A diaminonaphthalene polyether polyol, a method for preparing the same, and a polyurethane rigid foam
By introducing diaminonaphthalene polyether polyol and isocyanate polymerization, a rigid polyurethane foam with high temperature resistance, chemical stability and physical strength was prepared, which solved the problem of temperature resistance of polyurethane foam in high temperature environment and achieved long-term stability and low density foam performance at 160℃.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- WANHUA CHEM NINGBO RONGWEI POLYURETHANE
- Filing Date
- 2024-11-22
- Publication Date
- 2026-05-19
AI Technical Summary
Existing rigid polyurethane foams have insufficient temperature resistance in high-temperature environments, leading to dimensional deformation, carbonization, and increased thermal conductivity, which affects their long-term stability and service life in district heating applications.
Using diaminonaphthalene polyether polyol as raw material, polycyclic aromatic hydrocarbon structures are introduced through epoxidation synthesis and isocyanate polymerization to improve the chemical stability and physical strength of the foam skeleton, and rigid polyurethane foam is prepared in one step.
The prepared polyurethane foam, after being kept at 160℃ for 72 hours, showed a mass loss of less than 4%, a volume expansion of less than 4.5%, a radial compressive strength of ≥0.4 MPa, low density, and excellent performance.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of rigid polyurethane foam materials, specifically relating to a diaminonaphthalene polyether polyol, its preparation method, and its application in rigid polyurethane foam. Background Technology
[0002] Rigid polyurethane foam is prepared by mixing polyols, isocyanates, catalysts, foaming agents, foam stabilizers and other additives. It contains a large number of closed cells and has the advantages of in-situ foaming, durability and low thermal conductivity. It is one of the most widely used materials in the field of thermal insulation.
[0003] Generally, the upper limit of the operating temperature for rigid polyurethane foam is 100℃. Above this temperature, the foam is prone to dimensional deformation and even carbonization, leading to increased thermal conductivity, potential failure of the insulation layer, increased energy consumption, and a shortened service life. In district heating applications, rigid polyurethane foam is required to withstand temperatures of 130-140℃ and operate stably for over 30 years under these conditions. Therefore, extremely high requirements are placed on the temperature resistance of rigid polyurethane foam. To ensure the insulation quality of polyurethane foam in high-temperature environments and expand its practical applications, a more detailed study and optimization of its temperature resistance is essential.
[0004] CN107353385A discloses a method for preparing isocyanate chemicals containing a highly heat-resistant carbodiimide structure by bulk polymerization of polyisocyanates, followed by the composite of high-temperature resistant, high-strength polyhedral oligomeric silsesquioxanes and macromolecular polyols as the soft segments of polyurethane, thus producing a high-temperature resistant and thermodynamically stable rigid polyurethane foam. However, this preparation method requires two steps, which is not simple and efficient enough in practical applications.
[0005] CN103613737B discloses a high-temperature resistant polyurethane foam and its preparation method. This method introduces hydrophobic SiO2 with an average particle size of 7 μm as a filler, resulting in foams with significantly improved temperature resistance and mechanical strength. However, the introduction of SiO2 filler places high demands on the polyurethane foaming equipment, easily causing wear and shortening its service life.
[0006] Therefore, in view of the above problems, it is desirable 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 purpose of this invention is to provide a diaminonaphthalene-containing polyether polyol, its preparation method, and a rigid polyurethane foam. The diaminonaphthalene-containing polyether polyol is synthesized via epoxidation using diaminonaphthalene as an initiator. Further polymerization with isocyanate introduces polycyclic aromatic hydrocarbons into the polyurethane molecules, resulting in a more stable chemical structure and higher physical strength in the foam skeleton. This leads to superior temperature resistance and dimensional stability of the foam.
[0008] The technical solution adopted in this invention is as follows:
[0009] In a first aspect, the present invention provides a polyol containing diaminonaphthalene polyether, the structural formula of which is shown below:
[0010]
[0011] Where n is any integer from 2 to 6, such as 2, 3, 4, 5, 6.
[0012] The diaminonaphthalene polyether polyol of the present invention preferably has an average hydroxyl value of 150-400 mgKOH / g, more preferably 200-360 mgKOH / g, and a functionality of 4.
[0013] Secondly, the present invention provides a method for preparing the above-mentioned diaminonaphthalene polyether polyol.
[0014] A method for preparing a polyol containing diaminonaphthalene ether, specifically, involves an etherification reaction of 1,8-diaminonaphthalene and epoxide alkane, wherein the molar ratio of 1,8-diaminonaphthalene to epoxide alkane is 1:8 to 1:18.
[0015] As a preferred embodiment, in the method described in this invention, the alkylene oxide is propylene oxide;
[0016] As a preferred embodiment, the method described in this invention is carried out in the presence of an inert gas, such as nitrogen.
[0017] As a preferred embodiment, in the method described in this invention, a catalyst is added during the reaction process. The catalyst used is KOH, and the amount added is 0.8-1.5 wt% of 1,8-diaminonaphthalene.
[0018] As a preferred embodiment, the method described in this 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, in the method described in this invention, propylene oxide is added gradually in multiple stages, such as 2 or 3 times, with a reaction time of 3 to 5 hours and a reaction temperature of 80 to 160°C, preferably 100 to 130°C.
[0020] As a preferred embodiment, the method of the present invention, after the reaction is completed, performs a crude treatment, including the following steps: adding an appropriate amount of phosphoric acid to the product for neutralization, adjusting the pH to 5-7, and after the pH measurement is qualified, adding 0.1-0.5% of the total mass of polyether aluminum silicate adsorbent, cooling to 80-100℃, filtering, and collecting the filtrate to obtain crude polyether polyol; as a preferred embodiment, the method of the present invention, after the crude treatment, performs a purification process, such as dehydration treatment, including the following steps: removing water, unreacted propylene oxide and other by-products under a vacuum environment at 80-100℃.
[0021] The coarse treatment and refining described in this invention are commonly used technical solutions in the field of polyether polyol preparation, and this invention does not have any special limitations on them.
[0022] Thirdly, this invention provides the application of the above-mentioned diaminonaphthalene-containing polyether polyol in the preparation of rigid polyurethane foam: a rigid polyurethane foam comprising the following components: according to parts by weight,
[0023]
[0024] The polyether polyol composition of the present invention comprises the following components: based on the polyether polyol composition, according to parts by weight,
[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] 5-30 parts of propylene glycol polyether polyol, preferably 10-25 parts.
[0028] The sucrose polyether polyol described in this invention is obtained by ring-opening polymerization of sucrose with propylene oxide, with a hydroxyl value of 300-450 mg KOH / g and a viscosity of 2000-6000 mPa·s (25℃).
[0029] The propylene glycol polyether polyol of the present invention is obtained by ring-opening polymerization of propylene glycol and propylene oxide. The propylene glycol polyether polyol has a hydroxyl value of 60-150 mg KOH / g and a viscosity of 50-200 mPa·s (25℃).
[0030] The surfactant described in this invention is a siloxane surfactant, selected from one or more of B84806, LK221, Dongjun H3636, DC193, B8404, and AK8812, preferably B84806.
[0031] The catalyst described in this 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 described in this invention includes chemical and physical foaming agents, such as water, HCFC, HFC, cyclo / iso / n-pentane and other hydrofluorocarbons, fluorocarbons, and alkanes, preferably HFC, HCFC, water or cyclo / iso / n-pentane, and more preferably HFC-245fa foaming agent.
[0033] The isocyanate described in this invention is polymeric MDI (polymethylene polyphenyl polyisocyanate) with an NCO content of 30-32 wt%, preferably Wanhua Chemical's PM-200.
[0034] The preparation method of rigid polyurethane foam in this invention includes the following steps:
[0035] (1) According to a certain formula ratio, the polyether polyol composition, surfactant, catalyst and water are mixed, the temperature is controlled at 75-80℃, the foaming agent is added, the stirring speed is 80-100r / min, and the stirring is carried out for 40-50min to prepare the polyether polyol composition.
[0036] (2) The isocyanate is mixed with the polyether polyol mixture described in (1), sprayed, foamed, and cured to finally prepare rigid polyurethane foam.
[0037] Specifically, the mixing, spraying, and foaming of the polyether polyol mixture can all be carried out using existing technologies, and this invention does not impose 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 described in this invention is a one-step method, which is efficient and convenient;
[0041] (3) The foam produced by this invention can achieve good performance even with a low density, and the finished product density can reach 60-70 kg / m³. 3 Radial compressive strength ≥0.4 MPa; after being kept at 160℃ for 72 hours, mass loss <4% and volume expansion <4.5%. Detailed Implementation
[0042] The embodiments of the present invention are further illustrated below. However, the present invention is not limited to the listed embodiments, but should also include any other known modifications within the scope of the claims of the present invention.
[0043] The raw materials used in the examples and comparative examples are as follows:
[0044] Polyether polyol B: sucrose as the initiator, propylene oxide as the polymerizing monomer, hydroxyl value of 410 mg KOH / g, viscosity of 3500 mPa·s (25℃), Wanhua Chemical (Yantai) Rongwei Polyurethane Co., Ltd.
[0045] Polyether polyol C: Propylene glycol as the initiator, propylene oxide as the polymerizing monomer, hydroxyl value of 110 mg KOH / g, viscosity of 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 were purchased from Evonik Specialty Chemicals (Shanghai) Co., Ltd.
[0048] Organometallic salt catalysts: potassium isooctanoate, Xindian Chemical Materials (Shanghai) Co., Ltd.;
[0049] Foaming 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 performed 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 5cm from the core of polyurethane foam, measure the size and mass of the three samples, and then place them in a high temperature environment of 160℃ for 72h. Take out the foam, measure the size and mass of the three samples again, calculate the volume change and mass change of each sample before and after treatment, and finally take the average value.
[0054] Preparation Example 1
[0055] Preparation of polyether polyol A1:
[0056] 1) Add 500g of 1,8-diaminonaphthalene and 5g of KOH to the reaction vessel, fully purge with nitrogen, and stir.
[0057] 2) Raise the reaction temperature to 100℃, slowly add 750g of propylene oxide, and react at 100℃ until the propylene oxide is added. Then raise the temperature to 110℃ and mature for another hour.
[0058] 3) Raise the temperature to 120°C, add the remaining 750g of propylene oxide, and maintain the pressure of the reactor at 0.2-0.3 MPa until the remaining propylene oxide is added; then raise the temperature to 120-125°C and continue to mature for 2-3 hours.
[0059] 4) Add 7.5g of phosphoric acid to the reaction product, adjust the pH to 6, remove potassium ions from the solution, add 0.3% of the total mass of polyether aluminum silicate adsorbent, cool to 90℃, filter to obtain crude polyether polyol;
[0060] 5) The crude polyether polyol was subjected to vacuum at 90°C to remove water, unreacted propylene oxide and other byproducts, to obtain the final product polyether polyol A1, in which n is approximately 2 and the hydroxyl value was determined to be 360 mg KOH / g.
[0061] Preparation Example 2
[0062] Preparation of polyether polyol A2:
[0063] 1) Add 500g of 1,8-diaminonaphthalene and 5g of KOH to the reaction vessel, fully purge 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 propylene oxide is added, and then raise the temperature to 110°C and mature for another hour.
[0065] 3) Heat to 120°C, add the remaining 1500g of propylene oxide, and maintain the pressure of the reactor at 0.2-0.3 MPa until the remaining propylene oxide is added; then heat to 120-125°C and continue to mature for 2-3 hours.
[0066] 4) Add 7.5g of phosphoric acid to the reaction product, adjust the pH to 6, remove potassium ions from the solution, add 0.3% of the total mass of polyether as aluminum silicate adsorbent, cool to 90℃, and filter to obtain crude polyether polyol;
[0067] 5) The crude polyether polyol was vacuumed at 90°C to remove water, unreacted propylene oxide and other byproducts, to obtain the final product polyether polyol A2, in which n is about 4 and the hydroxyl value was measured to be 207 mg KOH / g.
[0068] Examples and Comparative Examples
[0069] Preparation of rigid polyurethane foam:
[0070] According to the different proportions of the comparative examples and embodiments in Table 1, the polyether polyol composition, surfactant, catalyst and water were mixed evenly, and then the foaming agent was added and mixed evenly to obtain the corresponding combined polyether. The prepared combined polyether and PM200 were added to the material tank respectively and mixed in a certain proportion by a spraying machine. The mixture was then sprayed onto a steel pipe that was rotating at a uniform speed and cured to obtain polyurethane foam. The mixing and foaming conditions were: material temperature 45℃, gauge pressure 700psi. The foam properties are shown in Table 2.
[0071] Table 1. Raw materials and parts by weight for Examples 1-5 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 isooctanoate 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 performance of Examples 1-5 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 Compressive 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] As shown in Tables 1 and 2, the polyurethane foams prepared in Examples 1 to 5 exhibit significantly lower rates of mass loss and volume expansion under high-temperature conditions compared to Comparative Example 1, and also demonstrate superior compressive strength compared to Comparative Example 1.
Claims
1. A rigid polyurethane foam, characterized in that, It comprises the following components: by weight, The structural formula of the diaminonaphthalene-containing polyether polyol is: Where n is any integer from 2 to 6.
2. The rigid polyurethane foam according to claim 1, characterized in that, The polyether polyol composition comprises the following components: Contains 10-20 parts of diaminonaphthalene polyether polyol; 35-50 parts of sucrose polyether polyol; 10-25 parts of propylene glycol polyether polyol.
3. The rigid polyurethane foam according to claim 1 or 2, characterized in that, The average hydroxyl value of the polyol containing diaminonaphthalene polyether is 150–400 mg KOH / g.
4. The rigid polyurethane foam according to claim 3, characterized in that, The average hydroxyl value of the diaminonaphthalene polyether polyol is 200–360 mg KOH / g.
5. The rigid polyurethane foam according to claim 1, characterized in that, The method for preparing the diaminonaphthalene-containing polyether polyol involves etherifying 1,8-diaminonaphthalene with propylene oxide to obtain the diaminonaphthalene-containing polyether polyol.
6. The rigid polyurethane foam according to claim 5, characterized in that, In the preparation method of the diaminonaphthalene-containing polyether polyol, the molar ratio of 1,8-diaminonaphthalene to propylene oxide is 1:8 to 1:
18.
7. The rigid polyurethane foam according to claim 6, characterized in that, In the preparation method of the diaminonaphthalene polyether polyol, the etherification reaction is carried out in an inert gas atmosphere at a reaction temperature of 80-160℃ and a relative pressure of 0.2-0.3MPa.
8. The rigid polyurethane foam according to claim 7, characterized in that, In the preparation method of the diaminonaphthalene polyether polyol, the reaction temperature is 100-130℃ and the reaction time is 3-5h.
9. The rigid polyurethane foam according to claim 8, characterized in that, In the preparation method of the diaminonaphthalene-containing polyether polyol, KOH is added as a catalyst during the etherification reaction process, and the amount added is 0.8-1.5 wt% of 1,8-diaminonaphthalene.
10. The rigid polyurethane foam according to any one of claims 1 or 2, characterized in that, The sucrose polyether polyol has a hydroxyl value of 300-450 mg KOH / g, a viscosity of 2000-6000 mPa·s, and a temperature of 25°C; and / or the propylene glycol polyether polyol has a hydroxyl value of 60-150 mg KOH / g, a viscosity of 50-200 mPa·s, and a temperature of 25°C.
11. The rigid polyurethane foam according to any one of claims 1 or 2, characterized in that, The surfactant is a siloxane surfactant, selected from one or more of B84806, LK221, Dongjun H3636, DC193, B8404, and AK8812.
12. The rigid polyurethane foam according to any one of claims 1 or 2, 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.
13. The rigid polyurethane foam according to any one of claims 1 or 2, characterized in that, The isocyanate mentioned is polymeric MDI with an NCO content of 30-32 wt%.
14. A method for preparing rigid polyurethane foam according to any one of claims 1-13, characterized in that, Includes the following steps: (1) According to a certain formula ratio, the polyether polyol composition, surfactant, catalyst and water are mixed and a foaming agent is added to prepare the polyether polyol composition. (2) The isocyanate is mixed with the polyether polyol mixture described in (1), sprayed, foamed, and cured to finally prepare rigid polyurethane foam.
15. The method for preparing rigid polyurethane foam according to claim 14, characterized in that, Step (1) The temperature is controlled at 75-80℃.