Diaminonaphthalene-containing polyether polyol, preparation method thereof and rigid polyurethane foam

Abstract

The invention discloses polyether polyol containing diaminonaphthalene, a preparation method of the polyether polyol and rigid polyurethane foam. The polyether polyol containing diaminonaphthalene is obtained through epoxidation synthesis by taking diaminonaphthalene as an initiator, and then polycyclic aromatic hydrocarbon can be introduced to polyurethane molecules through polymerization reaction with isocyanate, so that the obtained polyurethane rigid foam skeleton is more stable in chemical structure and higher in physical strength; the foam is more excellent in temperature resistance and dimensional stability.

Description

Technical Field

[0001] The invention belongs to the field of polyurethane rigid foam materials, and particularly relates to a diaminonaphthalene-containing polyether polyol, a preparation method thereof, and application of the polyol in polyurethane rigid foam. Background Art

[0002] Polyurethane rigid foam is made by mixing and foaming polyols, isocyanates, catalysts, foaming agents, foam stabilizers and other additives. It contains a large number of closed cells inside. It has the advantages of in-situ foaming, durability, and low thermal conductivity. It is currently one of the most widely used materials in the field of thermal insulation.

[0003] The general upper temperature limit for the use of polyurethane rigid foam is 100°C. Above this temperature, the foam is prone to dimensional deformation and even carbonization, resulting in increased thermal conductivity, even insulation failure, increased energy consumption, and a shortened service life. In centralized heating applications, polyurethane rigid foam is required to withstand temperatures of 130-140°C and operate stably in this high-temperature environment for more than 30 years. Therefore, very high requirements are placed on the heat resistance of polyurethane rigid foam. In order to ensure the thermal insulation quality of polyurethane foam in high-temperature environments and expand the practical application range of polyurethane foam, more detailed research and optimization of the heat resistance of polyurethane foam is very necessary.

[0004] CN107353385A discloses a method for preparing a heat-resistant and thermodynamically stable polyurethane rigid foam by polycondensing polyisocyanates in bulk polymerization to produce an isocyanate chemical containing a highly heat-resistant carbodiimide structure. This is then combined with a high-temperature-resistant, high-strength polyhedral oligomeric silsesquioxane and a macromolecular polyol as a polyurethane soft segment. However, this preparation method requires two steps, making it inefficient and unwieldy in practical applications.

[0005] CN103613737B discloses a high-temperature resistant polyurethane foam and a preparation method thereof. This method incorporates hydrophobic SiO2 with an average particle size of 7 μm as a filler, resulting in foam with significantly improved heat resistance and mechanical strength. However, the introduction of SiO2 filler places high demands on the polyurethane foaming equipment, which can easily cause equipment wear and shorten its service life.

[0006] Therefore, in view of the above problems, it is hoped to synthesize a high-temperature resistant polyether polyol to simply and efficiently improve the temperature resistance of polyurethane foam. Summary of the Invention

[0007] The present invention provides a diaminonaphthalene-containing polyether polyol, a preparation method thereof, and a polyurethane rigid foam. The diaminonaphthalene-containing polyether polyol is synthesized using diaminonaphthalene as an initiator through epoxidation, and then undergoes a polymerization reaction with isocyanate to introduce polycyclic aromatic hydrocarbons into the polyurethane molecules, thereby making the foam skeleton chemically more stable, increasing physical strength, and exhibiting superior temperature resistance and dimensional stability.

[0008] The technical solution adopted in the present invention is as follows:

[0009] In the first aspect, the present invention provides a diaminonaphthalene polyether polyol, the structural formula of which is shown as follows:

[0010]

[0011] Wherein, n is any integer between 2 and 6, such as 2, 3, 4, 5, or 6.

[0012] The diaminonaphthalene-containing polyether polyol of the present invention preferably has an average hydroxyl value of 150 to 400 mgKOH / g, more preferably 200 to 360 mgKOH / g, and a functionality of 4.

[0013] In a second aspect, the present invention provides a method for preparing the above-mentioned diaminonaphthalene-containing polyether polyol.

[0014] A method for preparing a diaminonaphthalene-containing polyether polyol comprises the following steps: performing an etherification reaction on 1,8-diaminonaphthalene and alkylene oxide to obtain the polyether polyol; the molar ratio of 1,8-diaminonaphthalene to alkylene oxide is 1:8 to 1:18.

[0015] As a preferred embodiment, in the method of the present invention, the alkylene oxide is propylene oxide;

[0016] As a preferred embodiment, the method of the present invention is carried out in the presence of an inert gas, such as nitrogen;

[0017] As a preferred embodiment, the method of the present invention adds a catalyst during the reaction, wherein the catalyst selected is KOH, and the addition amount is 0.8-1.5 wt% of 1,8-diaminonaphthalene;

[0018] As a preferred embodiment, the method of the present invention is carried out under a certain pressure, wherein the pressure is a relative pressure of 0.2 to 0.3 MPa;

[0019] As a preferred embodiment, the method of the present invention, propylene oxide is added gradually in multiple times, such as 2 times or 3 times, the reaction time is 3 to 5 hours, and the reaction temperature is 80 to 160° C., preferably 100 to 130° C.;

[0020] As a preferred embodiment, the method of the present invention is subjected to a crude treatment after the reaction is completed, comprising the following steps: adding an appropriate amount of phosphoric acid to the product for neutralization, adjusting the pH to 5-7, adding an aluminum silicate adsorbent in an amount of 0.1-0.5% of the total weight of the polyether after the pH is measured to be qualified, cooling to 80-100°C, filtering, and collecting the filtrate to obtain a crude polyether polyol; as a preferred embodiment, the method of the present invention is subjected to a refining treatment, such as a dehydration treatment, after the crude treatment, comprising the following steps: removing water, unreacted propylene oxide and other by-products under a vacuum environment of 80-100°C.

[0021] The rough treatment and refining described in the present invention are both technical solutions commonly used in the field of polyether polyol preparation, and the present invention has no special limitation thereto.

[0022] In a third aspect, the present invention provides the use of the above-mentioned diaminonaphthalene polyether polyol in the preparation of polyurethane rigid foam: a polyurethane rigid foam, comprising the following components: in parts by mass,

[0023]

[0024] The polyether polyol composition of the present invention comprises the following components: based on the polyether polyol composition, in parts by mass:

[0025] Contains 5-35 parts of diaminonaphthalene polyether polyol, preferably 10-20 parts;

[0026] 30-55 parts of sucrose polyether polyol, preferably 35-50 parts;

[0027] 5 to 30 parts of propylene glycol polyether polyol, preferably 10 to 25 parts.

[0028] The sucrose polyether polyol of the present invention is obtained by ring-opening polymerization of sucrose as an initiator and propylene oxide, has a hydroxyl value of 300-450 mgKOH / g and a viscosity of 2000-6000 mPa·s (25° C.).

[0029] The propylene glycol polyether polyol of the present invention is obtained by ring-opening polymerization of propylene glycol as an initiator and propylene oxide. The propylene glycol polyether polyol has a hydroxyl value of 60-150 mgKOH / g and a viscosity of 50-200 mPa·s (25° C.).

[0030] The surfactant described in the present invention is a siloxane surfactant, selected from one or more of B84806, LK221, Dongjun H3636, DC193, B8404, and AK8812, preferably B84806.

[0031] The catalyst of the present invention is selected from one or more of bis(dimethylaminoethyl) ether, pentamethyldiethylenetriamine, N,N-dimethylcyclohexylamine, triethylenediamine, 1,4-dimethylpiperazine, potassium isooctanoate, dibutyltin dilaurate, quaternary ammonium formate and potassium acetate.

[0032] The foaming agent of the present invention includes chemical and physical foaming agents, such as water, HCFC, HFC, cyclopentane, isopentane, and other hydrofluorocarbons, fluorocarbons, and alkane foaming agents, preferably HFC, HCFC, water, or cyclopentane, isopentane, and more preferably HFC-245fa foaming agent.

[0033] The isocyanate described in the present invention is polymeric MDI (polymethylene polyphenyl polyisocyanate) with an NCO content of 30 to 32 wt%, preferably PM-200 from Wanhua Chemical.

[0034] The preparation method of the polyurethane rigid foam plastic of the present invention comprises the following steps:

[0035] (1) According to a certain formula ratio, a polyether polyol composition, a surfactant, a catalyst and water are mixed, the temperature is controlled at 75-80° C., a foaming agent is added, the stirring speed is 80-100 r / min, and the stirring is carried out for 40-50 minutes to prepare a polyether polyol composition;

[0036] (2) The isocyanate is mixed with the polyether polyol combination material described in (1), sprayed, foamed, and cured to form a polyurethane rigid foam plastic.

[0037] Specifically, the mixing, spraying and foaming of the polyether polyol combination material can adopt existing technologies, and the present invention does not make any special limitations.

[0038] The present invention has the following beneficial effects:

[0039] (1) The rigid polyurethane foam prepared by the present invention has good temperature resistance, high physical strength and good dimensional stability;

[0040] (2) The polyurethane foam preparation method of the present invention adopts a one-step method, which is efficient and convenient;

[0041] (3) The foam produced by the present invention can achieve good performance even at a low density, and the finished product density can reach 60-70 kg / m 3 , radial compression strength ≥ 0.4Mpa, foam is kept at a constant temperature of 160℃ for 72h, mass loss is <4%, and volume expansion is <4.5%. DETAILED DESCRIPTION

[0042] The embodiments of the present invention are further described below with reference to the examples. However, the present invention is not limited to the examples listed, but also includes any other known changes within the scope of the rights claimed by the present invention.

[0043] The raw materials used in the examples and comparative examples are as follows:

[0044] Polyether polyol B: sucrose as initiator, propylene oxide as polymerization monomer, hydroxyl value 410 mgKOH / g, viscosity 3500 mPa·s (25°C), Wanhua Chemical (Yantai) Rongwei Polyurethane Co., Ltd.

[0045] Polyether polyol C: propylene glycol as initiator, propylene oxide as polymerization monomer, hydroxyl value 110 mgKOH / g, viscosity 120 mPa·s, Wanhua Chemical (Yantai) Rongwei Polyurethane Co., Ltd.

[0046] Surfactant: B84806, purchased from Evonik Specialty Chemicals (Shanghai) Co., Ltd.;

[0047] Amine catalysts: bis(dimethylaminoethyl) ether, pentamethyldiethylenetriamine, and triethylenediamine, purchased from Evonik Specialty Chemicals (Shanghai) Co., Ltd.

[0048] Organic metal salt catalyst: potassium 2-ethylhexanoate, Xindian Chemical Materials (Shanghai) Co., Ltd.

[0049] Blowing agent: HFC-245fa, purchased from Honeywell;

[0050] Isocyanate: PM200, Wanhua Chemical Group Co., Ltd.

[0051] Test method:

[0052] The test standard for compressive strength shall be implemented in accordance with GB / T8813-2020;

[0053] The test method for mass change and volume change is as follows: take three cubes with a side length of 5 cm from the core of the polyurethane foam, measure the size and mass of the three sample blocks, then place them in a high temperature environment of 160°C for 72 hours, take out the foam, and measure the size and mass of the three sample blocks again, calculate the volume change and mass change of each sample block before and after treatment, and finally take the average value.

[0054] Preparation Example 1

[0055] Preparation of polyether polyol A1:

[0056] 1) Add 500 g of 1,8-diaminonaphthalene and 5 g of KOH to a reactor, fully replace the atmosphere with nitrogen, and stir;

[0057] 2) The reaction temperature was raised to 100° C., 750 g of propylene oxide was slowly added, and the reaction was continued at 100° C. until the addition of propylene oxide was complete, and then the temperature was raised to 110° C. and matured for 1 hour;

[0058] 3) Raise the temperature to 120° C., add the remaining 750 g of propylene oxide, maintain the reactor pressure at 0.2-0.3 MPa, until the remaining propylene oxide is added; then raise the temperature to 120-125° C. and continue aging for 2-3 hours;

[0059] 4) adding 7.5 g of phosphoric acid to the reaction product, adjusting the pH to 6 to remove potassium ions from the solution, adding an aluminum silicate adsorbent at a concentration of 0.3% by weight of the total polyether, cooling the mixture to 90° C., and filtering to obtain a crude polyether polyol;

[0060] 5) The crude polyether polyol was evacuated at 90° C. to remove water, unreacted propylene oxide, and other by-products to obtain the final product, polyether polyol A1, wherein n is approximately 2 and the hydroxyl value is measured to be 360 ​​mgKOH / g.

[0061] Preparation Example 2

[0062] Preparation of polyether polyol A2:

[0063] 1) Add 500 g of 1,8-diaminonaphthalene and 5 g of KOH to a reactor, fully replace the atmosphere with nitrogen, and stir;

[0064] 2) Raise the reaction temperature to 100°C, slowly add 1500g of propylene oxide, react at 100°C until the addition of propylene oxide is complete, then raise the temperature to 110°C and mature for 1 hour;

[0065] 3) Raise the temperature to 120° C., add the remaining 1500 g of propylene oxide, maintain the reactor pressure at 0.2-0.3 MPa, until the remaining propylene oxide is added; then raise the temperature to 120-125° C. and continue aging for 2-3 hours;

[0066] 4) Add 7.5 g of phosphoric acid to the reaction product, adjust the pH to 6, remove potassium ions from the solution, add 0.3% of the total weight of the polyether as an aluminum silicate adsorbent, cool to 90° C., and filter to obtain a crude polyether polyol;

[0067] 5) The crude polyether polyol was evacuated at 90° C. to remove water, unreacted propylene oxide, and other by-products to obtain the final product, polyether polyol A2, wherein n is approximately 4 and the hydroxyl value is measured to be 207 mgKOH / g.

[0068] Examples and Comparative Examples

[0069] Preparation of polyurethane rigid foam:

[0070] According to the different proportions of the comparative examples and examples in Table 1, the polyether polyol composition, the surfactant, the catalyst and water were uniformly mixed, and then the foaming agent was added and mixed uniformly to obtain the corresponding combined polyether. The prepared combined polyether and PM200 were respectively added to a material tank and mixed in a certain proportion by a sprayer, and then sprayed on a steel pipe rotating at a uniform speed and cured to form a polyurethane foam. The mixing and foaming conditions were: material temperature 45° C., gauge pressure 700 psi, and the obtained foam properties are shown in Table 2.

[0071] Table 1 Raw materials and weight parts of Examples 1 to 5 and Comparative Example 1

[0072] raw material Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 <![CDATA[Polyether polyol A1]]> 10 20 20 20 0 0 <![CDATA[Polyether polyol A2]]> 0 0 0 0 20 0 Polyether polyol B 50 40 40 40 40 60 Polyether polyol C 25.5 25.5 25.6 25.4 24.5 25.5 B84806 2 2 2 2 2 2 Pentamethyldiethylenetriamine 1 1 1 1 1 1 triethylenediamine 2 2 2 2 3 2 Potassium 2-ethylhexanoate 2 2 2 2 2 2 water 1.5 1.5 1.4 1.6 1.5 1.5 HFC-245fa 6 6 6 6 6 6 PM200 150 150 140 160 150 150

[0073] Table 2 Foam properties of Examples 1 to 5 and Comparative Example 1

[0074] Physical properties Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 <![CDATA[Density kg / m 3 > 60 62 61 60 60 61 Compression strength / Mpa 0.4 0.43 0.41 0.44 0.41 0.35 Mass change / % (160℃, 72h) -3.89 -2.72 -3.54 -2.28 -1.45 -8.45 Volume change / % (160℃, 72h) 2.57 1.96 2.34 1.74 4.47 6.45

[0075] According to Tables 1 and 2, the polyurethane foams prepared in Examples 1 to 5 have significantly lower mass loss and volume expansion rates than those in Comparative Example 1 under high temperature conditions, and are also superior to Comparative Example 1 in terms of compressive strength.

Claims

1. A diaminonaphthalene polyether polyol having the structural formula: in, n is any integer from 2 to 6.

2. The diaminonaphthalene polyether polyol according to claim 1, characterized in that: The average hydroxyl value of the diaminonaphthalene-containing polyether polyol is 150 to 400 mgKOH / g, preferably 200 to 360 mgKOH / g.

3. A method for preparing a diaminonaphthalene polyether polyol, characterized in that: 1,8-diaminonaphthalene and propylene oxide are subjected to etherification reaction to obtain diaminonaphthalene-containing polyether polyol; preferably, the molar ratio of 1,8-diaminonaphthalene to propylene oxide is 1:8 to 1:

18.

4. The preparation method according to claim 3, characterized in that: The etherification reaction is carried out under an inert gas atmosphere at a reaction temperature of 80-160°C, preferably 100-130°C; the reaction pressure is a relative pressure of 0.2-0.3MPa; the reaction time is preferably 3-5h; preferably, KOH is added as a catalyst during the etherification reaction, and the added amount is 0.8-1.5wt% of 1,8-diaminonaphthalene.

5. A polyurethane rigid foam, characterized in that: The composition includes the following: in parts by mass: The polyether polyol composition comprises the following components: Contains 5-35 parts of diaminonaphthalene polyether polyol, preferably 10-20 parts; 30-55 parts of sucrose polyether polyol, preferably 35-50 parts; Propylene glycol polyether polyol 5-30 parts, preferably 10-25 parts; The diaminonaphthalene-containing polyether polyol is the diaminonaphthalene-containing polyether polyol according to any one of claims 1 to 2 or the diaminonaphthalene-containing polyether polyol prepared by the preparation method according to any one of claims 3 to 4.

6. The polyurethane rigid foam according to claim 5, characterized in that The sucrose polyether polyol has a hydroxyl value of 300-450 mgKOH / g and a viscosity of 2000-6000 mPa·s at 25°C; and / or: the propylene glycol polyether polyol has a hydroxyl value of 60-150 mgKOH / g and a viscosity of 50-200 mPa·s at 25°C.

7. The polyurethane rigid foam according to any one of claims 5 to 6, characterized in that: The surfactant is a siloxane surfactant, selected from one or more of B84806, LK221, Dongjun H3636, DC193, B8404, and AK8812.

8. The polyurethane rigid foam according to any one of claims 5 to 7, characterized in that: The catalyst is selected from one or more of bis(dimethylaminoethyl) ether, pentamethyldiethylenetriamine, N,N-dimethylcyclohexylamine, triethylenediamine, 1,4-dimethylpiperazine, potassium isooctanoate, dibutyltin dilaurate, quaternary ammonium formate and potassium acetate.

9. The polyurethane rigid foam according to any one of claims 5 to 8, characterized in that: The isocyanate is polymeric MDI, and the NCO content is preferably 30-32 wt%.

10. A method for preparing a polyurethane rigid foam, characterized in that: The steps include: (1) mixing a polyether polyol composition, a surfactant, a catalyst and water according to a certain formula ratio, and adding a foaming agent to prepare a polyether polyol composition; (2) mixing the isocyanate with the polyether polyol combination material described in (1), spraying, foaming, and curing to form a polyurethane rigid foam; Preferably, the temperature in step (1) is controlled at 75-80°C.

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