Abstract: A coating material and coating process for color coating articles, such as motor vehicle bodies, and coated articles produced therewith. The coating contains a paint vehicle composed of at least one curable liquid-crystal polymer (LCP), the colored appearance of the coating being determined by mesogens of the paint vehicle which exhibit an interference effect, the mesogens automatically aligning themselves substantially perpendicular to the surface of the article during application of the coating material and adopting a chiral-nematic configuration in which they form a helix having a pitch length which can be influenced by heat within a specified temperature range. The liquid-crystal polymers are such that they are not crosslinked by heat and also such that the temperature level at which the pitch length of the helix can be influenced is above the temperature at which the color coated article is used.

Abstract: An improved clarity copolyester of a diethylene glycol modified poly(ethylene terephthalate) has a b* value of less than 15, preferably less than 10. The copolyester composition has an inherent viscosity of about 0.4 to 1.0 dL/g and comprises (A) 100 mol percent dicarboxylic acid residue component, (B) 100 mol percent diol residue component, (C) catalyst residues and (D) color control agent residues. The dicarboxylic acid residue component comprises at least 75 mol percent of terephthalic acid residues. The diol residue component comprises 10 to 50 mol percent diethylene glycol residue and 50 to 90 mol percent ethylene glycol residue. The catalyst residues comprise 20 to 100 ppm manganese, 50 to 300 ppm antimony, 0 to 100 ppm titanium and 40 to 150 ppm phosphorus, based on the weight of the copolyester.

Abstract: The invention provides polyesters of terephthalic acid units and ethylene glycol units, having excellent melt moldability. The invention also provides molded articles having excellent transparency, impact resistance, gelation characteristics, appearance, tactility, mechanical properties, heat resistance, chemical resistance, and dimensional precision.

Abstract: An improved process for making polyetherester resins is disclosed. The process comprises reacting a polyether with a diol diester in the presence of a catalyst that promotes random insertion of the diester into carbon-oxygen bonds of the polyether to produce the polyetherester resin. The process of the invention offers many advantages, including higher resin yields, reduced by-product generation, and the ability to make resins with low color and low acid numbers. The resins are useful for making polyetherester thermosets.

Abstract: This invention relates to polymers having non-linear optical properties which polymers include fluorene moieties having at least one electron accepting group and at least one electon donating group substituted to different phenyl rings of the fluorene moiety.

Abstract: This invention relates to a polyester resin prepared by adding one or more dicarboxylic acid components to one or more glycol components containing 1,4-cyclohexanedimethanol equalling 100 mole %, the polyester resin having been prepared in the presence of a catalyst/stabilizer system consisting essentially of antimony compounds and phosphorous compounds and compounds selected from the group consisting essentially of zinc compounds, gallium compounds, and silicon compounds.

Abstract: The tensile strength properties of paper are improved by adding to paper stock a resin composition comprising a water-soluble polymer containing a polyhydric alcohol such as sorbitol in the backbone of the polymeric molecule.

Abstract: A novel process has been developed for the crystallization of poly(ethylenenaphthalenedicarboxylate) (PEN) and its copolymers. The process comprises the step of maintaining the amount of water in said poly(ethylenenaphthalenedicarboxylate) below a critical moisture content ceiling throughout processing such that a separate drying step is not required.

Abstract: A process for preparing linear copolyesters which contain omega-hydrocarboxylic acid units, from polyesters that contain at least 90 mol % polyethylene terephthalate units, as well as the usual amount of diethylene glycol units and possibly the known catalysts and stabilizers, includes adding to the already prepared polyester melt at least one compound of the group of lactones, optionally along with further additives but without additional catalysts in a system sealed off from gas exchange and at a higher pressure than the lactone vapor pressure in a proportion of up to 10 mol %, referred to the final melt, and mixed intensively with the melt. The resultant copolyesters, after a total dwell time of less than 30 minutes and a temperature in the range of 265.degree. to 310.degree. C.

Abstract: The present invention provides an novel polymer having 1-2,000 equivalents of an N-sulfoamino group/10.sup.6 g of weight of the polymer.The polymer has excellent dispersibility of inorganic fine particles, hygroscopicity, and dye-affinity. The polymer provides a binder resin in which a magnetic or non-magnetic metal or metal oxide can highly be dispersed. The polymer also provides a magnetic recording medium which is excellent in electromagnetic conversion characteristic, surface smoothness, adhesion to non-magnetic substrates, and durability. The polymer provides a magnetic recording medium with improved travelling, travelling durability, signal-to-noise ratio, and drop-out. The polymer also provides a polyester fiber which has a high fiber strength and an excellent hygroscopicity and can be colored with cationic dyes.

Abstract: This invention relates to a polyester resin prepared by adding one or more dicarboxylic acid components to one or more glycol components containing 1,4-cyclohexanedimethanol equalling 100 mole %,the polyester resin having been prepared in the presence of a catalyst/stabilizer system consisting essentially of antimony compounds and phosphorous compounds and compounds selected from the group consisting essentially of zinc compounds, gallium compounds, and silicon compounds.

Abstract: A copolyester consisting essentially of ethylene terephthalate units and further comprising 0.01 to 1 mole % based on the sum of the moles of total diol units and the moles of triol units of a triol unit represented by the following formula (I) and/or a triol unit represented by the following formula (II). ##STR1## wherein A is a group represented by formula --CH.sub.2 CH.sub.2 -- or formula --CH(CH.sub.3)CH.sub.2 --, B is a divalent hydrocarbon group, --CO--, --SO.sub.2 --, --0-- or a direct bond (-), and p, q, r, s, t and u are each an integer of 1 to 8. A process for producing the same and molded articles (in particular extrusion blow molded articles) therefrom. The copolyesters of the present invention are applicable to melt moldings accompanying melt extrusion, in particular extrusion blow molding, where parisons therefrom have good draw-down tendency and blow moldability.

Abstract: Polyesters obtained by reacting from 5 to 50 parts of at least one linear or branched, aliphatic or cycloaliphatic, at least dihydric alcohol, from 2 to 40 parts of at least one at least dibasic, aromatic carboxylic acid, from 0 to 40 parts of at least one 2-alkenyldicarboxylic anhydride, from 10 to 30 parts of at least one at least dibasic, linear or branched, aliphatic carboxylic acid, from 0 to 15 parts of an aliphatic, linear or branched hydroxy acid, from 0 to 15 parts of an aliphatic, linear or branched polyamine having at least one primary and at least one secondary or tertiary amino group, from 0 to 15 parts of a glycidyl ester of a branched, aliphatic monocarboxylic acid or of a glycidyl ether of a branched, aliphatic alcohol, and from 0 to 15 parts of polyhydroxyamine are useful, for example, as additives in coating compositions.

Abstract: An adherent film-forming composition comprising a carbamate-functional polyester polymer or oligomer, a hydroxy functional polymer derived from ethylenically unsaturated monomers and an aminoplast crosslinking agent is disclosed. The coating composition can be used to produce clear coats in composite color plus clear coatings exhibiting good levels of acid etch resistance as well as high intercoat adhesion. Also disclosed are a method of applying a composite color plus clear coating to a substrate and the coated article prepared by such a method.

Abstract: Polymer compositions are provided which comprise a first polyhydroxyalkanoate component and optionally a second polymer component, the composition have enhanced properties by using an inorganic oxygen containing compound in the composition. The inorganic oxygen containing compound may be acting as a transesterification catalyst.

Abstract: A biodegradable block copolymer made from the transesterfication of a poly(propylene fumarate) prepolymer and a poly(ethylene oxide) prepolymer. The block copolymer poly(propylene fumarate -co- ethylene oxide) is capable of crosslinking at body temperature. Crosslinking requires an appropriate crosslinking monomer and an initiator. The biodegradable block copolymer has utility as a vascular implant became it can be injected as a fluid into the vascular system and crosslinked in situ.

Abstract: The present invention relates to a polyester resin for use in a thermosetting coating composition, said polyester comprising an acid component, an alcohol component and a trifunctional branching agent; wherein the acid component consists of from 90 to 100 mole % of an aromatic acid or aromatic anhydride or mixture thereof and from 0 to 10 mole % of a polycarboxylic acid or polycarboxylic anhydride or mixture thereof; and wherein the alcohol component consists of at least 60 mole % of one or more glycols selected from the group consisting of CH.sub.3 --CH.sub.2 --C(CH.sub.2 OH).sub.2 --R.sub.1 wherein R.sub.1 is an alkyl and derivatives of said glycols, from 0 to 20 mole % of neopentylglycol, and of up to 20 mole % of a trifunctional branching agent.

Abstract: The present invention provides inks which contain a near infrared fluorophoric compound incorporated into a water-dissipatible polyester backbone. The inks of the present invention are preferably colorless or "invisible" but could be made slightly colored if desirable. Specifically, the inks of the present invention comprise:A. between about 1 and 10 weight percent of at least one water-dissipatable polyester having from about 0.1 ppm by weight to about 10% by weight of a thermally stable near infrared fluorophoric compound copolymerized therein;B. between about 5 and 75 weight percent of at least aliphatic humectant;C. between about 0 and 15 weight percent of at least one lower aliphatic alcohol of no more than 3 carbon atoms;D. water and optionally up to about 2 weight percent of one or more additives;wherein the weight percentages of components A-D equal 100%.

Abstract: This invention relates to a polyester resin prepared by adding one or more dicarboxylic acid components to one or more glycol components containing 1,4-cyclohexanedimethanol equalling 100 mole %,the polyester resin having been prepared in the presence of a catalyst/stabilizer system consisting essentially of antimony compounds and phosphorous compounds and compounds selected from the group consisting essentially of zinc compounds, gallium compounds, and silicon compounds.

Abstract: Graft and core-shell copolymers are provided which are useful as binders and are prepared from a peroxy-containing copolymer phase a) wherein the copolymer phase contains 0.01 to 20% by weight of residues of an olefinically di-unsaturated peroxy compound and from 80 to 99.99% by weight of residues of at least one comonomer and a polymer phase b) grafted thereon which is obtained by grafting one or more monomers. A process for preparing the copolymers is also provided.

Abstract: The present invention is directed to methods of preparing high purity polyalkylene oxide carboxylic acids. The methods include reacting a polyalkylene oxide such as polyethylene glycol with a t-butyl haloacetate in the presence of a base followed by treatment with an acid such as trifluoroacetic acid. The resultant polymer carboxylic acids are of sufficient purity so that expensive and time consuming purification steps required for pharmaceutical grade polymers are avoided.

Abstract: Coatings obtainable from crosslinkable polyesters resins based on perfluoropolyethers obtainable from hydroxy-terminated PFPE, with acid anhydride and/or a diacid, a polyol with functionality higher than 2 and optionally in mixtures of diols having a functionality of 2, the resins being also even 70% weight/weight soluble in xylene.

Abstract: A process for making polyetheresters is disclosed. A polyether is reacted with a carboxylic acid in the presence of a strong protic acid or a metal salt of a strong protic acid to promote insertion of the carboxylic acid into polyether carbon-oxygen bonds to produce a polyetherester. The polyetheresters are useful for various applications in the polyurethane and unsaturated polyester industries.

Abstract: A medicinal aerosol formulation containing a particulate drug and a dispersing aid derived from a hydroxyacid, a mercapto acid, or an amino acid.

Abstract: Water-soluble, biologically decomposable carbonic acid polyesters having the general formula (I): ##STR1## in which R.sub.1 represents a straight- or branched-chain, saturated or monounsaturated alkyl residue having from 6 to 22 carbon atoms;R.sub.2 represents a hydrogen or methyl group;R.sub.3 represents hydrogen or the group: ##STR2## n is an integer between 0 and 10; m is an integer between 5 and 16, andz is an integer between 1 and 3 are disclosed.The use of these compounds for preparation and lubricating agents for synthetic fibers is also disclosed.

Abstract: A resin composition for coating of the present invention includes a polyester containing an acid component and a polyol component, wherein the polyester is soluble or dispersible in a solvent consisting essentially of at least one solvent selected from the group consisting of cyclohexanone and isophorone; the polyester has a metal sulfonate group in an amount in the range of 0.1 to 5 mol % based on the total moles of the acid component or the polyol component and is slightly soluble in an organic solvent in the case where the content of the metal sulfonate group is 0%; and a specific gravity of the polyester at 30.degree. C. is in the range of 1.265 to 1.340.

Abstract: Hot-melt adhesives are based on a random copolyetherester formed from aromatic dicarboxylic acids, terephthalic acid and isophthalic acid wherein the molar proportion of terephthalic acid is at least 55% based on the acid content, with a butanediol content between 20 and 85 mol % and containing at least 10 mol % triethylene glycol; the remainder of the diol content is preferably diethylene glycol. Copolyetheresters of this type are distinguished by excellent adhesion properties, a low melting point, rapid crystallization, and good resistance to laundering and dry cleaning at a minimum viscosity of 80 Pas.

Abstract: This invention is a thermoplastic saturated polyester low profile additive (low profile additive) useful in sheet molding compounds for parts, especially vehicle parts, the additive has a major component derived from aromatic compounds such as terephthalic acid including recycled polyethylene terephthalate. Asymmetrical glycols are an important ingredient and can be used to digest recycled PET to make oligomeric glycols which are reacted with acids having fewer than 12 carbon atoms to make one of the low profile additives of this invention.

Abstract: Process for thermal solid-state treatment of chips of saturated polyester, where the chips are crystallized immediately before the thermal treatment and the thermal treatment is carried out in a static bed at a chip temperature that is equal to TE (1 .mu.m) .+-.2.degree. C., where TE (1 .mu.m) is the temperature at which a measurement probe placed on a crystallized chip is lowered by 1 .mu.m under defined conditions in a thermomechanical analysis. The crystallization preferably takes place in a fluidized bed at three different specified temperatures.

Abstract: The present invention relates to a laminate film useful as a material from which to manufacture surgical and other protective garments. The laminate film comprises at least one layer formed from a first polyetherester copolymer produced from the condensation reaction of dimethyl-1,4-cyclo hexane dicarboxylate and 1,4-cyclo hexane dimethanol and poly(tetramethylene ether glycol) and a second layer comprising a material selected from the group consisting of an ethylene-vinyl acetate copolymer, an ethylene methacrylate copolymer, a second polyetherester copolymer, an anhydride modified polyolefin copolymer, and a polyether block amide copolymer. The total amount of the first polyetherester copolymer present in the laminate is greater than or equal to 35 wt. % of the total weight of the laminate film to provide strength to the laminate film. The laminate film may be bonded to one or more layers of polyesters, polyolefins, polyamides, and non-woven fabrics.

Abstract: A heat resistant phosphorus-containing polymeric flame retardant and a process for preparing the same are disclosed. The process is characterized in that in polycondensation a selected metal salt serving as cocatalyst is used to catalyze a phosphorus-containing compound, a saturated dicarboxylic acid or the derivatives thereof, and a diol to form a high phosphorus content, high molecular weight flame retardant. The selected metal salts can promote the polymerization of phosphorus-containing compounds and polyester, and can inhibit side reactions and depolymerization so as to increase the phosphorus content of the resulting products and reduce the manufacturing cost. The flame retardants thus prepared can endure processing at an elevated temperature and thus are suitable for being applied in flame retardant fibers, fabrics, nonwoven fabrics, adhesives, and plastics.

Abstract: Novel polyesters prepared from a diol, a dicarboxylic acid or ester forming reactive derivative thereof and an aromatic amino acid, ester or alcohol are disclosed.

Abstract: There are disclosed a resin composition capable of exhibiting a high melt viscoelasticity comprising 100 parts by weight of an aromatic copolyester resin which contains a branching component unit having at least three ester-forming groups in the ratio of 0.01 to 5 moles per 100 moles in total of aromatic dicarboxylic acid units and which has a limiting viscosity of 0.4 to 1.0 dl/g, and 0.05 to 5 parts by weight of a compound having at least two acid anhydride groups in its molecule, and an aromatic polyester resin foamed body produced therefrom and a process for producing the foamed body.

Abstract: A polyester is provided which facilitates the separation of blood into light and heavy phases via centrifugation in a blood collection vessel. The polyester is useful as a component of a partitioning composition formulated to have appropriate specific gravity to be positioned intermediate the light and heavy blood phases during centrifugation. A partitioning composition including a polyester of the invention provides a particular advantage in blood collection vessels due to its lighter and more consistent coloration. The polyester composition can be prepared with relative ease compared to prior art polyesters useful in blood partitioning compositions.

Abstract: Disclosed are terpolymers having improved barrier properties and tensile strength relative to PET comprising copolyesters derived from acid components comprising about 45 to about 85 mol % terephthalic acid; about 10 to about 40 mol % of at least one naphthalenedicarboxylic acid and about 5 to about 15 mol % of at least one aliphatic dicarboxylic acid having 1 to 6 carbon atoms and glycol component comprising ethylene glycol. The copolyesters of the present invention may be formed into a variety of articles such as blood tubes, serum vials, containers, films and sheeting.

Abstract: Crosslinkable, polyaromatic, polyether or polyester oligomers can have glass transition temperatures above 900.degree. F. while exhibiting desirable toughness for aerospace applications and ease of processing. A plurality (i.e. three or more) of generally linear aryl arms extend outwardly like spokes from a central aromatic hub through ether or ester linkages. Each spoke usually includes electronegative linkages, and is capped with one or two crosslinking functionalities (i.e. unsaturated hydrocarbon sites) which may be thermally or chemically activated to complete the advanced composite during curing. Among other methods, linear and multidimensional polyether oligomers are synthesized using nitrophthalic anhydride or halophthalic anhydride, dialcohols, or polyols, diamines, and suitable end caps.

Abstract: The present invention provides a high molecular weight aliphatic polyester which is biodegradable by microorganisms in soils and which is utilized as a molded article as well as a method to prepare the same. This polyester has a structure shown below: ##STR1## as well as those analogous thereto.

Abstract: Polymer salts whose anionic component is a polyester which comprises the product of reaction of the individual components a), b) and c) and if desired d) and if desired e), wherea) is a dicarboxylic acid or a reactive derivative of a dicarboxylic acid, being free from sulfo groups,b) is a difunctional aromatic, aliphatic or cycloaliphatic sulfo compound whose functional groups are hydroxyl or carboxyl, or hydroxyl and carboxyl,c) is an aliphatic, cycloaliphatic or aromatic diol, a polyetherdiol or a polycarbonatediol,d) is a polyfunctional compound (functionality>2) whose functional groups are hydroxyl or carboxyl, or hydroxyl and carboxyl, ande) is a monocarboxylic acidand whose cationic component comprises hydrogen atoms, metal cations, substituted ammonium cations, immonium cations, guanidinium cations, phosphonium, arsonium or stibonium cations or a mixture of the abovementioned cations, are suitable as charge control agents and charge improvers in electrophotographic toners and developers, in triboele

Abstract: Coatings obtainable from crosslinkable polyesters resins based on perfluoropolyethers obtainable from hydroxy-terminated PFPE, with acid anhydride and/or a diacid, a polyol with functionality higher than 2 and optionally in mixtures of diols having a functionality of 2, the resins being also even 70% weight/weight soluble in xylene.

Abstract: The invention is a polyester composition containing crosslinked polymer particles with ester bonds at the main chain. The particles are excellent in affinity to polyesters, and so the films formed from the polyester compositions do not have the particles falling off during high speed running, and do not have flaws in the film surfaces. The invention can prevent the generation of white powder and the flaws of magnetic faces caused by falling-off particles, and prevent the contamination in the production of films, even though these are problems caused when various conventional particles are added, and is especially suitable for use as products such as magnetic films.

Abstract: Macrocyclic polyester oligomer compositions comprising alkylene isophthalate or terephthalate units or the like are prepared by the reaction of a diol with a diacid chloride in the presence of at least one amine characterized by substantially no steric hindrance around the basic nitrogen atom. The reaction is conducted under substantially anhydrous conditions and at a temperature from about -25.degree. to about +25.degree. C. The resulting macrocyclic oligomers may be converted to linear polyesters by contact with catalysts including basic reagents, stannous alkoxides, organotin compounds, titanate esters and metal acetylacetonates.

Abstract: Disclosed are polyester particles adapted to be extrusion blow molded into articles having improved rheological qualities and a process for producing such particles, said particles comprising a polyester having repeat units from about 40 to 100 mol % terephthalic acid, about 80-98 mol % ethylene glycol, about 0.5-10 mol % 1,4-cyclohexanedimethanol, about 3-10 mol % diethylene glycol, and about 0.05-1.

Abstract: A method for producing a high molecular weight aliphatic polyester, wherein:(A) 100 parts by weight of polyester (a) with a number average molecular weight of at least 10,000, and a weight average molecular weight of at least 30,000, and with end-groups that are substantially hydroxyl groups, and with a melting point of at least 60.degree. C., the polyester (a) having been obtained by reacting the following three ingredients: (i) a glycol ingredient; (ii) an aliphatic dicarboxylic acid ingredient; and (iii) a trifunctional or tetrafunctional ingredient reacts with(B) 0.1-3 parts by weight of a poly-isocyanate in a melted state of the polyester (a).The method provides a high molecular weight aliphatic polyester which has good properties and a melt viscosity required for molding and forming and has a wide molecular weight distribution. The high molecular weight aliphatic polyester is applicable to a variety of fields, such as films, moldings and formings, fibers, etc.

Abstract: Specific ester products obtainable by esterifying a selected polyethylene glycol with a dicarboxylic acid in a molar ratio of 1:0.25 to 1 are described. The novel ester compounds are efficient and easily biodegradable spin finishes.

Abstract: The present invention is directed to a method for treating cross-linked (cured) filled or untilled unsaturated polyester for deriving an alcohol recycle reactant useful in the synthesis of alcohol-formed derivative products. The first step of the method is the attrition of the cured unsaturated polyester to form particulates thereof. In the next step of the process, at least a fraction of any filler or fiberglass in the cured unsaturated polyester is separated to form a cured unsaturated polyester regrind. The next step is the subjecting of the cured unsaturated polyester regrind to agitated, uncatalyzed or catalyzed glycolysis in the presence of excess glycol and, optionally, a transesterification catalyst under agitation at elevated transesterification temperature. The final step of the process is the recovery of the recycle alcohol reactant for use in the synthesis of alcohol-formed derivative products.

Abstract: The invention relates to a dendritic macromolecule of the polyester type comprising a central initiator molecule or initiator polymer having one or more reactive hydroxyl groups (A). The groups (A) are under formation of an initial tree structure bonded to reactive carboxyl groups (B) of a monomeric chain extender having the two reactive groups (A) and (B). The tree structure is optionally extended and further branched from the initiator molecule or initiator polymer by addition of further molecules of a monomeric chain extender by means of bonding between the reactive groups (A) and (B) thereof and is thereafter optionally further extended by reaction with a chain stopper. The invention also comprises a process for preparation of the dendritic macromolecule.

Abstract: This invention provides an improved process for preparing phenol-functional polyester resins which are useful in thermosetting coating compositions. The process involves a polycondensation reaction comprising a two-step charging procedure and suitable reaction conditions.

Abstract: A resin composition for toners, composed essentially of a suspension polymerizate of:(a) 5 to 40% by weight per total polymer of a polyester comprising at least one aromatic diol component an at least one aliphatic diol component, and having a weight average molecular weight of 3,000 to 30,000, an acid value of 0.5 to 10 mgKOH/g, and an OH value of 10 to 60 mgKOH/g;(b) 60 to 95% by weight per total polymer of a vinyl monomer; and(c) 0.1 to 1.0% by weight per total polymer of a divinyl monomer,wherein said suspension polymerizate hasa glass transition temperature of 40.degree. to 70.degree. C.,an acid value of 0.1 to 10 mgKOH/g, anda softening temperature of 100.degree. to 160.degree. C.

Abstract: Unsaturated linear polymers have repeating units of a reaction product of a first monomer, a second monomer, a third monomer and optionally a fourth monomer. The linear polymers have a glass transition temperature ranging from about 52.degree. C. to about 61.degree. C. The first monomer should have a weight average molecular weight less than 200. The second monomer may be a dicarboxylic acid or diester which is different than the third monomer. A concentration of second residues of the polymer, derived from the second monomer, ranges from about 3 wt. % to about 15 wt. %, based on the total weight of the polymer. The third monomer is an aromatic dicarboxylic acid or an ester thereof. In the polymer, a concentration of third residues, derived from the third monomer, ranges from about 40 wt. % to about 55 wt. %, based on the total weight of the polymer. The fourth monomer is a diol having a higher molecular weight than the first monomer.

Abstract: A segmented copolyester-ether polymer comprises 9.5 to 33 percent by weight hard segment residues of polybutylene terephthalate and 0.5 to 67 percent by weight soft segment residues of a polyether polyol comprised of n units of residue (1) and m units of residue (2), wherein the total value of n+m is in the range 2 to 70, m/(n+m) is in the range 0.05 to 0.98, and residues (1) and (2) have the structures: ##STR1## The polyether polyol is further characterized in that at least 95 percent of the hydroxyl groups are primary hydroxyl groups.