Preparation method of polyether polyol

Abstract

The invention relates to the technical field of chemical industry, and provides a preparation method of polyether polyol, which comprises the following steps: polymerizing an initiator and alkylene oxide under the catalysis of a catalyst to form polyether polyol; the catalyst comprises an inorganic catalyst and a guanidino benzimidazole compound, and the mass ratio of the inorganic catalyst to the guanidino benzimidazole compound is (1: 5)-(5: 1). According to the technical scheme, the problems of unstable hydroxyl value and non-uniform index distribution of polyether polyol in related technologies are solved.

Description

Technical Field

[0001] The invention relates to the technical field of chemical industry, and in particular to a method for preparing polyether polyol. Background Art

[0002] In the modern industrial field, the performance and quality of materials are of vital importance. As an important chemical raw material, polyether polyols are widely used in many fields such as polyurethane, coatings, adhesives, etc. The traditional preparation method of polyether polyols may have certain limitations in terms of product performance. On the one hand, the instability of hydroxyl value is one of the outstanding problems of current polyether polyols. The fluctuation of hydroxyl value will directly affect the performance of polyether polyols, such as reactivity, viscosity, hardness, etc. In practical applications, unstable hydroxyl value may make product quality difficult to control, affecting the performance and service life of the final product; on the other hand, the index distribution problem also plagues the production of polyether polyols. The uneven index distribution will lead to a wide molecular weight distribution of polyether polyols, which will in turn affect its physical and chemical properties. Polyether polyols with a wide molecular weight distribution may have problems such as inconsistent reaction rate and phase separation during the reaction process, affecting the performance and processing technology of the product. In addition, the index distribution problem may also lead to a decrease in the storage stability of polyether polyols and increase the risk of products during storage and transportation. Therefore, a preparation method of polyether polyols is proposed, which is of great significance for solving the current problems of unstable hydroxyl value and uneven index distribution of polyether polyols to meet market demand. Summary of the invention

[0003] The invention provides a method for preparing a polyether polyol, which solves the problems of unstable hydroxyl value and uneven index distribution of the polyether polyol in the related art.

[0004] The technical scheme of the present invention is as follows: The present invention provides a method for preparing a polyether polyol, comprising the following steps: polymerizing an initiator and an alkylene oxide under the catalysis of a catalyst to form a polyether polyol; The catalyst comprises an inorganic catalyst and a guanidinobenzimidazole compound, and the mass ratio of the inorganic catalyst to the guanidinobenzimidazole compound is 1:5 to 5:1.

[0005] As a further technical solution, the mass ratio of the inorganic catalyst to the guanidinobenzimidazole compound is 2:1~2.

[0006] As a further technical solution, the guanidinobenzimidazole compound includes one or more of 2-guanidinobenzimidazole, (5-methyl-1H-benzimidazole-2-yl)-guanidine, and 2-(5,6-dimethyl-1H-benzimidazole-2-yl)guanidine.

[0007] As a further technical solution, the inorganic catalyst includes one or more of sodium carbonate, potassium carbonate, and lithium carbonate.

[0008] As a further technical solution, the inorganic catalyst is a supported catalyst, the carrier is sepiolite, and the precursor of the active component is one or more of sodium carbonate, lithium carbonate, and potassium carbonate.

[0009] As a further technical solution, the precursor of the active component is composed of sodium carbonate and lithium carbonate, and the mass ratio of sodium element to lithium element in the precursor of the active component is 3:1~2.

[0010] In the present invention, sodium carbonate and lithium carbonate are used as precursors of active components to prepare a supported catalyst, which promotes uniform dispersion of active components, reduces agglomeration and stability, facilitates catalyst recovery, and improves hydroxyl value stability and index distribution uniformity of polyether polyols.

[0011] In the present invention, the mass ratio of sodium element to lithium element in the supported catalyst is adjusted, the alkalinity strength of the catalyst is adjusted, the catalytic reaction rate is controlled, the product quality of the polyether polyol is improved, and the hydroxyl value stability and index distribution uniformity of the polyether polyol are promoted.

[0012] As a further technical solution, the preparation method of the supported catalyst comprises the following steps: dispersing sepiolite in a precursor solution of an active component, heating and stirring to impregnate and load the solution, and calcining the solution to obtain the supported catalyst.

[0013] As a further technical solution, the temperature of the heating and stirring is 30-100° C., the temperature of the roasting is 450-550° C., and the time of the roasting is 1-3 hours.

[0014] As a further technical solution, the initiator includes any one of ethylene glycol, propylene glycol, and glycerol.

[0015] As a further technical solution, the alkylene oxide includes any one of ethylene oxide, propylene oxide and butylene oxide.

[0016] The working principle and beneficial effects of the present invention are: In the present invention, an inorganic catalyst and a guanidinobenzimidazole compound are added as a catalyst at the same time, and the mass ratio of the two is adjusted to exert the synergistic effect of the two, adjust the catalytic activity of the catalyst, stabilize the reaction intermediates, guide the polymerization reaction to proceed in an orderly manner, promote the efficient and stable polymerization reaction, and enhance the hydroxyl value stability and index distribution uniformity of the polyether polyol. DETAILED DESCRIPTION

[0017] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] In the following examples and comparative examples: Sepiolite: particle size is 200 mesh.

[0019] Example 1 A preparation method of polyether polyol comprises the following steps: adding 100 mL of propylene glycol and 5 g of a catalyst into an autoclave, stirring and heating to 110° C., evacuating to a vacuum degree of -0.1 MPa, introducing 850 g of ethylene oxide into the autoclave, setting the pressure to 0.3 MPa, reacting for 60 minutes, cooling to 80° C., filtering to obtain the polyether polyol; wherein the 5 g of the catalyst consists of an inorganic catalyst and a guanidinobenzimidazole compound in a mass ratio of 3:1, the inorganic catalyst is sodium carbonate, and the guanidinobenzimidazole compound is 2-guanidinobenzimidazole.

[0020] Example 2 A preparation method of polyether polyol comprises the following steps: adding 100 mL of propylene glycol and 5 g of a catalyst into an autoclave, stirring and heating to 120° C., evacuating to a vacuum degree of -0.1 MPa, introducing 850 g of ethylene oxide into the autoclave, setting the pressure to 0.4 MPa, reacting for 45 minutes, cooling to 80° C., filtering to obtain the polyether polyol; wherein the 5 g of the catalyst consists of an inorganic catalyst and a guanidinobenzimidazole compound in a mass ratio of 3:1, and the guanidinobenzimidazole compound is 2-guanidinobenzimidazole.

[0021] Example 3 A preparation method of a polyether polyol comprises the following steps: adding 100 mL of propylene glycol and 5 g of a catalyst into an autoclave, stirring and heating to 130° C., evacuating to a vacuum degree of -0.1 MPa, introducing 850 g of ethylene oxide into the autoclave, setting a pressure of 0.5 MPa, reacting for 30 minutes, cooling to 80° C., and filtering to obtain the polyether polyol; wherein the 5 g of the catalyst consists of an inorganic catalyst and a guanidinobenzimidazole compound in a mass ratio of 3:1, the inorganic catalyst is sodium carbonate, and the guanidinobenzimidazole compound is 2-guanidinobenzimidazole.

[0022] Example 4 Compared with Example 1, the difference of Example 4 is that 5 g of the catalyst is composed of an inorganic catalyst and a guanidinobenzimidazole compound in a mass ratio of 2:1.

[0023] Example 5 Compared with Example 1, the difference of Example 5 is that 5 g of the catalyst is composed of an inorganic catalyst and a guanidinobenzimidazole compound in a mass ratio of 2:2.

[0024] Example 6 Compared with Example 1, the difference of Example 6 is that 5 g of the catalyst is composed of an inorganic catalyst and a guanidinobenzimidazole compound in a mass ratio of 2:3.

[0025] Example 7 Compared with Example 5, Example 7 is different in that 2-guanidinobenzimidazole is replaced by an equal amount of (5-methyl-1H-benzimidazol-2-yl)-guanidine.

[0026] Example 8 The preparation method of the supported catalyst comprises the following steps: dissolving sodium carbonate in 500 mL of water to prepare a solution containing 5 wt% of sodium element, dispersing 100 g of sepiolite in the sodium ion solution, heating to 100° C., stirring and impregnating the supported catalyst until the solvent is completely evaporated, and calcining at 550° C. for 3 hours to obtain the supported catalyst.

[0027] Compared with Example 7, the difference of Example 8 is that the inorganic catalyst is a supported catalyst obtained by the above preparation method.

[0028] Example 9 Compared with Example 8, the difference of Example 9 is that sodium carbonate is replaced by lithium carbonate, and a solution containing 5 wt% of lithium element is prepared.

[0029] Example 10 Compared with Example 9, the difference of Example 10 is that sodium carbonate is partially replaced with lithium carbonate to prepare a mixed solution containing 3.75 wt% of sodium element and 1.25 wt% of lithium element.

[0030] Embodiment 11 Compared with Example 9, the difference of Example 11 is that sodium carbonate is partially replaced with lithium carbonate to prepare a mixed solution containing 3wt% of sodium element and 2wt% of lithium element.

[0031] Comparative Example 1 Compared with Example 1, Comparative Example 1 is different in that the catalyst is only an inorganic catalyst.

[0032] Comparative Example 2 Compared with Example 1, the difference of Comparative Example 2 is that the catalyst is only 2-guanidinobenzimidazole.

[0033] The polyether polyols prepared in Examples 1 to 11 and Comparative Examples 1 to 2 were tested according to the following method: 1. Hydroxyl value: According to the test method A specified in GB / T 12008.3-2009 "Plastic polyether polyols Part 3: Determination of hydroxyl value", the hydroxyl value of the test sample is tested.

[0034] 2. Distribution index D: D = weight average molecular weight / number average molecular weight. The weight average molecular weight can be replaced by the viscosity average molecular weight. The number average molecular weight is obtained from the hydroxyl value. The viscosity average molecular weight is calculated as follows: viscosity average molecular weight = anti-log (90.493log-viscosity + 3.0646). The viscosity is determined by test method A specified in GB / T 12008.7-2010 "Plastic polyether polyols Part 7: Determination of viscosity". The viscosity of the sample is tested and the viscosity average molecular weight is calculated, thereby obtaining the distribution index D of the sample.

[0035] The test results are shown in the following table: Table 1 Performance test results of polyether polyols prepared in Examples 1 to 11 and Comparative Examples 1 to 2

[0036] Compared with Example 1, only an inorganic catalyst is added to Comparative Example 1, and only 2-guanidinobenzimidazole is added as a catalyst to Comparative Example 2. As a result, the hydroxyl value and distribution index of Example 1 are both less than those of Comparative Examples 1 and 2, indicating that the inorganic catalyst and 2-guanidinobenzimidazole play a synergistic role and can improve the hydroxyl value stability and index distribution uniformity of the polyether polyol. Compared with Example 1, Examples 4 to 6 add inorganic catalysts and 2-guanidinobenzimidazole in different mass ratios. As a result, the hydroxyl value and distribution index of Examples 4 and 5 are both less than those of Examples 1 and 6, indicating that when the mass ratio of the inorganic catalyst to 2-guanidinobenzimidazole is 2:1 to 2, the hydroxyl value stability and index distribution uniformity of the obtained polyether polyol are better.

[0037] Compared with Example 7, Example 8 adds a supported catalyst, and the hydroxyl value and distribution index of Example 8 are both lower than those of Example 7, indicating that the supported catalyst can improve the hydroxyl value stability and index distribution uniformity of the polyether polyol. Compared with Example 9, Example 10 simultaneously adds sodium carbonate and lithium carbonate as active ingredients, and the hydroxyl value and distribution index of Example 10 are both lower than those of Example 9, indicating that the sodium element and the lithium element play a synergistic role and can improve the hydroxyl value stability and index distribution uniformity of the polyether polyol.

[0038] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a polyether polyol, It is characterized in that The following steps are involved: The initiator and the alkylene oxide are polymerized under the catalysis of the catalyst to form a polyether polyol; the catalyst comprises an inorganic catalyst and a guanidinobenzimidazole compound, and the mass ratio of the inorganic catalyst to the guanidinobenzimidazole compound is 1:5 to 5:

1.

2. A method for preparing a polyether polyol according to claim 1, It is characterized in that The mass ratio of the inorganic catalyst to the guanidinobenzimidazole compound is 2:1-2.

3. A method for preparing a polyether polyol according to claim 1, It is characterized in that The guanidinobenzimidazole compound includes one or more of 2-guanidinobenzimidazole, (5-methyl-1H-benzimidazol-2-yl)-guanidine, and 2-(5,6-dimethyl-1H-benzimidazol-2-yl)guanidine.

4. A method for preparing a polyether polyol according to claim 1, It is characterized in that The inorganic catalyst includes one or more of sodium carbonate, potassium carbonate and lithium carbonate.

5. A method for preparing a polyether polyol according to claim 1, It is characterized in that The inorganic catalyst is a supported catalyst, the carrier is sepiolite, and the precursor of the active component is one or more of sodium carbonate, lithium carbonate and potassium carbonate.

6. A method for preparing a polyether polyol according to claim 5, It is characterized in that The precursor of the active component consists of sodium carbonate and lithium carbonate, and the mass ratio of sodium element to lithium element in the precursor of the active component is 3:1-2.

7. A method for preparing a polyether polyol according to claim 5, It is characterized in that The preparation method of the supported catalyst comprises the following steps: dispersing sepiolite in a precursor solution of an active component, heating and stirring to impregnate and load the solution, and calcining the solution to obtain the supported catalyst.

8. A method for preparing a polyether polyol according to claim 7, It is characterized in that The temperature of the heating and stirring is 30-100° C., the temperature of the roasting is 450-550° C., and the time of the roasting is 1-3 hours.

9. A method for preparing a polyether polyol according to claim 1, It is characterized in that The initiator includes any one of ethylene glycol, propylene glycol and glycerol.

10. The method for preparing a polyether polyol according to claim 1, It is characterized in that The alkylene oxide includes any one of ethylene oxide, propylene oxide and butylene oxide.

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