermediate to form the acrylic composition. A method of forming the acrylic composition via free-radical polymerization includes the steps of reacting the initiator and the first compound to form the functionalized intermediate, and reacting the core molecule with the functionalized intermediate to form the acrylic composition.

Abstract: Star polymers of soft segment forming monomers are useful in forming surgical devices. The star polymers can be endcapped with diketene acetals, mixed with a filler and/or cross-linked. The polymer compositions are useful, for example, as fiber coatings, surgical adhesives or bone putty, or tissue growth substrate.

Abstract: Novel ester compounds having formulae (1) to (4) wherein A1 is a polymerizable functional group having a carbon-carbon double bond, A2 is oxygen, methylene or ethylene, R1 is a monovalent hydrocarbon group, R2 is H or a monovalent hydrocarbon group, any pair of R1 and/or R2 may form an aliphatic hydrocarbon ring, R3 is a monovalent hydrocarbon group, and n is 0 to 6 are polymerizable into polymers. Resist compositions comprising the polymers as a base resin are thermally stable and sensitive to high-energy radiation, have excellent sensitivity and resolution, and lend themselves to micropatterning with electron beam or deep-UV.

Abstract: A polymer for forming an organic anti-reflective coating layer between an etching layer and a photoresist layer to absorb an exposure light in a photolithography process and a composition comprising the same are disclosed. The polymer for forming an organic anti-reflective coating layer has repeating units represented by wherein, R is a substituted or non-substituted alky group of C1 to C5.

Abstract: A glycolic acid copolymer comprising (a) 80 to less than 95% by mole of glycolic acid monomer units, (b) 5.0 to 20.0% by mole of non-glycolic, hydroxycarboxylic acid monomer units, and (c) 0 to 0.10% by mole of diglycolic acid monomer units, the non-glycolic, hydroxycarboxylic acid monomer units (b) constituting a plurality of segments each independently consisting of at least one monomer unit (b), wherein the segments have an average chain length of from 1.00 to 1.50 in terms of the average number of monomer unit or units (b), the total of the components (a), (b) and (c) being 100% by mole, the glycolic acid copolymer having a weight average molecular weight of 50,000 or more.

Abstract: Disclosed are copolymers of cyclic esters, e.g., caprolactone, and cyclic formals of substituted or unsubstituted diols, e.g., 1,3-dioxepane. The copolymers can provide a low melting temperature rendering them liquids at room temperature. Elastomeric polyurethanes prepared from such copolymers can exhibit a low Tg transition and good resistance to hydrolysis and oxidation. The copolymers are particularly useful for elastomers, coatings, adhesives, inks or binders requiring low temperature flexibility and good resistance to hydrolysis and oxidation.

Abstract: Disclosed is a method for preparing a biodegradable polymer in the form of uniform powder or spherical particles by dispersion polymerization without a grinding step. The method for preparing a biodegradable polyester includes dispersing a monomer in the presence of a catalyst in a dispersion solvent to form a solid or liquid phase for dispersion polymerization and thereby to yield a biodegradable aliphatic polyester in the form of spherical particles or powder, the monomer comprising a mixture of a first compound (e.g., lactide or glycolide) and a second compound being selected from the group consisting of polyhydric alcohols (e.g., glycerin, erythritol, penterythritol or dipentaerythritol) and carprolactone. The present invention readily prepares a biodegradable polymer having a high molecular weight in the form of uniform powder or spherical particles.

Abstract: This invention provides a thermosetting resin compound containing 25% or more by volume of anisotropic structure in the resin ingredient, wherein a structure constituting said anisotropic structure has a covalent bond and the maximum diameter of the structure is 400 nm or more. The resin ingredient of said thermosetting resin compound is preferably a hardened epoxy resin compound containing a mesogen-structured epoxy resin monomer and an epoxy resin hardening agent. The epoxy resin monomer in the thermosetting resin compound is preferably an epoxy resin monomer expressed by the following formula: E-M-S-M-E, wherein E, M, and S respectively indicate an epoxy group, a mesogen group, and a spacer. Therefore, this invention can provide a highly thermal conductive hardened thermosetting resin compound whose thermal conductivity is increased highly.

Abstract: A poly(thio)ester (co)polymer which comprises a repeating structural unit represented by the formula (1-A) as an essential structural unit: [wherein R11 is a divalent aliphatic hydrocarbon group which may contain at least one sulfur atom in a sulfide group; R12 is a mono- or poly-cyclic aliphatic or aromatic dicarboxylic acid residue; and X11 and X12 are each independently an oxygen atom or sulfur atom, and when X11 and X12 are the oxygen atoms, R11 is a divalent aliphatic hydrocarbon group containing at least one sulfur atom in the sulfide group]; and an optical component obtainable by molding the poly(thio)ester (co)polymer. The poly(thio)ester (co)polymer is excellent in transparency and optical characteristics (e.g., a higher refractive index, higher Abbe number, and lower birefringence), and has also good mechanical characteristics and thermal characteristics, and further is excellent in melt fluidity and injection moldability.

Abstract: An epoxy composition includes an epoxy resin, a latent curing agent, and a catalyst. The composition includes two epoxide groups per molecule, and the latent curing agent is preferably a dicyanopolyamide, and most preferably dicyandiamide. The catalyst includes 2,4-toluene bis dimethyl urea, preferably in a concentration exceeding 70% by weight. The composition can be used in prepregs. The relative concentrations of the epoxy resin, curing agent, and catalyst are selected to achieve desired properties, including specific curing times and temperatures, and glass transition temperatures that enable a cured resin composition to be removed from a mold after being heated to its curing temperature, without being cooled. Exemplary formulations have reduced cure times, at both high and low curing temperatures, as compared to prior art formulations.

Abstract: The present invention relates to a composition based on renewable raw materials which is particularly characterized by containing at least one tin-containing compound, an article made thereof as well as a process for the preparation of such an article. The composition according to the present invention exhibits an increased curing rate, i.e. a shortened “incubation time”, compared to those compositions based on renewable raw materials currently available in the prior art. Furthermore, the composition according to the present invention can advantageously use particularly in casting and rotational casting processes, respectively.

Abstract: Thermally re-mendable cross-linked polymeric materials that can be repeatedly mended or repaired by simple thermal treatment. The polymeric materials are made by polymerizing furan monomers and maleimide monomers via the Diels-Alder (DA) reaction wherein the furan monomers have at least three furan moieties and the maleimide monomers have at least three maleimide moieties. The intermonomer linkages that form between the furan and maleimide monomers are thermally reversible and do not require the addition of catalysts, additional monomer or special surface treatments.

Abstract: A method of spherifying a sustained release ionic conjugate which contains a free carboxyl group-containing polymer and a free amino group-containing drug which are ionically bonded to each other.

Abstract: The heat-curable resin composition of the present invention comprises an epoxy-containing resin and a curing agent, wherein the curing agent is cyclohexanetricarboxylic acid and/or an anhydride thereof The heat-curable resin composition exhibits an excellent curability without using an curing accelerator and provides a colorless transparent cured product which is little discolored under high-temperature conditions and irradiation conditions of high-energy light. The heat-curable resin composition is suitable for producing coating compositions, adhesives, shaped articles, protective films for color filters and sealing materials for photosemiconductors such as blue LED and white LED.

Abstract: The invention relates to a process for the preparation of water-soluble polymers containing polyalkylene glycol ether side chains and having molecular weights of from 15,000 to 65,000 by solution polymerization of esters of ethylenically unsaturated carboxylic acids and polyalkylene glycols which are masked on the end groups at one end, if desired together with another monomer in at least one hydrocarbon at monomer concentrations of from 70 to 95% by weight in the presence of free-radical-forming polymerization initiators and, if desired, polymerization regulators at temperatures of up to 200° C., removal of the solvent used in the solution polymerization, and dissolution of the polymers in water to give from 50 to 80% strength by weight solutions, with polymers containing acid groups being neutralized if desired.

Abstract: The invention relates to a process for preparing reabsorbable polyesters by bulk polymerisation, wherein the reaction components are melted and homogenised in a stirred reactor, the reaction mixture is then transferred into a number of smaller-volume containers, the reaction mixture is polymerised in these containers and the polyester obtained is isolated by removing it from the containers, and the use of the reabsorbable polyesters thus produced for preparing reabsorbable implants.

Abstract: Thermally re-mendable cross-linked polymeric materials that can be repeatedly mended or repaired by simple thermal treatment. The polymeric materials are made by polymerizing furan monomers and maleimide monomers via the Diels-Alder (DA) reaction wherein the furan monomers have at least three furan moieties and the maleimide monomers have at least three maleimide moieties. The intermonomer linkages that form between the furan and maleimide monomers are thermally reversible and do not require the addition of catalysts, additional monomer or special surface treatments.

Abstract: Gel formation is prevented in the reaction between a sulfonyl-chloride-containing resin and a polyamine by first forming an adduct between the resin with an aminophenol. The prevention of gel formation enables sulfonyl-chloride containing resin to be used in admixture with acrylates and epoxy resin to form a polyamine-curable adhesive composition having excellent adhesive properties and chemical resistance.

Abstract: A process is provided for manufacturing homo- and copolyesters of lactic acid by ring scission polymerization of its cyclic monomers in the presence of an initiator. Polymerization is carried out in the molten phase in the presence of an initiator system containing a compound of tin and at least one additional initiator chosen from the compounds of metal of the fourth subgroup.

Abstract: A polyhydroxyalkanoate (PHA) having a desired configuration is produced using a raw material containing &ohgr;-(4-vinylphenyl)-alkanoic acid and (&ohgr;-substituted alkanoic acid in which a group having a ring structure selected from phenyl, thienyl, and cyclohexyl structures substitutes therefor on the end thereof by producing a PHA copolymer containing the corresponding 3-hydroxy-&ohgr;-(4-vinylphenyl)-alkanoate unit and the corresponding 3-hydroxy-&ohgr;-substituted alkanoate unit by making use of a microorganism capable of producing the PHA or by oxidizing a predetermined portion of the corresponding PHA.

Abstract: A photothermosetting composition is described which contains a base resin (A), a photopolymerizable photomonomer or photooligomer (B), a photoinitiator (C), an epoxide compound containing at least two epoxy groups (D), and an organic solvent. The base resin (A) an epoxide compound (a) containing at least two epoxy groups, an unsaturated monobasic acid (b), a saturated or unsaturated dibasic acid (c), and a saturated or unsaturated acid anhydride (d) according to the ratio of (a)/(b)/(c) of 1:0.90˜0.95:0.025˜0.050 and the acid value of the base resin is in the range of 40˜49 mg KOH/g. This photothermosetting component was coating on the substrate, and then dried by baking, exposed by light, developed, irradiated by ultraviolet light or heated, and cured to form a solder mask.

Abstract: A pigment dispersant that is useful in a cathodic electrocoating composition that is the reaction product of (1) an adduct of an alkyl aminoalkyl amine and an alkylene carbonate; (2) an organic acid to form a tertiary amine salt and (3) an epoxy resin that is reacted with the tertiary amine salt to form a quaternary ammonium salt.

Abstract: There are provided a photosensitive polymer having a copolymer of alkyl vinyl ether and a resist composition containing the same. The photosensitive polymer includes a copolymer of alkyl vinyl ether and maleic anhydride, represented by the following structure: wherein X is one of a linear alkyl vinyl ether and a cyclic alkyl vinyl ether, which are respectively represented by the structures wherein y is one of the integer values 1 through 4, R1 is one of a hydrogen atom and a methyl group, R2 is a C1 to C20 hydrocarbon, and R3 is one of a hydrogen atom, a C1 to C3 alkyl group and an alkoxy group.

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 relates to a thermosetting composition which comprises: (A) a polyhemiacetal ester resin having a repeat unit represented by formula (1): wherein R1 and R2 are a bivalent organic group, and Y is an oxygen atom or a sulfur atom, and (B) a compound having in the molecule two or more reactive functional groups which can form a chemical bond with the carboxyl group, and optionally, (C) an acid catalyst. The thermosetting composition gives cured products having excellent chemical properties, physical properties, adhesion, smoothness and weathering resistance at relatively lower temperatures and have excellent storage stability, and can be utilized as solvent cutback type, solventless liquid type of 100% effective component or powder thermosetting compositions.

Abstract: A gas barrier polymer composition with active hydrogen functionality is provided. The polymer may be prepared by reacting a solution of organic diacid containing at least one active hydrogen group and diglycidyl ether in the presence of an optional catalyst. The pressure, temperature, and time parameters of the reaction are preferably regulated to prevent degradation and subsequent incorporation of degradation products of organic diacid containing at least one active hydrogen group into the gas barrier polymer composition. A formulation of the gas barrier polymer composition and a carrier may be used to coat plastic materials, containers, and preforms. The gas barrier polymer composition may also be employed in a method of making multilayer packaging materials or container preforms. The multilayer packaging materials or preforms can be used to make containers useful in packaging gas sensitive substances.

Abstract: To increase the melt strength and increase high shear thinning of a polyester composition, a polar chain terminator that contains a nonionic group or an ionic group neutralized with a counterion is added at a level of 0.05 to 20 mole percent. Optionally, up to 2.0 mole percent of a tri-functional or greater branching agent is added to the polyester composition. Optionally, up to 30 mole percent of a polar midchain difunctional monomer that contains a nonionic group or an ionic group neutralized with a counterion is added. The polyester composition is based on 100 mole percent diacid component and 100 mole percent glycol component.

Abstract: Hydrogels of polymerized and crosslinked macromers comprising hydrophilic oligomers having biodegradable monomeric or oligomeric extensions, which biodegradable extensions are terminated on free ends with end cap monomers or oligomers capable of polymerization and cross linking are described. The hydrophilic core itself may be degradable, thus combining the core and extension functions. Macromers are polymerized using free radical initiators under the influence of long wavelength ultraviolet light, visible light excitation or thermal energy. Biodegradation occurs at the linkages within the extension oligomers and results in fragments which are non-toxic and easily removed from the body. Preferred applications for the hydrogels include prevention of adhesion formation after surgical procedures, controlled release of drugs and other bioactive species, temporary protection or separation of tissue surfaces, adhering of sealing tissues together, and preventing the attachment of cells to tissue surfaces.

Abstract: A perfluorodicarboxylic fluoride of the formula: F—CO—CF2—O—Rf—O—CF2—CO—F or perfluorodiketone of the formula: R1—CO—Rf—CO—R1 wherein Rf is a perfluoroalkylene group and R1 is a C1-8 perfluoroalkyl group is mixed with an alkali metal fluoride in an aprotic polar solvent to form an initiator solution. Hexafluoropropene oxide is fed to the initiator solution for polymerization, obtaining difunctional hexafluoropropene oxide polymers of high purity.

Abstract: An improved process for Polytetramethylene-Ether-Glycol-Diesters of the formula R—CO—O(CH2—CH2—CH2—CH2—O)n-COR1, in which R and R1 are identical or different and are alkyl radicals or derivatives thereof, by polymerization of tetrahydrofuran in the presence of a heterogeneous polymerization catalyst and in the presence of a carboxylic anhydride. The use of aluminum silicate catalyst composed of acid-activated and calcinated natural halloysite instead of the known catalytic silicates as bentonite, zeolite or kaolinite. The new catalyst with a very long lifetime produces polymers having more uniform properties and narrow molecular weight distribution even with a relative impure monomer.

Abstract: The present invention relates to a process for preparing (meth)acrylic acid esters by1) reacting hydroxyl group-containing polyethers, polyesters or polyester ethers with (meth)acrylic acid in the presence of an acid esterification catalyst and a solvent to form (meth)acrylic acid esters, and2) reacting the acid esterification catalyst acid and unreacted (meth)acrylic acid with a compound containing two or more epoxide groups in the presence of the solvent used in step 1).

Abstract: Cycloaliphatic epoxy compounds represented by general formula (I): ##STR1## wherein R.sup.1 and R.sup.2 are hydrogen atoms, or R.sup.1 and R.sup.2 taken together represent an epoxy group, R.sup.3 and R.sup.4 are the same or different and each represents a hydrogen atom or a methyl group, and Q is a linear or branched alkanediyl group with 2 to 16 carbon atoms and with the proviso that the adjacent nitrogen and oxygen atoms are not attached to the same carbon atom. The cycloaliphatic epoxy compounds can be used to produce cured epoxy resin compositions exhibiting superior mechanical properties, e.g., tensile and flexural strength and toughness.

Abstract: A photopolymerizable material is provided that is suitable for use in the production of coatings or resists on printed circuit boards, for example The material is an ethylenically unsaturated polymerizable reaction product of a polyepoxide and a mixture of (i) a major proportion of an ethylenically unsaturated carboxylic acid and (ii) a minor. proportion of a saturated aliphatic or aromatic carboxylic acid, the reaction product being further modified by reaction with a dicarboxylic acid or anhydride thereof.

Abstract: Poly(ester-ethers) are produced by the copolymerization of tetrahydrofurans and cyclic carboxylic anhydrides using selected metal perfluoroalkylsulfonates and related compounds as catalysts. The resulting copolymers are useful as intermediates for monomers for use in other polymerizations.

Abstract: Compounds containing two cyclic hydrocarbon moieties which are substituted to provide crosslinking functionality and which are linked to each other by secondary or tertiary oxycarbonyl containing moiety are basis for compositions which are cured to provide cured thermosets for encapsulation and underfill for electronic components that are thermally decomposable to allow repair, replacement, recovery or recycling of operative electronic components from assemblies that are inoperative.

Abstract: Coating compositions comprised of a film forming polymer which is the reaction product of (a) a compound containing pendant and/or terminal hydroxyl or epoxy functional groups and (b) citric acid or citric acid anhydride. The coating compositions have enhanced adhesion to galvanized and galvanealed steel substrates without the use of a chrome containing wash primer.

Abstract: Disclosed is a process for the continuous preparation of a polyester-based polymer having excellent quality which is useful as materials for medical care, coatings, and wrapping. In the process for the continuous preparation, a column-type continuous reactor is essentially employed.

Abstract: Hydroxy-functional polyester oligomers are prepared by contacting a hydroxy-functional aliphatic dicarboxylic acid or a mixture of dicarboxylic acids containing hydroxy-functional aliphatic diacids, with a diglycidyl ether or diglycidyl ester in the presence of an onium catalyst in an ether solvent under conditions suitable for forming the oligomer. The oligomers can be used as hot melt adhesives, adhesive tackifiers, plasticizers, heat-curable adhesives and heat-curable coatings. Some of these materials are biodegradable and are therefore suitable for application to compostable end products.

Abstract: A process for polymerizing oxiranes, oxetanes, oxepanes, dioxolanes, trioxanes, and tetrahydrofurans to their respective polymers by contacting them with a selected metal compound is disclosed; and also a process for depolymerizing polytetrahydrofurans to monomeric tetrahydrofurans by contacting the polymer with a selected metal compound at a temperature of about 100.degree. C. to about 250.degree. C. The catalysts may be in solution or part of a heterogeneous solid, and selected organic compounds are used as accelerators in the polymerizations. The polymeric products, some of which are novel, may be used as polyether monomers for further polymerization, as by reaction with isocyanates to produce polyurethanes, and other useful polymers. Some of the polymeric products are relatively high in molecular weight and are suitable for direct use, for instance as spandex fibers.