Abstract: A torsional vibration damper or other vibration damping device with a rubber vibration absorbing element. The rubber element is a peroxide-cured composition based on 100 parts of ethylene-alpha-olefin elastomer, and 5 to 100 parts of polyvinyl butyral polymer which may have a molecular weight from about 40,000 to about 250,000. The composition may also include a compatibilizer or homogenizer, such as chlorinated polyethylene. The polyvinyl butyral increases the damping of the composition, and the compatibilizer improves the temperature stability of the damping.

Abstract: A functionalized polymer includes a polymer chain and, bonded thereto, an functional group having the general formula —NHAR1 where A is an oxygen atom, a sulfinyl (thionyl) group, a sulfonyl group, a quaternary phosphonium group, or a secondary amino group and where R1 is a hydrogen atom or a moiety of the general formula —CH2Z where Z is H or a substituted or unsubstituted aryl, alkyl, alkenyl, alkenaryl, aralkenyl, alkaryl, or aralkyl group. The material can be the reaction product of a living polymer and a compound that includes protected imine functionality. The functional group can interact with particulate filler such as, e.g., carbon black.

Abstract: A reworkable thermoset epoxy-containing material that allows for a reworkable assembly such as a reworkable waferlevel underfilled microelectronic package. A method for using the reworkable thermoset material in the formation of a microelectronic package using this material.

Abstract: Provided is a method of producing a low viscosity phenol-modified aromatic hydrocarbon formaldehyde resin (C), including subjecting an aromatic hydrocarbon formaldehyde resin (A) and a phenol (B) to condensation reaction under the presence of an acid catalyst. The method includes: terminating, when a reaction mixture has a viscosity at 25° C. of 200 to 1,500 mPa·S, the condensation reaction by adding an inorganic basic compound and/or a tertiary amine compound having a boiling point of 300° C. or more; and distilling and removing the phenol (B) unreacted and a low boiling component after termination of the condensation reaction, whereby there can be produced a low viscosity phenol-modified aromatic hydrocarbon formaldehyde resin which is kept in a liquid state and contains small amounts of unreacted phenols, and in which increase in viscosity is small even after removal of low boiling components.

Abstract: The present invention relates to biodegradable biocompatible polyketals, methods for their preparation, and methods for treating animals by administration of biodegradable biocompatible polyketals. In one aspect, a method for forming the biodegradable biocompatible polyketals comprises combining a glycol-specific oxidizing agent with a polysaccharide to form an aldehyde intermediate, which is combined with a reducing agent to form the biodegradable biocompatible polyketal. The resultant biodegradable biocompatible polyketals can be chemically modified to incorporate additional hydrophilic moieties. A method for treating animals includes the administration of the biodegradable biocompatible polyketal in which biologically active compounds or diagnostic labels can be disposed. The present invention also relates to chiral polyketals, methods for their preparation, and methods for use in chromatographic applications, specifically in chiral separations.

Abstract: A liquid composition having a microcapsule, the microcapsule having an aldehyde-containing resin, and one or more formaldehyde scavenger which reacts with formaldehyde to achieve more than about 60% reaction completeness in about 15 minutes time at pH 8 and at about 21° C. A liquid composition having a microcapsule, the microcapsule having an aldehyde-containing resin, one or more sulfur-based formaldehyde scavenger and optionally a non-sulfur-based formaldehyde scavenger.

Abstract: The invention provides a golf ball material composed of an ionomeric resin composition obtained by melt-blending under applied heat one or more compounds selected from among UV/EB-curable materials with, in the presence of a peroxide, a non-ionomeric thermoplastic resin and an ionomeric resin; or of an ionomeric resin composition obtained by using, instead of the ionomeric resin, an acid-containing polymer base of the ionomeric resin and subjecting the acid-containing polymer composition similarly prepared by melt-blending under applied heat to an acid-neutralizing reaction with a metal ionic species. Methods for preparing such a material, and golf balls which include as a component therein a molding made of the golf ball material are also provided. The golf ball material has a good thermal stability, flow and processability, and can thus be used to obtain high-performance golf balls endowed with an excellent abrasion resistance, scuff resistance, durability and flexibility without a loss of rebound.

Abstract: The invention relates to an adhesive composition comprising a formaldehyde-containing aminoplast resin and a catalysing compound, with the catalysing compound being an acid or is able to release an acid with a pKa lower than 4 and with the formaldehyde-containing aminoplast resin having a F/(NH2)2 ratio lower than or equal to 1. The catalysing compound comprises at most 11 wt. % of an ammonium salt. The invention also relates to a process for the preparation of board material using the adhesive composition according to the invention and to the board material thus obtainable.

Abstract: Provided is an oxymethylene copolymer composition for a stretched material having a high strength and a high elastic modulus, the composition including: an oxymethylene copolymer; and a crosslinkable compound to be blended with the oxymethylene copolymer in an amount of 0.001 to 0.05 part by mass with respect to 100 parts by mass of the oxymethylene copolymer. The present invention also relates to a stretched material obtained by using the oxymethylene copolymer composition. Further, the present invention relates to a structure obtained by the secondary processing of the above stretched material, and a structure obtained by using the above oxymethylene copolymer composition in a bonding layer of the structure. The present invention also relates to a method of producing a structure, the method including: using the oxymethylene copolymer composition in a bonding layer of the structure; and removing a polyalkylene glycol component with water or a solvent.

Abstract: The invention provides methods and compositions having one-dimensional nanoparticle chains. A one-dimensional nanoparticle chain can comprise a linear substantially non-crosslinked polymer having pendant groups and asymmetrically functionalized nanoparticles attached to the polymer through the pendant groups. Additionally, an asymmetrically functionalized nanoparticle can comprise a nanoparticle core having an outer surface, a primary group of first ligands attached to a substantially continuous primary region of the outer surface, and a secondary group of second ligands attached to a substantially continuous secondary region of the outer surface, such that the primary group of first ligands and the secondary group of second ligands comprise a different ligand population.

Abstract: The present invention provides epoxy curing agent compositions comprising alkylated aminopropylated alkylenediamine compounds. Amine-epoxy compositions and articles produced from these amine-epoxy compositions are also disclosed.

Abstract: A retardation film comprising a monolayer film having a birefringent chain polymer orientated. The polymer has a repeating unit of the structure of the general formula: (V) wherein R3 is a hydrogen atom or C1-C8 alkyl; each of R4 and R8 independently is a hydrogen atom, C1-C4 linear or branched alkyl, C1-C4 linear or branched alkoxyl, C1-C4 linear or branched thioalkoxyl, halogen, nitro, amino, hydroxyl or thiol (with the proviso that R4 and R8 are not simultaneously hydrogen atoms); and each of R5, R6 and R7 independently is a hydrogen atom or a substituent. This retardation film can be a relatively thin layer, and exhibits such a wavelength dispersion that with respect to light rays of wavelength ? of approximately the entire visible region, the phase contrast is about ?/2 or about ?/4.

Abstract: The present invention provides a method for modifying a composite resin, capable of efficiently obtaining a composite resin with the impact resistance or the like improved. A method for modifying a composite resin containing both an amorphous resin and a crystalline resin or either, and a carbon compound, wherein a modified carbon compound having a wet index (measurement temperature 25° C.) of 40 dyn/cm or more with a silicatizing flame treatment, in which a modifier compound having at least a silane atom is used as a fuel, applied on the surface of a carbon black, a graphite or the like as a carbon compound.

Abstract: Described is a radially multi-branched polymer represented by the following formula (I): ABi (I), which includes a central molecule (A) to which side-branches (B) are bonded in at least three positions (i?3). Also described are methods for preparing a multi-branched polymer as well as a porous insulating film including a multi-branched polymer.

Abstract: A polymer coating for implantable medical devices based on polyorthoesters and methods for fabricating the coating are disclosed. The implantable medical devices made of polyorthoesters and methods for fabricating thereof are also disclosed.

Abstract: A coating composition comprising a film forming binder of a. at least one polymer that has pendant groups, such as, hydroxyl, carboxyl, glycidyl, amine, amide, silane and mixtures thereof that are reactive with a crosslinking component and the polymer has a glass transition temperature (Tg) of 10 to 80° C.; b. a polytrimethylene ether diol having a Mn (number average molecular weight) of 500 to 5,000; and c. a crosslinking component, such as, organic polyisocyanates, melamine formaldehydes, alkylated melamine formaldehydes, benzoquanamine formaldehyde, urea formaldehyde, polyepoxides, silane resin and any mixtures thereof; wherein the coating composition can be used as a clear coating composition and can contain pigments and may be used as a pigmented top coating, a pigmented base coating, a primer or primer surfacer coating and is useful for coating automobile and truck bodies and parts, industrial equipment, appliances and exterior structures.

Abstract: A coating composition comprising components A, B and optionally C, wherein component A comprises at least one hydroxy-terminated polyarylate. Component B is an organic species which can react with the hydroxy terminal groups of component A, and component C is a catalyst or mixture of catalysts. The hydroxy-terminated polyarylates are prepared by a solution polymerization method.

Abstract: There are disclosed a phosphorus-containing carboxylic acid derivative which has a group containing phosphorus atom and has in its molecule, a group represented by the following formula (1): wherein R1, R2 and R3 are each hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, and Y is oxygen atom or sulfur atom; a process for producing the derivative; and a flame retardant comprising the foregoing derivative as an effective ingredient. The present invention can provide the phosphorus-containing carboxylic acid derivative and a flame retardant which are each excellent in solubility in an organic solvent, compatibility with a variety of resins, stability and flame retardancy.

Abstract: Polymeric compositions containing spiroorthocarbonate groups and another functional group which reacts with hydroxyl groups are readily crosslinked on contact with water. These compositions are useful as sealants, coatings and encapsulants.

Abstract: The invention is to provide a polymer, having a high affinity to water, is liquid in spite of being a polymer, simultaneously possesses also a thermal stability and is suitably used as a heating medium or a lubricant. It is the polyacetal (co)polymer, being liquid at room temperature, prepared by copolymerizing (A) 75 to 100 mol % of 1,3-dioxolane and (B) 25 to 0 mol % of trioxane and having the total amount of terminal groups of 15 to 300 mmol/kg and an amount of a hemiformal terminal group of 80 mmol/kg or less.

Abstract: A flame retarding and smoke suppressing additive powder that can be mixed with resins includes a carbonific material, a heat activated blowing agent, a heat activated halogen material, a phosphate material, and an inorganic material. The additive powder, when added to a curable or hardenable resin, forms a mixture where the additive powder is about 20-30%, by weight, of the mixture. The resin can be styrenic, olefinic, acrylic, cellulosic, polyester, or polyamide such as are commonly used in the manufacture of fiberglass reinforced structures and moldable plastics.

Abstract: Reworkable thermoset acid-cleavable acetal and ketal based epoxy oligomers can be B-staged into a tack free state. Compositions containing the epoxy oligomers are employed in a reworkable assembly such as a wafer-level underfilled microelectronic package.

Abstract: A composition for a bottom anti-reflective coating material and a method for forming a resist pattern using the composition, which are high in the dry etching rate, high in the resolution, excellent in the resist film thickness dependency and high in the effect of preventing reflective light against exposure light, and provide no intermixing with the photoresist layer, are disclosed, wherein the composition for a bottom anti-reflective coating material comprises a naphthalene group-containing polymer compound having a specific structure.

Abstract: To provide a polyacetal resin composition which is highly rigid and has excellent surface hardness, sliding characteristics, etc. That is, a polyacetal resin composition, produced by blending 100 parts by weight of a polyacetal resin (A) with 0.01-100 part(s) by weight of a branched polyacetal copolymer (B) which is obtained by copolymerization of 100 parts by weight of trioxane (a), 0.01-10 part(s) by weight of a monofunctional glycidyl compound (b) and 0-20 part(s) by weight of a cyclic ether compound (c) which is copolymerizable with trioxane.

Abstract: By blending novel organosiloxane polymers of the invention with a crosslinking agent and a photoacid generator, photo-curable resin compositions are formulated which can be exposed to radiation in a broad wavelength range and readily form a thin film without oxygen attack. From the compositions, fine patterns having improved dry etching resistance can be formed. Cured coatings of the compositions having improved substrate adhesion, heat resistance, and electrical insulation are suitable as a protective film for electric and electronic parts.

Abstract: A polyoxymethylene having enhanced thermal stability and resistance to depolymerization is obtained by using an alkylated melamine compound of formula (1) as a polymerization terminating agent in a polymerization of formaldehyde or a cyclic oligomer thereof and an optional comonomer in the presence of an acid catalyst: wherein, R1 to R6 are each independently H, C1-4 alkyl or CH2OR7; R7 is H, C1-4 alkyl or R8COOR9; R8 is —(CH2)n—, n being an integer of 1 to 4; and R9 is C1-4 alkyl.

Abstract: Novel cold-curing mixtures comprising epoxide compounds, curing agents, additives and optionally further auxiliary and filler materials, which have low irritant potential, which are free of solvents and are self-levelling and which, in the cured state, are colorfast and have a surface which, in terms of optical and tactile properties, is faultless.

Abstract: The present invention relates to polyurethanes containing secondary amide groups in the backbones of the polyurethanes, wherein the secondary amide groups (calculated as NH—CO—, MW 43) are present in an amount of 1 to 14% by weight, based on the weight of the polyurethanes, and correspond to the formula —X1—R1—NH—C(O)—R2—X2—  (I) wherein X1 and X2 are the same or different and represent the groups obtained by removing a hydrogen atom from a hydroxy group or a primary or secondary amino group and R1 and R2 are the same or different and represent linear or branched hydrocarbon groups that are optionally substituted by groups that do not contain isocyanate-reactive hydrogen atoms. The present invention also relates to one-component, thermoset compositions containing the polyurethanes with secondary amide groups in the backbone and a cross-linking component that is reactive with amide groups.

Abstract: A polyoxymethylene resin composition, having enhanced tensile elongation, thermal stability, processibility and impact resistance, comprises: (i) from 45 to less than 97% % by weight of a polyoxymethylene resin (Component A); (ii) from 1 to less than 20% by weight of a thermoplastic polyester elastomer (Component B); (iii) from 2 to 35% by weight of a thermoplastic polyurethane elastomer (Component C); and (iv) from 0.1 to less than 10% by weight of a maleic anhydride-grafted aliphatic polyolefinic rubbery polymer (Component D), based on the total weight of Components A, B, C and D.

Abstract: A polyoxymethylene copolymer having a melting point of 167° to 173° C. and containing a low molecular weight polyoxymethylene copolymer in an amount of not higher than 5000 ppm, and a composition thereof. The copolymer is obtainable by subjecting unstable terminal groups to heat treatment in the presence of 0.05 to 50 ppm by weight of a quaternary ammonium compound. Further, the above composition is used for working parts such as a gear and a cam; apparatuses for image, music and telecommunication; interior and exterior parts for an automobile; and the like.

Abstract: The present invention provides: a process for producing a high molecular weight thermoplastic resin composition, which can give the high molecular weight thermoplastic resin composition with good reproducibility and stably; and uses of the resultant resin composition. The process for producing a high molecular weight thermoplastic resin composition comprises the step of mixing a thermoplastic resin with pyromellitic dianhydride to carry out a reaction therebetween to convert the thermoplastic resin into a high molecular weight one, and this process is characterized in that the pyromellitic dianhydride has at least one of the following properties in particle form: (1) intrinsically linear or needle-like particle forms; (2) a bulk density of 0.4˜0.9 g/ml; and (3) a rest angle of 50˜70 degrees.

Abstract: A toughened polyacetal resin composition, and a process for making same, is provided by mixing a polyacetal masterbatch component, prepared from polyacetal and a relatively large amount of polyurethane, with a polyacetal dilution component so as to generate a blended composition in which the content of the thermoplastic polyurethane is about 1 to about 15 wt % of the total weight of the blended composition.

Abstract: A process for the hydrogenation of aromatic polymers is disclosed. Accordingly, the solvent used comprise an ether that contains no &agr;-hydrogen atom on a carbon atom adjacent to the ether function. The process results in virtually complete hydrogenation of the aromatic units.

Abstract: To provide a resin material in which various properties of a polyacetal resin such as excellent appearance, slidability and thermal stability are maintained and a rigidity is improved as well. That is, a polyacetal copolymer which is prepared by a copolymerization of 100 parts by weight of trioxane (A), 0.0005 to 2 parts by weight of the component (B), which is a compound (B-1) having at least three glycidyl groups in the molecule or a compound (B-2) having at least two epoxy groups in the molecule, and 0 to 20 parts by weight of a cyclic ether compound (C) copolymerizable with trioxane, and which has a total terminal group amount of 15 to 150 mmol/kg, when (B) is (B-2).

Abstract: A polyacetal resin composition comprising 30-90% by weight of polyacetal copolymer (A) having a melt index of less than 1.0 g/10 min. and 70-10% by weight of polyacetal copolymer (B) having a melt index of 1.0-100 g/10 min., both melting points of (A) and (B) being 155°-162° C., or a difference in melting point between (A) and (B) being not less than 6° C., has distinguished toughness and creep resistance.

Abstract: A polyacetal resin composition comprising a polyacetal resin and a polycarbodiimide compound. The polyacetal resin composition is free from the problems of conventional polyacetal resins and has good water resistance at high temperatures.

Abstract: To provide a polyacetal composition with improved toughness, wear resistance, and flowability. The polyacetal composition contains 100 wt % of polyacetal and 0.5-5 wt % of a block copolymer, which has its central portion made of an amorphous polymer that forms an elastic domain at room temperature and which has polyethylene glycol chains with molecular weight of 2000 or higher at its two ends.

Abstract: A composition for the detackification and clarification of acid and alkaline paint and lacquer waste waters and paint spray booth wastes, comprising:an inorganic-organic and/or organic adduct alloy polymer composition having the formula:A.multidot.B.sup.+ .multidot.D.sup.+wherein: A=[(SiO.sub.2 /Me.sup.I.sub.2 O).sub.u Me.sup.II.sub.m Me.sub.m.sup.III(OH).sbsp.p.sup.(SO.sbsp.4.sup.).sbsp.y.sup.(Aci) (2m+3n)-p-2y].sub.rwhere r=1 to 98% bw; u=0 to 10% bw; ##STR1## where: x=0 to 98% bw; Z is a divalent substituted or unsubstituted aliphatic, cycloaliphatic, heterocyclic or aromatic radicalD.sup.+ =(PQAM).sub.wwherew=2 to 98% b.w. of polyquaternized polymer (PQAM)Me.sub.m.sup.II is selected from the divalent cationic group comprising: Mg, Zn, Ca, and Fe.sup.2+m=0 to 5Me.sub.n.sup.III is a tri-or more valent metal selected from the group comprising: Fe, Al, and Al--Zn complexes;n=1 to 20Aci is selected from the monovalent anionic group comprising Cl.sup.-, Br.sup.-, I.sup.-, NO.sub.3 --, H.sub.2 PO.sub.4 --, CH.

Abstract: This invention relates to methods for preparing novel, solid-phase transfer reagents, specifically phosgenated oxime resins and non-symmetrical ureas, that are useful as supports in combinatorial synthesis for the creation of libraries of compounds for lead identification.

Abstract: This invention relates to a process for producing acidic aqueous solutions of melamine-aldehyde type polymers, and particularly melamine-formaldehyde polymer, which have significantly reduced levels of free aldehyde. The process involves the addition of hydrogen peroxide and/or iron in the form of ferric ion to the acidification stage of the production of melamine-formaldehyde polymers. When the process is conducted at elevated temperatures, in the range of 150-180.degree. F., iron is not required to cause destruction of the free formaldehyde. At lower temperatures the presence of iron may be required to achieve satisfactory rates of reaction. The process reduces levels of free formaldehyde to less than 0.1% by weight, such that the polymer solution may be used in a variety of applications with reduced environmental risk.

Abstract: Polymer blends obtainable by thermal treatment, at not less than 150.degree. C., of a mixture containing at least one high-performance polymer and from 15 to 99 parts by weight or preferably from 40 to 90 parts by weight and particularly preferably from 55 to 75 parts by weight, of a polymer containing sulfoxide groups, and crosslinked or partly crosslinked polymer blend obtainable by thermal treatment, at not less than 150.degree. C., of a mixture containing at least one of the high-performance polymers polyesters, partly fluorinated polymers, polyethersulfones, polysulfones, polyetherimides, polyamidoimides or polyacetals and at least one polymer containing sulfoxide groups, are distinguished by high thermal and chemical stability. Polymers containing sulfoxide groups are polyarylene sulfoxides, in particular polyphenylene sulfoxide. The polymer blends are used for the production of fibers, films or shaped articles.

Abstract: Thermoplastic molding materials containA) from 50 to 99% by weight, based on the total weight of the molding material, of a toughened polymer,B) from 1 to 20% by weight, based on the total weight of the molding material, of a blend ofB.sub.1) a copolymer comprising polymerized units which are derived from a polymerizable carboxylic acid or derivatives thereof andB.sub.2) a polyamide,C) from 0 to 40% by weight of a fibrous or particulate filler or of a mixture thereof andD) from 0 to 20% by weight of conventional additives and processing assistants.

Abstract: The invention concerns redispersible polymer powders characterized by a proportion of 3 to 30% by wt relative to the polymer weight of condensation products of amino-s-triazine/formaldehyde/sulfite with molar ratios of amino-s-triazine to formaldehyde to sulfite of 1/1.3-6.0/0.3-1.5 and with a low free formaldehyde content. These condensation products of amino-s-triazine/formaldehyde/sulfite are exceedingly effective protective colloids when spray-drying polymer dispersions and can be combined in problem-free manner with casein.

Abstract: Branched, dendrimeric macromolecules having a central nucleus and a series of polyoxaalkylene chains that radiate from the nucleus and spread into the surrounding space branching a cascade fashion until the desired size results. Molecules formed in this manner are free of excessive functional crowding on their outer surfaces. Synthetic methods of preparing these molecules and their uses are described.

Abstract: The claimed invention is an uncured thermosetting composition which is capable of curing upon exposure to actinic radiation, said composition comprising an acetal diacrylate of the formula: ##STR1## wherein R.sub.1 and R.sub.2 are individually hydrogen, C.sub.1-6 alkyl, aryl, or substituted aryl; R.sub.3 and R.sub.4 are individually C.sub.1-6 alkyl, aryl, substituted alkyl, or aryl alkyl; and R.sub.5 and R.sub.6 are individually hydrogen or C.sub.1-6 alkyl; and a free radical curing agent.

Abstract: Provided by the present invention are novel diguanamine derivatives, led by 2,5/2,6-bis(4,6-diamino-1,3,5-triazin-2-yl)-bicyclo?2.2.l!heptanes and 1,3/1,4-bis(4,6-diamino-1,3,5-triazin-2-yl)-cyclo-hexanes, and derivatives thereof, applications of these compounds in fields such as adhesives and paints, utilization of these compounds in flame-retarding, thermal stabilization and compatibilization methods of resins, thermosetting molding compositions and thermosetting expansion-molding compositions making use of these compounds, as well as polymeric microspheres also using these compounds. These compounds are expected to find wide spread industrial utility as various excellent properties can be obtained by using them.

Abstract: The present invention relates to biodegradable biocompatible polyacetals, methods for their preparation, and methods for treating mammals by administration of biodegradable biocompatible polyacetals. A method for forming the biodegradable biocompatible polyacetals combines a glycol-specific oxidizing agent with a polysaccharide to form an aldehyde intermediate which is combined with a reducing agent to form the biodegradable biocompatible polyacetal. The resultant biodegradable biocompatible polyacetals can be chemically modified to incorporate additional hydrophilic moieties. A method for treating mammals includes the administration of the biodegradable biocompatible polyacetal in which biologically active compounds or diagnostic labels can be disposed.

Abstract: This invention relates to methods for preparing novel, solid-phase transfer reagents, specifically phosgenated oxime resins and non-symmetrical ureas, that are useful as supports in combinatorial synthesis for the creation of libraries of compounds for lead identification.

Abstract: An objective of the invention is to provide a polyacetal resin composition which has excellent resistance to heat aging and grease resistance, has welded sections with no decrease in physical properties, and has improved friction characteristics, and molded articles therefrom. A polyacetal resin composition comprising per 100 parts by weight of a polyacetal resin, 2-7 parts by weight of a polymer composition based on an olefinic polymer having glycidyl-group-containing pendant chains and 0.5-2.5 parts by weight of a dimethyl siloxane polymer of a plasticity of at least one; a polyacetal resin composition further comprising 100 parts by weight of the preceding resin composition along with 0.05-0.5 parts by weight of carbon black; and molded articles therefrom.

Abstract: A toner resin composition and a method of making the same are disclosed. The toner resin composition comprises a polyester resin formed from a reaction between a polybasic acid or anhydride and a polyhydric alcohol, and a polyfunctional epoxy resin which is crosslinked to the polyester resin. The crosslinking is effected in the presence of a catalyst.