Polyurethane composition, product prepared using the polyurethane composition, and method for preparing the product

Abstract

A polyurethane composition is provided. The polyurethane composition includes: (A) a polyurethane prepolymer, which is prepared by reacting at least one polyisocyanate compound with a first polyol component; and (B) a second polyol component; wherein at least one of the first polyol component and the second polyol component includes an ester / ether random copolymer polyol, which is synthesized by reacting a starting material polyether polyol with at least one monomer polyol and at least one monomer multifunctional carboxylic acid or its anhydride. The polyurethane foam prepared by using the polyurethane composition can achieve suppressed internal heat accumulation, high thermal stability, excellent tear strength, enhanced wear resistance and good hydrolysis resistance. A polyurethane product prepared with the foam, a method for preparing the polyurethane foam, and a method for improving the performance characteristics of the polyurethane foam are also provided.

Description

Technical Field

[0001] The present invention relates to a polyurethane composition, a polyurethane foam and a molded product prepared by using the composition, a method for preparing the polyurethane foam, and a method for improving the performance characteristics of the polyurethane foam. The polyurethane composition exhibits reduced viscosity, and the polyurethane foam exhibits excellent characteristics such as suppressed internal heat accumulation, high thermal stability, excellent tear strength, enhanced wear resistance, and good hydrolysis resistance. Background Art

[0002] Microcellular polyurethane foam has a density of about 100-900 kg / m 3 The foamable polyurethane material of the present invention is generally made by a two-component process including a step of reacting a first component with a second component, wherein the first component mainly includes a polyol and optional additives such as a blowing agent, a catalyst, a surfactant, and the second component includes a polyurethane-prepolymer obtained by reacting a polyol with a polyisocyanate. The two components are blended at high speed and then transferred to various molds with a desired shape. In the past decades, microcellular polyurethane foam has been used for a wide range of end-use applications, such as shoemaking (e.g., soles) and the automotive industry (e.g., bumpers and handrails consisting of whole skin foam). Recently, microcellular polyurethane foam has been explored in solid tire applications. The reason why these microcellular polyurethane solid tires are attractive is because the deflation risk inherent in all pneumatic rubber tires and the maintenance cost that may cause potential safety issues and increases is eliminated.

[0003] The use of polyurethanes in tire applications has always been challenging due to their inherent property of generating "internal heat". Internal heat buildup originates from the conversion of mechanical energy into heat inside the polyurethane and is characterized by a significant increase in tire temperature during rolling, especially at higher speeds and loads. As the temperature increases, material failures, including fatigue cracking and / or melting, are usually observed. Therefore, the upper limit of the speed and load at which a polyurethane tire can operate is determined by the internal heat buildup and, of course, by the thermal stability of the polyurethane tire. Great efforts have been made to increase the thermal stability of polyurethanes by introducing functional moieties, such as isocyanurate groups, oxazolidone groups, oxalamide groups or borate groups, or to reduce the "internal heat buildup" in polyurethanes by using special isocyanates, such as 1,5-naphthalene diisocyanate. However, the above modifications by using chemicals with special groups or special isocyanates are generally too expensive to be commercialized.

[0004] It is noteworthy that formulations based on mixtures of polyester polyols and polyether polyols are reported to be good candidates for the manufacture of polyurethane solid tires. These tires show good modality, wear resistance, puncture resistance, high resilience and low compression set. However, blends of polyether polyols and polyester polyols tend to bring disadvantages in processing characteristics, such as shorter operating time due to segmentation and a deterioration in the balance of properties between tear strength, internal heat accumulation and thermal stability that may be caused by incompatibility between polyether and polyester structures.

[0005] For the above reasons, the polyurethane manufacturing industry still needs to develop a polyurethane composition that can improve its above performance characteristics in an economical and affordable way. After continuous exploration, the inventors have surprisingly developed a polyurethane composition that can achieve one or more of the above goals. Summary of the invention

[0006] The present disclosure provides a novel polyurethane composition, a polyurethane foam and a molded product prepared by using the composition, a method for preparing the polyurethane foam, and a method for improving performance characteristics of the polyurethane foam.

[0007] In a first aspect of the present disclosure, the present disclosure provides a polyurethane composition, comprising:

[0008] (A) at least one polyurethane prepolymer prepared by reacting at least one polyisocyanate compound with a first polyol component; and

[0009] (B) a second polyol component;

[0010] Wherein at least one of the first polyol component and the second polyol component comprises an ester / ether random copolymer polyol, and the ester / ether random copolymer polyol is synthesized by reacting a starting material polyether polyol with at least one monomer polyol comprising 2 to 12 carbon atoms and a hydroxyl functionality of 1.5-3.0 and at least one monomer multifunctional carboxylic acid or its anhydride comprising 2 to 20 carbon atoms and a carboxylic acid functionality of 1.5-3.0. According to a preferred embodiment of the present disclosure, the starting material polyether polyol used to prepare the ester / ether random copolymer polyol is poly(C 2 -C 10 ) alkylene glycol or more (C 2 -C 10) copolymers of alkylene glycols. For example, the starting material polyether polyol can be selected from the group consisting of: (i) polytetramethylene glycol having a molecular weight of 200-3,000 g / mol and a hydroxyl functionality of 1.5-3.0; (ii) polyether polyols based on one or more of ethylene oxide, 1,2-propylene oxide, 1,2-butylene oxide and 2,3-butylene oxide having a molecular weight of 200-3,000 g / mol and a hydroxyl functionality of 1.5-3.0; and combinations thereof. According to another preferred embodiment, the monomer polyol is selected from the group consisting of ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 1,4-butynediol, 1,5-pentanediol, neopentyl glycol, 1,4-bis(hydroxymethyl)cyclohexane, 1,2-bis(hydroxymethyl)cyclohexane, 1,3-bis(hydroxymethyl)cyclohexane, 2-methylpropane-1,3-diol, methylpentanediol, diethylene glycol, The present invention relates to a monomeric polyfunctional carboxylic acid or anhydride thereof, wherein the monomeric polyfunctional carboxylic acid or anhydride thereof is selected from the group consisting of suberic acid, azelaic acid, adipic acid, phthalic acid, isophthalic acid, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrachlorophthalic anhydride, endomethylene-tetrahydro-phthalic anhydride, glutaric anhydride, alkenyl succinic acid, maleic acid, maleic anhydride, fumaric acid and dimer fatty acid. According to another preferred embodiment of the present invention, the molecular weight of the ester / ether random copolymer polyol is 800 to 6,000 g / mol and the average hydroxyl functionality is 1.5 to 3.0, and the weight ratio between the ether segment and the ester segment in the ester / ether random copolymer polyol is 0.05 / 0.95 to 0.95 / 0.05.

[0011] In a second aspect of the present disclosure, the present disclosure provides a microcellular polyurethane foam prepared using the polyurethane composition as described above, wherein the repeating units derived from the ester / ether random copolymer polyol are covalently linked to the polyurethane backbone of the polyurethane microcellular polyurethane foam, and the density of the microcellular polyurethane foam is 100-900 kg / m 3 .

[0012] In a third aspect of the present disclosure, the present disclosure provides a molded product prepared from the above-mentioned microcellular polyurethane foam, wherein the molded product is selected from the group consisting of: tires, footwear, soles, furniture, pillows, cushions, toys and linings.

[0013] In a fourth aspect of the present disclosure, the present disclosure provides a method for preparing the microcellular polyurethane foam, the method comprising the following steps:

[0014] i) reacting at least one polyisocyanate compound with a first polyol component to form the polyurethane prepolymer; and

[0015] ii) reacting the polyurethane prepolymer with a second polyol component to form the microcellular polyurethane foam;

[0016] Repeating units derived from the ester / ether random copolymer polyol are covalently linked in the polyurethane backbone of the polyurethane microcellular polyurethane foam.

[0017] In the fifth aspect of the present disclosure, the present disclosure provides a method for improving the performance characteristics of microcellular polyurethane foam, the method comprising the following steps: covalently linking repeating units derived from the above-mentioned ester / ether random copolymer polyol into the polyurethane backbone of the polyurethane microcellular polyurethane foam, wherein the ester / ether random copolymer polyol is synthesized by reacting the starting material polyether polyol with at least one monomer polyol comprising 2 to 12 carbon atoms and a hydroxyl functionality of 1.5-3.0 and at least one monomer multifunctional carboxylic acid or its anhydride comprising 2 to 20 carbon atoms and a carboxylic acid functionality of 1.5-3.0; and the performance characteristics include at least one of the following: internal heat accumulation, thermal stability, tear strength, viscosity, abrasion resistance and hydrolysis resistance.

[0018] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1-2 A photograph showing a polyurethane solid tire prepared by using a material that does not contain an ester / ether random copolymer polyol;

[0020] Figure 3-5 A photograph of a polyurethane solid tire prepared by an embodiment according to the present disclosure is shown. DETAILED DESCRIPTION

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs. In addition, all publications, patent applications, patents and other references mentioned herein are incorporated by reference.

[0022] As disclosed herein, "and / or" means "and, or as an alternative". Unless otherwise indicated, all ranges are inclusive. Unless otherwise indicated, all percentages and ratios are calculated by weight, and all molecular weights are number average molecular weights. In the context of the present disclosure, the starting material polyether polyols and C 2 -C 12 Monomer polyols and C2 -C 20 The ester / ether random copolymer polyol obtained by the condensation polymerization of monomeric multifunctional carboxylic acids or their anhydrides is simply referred to as "ester / ether random copolymer polyol".

[0023] According to one embodiment of the present disclosure, the polyurethane composition is a "two-component", "two-part" or "two-pack" composition comprising at least one polyurethane-prepolymer component (A) and an isocyanate-reactive component (B), wherein the polyurethane-prepolymer comprises free isocyanate groups and is prepared by reacting at least one polyisocyanate compound with a first polyol component, and the isocyanate-reactive component (B) is a second polyol component. The polyurethane-prepolymer component (A) and the isocyanate-reactive component (B) are transported and stored separately and combined shortly before or immediately before application during the manufacture of a polyurethane product such as a solid tire. Once the two components are combined, the isocyanate groups in component (A) react with the isocyanate-reactive groups (specifically, hydroxyl groups) in component (B) to form a polyurethane. Without being bound by any particular theory, it is believed that the polyether polyol, C 2 -C 12 Monomer polyols and C 2 -C 20 The ester / ether random copolymer polyol of the reaction of the monomeric multifunctional carboxylic acid or its anhydride is contained in at least one of the first polyol component and the second polyol component to incorporate the repeating unit (residue part) of the ester / ether random copolymer polyol into the polyurethane backbone of the final polyurethane foam, so that the performance characteristics of the polyurethane foam can be effectively improved. According to one embodiment of the present disclosure, the first polyol component includes polyether polyol derived from the starting material, C 2 -C 12 Monomer polyols and C 2 -C 20 The first polyol component comprises an ester / ether random copolymer polyol derived from a polyfunctional carboxylic acid or an anhydride thereof, and the second polyol component does not include the ester / ether random copolymer polyol. According to an alternative embodiment of the present disclosure, the second polyol component comprises a polyether polyol derived from a starting material, a C 2 -C 12 Monomer polyols and C 2 -C 20 The first polyol component comprises an ester / ether random copolymer polyol derived from a reaction of a monomeric multifunctional carboxylic acid or an anhydride thereof, while the first polyol component does not include the ester / ether random copolymer polyol. According to an alternative embodiment of the present disclosure, both the first polyol component and the second polyol component comprise polyether polyols derived from the starting materials, C 2 -C 12 Monomer polyols and C 2 -C 20Ester / ether random copolymer polyols prepared by reacting monomeric multifunctional carboxylic acids or their anhydrides. Ester / ether random copolymer polyols are prepared by reacting monomeric multifunctional carboxylic acids or their anhydrides. 2 -C 20 The carboxyl group in the monomer multifunctional carboxylic acid or its anhydride reacts with the starting material polyether polyol and C 2 -C 12 The polyols are prepared by condensation polymerization (esterification reaction) between the hydroxyl groups contained in the monomer polyols. It should be particularly emphasized that the prior art has not disclosed the inclusion of such ester / ether random copolymer polyol parts in the polyurethane backbone. For example, due to the high reactivity between isocyanate groups and isocyanate-reactive groups, the reaction between polyisocyanate compounds and, for example, polyether polyol / polyester polyol physical blends will never form the above-mentioned residual part of the ester / ether random copolymer polyol of the present disclosure.

[0024] In various embodiments, the molecular weight of the starting material polyether polyol for preparing the ester / ether random copolymer polyol is 100 to 3,000 g / mol, and preferably 200 to 2,000 g / mol. For example, the molecular weight of the ester / ether random copolymer polyol can be in the numerical range obtained by combining any two of the following endpoint values: 200, 250, 300, 350, 400, 450, 500, 550, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700, 2800, 2900 and 3000 g / mol. In various embodiments, the average hydroxyl functionality of the starting material polyether polyol for preparing the ester / ether random copolymer polyol is 1.5 to 3.0, and the average hydroxyl functionality can be in the range of values ​​obtained by combining any two of the following endpoint values: 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9 and 3.0. According to a preferred embodiment of the present disclosure, the starting material polyether polyol for preparing the ester / ether random copolymer polyol is selected from the group consisting of polyethylene glycol, polypropylene glycol, polytetramethylene glycol, poly(2-methyl-1,3-propane diol) and any copolymer thereof, such as poly(ethylene oxide-propylene oxide) diol.

[0025] According to a particularly preferred embodiment of the present disclosure, the starting material polyether polyol is selected from the group consisting of: (i) polytetramethylene glycol having a molecular weight of 200-3,000 g / mol and a hydroxyl functionality of 1.5-3.0; (ii) polyether polyols based on one or more of ethylene oxide, 1,2-propylene oxide, 1,2-butylene oxide and 2,3-butylene oxide having a molecular weight of 200-3,000 g / mol and a hydroxyl functionality of 1.5-3.0; and combinations thereof. According to a most preferred embodiment of the present disclosure, the starting material polyether polyol for preparing the ester / ether random copolymer polyol is polytetramethylene glycol having a molecular weight of 200-3,000 g / mol and a hydroxyl functionality of 1.5-3.0.

[0026] According to one embodiment of the present disclosure, the above-mentioned starting material polyether polyol can be prepared by polymerizing one or more linear or cyclic alkylene oxides selected from propylene oxide (PO), ethylene oxide (EO), butylene oxide, tetrahydrofuran, 2-methyl-1,3-propanediol and mixtures thereof with appropriate starting molecules in the presence of a catalyst. Typical starting molecules include compounds having at least 1, preferably 1.5 to 3.0 hydroxyl groups in the molecule or having 1 or more primary amine groups. Suitable starting molecules having at least 1 and preferably 1.5 to 3.0 hydroxyl groups in the molecule are, for example, selected from the group including: ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butenediol, 1,4-butynediol, 1,5-pentanediol, neopentyl glycol, 1,4-bis(hydroxymethyl)-cyclohexane, 1,2-bis(hydroxymethyl)cyclohexane, 1,3-bis(hydroxymethyl)-cyclohexane In some embodiments, the present invention relates to alkylene glycol, 2-methylpropane-1,3-diol, methylpentanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, dibutylene glycol, polybutylene glycol, trimethylolpropane, glycerol, pentaerythritol, castor oil, sugar compounds, such as glucose, sorbitol, mannitol and sucrose, polyphenols, resols, such as oligomeric condensation products of phenol and formaldehyde and Mannich condensates (Mannich condensates) of phenol, formaldehyde and dialkanolamine and melamine. For example, the starting molecule with one or more primary amine groups in the molecule can be selected from the group consisting of aniline, EDA, TDA, MDA and PMDA, more preferably selected from the group including TDA and PMDA, and most preferably TDA. When TDA is used, all isomers can be used alone or in any desired mixture. For example, 2,4-TDA, 2,6-TDA, a mixture of 2,4-TDA and 2,6-TDA, 2,3-TDA, 3,4-TDA, a mixture of 3,4-TDA and 2,3-TDA, and a mixture of all the above isomers can be used. The catalyst used to prepare the starting material polyether polyol can include a basic catalyst for anionic polymerization, such as potassium hydroxide, or a Lewis acid catalyst for cationic polymerization, such as boron trifluoride. Suitable polymerization catalysts can include potassium hydroxide, cesium hydroxide, boron trifluoride or a dicyanide complex (DMC) catalyst, such as zinc hexacyanocobaltate or a quaternary phosphazenium compound. In a preferred embodiment of the present disclosure, the starting material polyether polyol comprises polyethylene, (methoxy)polyethylene glycol (MPEG), polyethylene glycol (PEG), poly(propylene glycol), polytetramethylene glycol, poly(2-methyl-1,3-propane diol) or a copolymer of ethylene oxide and propylene oxide (polyethylene glycol-propylene glycol) having primary or secondary hydroxyl end groups.

[0027] In various embodiments, the monomeric polyol is selected from the group consisting of ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 1,4-butynediol, 1,5-pentanediol, neopentyl glycol, 1,4-bis(hydroxymethyl)cyclohexane, 1,2-bis(hydroxymethyl)cyclohexane, 1,3-bis(hydroxymethyl)cyclohexane, 2-methylpropane-1,3-diol, methylpentanediol, diethylene glycol. , triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, dibutylene glycol and polybutylene glycol; and the monomeric multifunctional carboxylic acid is independently selected from the group consisting of suberic acid, azelaic acid, phthalic acid, isophthalic acid, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrachlorophthalic anhydride, endomethylene-tetrahydro-phthalic anhydride, glutaric anhydride, alkenyl succinic acid, maleic acid, maleic anhydride, fumaric acid and dimer fatty acid.

[0028] According to a preferred embodiment, the starting material polyether polyol is the only reactant that reacts with the polyol and the monomeric multifunctional carboxylic acid, and no other polymeric reactants, such as polyester polyols, are included in the system for preparing the ester / ether random copolymer polyol. Specifically, the reaction of the starting material polyether polyol, the monomeric polyol and the monomeric multifunctional carboxylic acid or its anhydride will form a copolymer comprising only repeating units derived from the above-mentioned reactants.

[0029] Catalysts can be used in the production of ester / ether random copolymer polyols. Examples of catalysts can include p-toluenesulfonic acid; titanium (IV) based catalysts such as tetraisopropyl titanate, tetra(n-butyl) titanate, tetraoctyl titanate, titanium acetate, diisopropoxybis(acetylacetonate)titanium and diisopropoxybis(ethyl acetoacetate)titanium; zirconium based catalysts such as zirconium tetraacetylacetonate, zirconium hexafluoroacetylacetonate, zirconium trifluoroacetylacetonate, tetra(ethyl trifluoroacetylacetonate)zirconium, tetra(2,2,6,6-tetramethyl-heptyl)pyruvate, tetra(ethyl ... dibutyltin diacetate, dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate, dioctyltin diacetate, dimethyltin dineodecanoate, dimethylhydroxy(oleate)tin, and dioctyltin dilaurate.

[0030] According to one embodiment of the present disclosure, the molecular weight of the ester / ether random copolymer polyol prepared by the reaction of the starting material polyether polyol, the monomer polyol and the monomer multifunctional carboxylic acid or its anhydride can be at least 800g / mol, such as 800g / mol to 6,000g / mol. The ester / ether random copolymer polyol of the present disclosure includes a "polyether portion" derived from the starting material polyether polyol and a "polyester portion" derived from the reaction between the carboxyl group of the monomer multifunctional carboxylic acid or its anhydride and the free hydroxyl groups contained in the monomer polyol and the starting material polyether polyol. According to one embodiment of the present disclosure, the weight ratio between the polyether portion and the polyester portion is 0.05 / 0.95 to 0.95 / 0.05, preferably 0.25 / 0.75 to 0.75 / 0.25. The weight ratio can be appropriately adjusted according to the specific functionality and molecular weight of these reactants, provided that the resulting ester / ether random copolymer polyol includes more than one free hydroxyl group and the average hydroxyl functionality is 1.5 to 3.0, such as 1.5-2.0. For example, the average hydroxyl functionality of the ester / ether random copolymer polyol can be within the range of values ​​obtained by combining any two of the following endpoint values: 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9 and 3.0. According to another embodiment of the present disclosure, the ester portion / block is present in the polyurethane in an amount of 1.0 wt% to 52 wt%, and the polyether portion is present in the polyurethane in an amount of 1.0 wt% to 70 wt%, based on the total weight of the produced polyurethane.

[0031] In various embodiments, the polyisocyanate compound refers to an aliphatic, alicyclic, aromatic or heteroaromatic compound having at least two isocyanate groups. In a preferred embodiment, the polyisocyanate compound can be selected from the group consisting of: a C 4 -C 12 Aliphatic polyisocyanate, C comprising at least two isocyanate groups 6 -C 15 Cycloaliphatic or aromatic polyisocyanates, C 7 -C 15Aromatic aliphatic polyisocyanates and combinations thereof. In another preferred embodiment, suitable polyisocyanate compounds include m-phenylene diisocyanate, 2,4-toluene diisocyanate and / or 2,6-toluene diisocyanate (TDI), various isomers of diphenylmethane diisocyanate (MDI), carbodiimide-modified MDI products, hexamethylene-1,6-diisocyanate, tetramethylene-1,4-diisocyanate, cyclohexane-1,4-diisocyanate, hexahydrotoluene diisocyanate, hydrogenated MDI, naphthyl-1,5-diisocyanate, isophorone diisocyanate (IPDI) or mixtures thereof. Typically, the amount of the polyisocyanate compound may vary based on the actual requirements of the polyurethane foam and polyurethane tire. For example, as an illustrative embodiment, the content of the polyisocyanate compound can be 15wt% to 60wt%, or 20wt% to 50wt%, or 23wt% to 40wt%, or 25wt% to 35wt%, based on the total weight of the polyurethane composition. According to a preferred embodiment of the present disclosure, the amount of the polyisocyanate compound is appropriately selected so that the isocyanate group is present in a stoichiometric molar amount relative to the total molar amount of the hydroxyl groups contained in the first polyol component, the second polyol component and any additional additives or modifiers.

[0032] Additionally or alternatively, the first polyol component and the second polyol component may include polyols (hereinafter referred to as "polyols") other than ester / ether random copolymer polyols. According to one embodiment of the present application, the first polyol component only includes ester / ether random copolymer polyols, and the second polyol component includes polyols. According to another embodiment of the present application, the second polyol component only includes ester / ether random copolymer polyols, and the first polyol component includes polyols. According to another embodiment of the present application, both the first polyol component and the second polyol component only include ester / ether random copolymer polyols and do not include any other polyols as reactants. According to another embodiment of the present application, the first polyol component includes ester / ether random copolymer polyols and polyols, and the second polyol component includes polyols. According to another embodiment of the present application, the second polyol component includes ester / ether random copolymer polyols and polyols, and the first polyol component includes polyols. According to another embodiment of the present application, the second polyol component includes ester / ether random copolymer polyols and polyols, and the first polyol component includes ester / ether random copolymer polyols and polyols. According to a preferred embodiment of the present disclosure, the residue part of polytetramethylene glycol is covalently linked in the main chain of the produced polyurethane. The residue part of polytetramethylene glycol can be derived from the polytetramethylene glycol used to prepare the ester / ether random copolymer polyol, derived from a polyol other than the ester / ether random copolymer polyol, or a combination thereof. According to a particularly preferred embodiment of the present disclosure, the residue part of polytetramethylene glycol can be present in the main chain of the produced polyurethane in an amount of 1.0wt% to 70wt%, preferably 5.0wt% to 35wt%, based on the total weight of the polyurethane.

[0033] According to various embodiments of the present application, the polyol other than the ester / ether random copolymer polyol may be selected from the group consisting of: a C 2 -C 16 Aliphatic polyols, C 6 -C 15 Alicyclic or aromatic polyols, C 7 -C 15 Aromatic aliphatic polyols, polyester polyols having a molecular weight of 100 to 3,000 and an average hydroxyl functionality of 1.5 to 5.0, polymer polyols having a solids content of 1-50%, an OH value of 10-149 and a hydroxyl functionality of 1.5-5.0 having a core phase and a shell phase based on polyols, supplementary polyether polyols, and combinations thereof, wherein the supplementary polyether polyol is a poly(C 2 -C 10 ) alkylene glycol or more (C 2 -C 10) copolymer of alkylene glycol; wherein the supplementary polyether polyol may be the same as or different from the starting material polyether polyol. According to a preferred embodiment of the present application, the polyol other than the ester / ether random copolymer polyol may be selected from the group consisting of: polyethylene glycol, polypropylene glycol and polytetramethylene glycol. In the context of the present disclosure, the above-mentioned polymer polyol refers to a composite particle with a core-shell structure. The shell phase may include at least one polyol other than the ester / ether random copolymer polyol, for example, the polyol may be selected from the group consisting of: polyethylene, (methoxy) polyethylene glycol (MPEG), polyethylene glycol (PEG), poly(propylene glycol), polytetramethylene glycol, poly(2-methyl-1,3-propane diol) or a copolymer of ethylene oxide and propylene oxide (polyethylene glycol-propylene glycol) with primary hydroxyl end groups or secondary hydroxyl end groups. The core phase may be micro-sized and may include any polymer compatible with the shell phase. For example, the core phase may include polystyrene, polyacrylonitrile, polyester, polyolefin or polyether (in terms of composition or degree of polymerization) different from the polystyrene, polyacrylonitrile, polyester, polyolefin or polyether of the shell phase. According to a preferred embodiment of the application, the polymer polyol is a composite particle with a core-shell structure, wherein the core is a micro-sized core consisting of SAN (styrene and acrylonitrile), and the shell phase is composed of PO-EO polyol. This polymer polyol can be prepared by free radical copolymerization of styrene, acrylonitrile and poly (EO-PO) polyols comprising ethylenically unsaturated groups.

[0034] The polyurethane prepolymer prepared by reacting the polyisocyanate compound with the first polyol component has an NCO group content of 2 to 50 wt %, preferably 6 to 49 wt %.

[0035] The reaction between the polyisocyanate compound and the first polyol component and the reaction between the polyurethane-prepolymer and the second polyol component can occur in the presence of one or more catalysts that can promote the reaction between the isocyanate groups and the hydroxyl groups. Without being bound by theory, the catalyst can include, for example, glycine salts; tertiary amines; tertiary phosphines, such as trialkylphosphines and dialkylbenzylphosphines; morpholine derivatives; piperazine derivatives; various metal chelates, such as those obtained from acetylacetone, benzoylacetone, trifluoroacetylacetone, ethyl acetoacetate, and the like, and metals such as Be, Mg, Zn, Cd, Pd, Ti, Zr, Sn, As, Bi, Cr, Mo, Fe, Co, and Ni; acidic metal salts of strong acids, such as ferric chloride and tin chloride; organic acids and alkali metals, alkaline earth metals, Al; , Sn, Pb, Mn, Co, Ni and Cu and other metal salts; organic tin compounds, such as tin (II) salts of organic carboxylic acids, for example, tin (II) diacetate, tin (II) dioctoate, tin (II) diethylhexanoate and tin (II) dilaurate, and dialkyltin (IV) salts of organic carboxylic acids, for example, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate and dioctyltin diacetate; bismuth salts of organic carboxylic acids, for example, bismuth octoate; organic metal derivatives of trivalent and pentavalent metal carbonyls of As, Sb and Bi and iron and cobalt; or mixtures thereof.

[0036] The tertiary amine catalyst comprises an organic compound containing at least one tertiary nitrogen atom and capable of catalyzing the hydroxyl / isocyanate reaction. The tertiary amine, morpholine derivative and piperazine derivative catalyst may comprise, for example but not limited to, triethylenediamine, tetramethylethylenediamine, pentamethyldiethylenetriamine, bis(2-dimethylaminoethyl)ether, triethylamine, tripropylamine, tributylamine, tripentylamine, pyridine, quinoline, dimethylpiperazine, piperazine, N-ethylmorpholine, 2-methylpropylenediamine, methyltriethylenediamine, 2,4,6-tris(dimethylamino-methyl)phenol, N,N',N"-tris(dimethylamino-propyl)sym-hexahydrotriazine or a mixture thereof.

[0037] Typically, the catalyst used herein is present in an amount greater than zero and up to 3.0 wt%, preferably up to 2.5 wt%, more preferably up to 2.0 wt%, based on the total weight of the polyurethane composition.

[0038] In various embodiments of the present disclosure, the polyurethane composition includes one or more additives selected from the group consisting of: chain extenders, crosslinkers, foaming agents, foam stabilizers, tackifiers, plasticizers, rheology modifiers, antioxidants, fillers, colorants, pigments, water scavengers, surfactants, solvents, diluents, flame retardants, anti-slip agents, antistatic agents, preservatives, biocides, antioxidants, and combinations of two or more thereof. These additives can be transported and stored as separate components and incorporated into the polyurethane composition shortly before or immediately before component (A) and component (B) are combined. Alternatively, when component (A) and component (B) are chemically inert to isocyanate groups or isocyanate-reactive groups, these additives can be included in component (A) and component (B).

[0039] Chain extenders may be present in the reactants that form the polyurethane foam. Chain extenders are chemicals having two isocyanate reactive groups per molecule and an equivalent weight per isocyanate reactive group of less than 300, preferably less than 200 and particularly 31 to 125. The isocyanate reactive groups are preferably hydroxyl groups, aliphatic or aromatic primary amino groups or aliphatic or aromatic secondary amino groups. Representative chain extenders include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, dipropylene glycol, tripropylene glycol, 1,4-butanediol, cyclohexanedimethanol, ethylenediamine, phenylenediamine, bis(3-chloro-4-aminophenyl)methane, dimethylthiotoluenediamine and diethyltoluenediamine.

[0040] One or more crosslinking agents may also be present in the reactants that form the polyurethane foam. For purposes of the present invention, a "crosslinking agent" is a material having three or more isocyanate-reactive groups per molecule and an equivalent weight per isocyanate-reactive group of less than 300. Preferably, the crosslinking agent contains 3 to 8, particularly 3 to 4, hydroxyl, primary, secondary, or tertiary amine groups per molecule and an equivalent weight of 30 to about 200, particularly 50 to 125. Examples of suitable crosslinking agents include diethanolamine, monoethanolamine, triethanolamine, mono-, di-, or tri-(isopropanol)amine, glycerol, trimethylolpropane, pentaerythritol, and the like.

[0041] Chain extenders and crosslinkers are suitably used in small amounts, as hardness increases with increasing amounts of either of these materials. Chain extenders are suitably used in an amount of 0 to 25 parts by weight per 100 parts by weight of the polyol component. A preferred amount is 1 to 15 parts per 100 parts by weight of the polyol component. Crosslinkers are suitably used in an amount of 0 to 10 parts by weight per 100 parts by weight of the polyol component. A preferred amount is 0 to 5 parts per 100 parts by weight of the polyol component.

[0042] Fillers may be present in the polyurethane composition. Fillers are included primarily to reduce cost. Particulate rubber materials are particularly useful fillers. Such fillers may comprise 1 to 50% or more by weight of the polyurethane composition.

[0043] Suitable blowing agents include water, air, nitrogen, argon, carbon dioxide and various hydrocarbons, hydrofluorocarbons and hydrochlorofluorocarbons. Surfactants may be present in the reaction mixture. For example, if a porous tire filler is desired, a surfactant may be used because the surfactant stabilizes the foaming reaction mixture until the foaming reaction mixture can harden to form a porous polymer. Surfactants may also be used to wet filler particles and thus help disperse the filler particles into the reactive composition and elastomer. Silicone surfactants are widely used for this purpose and may also be used herein. The amount of the surfactant used is typically between 0.02 and 1 parts by weight per 100 parts by weight of the polyol component.

[0044] The present invention is applicable to the preparation of materials for a wide range of tires that can be used in a variety of applications. The tires can be used, for example, for bicycles, carts such as golf carts or shopping carts, motorized or non-motorized wheelchairs, cars or trucks, any other type of transportation including aircraft, and various types of agricultural, industrial and construction equipment. Large tires with an internal volume of 0.1 cubic meter or more are of particular interest.

[0045] According to various embodiments of the present disclosure, the density of the polyurethane foam is at least 100 kg / m 3 , such as 100 to 950kg / m 3 , 200 to 850 kg / m 3 , 300 to 800 kg / m 3 , 400 to 750 kg / m 3 , 500 to 700 kg / m 3 550 to 650 kg / m 3 or 580 to 620 kg / m 3 or about 600kg / m 3 .

[0046] According to a preferred embodiment of the present disclosure, the polyurethane composition is substantially free of water or moisture intentionally added thereto. For example, "free of water" or "anhydrous" means that, based on the total weight of the mixture of raw materials used to prepare the polyurethane composition, the mixture of all raw materials includes less than 3% by weight, preferably less than 2% by weight, preferably less than 1% by weight, more preferably less than 0.5% by weight, more preferably less than 0.2% by weight, more preferably less than 0.1% by weight, more preferably less than 100 ppm by weight, more preferably less than 50 ppm by weight, more preferably less than 10 ppm by weight, more preferably less than 1 ppm by weight of water.

[0047] According to another preferred embodiment of the present disclosure, the polyurethane composition does not include a modifying group covalently linked to the polyurethane backbone, such as an isocyanurate group, an oxazolidinone group, an oxamide group, or a borate group. According to another preferred embodiment of the present disclosure, the polyurethane composition does not include special and expensive isocyanates, such as 1,5-naphthalene diisocyanate. According to various aspects of the present application, improvements in performance characteristics have been successfully achieved without the need to incorporate any special and expensive modifying functional groups into the polyurethane backbone.

[0048] Examples

[0049] Some embodiments of the present invention will now be described in the following examples. However, the scope of the present disclosure is certainly not limited to the formulations described in these examples. Instead, the examples are merely illustrative of the present disclosure.

[0050] The information of the raw materials used in the examples is listed in Table 1 below:

[0051] Table 1: Raw materials used in the examples

[0052]

[0053] Characterization techniques

[0054] The viscosity of different polyols and prepolymers was determined at different temperatures using a viscosity analyzer (CAP, Brookfield). The acid value, hydroxyl value and NCO value were determined according to ASTM D4662, ASTM D4274 and ASTM D5155, respectively. The tensile strength, elongation at break and tear strength were determined on a Gotech AI-7000S1 universal testing machine according to test method DIN 53543. Dynamic mechanical analysis (DMA) was performed on a TARSA G2 analyzer at a frequency of 1 Hz in strain control mode. Thermogravimetric analysis (TGA) was performed on a TA-Q500 analyzer in an air atmosphere in the temperature range of 0°C to 600°C. At N 2 Differential scanning calorimetry (DSC) was performed on a TA Q1500 analyzer at a cooling rate of 10°C / min and a heating rate of 20°C / min under a 40°C atmosphere.

[0055] Preparation Example 1-2: Synthesis of Ester / Ether Random Copolymer Polyol

[0056] Two ester / ether random copolymer polyols according to the present disclosure, polyethylene polytetramethylene ether adipate (Mn=2000, PEPTMEA, Preparation Example 1) and polybutylene polytetramethylene ether adipate (Mn=2000, PBPTMEA, Preparation Example 2) and a control sample polyethylene butylene adipate (Mn=2000, PEBA2000) were synthesized according to the following general procedure using the recipe listed in Table 2.

[0057] Adipic acid (AA, 36.10 wt%), monoethylene glycol (MEG, 15.13 wt%) and polytetramethylene ether glycol 1000 (PTMEG1000, 48.77 wt%) were fed into a steel reactor equipped with a vacuum pump and an oil bath at room temperature under a nitrogen atmosphere. The system was kept at 180°C for 4 hours under stirring and then the reaction was continued at 240°C until the contents of the reactor showed an n acid value of less than 1.0 mg KOH / g (this took about 14 hours). When the removal rate of water slowed down, n-butyl titanate (TBT, 15 ppm in the final product) was added to the system and a vacuum (about 150 mbar) was used to accelerate the reduction of the acid value. The final product was cooled to 80°C, filtered, barreled, and sampled for characterization of acid value, hydroxyl value and viscosity determination. The products prepared in these two preparation examples 1-2 are referred to as PEPTMEA and PBPTMEA, respectively. The product prepared in the control example is referred to as PEBA 2000. All characterization results are also summarized in Table 2.

[0058] Table 2: Synthesis and characterization of ester / ether random copolymer polyols

[0059]

[0060] In the present invention, polyester polyol polybutylene adipate (Mn = 2000, PEBA2000) is used as a control sample, and the characterization results of the control sample are also listed in Table 2. It can be seen unexpectedly that PEPTMEA and PBPTMEA show significantly lower viscosity compared to the control sample, which is an effective proof of good processability. In addition, the products of the two preparation examples of the present invention also show a lower entropy change (ΔH), which indicates a lower crystallization tendency and better storage / processing stability.

[0061] Preparation Example 3-5: Synthesis of polyurethane prepolymer

[0062] Three different prepolymers were prepared by reacting the polyols prepared in the above examples and the commercially available polyether polyol PTMEG2000 with MDI according to the following general procedure with the formulations shown in Table 3. First, MDI (ISONATE 125MH) and an inhibitor (benzoyl chloride) were loaded into a tank reactor equipped with a vacuum pump and an oil bath, and then kept at a temperature of 60°C under stirring. Before filling into the reactor, the polyols were preheated at 60°C for 12 hours. During the feeding of the polyols, the reactor was kept at a temperature below 75°C. Then, the mixture was heated to 80°C and reacted for 150 minutes under stirring. Then, the system was cooled to 50°C, Isonate 143LP and Isonate PR7020 were added thereto, and the contents in the reactor were stirred for another 20 minutes. Subsequently, the final prepolymer product was obtained after quantifying the NCO content and degassing under vacuum for 30 minutes. The NCO content of the resulting prepolymer was about 19wt%. The characterization results are summarized in Table 3. Two carbodiimide-modified MDIs, Isonate 143LP and Isonate PR7020, were incorporated into the prepolymer to improve the storage stability of the prepolymer at low temperatures.

[0063] Table 3: Formulation and characterization of prepolymers.

[0064]

[0065] As shown in Table 3, Prepolymer-2 based on pure PTMEG2000 shows the lowest viscosity at 25°C, which is a result of higher flexibility and lower interchain interaction of PTMEG2000.

[0066] Examples 1-5: Preparation of microcellular polyurethane foam

[0067] The polyol component was prepared in advance by mixing together polyol, chain extender, catalyst, surfactant, blowing agent and other additives according to the formulation shown in Table 4. The polyurethane-prepolymer synthesized in the above preparation example was mixed with the polyol component at 50° C., and the mixture was injected into a metal mold at 50° C. using a low pressure machine (Green). The reaction between the polyol component and the prepolymer occurred immediately after mixing, and the molded sample was demolded after curing at 50° C. for 5 minutes. The cured polyurethane foam sample was stored at room temperature for at least 24 hours before testing.

[0068] As can be seen from the formulations shown in Table 4, Examples 1 and 2 are comparative examples that do not include the ester / ether copolymer polyol according to the present disclosure. Specifically, the polyol components of Examples 1 and 2 are blends of multiple polyether polyols, and the polyurethane-prepolymer components of Examples 1 and 2 are Prepolymer-1 and Prepolymer-2 prepared by using polyester polyol PEBA2000 and polyether polyol PTMEG2000, respectively.

[0069] Three strategies are adopted in Examples 3 to 5 of the present invention. Example 3 shows a specific embodiment of the present disclosure, wherein a polyurethane-prepolymer (prepolymer-3) is prepared by using ester / ether random polyol, pure MDI, modified MDI, a side reaction inhibitor, and a polyol component including polyether polyol, a chain extender, a blowing agent, a catalyst, a foam stabilizer, and other additives; that is, Example 3 only includes ester / ether random polyol in the polyurethane-prepolymer component. Example 4 shows another specific embodiment of the present disclosure, wherein a polyurethane-prepolymer (prepolymer-1) is prepared by using polyester polyol, pure MDI, modified MDI, a side reaction inhibitor, and a polyol component including ester / ether random polyol (PBPTMEA), a chain extender, a blowing agent, a catalyst, a foam stabilizer, and other additives; that is, Example 4 only includes ester / ether random polyol in the polyol component. Example 5 shows another specific embodiment of the present disclosure, wherein a polyurethane-prepolymer (prepolymer-3) is prepared by using an ester / ether random polyol, pure MDI, modified MDI, a side reaction inhibitor and a polyol component including an ester / ether block polyol (PBPTMEA), a chain extender, a blowing agent, a catalyst, a foam stabilizer and other additives; that is, Example 5 includes an ester / ether random polyol in both the polyurethane-prepolymer component and the polyol component.

[0070] The polyurethane foams prepared in Examples 1 to 5 were formed into a foam having a density of about 600 kg / m 3 The sample plates were prepared and the characterization results are summarized in Table 4 below.

[0071] Table 4: Formulations and characterizations of Examples 1 to 6

[0072]

[0073] Notes: a. Thermal stability was measured using TGA and DSC; and

[0074] b. Internal heat accumulation is characterized by DMA.

[0075] As to tear strength, it can be seen from Table 4 that, compared with the tear strength value of Comparative Example 1 which only adopts traditional polyether polyols and polyester polyols, the samples prepared in Examples 3-5, which include ester / ether random copolymer polyols according to the present disclosure in the polyurethane backbone, show significantly higher tear strength values. In addition, compared with the thermal stability of Example 2, Examples 3-5 show higher thermal stability as characterized by TGA and DSC. In other words, compared with the thermal stability of Comparative Example 2, the samples prepared in Examples 3-5 of the present invention can achieve improved thermal stability. Finally, compared with Example 1, Examples 3-5 of the present invention, which include ester / ether random copolymer polyols according to the present disclosure in the polyurethane backbone, show significantly lower internal heat accumulation.

[0076] Preparation and characterization of polyurethane tires.

[0077] By using the samples obtained in Examples 1 to 5 above, a molded product having a diameter of 24 inches and a molding density of 350 kg / m 3 The polyurethane solid tire was characterized by a rolling test to evaluate the comprehensive performance of the polyurethane solid tire. The rolling test was carried out at a linear speed of 30 km / h, a load of 65 kg and two 10 mm high obstacles and continued for 1 hour at room temperature. The test conditions and characterization results are summarized in Table 5.

[0078] Table 5: Rolling test results of earth tires prepared with materials from Examples 1-5.

[0079]

[0080] The tire samples prepared by using the polyurethane foams of Examples 1 and 2 showed a melting core after the rolling test. The core melting of Example 1 may be attributed to the high internal heat accumulation tendency, as indicated by the high hysteresis value. The core melting of Example 2 may be attributed to the poor thermal stability at high temperatures, as indicated by the TGA results. The tire samples prepared by using the polyurethane foams of Examples 3-5 of the present invention passed the rolling test due to the good balance of properties between tear strength, internal heat accumulation and thermal stability at high temperatures.

[0081] in conclusion

[0082] In view of the above, the ester / ether random copolymer polyols impart excellent processing and storage stability to the polyurethane system and impart an outstanding balance of properties between high tear strength, high abrasion resistance, low internal heat accumulation and high thermal stability to the final polyurethane material, thereby facilitating the production of microcellular parts and can be used in many related applications, such as solid tires.

Claims

1. A polyurethane composition comprising: (A) at least one polyurethane prepolymer prepared by reacting at least one polyisocyanate compound with a first polyol component; and (B) a second polyol component; wherein at least one of the first polyol component and the second polyol component comprises an ester / ether random copolymer polyol synthesized by reacting a starting material polyether polyol with at least one monomeric polyol comprising 2 to 12 carbon atoms and a hydroxyl functionality of 1.5-3.0 and at least one monomeric multifunctional carboxylic acid or its anhydride comprising 2 to 20 carbon atoms and a carboxylic acid functionality of 1.5-3.0, The starting material polyether polyol is selected from: (i) polytetramethylene glycol having a molecular weight of 200-3,000 g / mol and a hydroxyl functionality of 1.5-3.0; (ii) polyether polyols based on one or more of ethylene oxide, 1,2-propylene oxide, 1,2-butylene oxide and 2,3-butylene oxide having a molecular weight of 200-3,000 g / mol and a hydroxyl functionality of 1.5-3.0; and combinations thereof; and The molecular weight of the ester / ether random copolymer polyol is 800 to 6000 g / mol, and the average hydroxyl functionality is 1.5 to 3.

0.

2. The polyurethane composition according to claim 1, wherein the polyisocyanate compound is selected from the group consisting of: a C4-C5 polyisocyanate having at least two isocyanate groups; 12 Aliphatic polyisocyanate, C6-C6 polyisocyanate comprising at least two isocyanate groups 15 Alicyclic or aromatic polyisocyanates, C7-C8 polyisocyanates comprising at least two isocyanate groups 15 Aromatic aliphatic polyisocyanates and any combination thereof.

3. The polyurethane composition according to claim 1, wherein the starting material polyether polyol is selected from the group consisting of: (i) polytetramethylene glycol having a molecular weight of 200-2,000 g / mol and a hydroxyl functionality of 1.8-2.5; (ii) polyether polyols based on one or more of ethylene oxide, 1,2-propylene oxide, 1,2-butylene oxide and 2,3-butylene oxide having a molecular weight of 200-2,000 g / mol and a hydroxyl functionality of 1.8-2.5; and combinations thereof.

4. The polyurethane composition of claim 1, wherein the monomeric polyol is selected from the group consisting of ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 1,4-butynediol, 1,5-pentanediol, neopentyl glycol, 1,4-bis(hydroxymethyl)cyclohexane, 1,2-bis(hydroxymethyl)cyclohexane, 1,3-bis(hydroxymethyl)cyclohexane, 2-methylpropane-1,3-diol, methylpentanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, dibutylene glycol, and polybutylene glycol; and The monomeric multifunctional carboxylic acid or its anhydride is selected from the group consisting of adipic acid, suberic acid, azelaic acid, phthalic acid, isophthalic acid, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrachlorophthalic anhydride, endomethylene-tetrahydro-phthalic anhydride, glutaric anhydride, alkenylsuccinic acid, maleic acid, maleic anhydride, fumaric acid and dimerized fatty acids.

5. The polyurethane composition of claim 1, wherein the ester / ether random copolymer polyol has a molecular weight of 1000 to 6,000 g / mol and an average hydroxyl functionality of 1.8 to 2.5, and a weight ratio between the ether segments and the ester segments in the ester / ether random copolymer polyol is 0.05 / 0.95 to 0.95 / 0.

05.

6. The polyurethane composition of claim 1, wherein at least one of the first polyol component and the second polyol component comprises a polyol other than the ester / ether random copolymer polyol selected from the group consisting of: a C2-C4 polyol having at least two hydroxyl groups; 16 Aliphatic polyols, C6-C 15 Alicyclic or aromatic polyols, C7-C 15 Aromatic aliphatic polyols, polyester polyols having a molecular weight of 100 to 3,000 and an average hydroxyl functionality of 1.5 to 5.0, polymer polyols having a solids content of 1-50%, an OH value of 10 to 149 and a hydroxyl functionality of 1.5 to 5.0 having a core phase and a shell phase based on polyols, supplementary polyether polyols, and combinations thereof; wherein the supplementary polyether polyol is a poly(C2-C 10 ) alkylene glycol or multiple (C2-C 10 ) copolymers of alkylene glycols and combinations thereof, and the supplementary polyether polyol is the same as or different from the starting material polyether polyol.

7. A microcellular polyurethane foam prepared using the polyurethane composition according to any one of claims 1 to 6, wherein the repeating units derived from the ester / ether random copolymer polyol are covalently linked to the polyurethane backbone of the polyurethane microcellular polyurethane foam, and the density of the microcellular polyurethane foam is 100-900 kg / m 3 .

8. A molded product prepared using the microcellular polyurethane foam according to claim 7, wherein the molded product is selected from the group consisting of tires, footwear, soles, furniture, pillows, cushions, toys and linings.

9. A method for preparing the microcellular polyurethane foam according to claim 7, comprising the following steps: i) reacting at least one polyisocyanate compound with a first polyol component to form the polyurethane prepolymer; as well as ii) reacting the polyurethane prepolymer with the second polyol component to form the microcellular polyurethane foam; The repeating units derived from the ester / ether random copolymer polyol are covalently linked in the polyurethane backbone of the microcellular polyurethane foam.

10. A method for improving the performance characteristics of a microcellular polyurethane foam, the method comprising the steps of: covalently linking repeating units derived from an ester / ether random copolymer polyol synthesized by reacting a starting material polyether polyol with at least one monomeric polyol comprising 2 to 12 carbon atoms and having a hydroxyl functionality of 1.5-3.0 and at least one monomeric multifunctional carboxylic acid comprising 2 to 20 carbon atoms and having a carboxylic acid functionality of 1.5-3.0 into the polyurethane backbone of the microcellular polyurethane foam, wherein the performance properties comprise at least one of: internal heat build-up, thermal stability, tear strength, viscosity, abrasion resistance, and hydrolysis resistance; The starting material polyether polyol is selected from: (i) polytetramethylene glycol having a molecular weight of 200-3,000 g / mol and a hydroxyl functionality of 1.5-3.0; (ii) polyether polyols based on one or more of ethylene oxide, 1,2-propylene oxide, 1,2-butylene oxide and 2,3-butylene oxide having a molecular weight of 200-3,000 g / mol and a hydroxyl functionality of 1.5-3.0; and combinations thereof; and The molecular weight of the ester / ether random copolymer polyol is 800 to 6000 g / mol, and the average hydroxyl functionality is 1.5 to 3.0.

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