A block copolymer polycarbonate polyol and polyurethane and a method for preparing the same

Abstract

The application provides a block copolymer polycarbonate polyol and polyurethane and a preparation method thereof, and belongs to the technical field of polyurethane materials. The block copolymer polycarbonate polyol with the structure shown in formula I is obtained by introducing a block into the structure of an aliphatic polycarbonate polyol, so that the block copolymer polycarbonate polyol has the advantages of both polyether polyols and polyester polyols, and has excellent mechanical strength, hydrolysis resistance, solvent resistance, heat discoloration resistance, scratch resistance and weather resistance, and better flexibility. Meanwhile, the block copolymer polycarbonate polyol is prepared by using polycarbonate diols to replace part of aliphatic diols, so that the use of expensive aliphatic diols is reduced, the production cost of the block copolymer polycarbonate polyol is greatly reduced, and the application of the block copolymer polycarbonate polyol in polyurethane materials is more favorable.

Description

Technical Field

[0001] This invention belongs to the field of polyurethane materials technology, specifically relating to a block copolymer polycarbonate polyol and polyurethane and its preparation method. Background Technology

[0002] Polycarbonate polyols can be used to produce polyurethane, acrylic resins, polyesters, and other products. Compared with polyurethane materials synthesized from traditional polyols, the new generation of polycarbonate-type polyurethane materials synthesized from polycarbonate polyols have extremely strong performance advantages, such as excellent mechanical properties, hydrolysis resistance, heat resistance, oxidation resistance, abrasion resistance, and resistance to microbial degradation, making them suitable for the medical field.

[0003] Currently, the preparation of polycarbonate polyols mainly includes the following two methods:

[0004] 1. Polycarbonate diols are synthesized by copolymerizing CO2 with epoxides (such as ethylene oxide or propylene oxide). The advantages are low cost and the ability to comprehensively recover and utilize the greenhouse gas CO2, which is beneficial to environmental protection. However, the polycarbonate diols prepared in this way have a simple structure, and their properties, such as heat resistance, weather resistance, solvent resistance, and abrasion resistance, are relatively poor.

[0005] 2. Polycarbonate polyols are produced using transesterification polycondensation, specifically through the transesterification polycondensation reaction of dimethyl carbonate and aliphatic diols. Dimethyl carbonate can be directly prepared by the condensation of CO2 and methanol. The advantage of this method is that different polycarbonate diols with varying structures can be obtained by adjusting the type of aliphatic diol, and these polycarbonate diols exhibit excellent properties, such as superior weather resistance, mechanical properties, thermal stability, hydrolysis resistance, chemical resistance, flexibility, elasticity, heat fading resistance, and scratch resistance. Furthermore, the reaction conditions, including temperature and pressure, are relatively mild. However, this method has a disadvantage: some aliphatic diols, such as 1,6-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanediol, and isosorbide diol, are expensive and primarily used in the preparation of high-end polyurethane materials, limiting their widespread application in the polyurethane industry. Summary of the Invention

[0006] The purpose of this invention is to provide a block copolymer polycarbonate polyol and polyurethane and a method for preparing the same. The block copolymer polycarbonate polyol provided by this invention not only has excellent mechanical strength, hydrolysis resistance, solvent resistance, heat fading resistance, scratch resistance and weather resistance, but also reduces production costs.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A block copolymer polycarbonate polyol having the structure shown in Formula I:

[0009]

[0010] In Equation I, x, y, and z are independent integers greater than or equal to 1;

[0011] R1, R2, R3, and R4 are independently -(CH2). c -, 2≤c≤8, where c is an integer;

[0012] A has the structure shown in formula A1, A2, or A3:

[0013]

[0014] In equations A1, A2, and A3, m and n are independent integers greater than or equal to 1.

[0015] Preferably, the block copolymer polycarbonate polyol has a hydroxyl value of 10–300 mg KOH / g and an average molecular weight of 370–11200 g / mol.

[0016] This invention provides a method for preparing the block copolymer polycarbonate polyol described in the above technical solution, comprising the following steps:

[0017] Organic carbonate, polycarbonate diol and catalyst are mixed and subjected to transesterification reaction to obtain transesterification product system;

[0018] The transesterification product system is mixed with an aliphatic diol and subjected to transesterification polycondensation to obtain the block copolymer polycarbonate polyol.

[0019] Preferably, the polycarbonate diol has a structure shown in formula B1, B2, or B3:

[0020]

[0021]

[0022] In equations B1, B2, and B3, m and n are as defined in equations A1, A2, and A3.

[0023] Preferably, the aliphatic diol has 2 to 8 carbon atoms.

[0024] Preferably, the ratio of the total amount of the polycarbonate diol and the aliphatic diol to the amount of the dimethyl carbonate is 1:1.05 to 1.5; and the molar ratio of the polycarbonate diol to the aliphatic diol is 1:1 to 130.

[0025] Preferably, the organic carbonate includes one or more of dimethyl carbonate, diethyl carbonate, dipropyl carbonate, and diphenyl carbonate.

[0026] Preferably, the catalyst accounts for 0.001 to 0.5% of the total mass of the organic carbonate, polycarbonate diol, and catalyst; the catalyst includes one or more of the following: alkaline catalyst, organotitanium compound catalyst, organotin compound catalyst, and organoamine compound catalyst.

[0027] Preferably, the aliphatic diol includes one or more of ethylene glycol, 1,3-propanediol, neopentyl glycol, 1,4-butanediol, 1,3-butanediol, 1,5-pentanediol, 1,4-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,4-cyclohexanediol, 1,4-cyclohexanediol, and isosorbide.

[0028] Preferably, the transesterification reaction is carried out under reflux conditions, and the transesterification reaction time is 1 to 6 hours; the transesterification polycondensation reaction includes: heating the mixture of the transesterification product system and the aliphatic diol from the starting temperature to the ending temperature; the starting temperature is 100 to 140°C, the ending temperature is 140 to 240°C, and the heating rate is 5 to 20°C / h.

[0029] The present invention also provides a method for preparing polyurethane, comprising the following steps:

[0030] A block copolymer polycarbonate polyol was mixed with diphenylmethane diisocyanate and subjected to a nucleophilic addition reaction to obtain a prepolymer;

[0031] Stannous octoate, 1,4-butanediol and the prepolymer were mixed and subjected to a chain extension reaction to obtain polyurethane;

[0032] The block copolymer polycarbonate polyol is the block copolymer polycarbonate polyol described in the above technical solution or the block copolymer polycarbonate polyol prepared by the preparation method described in the above technical solution.

[0033] The present invention also provides a polyurethane, which is prepared by the preparation method described in the above technical solution.

[0034] This invention provides a block copolymer polycarbonate polyol. By introducing blocks into the structure of an aliphatic polycarbonate polyol, this invention yields a block copolymer polycarbonate polyol that combines the advantages of both polyether polyols and polyester polyols. It not only possesses the excellent mechanical strength, hydrolysis resistance, solvent resistance, heat fading resistance, scratch resistance, and weather resistance of ordinary aliphatic polycarbonate polyols, but also exhibits better flexibility. Furthermore, this invention uses polycarbonate diols to replace some aliphatic diols in the preparation of the block copolymer polycarbonate polyol, reducing the use of expensive aliphatic diols and significantly lowering the production cost of the block copolymer polycarbonate polyol. This makes it more suitable for application in polyurethane materials and has broad market prospects. Detailed Implementation

[0035] This invention provides a block copolymer polycarbonate polyol having the structure shown in Formula I:

[0036]

[0037] In Formula I, x, y, and z are preferably integers greater than or equal to 1, and more preferably 1≤x≤60, 1≤y≤60, and 1≤z≤15;

[0038] R1, R2, R3, and R4 are independently -(CH2). c - where c is an integer, and c is the number of carbon atoms in R1, R2, R3 and R4. The preferred value of c is 2≤c≤8; more preferably, the number of carbon atoms in R1 is 3 to 8, the number of carbon atoms in R3 is 3 to 6, and the number of carbon atoms in R4 is 3 to 8.

[0039] A has the structure shown in formula A1, A2, or A3:

[0040]

[0041] In formulas A1, A2 and A3, m and n are preferably integers greater than or equal to 1, and more preferably m = 1 to 4 and n = 1 to 20.

[0042] In this invention, the hydroxyl value of the block copolymer polycarbonate polyol is preferably 10-300 mgKOH / g, more preferably 20-250 mgKOH / g; the average molecular weight is preferably 370-11200 g / mol, more preferably 450-6000 g / mol; the molecular weight distribution (PD) is preferably 1.5-2.0, more preferably 1.5509-1.8243; the acid value is preferably 0.01-0.1 mgKOH / g, more preferably 0.027-0.039 mgKOH / g; and the hue (ColorAPHA / 75℃) is preferably 0-100, more preferably 3-16.

[0043] This invention provides a method for preparing the block copolymer polycarbonate polyol described in the above technical solution, comprising the following steps:

[0044] Organic carbonate, polycarbonate diol and catalyst are mixed and subjected to transesterification reaction to obtain transesterification product system;

[0045] The transesterification product system is mixed with an aliphatic diol and subjected to transesterification polycondensation to obtain the block copolymer polycarbonate polyol.

[0046] In this invention, unless otherwise specified, all raw materials used are commercially available products well known to those skilled in the art or prepared using methods well known to those skilled in the art.

[0047] This invention involves mixing an organic carbonate, a polycarbonate diol, and a catalyst to perform a transesterification reaction, yielding a transesterification product system. In this invention, the organic carbonate preferably includes one or more of dimethyl carbonate, diethyl carbonate, dipropyl carbonate, and diphenyl carbonate, more preferably dimethyl carbonate and / or diethyl carbonate, and even more preferably dimethyl carbonate.

[0048] The polycarbonate diol of the present invention preferably has the structure shown in formula B1, B2 or B3:

[0049]

[0050] In formulas B1, B2, and B3 of this invention, m and n are as defined in formulas A1, A2, and A3. m and n are preferably integers greater than or equal to 1, and more preferably m = 1–4 and n = 1–20. In this invention, the molecular weight of the polycarbonate diol is preferably 250–4000 g / mol, more preferably 400–3000 g / mol, and even more preferably 500–2000 g / mol. In the embodiments of this invention, a polypropylene carbonate diol with a molecular weight of 500–2000 g / mol is specifically used. This invention does not impose any special limitations on the preparation method of the polycarbonate diol; any preparation method well known to those skilled in the art can be used. In the embodiments of this invention, the technical solution disclosed in CN91109459.8 is specifically referenced, which uses a polypropylene carbonate diol with a molecular weight of 500–2000 g / mol synthesized by copolymerization of CO2 and propylene oxide. In this invention, CO2 and propylene oxide are copolymerized to produce polycarbonate diol, which can reduce production costs and achieve comprehensive recovery and utilization of greenhouse gas CO2, which is beneficial to environmental protection.

[0051] In this invention, the mass of the catalyst is preferably 0.001-0.5% of the total mass of the organic carbonate, polycarbonate diol, and catalyst, more preferably 0.005-0.3% of the total mass of the organic carbonate, polycarbonate diol, and catalyst. The catalyst of this invention preferably includes one or more of the following: an alkaline catalyst, an organotitanium compound catalyst, an organotin compound catalyst, and an organic amine compound catalyst; the alkaline catalyst preferably includes one or more of sodium, potassium, lithium, and aluminum and their metal carbonates, metal alkoxides, metal oxides, and metal hydroxides, more preferably sodium hydroxide; the organotitanium compound catalyst preferably includes one or more of tetrabutyl titanate, tetraisopropyl titanate, and titanium acetylacetonate, more preferably tetrabutyl titanate or tetraisopropyl titanate; the organotin compound catalyst preferably includes one or more of dibutyltin dilaurate, di(dodecyl sulfide)dibutyltin, and dibutyltin diacetate, more preferably dibutyltin dilaurate; the organic amine compound catalyst preferably includes one or more of triethylamine, tripropylamine, and triethylenediamine, more preferably triethylenediamine.

[0052] In this invention, the transesterification reaction is preferably carried out under reflux conditions; the reflux temperature is preferably 120–140°C, more preferably 125–135°C; the transesterification reaction time is preferably 1–6 h, specifically 1 h, 2 h, 3 h, 4 h, 5 h, or 6 h. In this invention, the transesterification reaction is preferably carried out under a protective atmosphere, which preferably includes nitrogen or argon, more preferably argon; the purity of the protective atmosphere is preferably 99.99%. The transesterification reaction of this invention is preferably carried out in a dry reactor. In this invention, the transesterification reaction preferably involves controlling the temperature at the top of the distillation tube in the reactor to a first distillation temperature, distilling off the first byproduct; removing the first byproduct and the azeotrope of the organic carbonate, and taking a sample when no fraction is distilled off for a first hydroxyl value test until the hydroxyl value is 0. In this invention, the first distillation temperature is preferably 62–65°C; the first byproduct is methanol. In this invention, the first hydroxyl value test preferably uses the N-methylaminopyridine-catalyzed acetic anhydride method to test the hydroxyl value of the reaction solution. This invention utilizes organic carbonate, polycarbonate diol, and a catalyst as raw materials for transesterification to obtain a transesterification product system. In this system, the hydroxyl groups at both ends of the polycarbonate diol attack the carbonyl groups in the organic carbonate structure under the action of the catalyst, transferring hydrogen ions to the oxygen ions of the methoxy group. The ester bonds on the organic carbonate break, generating the byproduct methanol. Due to the excess of organic carbonate, both hydroxyl groups on both sides of the polycarbonate diol are linked to carbonate groups. The catalyst used in this invention is characterized by high selectivity, high activity, and low dosage, exhibiting excellent catalytic effects for both the transesterification reaction and subsequent transesterification polycondensation. Furthermore, since the byproduct methanol and the raw material dimethyl carbonate form an azeotrope with a boiling point of 64°C, this invention performs distillation at the first distillation temperature. This not only effectively removes the byproduct but also reduces the content of dimethyl carbonate distilled, minimizing raw material waste, lowering subsequent separation costs, and ensuring product quality.

[0053] After the transesterification reaction, the present invention requires no post-processing. The resulting transesterification product system (containing the transesterification product system) is directly mixed with an aliphatic diol and subjected to transesterification polycondensation reaction to obtain a block copolymer polycarbonate polyol. In the present invention, the aliphatic diol preferably has 2 to 8 carbon atoms, more preferably 4 to 6; the aliphatic diol preferably includes one or more of ethylene glycol, 1,3-propanediol, neopentyl glycol, 1,4-butanediol, 1,3-butanediol, 1,5-pentanediol, 1,4-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,4-cyclohexanediol, and isosorbide, further preferably one or more of ethylene glycol, 1,5-pentanediol, 1,4-pentanediol, 1,6-hexanediol, and 1,4-cyclohexanediol, more preferably 1,5-pentanediol and 1,6-hexanediol. In this invention, the ratio of the total amount of the polycarbonate diol and the aliphatic diol to the amount of the dimethyl carbonate is preferably 1:1.05 to 1.5, more preferably 1:1.2 to 1.4. In this invention, the molar ratio of the polycarbonate diol to the aliphatic diol is preferably 1:1 to 130, more preferably 1:3 to 50.

[0054] In this invention, the transesterification polycondensation reaction preferably includes: heating the mixture of the transesterification product system and the aliphatic diol from an initial temperature to a final temperature; specifically, heating the mixture of the transesterification product system and the aliphatic diol from an initial temperature to a final temperature. In this invention, the initial temperature is preferably 100–140°C, more preferably 105–130°C; the final temperature is preferably 140–240°C, more preferably 170–230°C; the heating rate is 5–20°C / h, more preferably 10–15°C / h. The transesterification polycondensation reaction of this invention is preferably carried out in a dry reactor. In this invention, the aliphatic diol is preferably added to the transesterification product system; the addition method is preferably dropwise; the dropwise frequency is preferably 200–1000 g / h, more preferably 300–800 g / h; the temperature is preferably 60–90°C, more preferably 80°C. In this invention, the temperature at the top of the distillation tube in the reactor is preferably controlled at the second distillation temperature to distill off the second by-product. After removing the second by-product, a sample is taken when no fraction is distilled off for a second hydroxyl value test until the hydroxyl value reaches 10–300 mg KOH / g. Then, vacuum distillation is performed to obtain a block copolymer polyol. In this invention, the second distillation temperature is preferably 61–65°C; the second by-product is methanol; the pressure of the vacuum distillation is preferably ≤5 kPa, more preferably 0.001–1 kPa; the time of the vacuum distillation is preferably 1–6 h, more preferably 2–5 h. In this invention, cooling treatment is preferably performed after vacuum distillation. This invention does not have special limitations on the method and conditions of the cooling treatment; any cooling treatment method well known to those skilled in the art can be used. In this invention, the second hydroxyl value test preferably uses the N-methylaminopyridine-catalyzed acetic anhydride method to accurately test the hydroxyl value of the reaction solution. Then, based on the target hydroxyl value, it is determined whether it is qualified (i.e., whether the hydroxyl value reaches 10–300 mg KOH / g), the reaction is monitored, and the reaction endpoint is determined. This invention uses the N-methylaminopyridine-catalyzed acetic anhydride method to test the hydroxyl value of the reaction solution, allowing for the control of the product's molecular weight as required. The prepared block copolymer polycarbonate diol has good color (less than 20), a narrow molecular weight distribution range, and high product quality. This invention introduces blocks into the structure of aliphatic polycarbonate polyols to obtain block copolymer polycarbonate polyols, enabling them to combine the advantages of polyether polyols and polyester polyols. They not only possess the excellent mechanical strength, hydrolysis resistance, solvent resistance, heat fading resistance, scratch resistance, and weather resistance of ordinary aliphatic polycarbonate polyols, but also exhibit better flexibility. Furthermore, this invention uses polycarbonate diols to replace some aliphatic diols in the preparation of block copolymer polycarbonate polyols, reducing the use of expensive aliphatic diols and significantly lowering the production cost of block copolymer polycarbonate polyols.Meanwhile, this invention does not require complex separation methods; block copolymer polycarbonate polyols can be directly prepared through a two-step reaction with a yield of over 96%. Furthermore, since both -OH groups on both sides of the aliphatic diol are primary hydroxyl groups, the block copolymer polycarbonate polyol obtained through transesterification also has primary hydroxyl groups at both ends. Due to the steric hindrance effect of the alcohol, the block copolymer polycarbonate polyol exhibits high reactivity, which is more conducive to its application in polyurethane materials.

[0055] This invention also provides a method for preparing polyurethane, comprising the following steps:

[0056] A block copolymer polycarbonate polyol was mixed with diphenylmethane diisocyanate and subjected to a nucleophilic addition reaction to obtain a prepolymer;

[0057] Stannous octoate, 1,4-butanediol and the prepolymer were mixed and subjected to a chain extension reaction to obtain polyurethane;

[0058] The block copolymer polycarbonate polyol is the block copolymer polycarbonate polyol described in the above technical solution or the block copolymer polycarbonate polyol prepared by the preparation method described in the above technical solution.

[0059] This invention involves mixing block copolymer polycarbonate polyol with diphenylmethane diisocyanate and performing a chain extension reaction to obtain a prepolymer. In this invention, the molar ratio of the block copolymer polycarbonate polyol to diphenylmethane diisocyanate is preferably 0.95–1.05:2.9–3.1, more preferably 1:3; the temperature of the nucleophilic addition reaction is preferably 75–85°C, more preferably 80°C, and the time is preferably 3–8 h, more preferably 5 h. In this invention, the solvent for the nucleophilic addition reaction preferably includes one or more of toluene, butanone, dimethylformamide, acetone, cyclohexanone, and ethyl acetate, more preferably dimethylformamide or cyclohexanone. The role of the solvent in this invention is to ensure sufficient dispersion of the prepolymer.

[0060] After obtaining the prepolymer, the present invention preferably mixes stannous octoate, 1,4-butanediol, and the prepolymer to carry out a chain extension reaction to obtain polyurethane. In the present invention, the molar ratio of stannous octoate, 1,4-butanediol, and the prepolymer is preferably 0.00004–0.001:1–1.05:1–1.05, more preferably 0.0004:1:1.01; the temperature of the chain extension reaction is preferably 60–80°C, more preferably 70°C, and the time is preferably 0.5–2 h, more preferably 1 h. In the present invention, the chain extension reaction is preferably followed by drying; the drying temperature is 100–130°C, more preferably 120°C; the present invention does not have a particular limitation on the drying time, and a drying time well known to those skilled in the art can be used.

[0061] The present invention also provides polyurethane prepared by the preparation method described in the above technical solution.

[0062] To further illustrate the present invention, the block copolymer polycarbonate polyol and polyurethane and their preparation method provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0063] The embodiments of the present invention are carried out in a reactor equipped with a heating and stirring system, a temperature measuring device, a distillation and fractionation system, and a constant pressure feeding system.

[0064] The polypropylene carbonate diol used in the embodiments of this invention was prepared in the laboratory. Specifically, it refers to the technical solution published in CN91109459.8, which uses polypropylene carbonate diol with a molecular weight of 500-2000 g / mol synthesized by copolymerization of CO2 and propylene oxide; all other reagents used are commercially available.

[0065] Example 1

[0066] Add 335.9 g (0.672 mol) of polypropylene carbonate diol (structural formula B1, molecular weight approximately 500 g / mol) and 345.9 g (3.84 mol) of dimethyl carbonate to a dry reactor. Purge the reactor with argon gas to remove air, then add 285 mg (7.1 mmol) of sodium hydroxide. Start the heating and stirring system under an argon atmosphere and raise the reactor temperature to 130°C at atmospheric pressure. Maintain the temperature at the top of the reactor at 62–65°C during stirring. Promptly distill off the azeotrope of the first byproduct, methanol and dimethyl carbonate. Continue stirring and heating for 2 hours. Take a sample when no fraction is distilled off and perform the first hydroxyl value test using the N-methylaminopyridine-catalyzed acetic anhydride method. When the hydroxyl value is... At 0:00, 141.8 g (1.2 mol) of 1,6-hexanediol and 125.0 g (1.2 mol) of 1,5-pentanediol at 80℃ were added dropwise to the reactor at a rate of 500–600 g / h using a constant pressure feeding system. After the addition was complete, the reactor was heated to 130℃ and refluxed for 4 hours. The temperature was gradually increased to 230℃ at a rate of 5–20℃ / h, and the distillation temperature at the top of the distillation tube was controlled at 61–65℃ to distill off the second byproduct, methanol, and the reaction was controlled to promote the forward reaction. The hydroxyl value was tested again. When the hydroxyl value was 10–300 mg KOH / g, the reactor was distilled under reduced pressure for 3 hours at a pressure ≤5 kPa. After cooling to 50℃, liquid block copolymer polycarbonate polyol was obtained with a yield of 96.5%.

[0067] The block copolymer polycarbonate polyol has a hydroxyl value of 110.2 mgKOH / g, an acid value of 0.032 mgKOH / g, a molecular weight distribution (PD) of 1.7698, an average molecular weight of 1018 g / mol, and a hue (ColorAPHA / 75℃) of 13.

[0068] Example 2

[0069] 109.2 g (0.22 mol) of polypropylene carbonate diol (structural formula B2, molecular weight approximately 500 g / mol) and 306.3 g (3.40 mol) of dimethyl carbonate were added to a dry reactor, and argon gas was introduced to purge the air from the reactor. Then, 204 mg (0.598 mmol) of tetrabutyl titanate was added, and the heating and stirring system was turned on under an argon atmosphere. The reactor temperature was raised to 130 °C under normal pressure, and the temperature at the top of the reactor was controlled at 62–65 °C during stirring. The azeotrope of the first byproduct, methanol and dimethyl carbonate, was promptly distilled off and removed. The reaction was continued with stirring and heating for 3 hours. When no fraction was distilled off, a sample was taken, and the first hydroxyl value was tested using the N-methylaminopyridine-catalyzed acetic anhydride method. When the hydroxyl value... When the hydroxyl value is 0, 141.8 g (1.2 mol) of 1,6-hexanediol and 125.0 g (1.2 mol) of 1,5-pentanediol at 80℃ are added dropwise to the reactor at a rate of 500-600 g / h using a constant pressure feeding system. After the addition is complete, the mixture is heated to 130℃ and refluxed for 6 hours. The temperature is gradually increased to 230℃ at a rate of 5-20℃ / h, and the distillation temperature at the top of the distillation tube is controlled at 61-65℃ to distill off the second byproduct, methanol, and the reaction is controlled to promote the forward reaction. The hydroxyl value is tested again. When the hydroxyl value is 10-300 mg KOH / g, the mixture is then distilled under reduced pressure for 4 hours at a pressure ≤5 kPa. After cooling to 50℃, liquid block copolymer polycarbonate polyol is obtained with a yield of 96.2%.

[0070] The block copolymer polycarbonate polyol has a hydroxyl value of 55.1 mgKOH / g, an acid value of 0.032 mgKOH / g, a molecular weight distribution (PD) of 1.7149, an average molecular weight of 2036 g / mol, and a hue (ColorAPHA / 75℃) of 11.

[0071] Example 3

[0072] Add 332.5 g (0.67 mol) of polypropylene carbonate diol (structural formula B1, molecular weight approximately 500 g / mol) and 359.5 g (3.99 mol) of dimethyl carbonate to a dry reactor, and purge the air from the reactor with argon gas. Then add 288 mg (0.845 mmol) of tetrabutyl titanate, turn on the heating and stirring system under an argon atmosphere, and raise the reactor temperature to 130 °C under normal pressure. During stirring, maintain the temperature at the top of the reactor at 62–65 °C. Distill off the azeotrope of the first byproduct, methanol and dimethyl carbonate, promptly, and continue stirring and heating for 4 hours. Take a sample when no fraction is distilled off, and perform the first hydroxyl value test using the N-methylaminopyridine-catalyzed acetic anhydride method. When the hydroxyl value... When the hydroxyl value is 0, 141.8 g (1.2 mol) of 1,6-hexanediol and 125.0 g (1.2 mol) of 1,5-pentanediol at 80℃ are added dropwise to the reactor at a rate of 500-600 g / h using a constant pressure feeding system. After the addition is complete, the mixture is heated to 130℃ and refluxed for 5 hours. The temperature is gradually increased to 230℃ at a rate of 5-20℃ / h, and the distillation temperature at the top of the distillation tube is controlled at 61-65℃ to distill off the second byproduct, methanol, and the reaction is controlled to promote the forward reaction. The hydroxyl value is tested again. When the hydroxyl value is 10-300 mg KOH / g, the mixture is then distilled under reduced pressure for 3 hours at a pressure ≤5 kPa. After cooling to 50℃, liquid block copolymer polycarbonate polyol is obtained with a yield of 96.5%.

[0073] The block copolymer polycarbonate polyol has a hydroxyl value of 54.9 mgKOH / g, an acid value of 0.039 mgKOH / g, a molecular weight distribution (PD) of 1.5509, an average molecular weight of 2044 g / mol, and a hue (ColorAPHA / 75℃) of 15.

[0074] Example 4

[0075] 330.2 g (0.330 mol) of polypropylene carbonate diol (structural formula B1, molecular weight approximately 1000 g / mol) and 319.7 g (3.55 mol) of dimethyl carbonate were added to a dry reactor, and argon gas was introduced to purge the air from the reactor. Then, 275 mg (0.435 mmol) of dibutyltin dilaurate was added, and the heating and stirring system was turned on under an argon atmosphere. The reactor temperature was raised to 130 °C under normal pressure. During stirring, the temperature at the top of the reactor was controlled at 62–65 °C. The azeotrope of the first byproduct, methanol and dimethyl carbonate, was distilled off and removed in time. The reaction was continued with stirring and heating for 1 hour. When no distillate was distilled off, a sample was taken, and the first hydroxyl value test was performed using the N-methylaminopyridine-catalyzed acetic anhydride method. When the hydroxyl value is 0, 141.8 g (1.2 mol) of 1,6-hexanediol and 125.0 g (1.2 mol) of 1,5-pentanediol at 80°C are added dropwise to the reactor at a rate of 500–600 g / h using a constant pressure feeding system. After the addition is complete, the mixture is heated to 130°C and refluxed for 5 hours. The temperature is gradually increased to 230°C at a rate of 5–20°C / h, and the distillation temperature at the top of the distillation tube is controlled at 61–65°C to distill off the second byproduct, methanol, and the reaction is controlled to proceed in the forward direction. The hydroxyl value is tested again. When the hydroxyl value is 10–300 mg KOH / g, the mixture is then distilled under reduced pressure for 2 hours at a pressure ≤5 kPa. After cooling to 50°C, liquid block copolymer polycarbonate polyol is obtained with a yield of 96.7%.

[0076] The block copolymer polycarbonate polyol has a hydroxyl value of 55.4 mgKOH / g, an acid value of 0.028 mgKOH / g, a molecular weight distribution (PD) of 1.5713, an average molecular weight of 2025 g / mol, and a hue (ColorAPHA / 75℃) of 12.

[0077] Example 5

[0078] 172.7 g (0.345 mol) of polypropylene carbonate diol (structural formula B1, molecular weight approximately 500 g / mol) and 328.9 g (3.65 mol) of dimethyl carbonate were added to a dry reactor, and argon gas was introduced to purge the air from the reactor. Then, 231 mg (0.366 mmol) of dibutyltin dilaurate was added, and the heating and stirring system was turned on under an argon atmosphere. The reactor temperature was raised to 130 °C under normal pressure. During stirring, the temperature at the top of the reactor was controlled at 62–65 °C. The azeotrope of the first byproduct, methanol and dimethyl carbonate, was distilled off and removed in time. The reaction was continued with stirring and heating for 1 hour. When no distillate was distilled off, a sample was taken, and the first hydroxyl value test was performed using the N-methylaminopyridine-catalyzed acetic anhydride method. When the hydroxyl value is 0, 141.8 g (1.2 mol) of 1,6-hexanediol and 125.0 g (1.2 mol) of 1,5-pentanediol at 80°C are added dropwise to the reactor at a rate of 500–600 g / h using a constant pressure feeding system. After the addition is complete, the mixture is heated to 130°C and refluxed for 5 hours. The temperature is gradually increased to 230°C at a rate of 5–20°C / h, and the distillation temperature at the top of the distillation tube is controlled at 61–65°C to distill off the second byproduct, methanol, and the reaction is controlled to promote the forward reaction. The hydroxyl value is tested again. When the hydroxyl value is 10–300 mg KOH / g, the mixture is then distilled under reduced pressure for 3 hours at a pressure ≤5 kPa. After cooling to 50°C, liquid block copolymer polycarbonate polyol is obtained with a yield of 96.7%.

[0079] The block copolymer polycarbonate polyol has a hydroxyl value of 37.9 mg KOH / g, an acid value of 0.028 mg KOH / g, a molecular weight distribution (PD) of 1.8243, an average molecular weight of 2960 g / mol, and a color (Color APHA / 75℃) of 12.

[0080] Example 6

[0081] 169.7 g (0.170 mol) of polypropylene carbonate diol (structural formula B2, molecular weight approximately 1000 g / mol) and 308.1 g (3.42 mol) of dimethyl carbonate were added to a dry reactor, and argon gas was introduced to purge the air from the reactor. Then, 224 mg (1.993 mmol) of triethylenediamine was added, and the heating and stirring system was turned on under an argon atmosphere. The reactor temperature was raised to 130 °C under normal pressure, and the temperature at the top of the reactor was controlled at 62–65 °C during stirring. The azeotrope of the first byproduct, methanol and dimethyl carbonate, was promptly distilled off and removed. The reaction was continued with stirring and heating for 5 hours. When no fraction was distilled off, a sample was taken, and the first hydroxyl value test was performed using the N-methylaminopyridine-catalyzed acetic anhydride method. When the hydroxyl value... When the hydroxyl value is 0, 141.8 g (1.2 mol) of 1,6-hexanediol and 125.0 g (1.2 mol) of 1,5-pentanediol at 80℃ are added dropwise to the reactor at a rate of 500–600 g / h using a constant pressure feeding system. After the addition is complete, the mixture is heated to 130℃ and refluxed for 5 hours. The temperature is gradually increased to 230℃ at a rate of 5–20℃ / h, and the distillation temperature at the top of the distillation tube is controlled at 61–65℃ to distill off the second byproduct, methanol, and the reaction is controlled to promote the forward reaction. The hydroxyl value is tested again. When the hydroxyl value is 10–300 mg KOH / g, the mixture is then distilled under reduced pressure for 3 hours at a pressure ≤5 kPa. After cooling to 50℃, liquid block copolymer polycarbonate polyol is obtained with a yield of 96.9%.

[0082] The block copolymer polycarbonate polyol has a hydroxyl value of 37.8 mg KOH / g, an acid value of 0.039 mg KOH / g, a molecular weight distribution (PD) of 1.7869, an average molecular weight of 2968 g / mol, and a hue (Color APHA / 75℃) of 15.

[0083] Example 7

[0084] 322.6 g (0.323 mol) of polypropylene carbonate diol (structural formula B1, molecular weight approximately 1000 g / mol) and 338.1 g (3.75 mol) of dimethyl carbonate were added to a dry reactor, and argon gas was introduced to purge the air from the reactor. Then, 291 mg (1.025 mmol) of tetraisopropyl titanate was added, and the heating and stirring system was turned on under an argon atmosphere. The reactor temperature was raised to 130 °C under normal pressure, and the temperature at the top of the reactor was controlled at 62–65 °C during stirring. The azeotrope of the first byproduct, methanol and dimethyl carbonate, was promptly distilled off and removed. The reaction was continued with stirring and heating for 2 hours. When no fraction was distilled off, a sample was taken, and the first hydroxyl value test was performed using the N-methylaminopyridine-catalyzed acetic anhydride method. When the hydroxyl value... When the hydroxyl value is 0, 141.8 g (1.2 mol) of 1,6-hexanediol and 125.0 g (1.2 mol) of 1,5-pentanediol at 80℃ are added dropwise to the reactor at a rate of 500-600 g / h using a constant pressure feeding system. After the addition is complete, the mixture is heated to 130℃ and refluxed for 6 hours. The temperature is gradually increased to 230℃ at a rate of 5-20℃ / h, and the distillation temperature at the top of the distillation tube is controlled at 61-65℃ to distill off the second byproduct, methanol, and the reaction is controlled to promote the forward reaction. The hydroxyl value is tested again. When the hydroxyl value is 10-300 mg KOH / g, the mixture is then distilled under reduced pressure for 4 hours at a pressure ≤5 kPa. After cooling to 50℃, liquid block copolymer polycarbonate polyol is obtained with a yield of 97.2%.

[0085] The block copolymer polycarbonate polyol has a hydroxyl value of 28.6 mgKOH / g, an acid value of 0.027 mgKOH / g, a molecular weight distribution (PD) of 1.7407, an average molecular weight of 4095 g / mol, and a hue (ColorAPHA / 75℃) of 16.

[0086] Example 8

[0087] Add 318.5 g (0.159 mol) of polypropylene carbonate diol (structural formula B2, molecular weight approximately 2000 g / mol) and 318.4 g (3.53 mol) of dimethyl carbonate to a dry reactor, and purge the air from the reactor with argon gas. Then add 272 mg (0.800 mmol) of tetrabutyl titanate, turn on the heating and stirring system under an argon atmosphere, and raise the reactor temperature to 130°C under normal pressure. During stirring, maintain the temperature at the top of the reactor at 62–65°C. Distill off the azeotrope of the first byproduct, methanol and dimethyl carbonate, promptly, and continue stirring and heating for 1 hour. Take a sample when no fraction is distilled off, and perform the first hydroxyl value test using the N-methylaminopyridine-catalyzed acetic anhydride method. When the hydroxyl value... When the hydroxyl value is 0, 141.8 g (1.2 mol) of 1,6-hexanediol and 125.0 g (1.2 mol) of 1,5-pentanediol at 80℃ are added dropwise to the reactor at a rate of 500–600 g / h using a constant pressure feeding system. After the addition is complete, the mixture is heated to 130℃ and refluxed for 5 hours. The temperature is gradually increased to 230℃ at a rate of 5–20℃ / h, and the distillation temperature at the top of the distillation tube is controlled at 61–65℃ to distill off the second byproduct, methanol, and the reaction is controlled to promote the forward reaction. The hydroxyl value is tested again. When the hydroxyl value is 10–300 mg KOH / g, the mixture is then distilled under reduced pressure for 3 hours at a pressure ≤5 kPa. After cooling to 50℃, liquid block copolymer polycarbonate polyol is obtained with a yield of 97.3%.

[0088] The block copolymer polycarbonate polyol has a hydroxyl value of 27.4 mgKOH / g, an acid value of 0.027 mgKOH / g, a molecular weight distribution (PD) of 1.7510, an average molecular weight of 4095 g / mol, and a hue (ColorAPHA / 75℃) of 11.

[0089] Comparative Example 1

[0090] This comparative example uses SYHP1000 polycarbonate diol from Shanghai Shuyu Chemical Co., Ltd., which has a molecular weight of 1000 g / mol and is obtained by copolymerization of 1,6-hexanediol and 1,5-pentanediol as soft chains.

[0091] Comparative Example 2

[0092] This comparative example uses SYHP2000 polycarbonate diol from Shanghai Shuyu Chemical Co., Ltd., which has a molecular weight of 2000 g / mol and is obtained by copolymerization of 1,6-hexanediol and 1,5-pentanediol as soft chains.

[0093] Application Example 1

[0094] Polyurethane 1 was synthesized using the block copolymer polycarbonate polyol with a molecular weight of 1018 g / mol prepared in Example 1 (hereinafter referred to as PCDL-1) as a raw material, and the steps are as follows:

[0095] 10.18 g of PCDL-1 and 7.51 g of diphenylmethane diisocyanate were mixed and reacted at 80 °C for 5 h to obtain a prepolymer. Then, 33 mL of dimethylformamide was added as a solvent to disperse the prepolymer. Subsequently, 0.01 g of stannous octoate catalyst and 1.80 g of 1,4-butanediol were added, and the mixture was reacted at 70 °C for 1 h to form a film. The film was placed in a dryer and dried at 120 °C for 2 h to obtain polyurethane 1.

[0096] Application Example 2

[0097] Polyurethane 2 was prepared using the block copolymer polycarbonate diol with a molecular weight of 2036 g / mol prepared in Example 2 (hereinafter referred to as PCDL-2) as the raw material, and the steps are as follows:

[0098] 20.36 g of PCDL-2 and 7.51 g of diphenylmethane diisocyanate were mixed and reacted at 80 °C for 5 h to obtain a prepolymer. Then, 50 mL of dimethylformamide was added as a solvent to disperse the prepolymer. Subsequently, 0.015 g of stannous octoate catalyst and 1.80 g of 1,4-butanediol were added, and the mixture was reacted at 70 °C for 1 h to form a film. Finally, the film was placed in a dryer and dried at 120 °C for 2 h to obtain polyurethane 2.

[0099] Application Example 3

[0100] Polyurethane 2 was prepared using the block copolymer polycarbonate diol with a molecular weight of 2044 g / mol prepared in Example 3 (hereinafter referred to as PCDL-3) as the raw material, and the steps are as follows:

[0101] 20.44 g of PCDL-3 was mixed with 7.51 g of diphenylmethane diisocyanate and reacted at 80 °C for 5 h to obtain a prepolymer. Then, 50 mL of dimethylformamide was added as a solvent to disperse the prepolymer. Subsequently, 0.015 g of stannous octoate catalyst and 1.80 g of 1,4-butanediol were added, and the mixture was reacted at 70 °C for 1 h to form a film. Finally, the film was placed in a dryer and dried at 120 °C for 2 h to obtain polyurethane 3.

[0102] Application Example 4

[0103] Polyurethane 2 was prepared using the block copolymer polycarbonate diol with a molecular weight of 2044 g / mol prepared in Example 4 (hereinafter referred to as PCDL-4) as the raw material, and the steps are as follows:

[0104] 20.25 g of PCDL-4 and 7.51 g of diphenylmethane diisocyanate were mixed and reacted at 80 °C for 5 h to obtain a prepolymer. Then, 50 mL of dimethylformamide was added as a solvent to disperse the prepolymer. Subsequently, 0.015 g of stannous octoate catalyst and 1.80 g of 1,4-butanediol were added, and the mixture was reacted at 70 °C for 1 h to form a film. Finally, the film was placed in a dryer and dried at 120 °C for 2 h to obtain polyurethane 4.

[0105] Comparative Application Example 1

[0106] Comparative Polyurethane 1 was synthesized using polycarbonate diol (hereinafter referred to as SYHP1000) with a molecular weight of 1000 g / mol as the raw material. The steps are as follows:

[0107] 10.0 g of SYHP1000 and 7.51 g of diphenylmethane diisocyanate were mixed and reacted at 80 °C for 5 h to obtain a prepolymer. Then, 33 mL of dimethylformamide was added as a solvent to disperse the prepolymer. Subsequently, 0.01 g of stannous octoate catalyst and 1.80 g of 1,4-butanediol were added, and the mixture was reacted at 70 °C for 1 h to form a film. Finally, the film was placed in a dryer and dried at 120 °C for 2 h to obtain comparative polyurethane 1.

[0108] Comparative Application Example 2

[0109] Comparative Polyurethane 2 was synthesized using polycarbonate diol (hereinafter referred to as SYHP2000) with a molecular weight of 2000 g / mol as the raw material. The steps are as follows:

[0110] 20.0 g of SYHP2000 and 7.51 g of diphenylmethane diisocyanate were mixed and reacted at 80 °C for 5 h to obtain a prepolymer. Then, 50 mL of dimethylformamide was added as a solvent to disperse the prepolymer. Subsequently, 0.015 g of stannous octoate catalyst and 1.80 g of 1,4-butanediol were added, and the mixture was reacted at 70 °C for 1 h to form a film. Finally, the film was placed in a dryer and dried at 120 °C for 2 h to obtain comparative polyurethane 2.

[0111] Performance tests were conducted on the products obtained from test cases 1-4 and comparative application examples 1-2, respectively, and the test methods were in accordance with GB / T531.1-2008, ISO527 and ISO34. Among them, the test conditions for the retention rate of tensile strength after aging included the following: (1) Heat resistance test: heating in an oven at 120℃ for 50 days; (2) Water resistance test: immersion in water at 80℃ for 60 days; (3) Oil resistance test: immersion in CS150 at 100℃ for 30 days; (4) Weather resistance test: exposure to radiation of 35Wm 2 / nm, black mark temperature 62~68℃, drying for 102min followed immediately by water spraying for 18min, repeated for 200h. The test results are shown in Table 1:

[0112] Table 1 shows the performance test results of polyurethane in Application Examples 1-4 and Comparative Application Examples 1-2.

[0113]

[0114] As shown in Table 1, the mechanical strength, hydrolysis resistance, solvent resistance, heat fading resistance, scratch resistance, and weather resistance of the polyurethanes prepared in Examples 1-4 are basically consistent with or better than those of the comparative examples 1-2. It can be seen that by using polycarbonate diols to replace part of the aliphatic diols in the preparation of block copolymer polycarbonate polyols, the present invention can achieve performance that is basically consistent with or better than that of similar aliphatic polycarbonate polyols; at the same time, it reduces the use of expensive aliphatic diols, greatly reducing the production cost of block copolymer polycarbonate polyols, and has broad market application prospects.

[0115] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A block copolymerized polycarbonate polyol having a structure shown in Formula I: wherein x, y and z are independently integers greater than or equal to 1; A has a structure shown in Formula A1, A2 or A3: wherein m and n are independently integers greater than or equal to 1. The block copolymerized polycarbonate polyol has a hydroxyl value of 10 to 300 mgKOH / g and an average molecular weight of 370 to 11200 g / mol. R1, R2, R3, and R4are independently -(CH2) c - 2 < c < 8, c is an integer; 3.A method for preparing the block copolymerized polycarbonate polyol according to claim 1 or 2, comprising the following steps: mixing an organic carbonate, a polycarbonate diol and a catalyst to perform a transesterification reaction to obtain a transesterification product system; mixing the transesterification product system and an aliphatic diol to perform a transesterification polycondensation reaction to obtain the block copolymerized polycarbonate polyol; wherein the polycarbonate diol has a structure shown in Formula B1, B2 or B3: wherein m and n are defined as in Formula A1, A2 and A3; the aliphatic diol has a carbon atom number of 2 to 8; the ratio of the total amount of substance of the polycarbonate diol and the aliphatic diol to the amount of substance of the organic carbonate is 1:1.05 to 1.5; and the molar ratio of the polycarbonate diol to the aliphatic diol is 1:1 to 130. The organic carbonate includes one or more of dimethyl carbonate, diethyl carbonate, dipropyl carbonate and diphenyl carbonate.

2. The block copolymeric polycarbonate polyol of claim 1, wherein, The catalyst includes one or more of an alkaline substance catalyst, an organic titanium compound catalyst, an organic tin compound catalyst and an organic amine compound catalyst. The aliphatic diol includes one or more of ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol and 1,7-heptanediol. The transesterification reaction is performed under reflux conditions, and the transesterification reaction time is 1 to 6 h. The transesterification polycondensation reaction includes: heating the mixture of the transesterification product system and the aliphatic diol from a starting temperature to a terminal temperature; the starting temperature is 100 to 140℃, the terminal temperature is 140 to 240℃, and the heating rate is 5 to 20℃ / h. 9.A method for preparing a polyurethane, comprising the following steps: mixing a block copolymerized polycarbonate polyol with diphenylmethane diisocyanate to perform a nucleophilic addition reaction to obtain a prepolymer; mixing stannous octoate and 1,4-butanediol with the prepolymer to perform a chain extension reaction to obtain the polyurethane; wherein the block copolymerized polycarbonate polyol is the block copolymerized polycarbonate polyol according to any one of claims 1 to 2 or prepared by the method according to any one of claims 3 to 8. 10.The polyurethane prepared by the method according to claim 9. ​ 4. The preparation method according to claim 3, characterized in that, ​ 5. The production method according to claim 3 or 4, characterized by, ​ 6. The preparation method according to claim 3, characterized in that, ​ 7. The production method according to claim 3 or 4, characterized by, ​ 8. The production method according to claim 3 or 6, characterized by, ​ ​ ​ ​ ​ ​ ​

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