阅读说明：本技术 聚醚组合物和以其为原料的聚氨酯硬泡及其制备方法 (Polyether composition, polyurethane rigid foam using polyether composition as raw material and preparation method of polyurethane rigid foam ) 是由 夏伟如 李玉博 于 2021-08-16 设计创作，主要内容包括：本发明公开了一种聚醚组合物,原料包括膨胀微球、聚酯多元醇和特定起始剂的聚醚多元醇。本发明还公开了以这种聚醚组合物为原料的聚氨酯硬泡及其制备方法以及用该聚氨酯硬泡制得的复合材料。本发明提供的聚醚组合物与其他原料混合后制备聚氨酯硬泡使得整体具有较好的韧性和良好的高温膨胀性,在包覆纤维预浸料树脂在高温模压固化时,产生合适的膨胀力,能使复合材料既紧密地贴合成型模具而具有光洁饱满的外观,而且使外层复合材料和芯材也能紧密结合,具有优异的强度。与其他传统工艺相比,本发明工艺简单,投入少,成本低,效率高,有利于降低生产成本和提高生产效率,具有很高的经济价值。(The invention discloses a polyether composition, which comprises raw materials of expanded microspheres, polyester polyol and polyether polyol of a specific initiator. The invention also discloses a polyurethane rigid foam using the polyether composition as a raw material, a preparation method thereof and a composite material prepared by the polyurethane rigid foam. The polyether composition provided by the invention is mixed with other raw materials to prepare the polyurethane rigid foam, so that the whole polyurethane rigid foam has better toughness and good high-temperature expansibility, and when the fiber-coated prepreg resin is molded and cured at high temperature, a proper expansive force is generated, so that the composite material can be tightly attached to a molding die to have a smooth and plump appearance, and the outer-layer composite material and the core material can be tightly combined to have excellent strength. Compared with other traditional processes, the method has the advantages of simple process, less investment, low cost, high efficiency, contribution to reducing the production cost and improving the production efficiency and very high economic value.)

1. The polyether composition is characterized by comprising 3-8 parts of expanded microspheres and also comprising the following components in parts by weight:

30-60 parts of first polyether polyol;

35-55 parts of second polyether polyol;

5-15 parts of polyester polyol;

the first polyether polyol is polyether polyol taking pentaerythritol as an initiator or taking pentaerythritol and glycerol as co-initiators;

the second polyether polyol is polyether polyol taking sucrose and glycerin as co-initiators or taking sucrose and diethylene glycol as co-initiators.

2. The polyether composition of claim 1, the first polyether polyol having a functionality of from 3.6 to 4 and a hydroxyl number of 380-590 mgKOH/g; and/or the presence of a gas in the gas,

the second polyether polyol has a functionality of 4.7 to 5.1 and a hydroxyl value of 340-; and/or the presence of a gas in the gas,

the polyester polyol has a functionality of 2.3-2.4 and a hydroxyl value of 270-300 mgKOH/g.

3. The polyether composition according to claim 1 or 2, further comprising the following raw materials in parts by weight:

4. the polyether composition of claim 3 wherein the catalyst comprises at least one of N, N-dimethylcyclohexylamine, triethylenediamine;

the surfactant is a polysiloxane-polyether copolymer for hard foam in a non-hydrolytic Si-C bond form;

the physical blowing agent comprises at least one of monofluorodichloroethane, 1,1,1,3, 3-pentafluoropropane, 1,1,1,3, 3-pentafluoro-n-butane, 1,1,1,2,3,3, 3-heptafluoropropane, trans-1-chloro-3, 3, 3-trifluoropropene, trans-1, 3,3, 3-tetrafluoropropene, 1,1,4,4, 4-hexafluoro-2-butene, n-butane, isobutane, cyclopentane, isopentane, n-pentane, and methyl formate;

the flame retardant comprises at least one of tris (chloroisopropyl) phosphate, tris (chloroethyl) phosphate, dimethyl methylphosphonate, diethyl ethylphosphonate and triethyl phosphate.

5. A rigid polyurethane foam comprising the polyether composition of any one of claims 1 to 4 and further comprising an isocyanate, wherein the mass ratio of the polyether composition to the isocyanate is 151.25 to 157.7: 85-98.

6. A method for preparing the rigid polyurethane foam of claim 5, comprising the steps of:

and mixing and foaming the polyether composition and isocyanate to obtain the rigid polyurethane foam.

7. The method according to claim 6, wherein the polyether composition is prepared by a method comprising:

(1) cooling the first polyether polyol, the second polyether polyol, the polyester polyol, the surfactant, the catalyst, the water and the flame retardant to below 15 ℃ to obtain a premix;

(2) and mixing the premix with a physical foaming agent and expanded microspheres for foaming at a temperature of not higher than 15 ℃.

8. The preparation method according to claim 7, wherein the temperature of the raw materials before mixing and foaming is controlled to be 18-20 ℃, the pressure is controlled to be 140-160bar, and the foaming time is controlled to be 15-23 min.

9. A composite material characterized in that its raw material comprises the rigid polyurethane foam of claim 5.

10. A method of preparing the composite material of claim 9, comprising the steps of:

processing the polyurethane rigid foam into a required shape, coating epoxy resin glue solution on the surface, wrapping fiber cloth, and putting the fiber cloth into a mold for heating and forming;

preferably, the temperature of the heating forming is 110-160 ℃.

Technical Field

The invention relates to the technical field of polyurethane composite materials, in particular to a polyether composition, a polyurethane hard foam taking the polyether composition as a raw material and a preparation method of the polyurethane hard foam.

Background

The carbon fiber and glass fiber composite material is a product obtained by high-temperature curing and molding after fiber prepreg resin or other methods are combined with resin, has the characteristics of high temperature resistance, friction resistance, electric conduction, heat conduction and corrosion resistance, and is mainly applied to the fields of sports equipment, aerospace, medical equipment and the like.

The traditional composite material forming process has the problems of air inflation compression molding in wind pipes, hand lay-up process, resin transfer molding technology, thermal self-expansion forming process and the like. The method is favored because the working procedures are simple, equipment is less and investment is small, however, the high-energy glue is required to be cut and becomes a molten state to expand when being heated at high temperature, the die corners cannot be ensured to be filled with materials, appearance is not full or even waste products are easy to cause, particularly for products with complicated die cavities, the high-energy glue in the molten state cannot be filled with complicated die cavities, and the process cannot produce products with complicated shapes.

Disclosure of Invention

Therefore, the technical problem to be solved by the invention is the defect of complex process in the existing composite material preparation process, and further provides a polyether composition, a polyurethane hard foam using the polyether composition as a raw material and a preparation method of the polyurethane hard foam.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

the invention provides a polyether composition, which comprises 3-8 parts of expanded microspheres and also comprises the following components in parts by weight:

30-60 parts of first polyether polyol;

35-55 parts of second polyether polyol;

5-15 parts of polyester polyol;

the first polyether polyol is polyether polyol which takes pentaerythritol as an initiator or takes pentaerythritol and glycerol as co-initiators, wherein the mass ratio of pentaerythritol in the initiator is 59.6-100%;

the second polyether polyol is polyether polyol taking sucrose and glycerol as co-initiators or taking sucrose and diethylene glycol as co-initiators, wherein the mass ratio of sucrose in the initiators is 65.7-77.8%;

preferably, the expansion temperature of the expanded microspheres is 110-160 ℃, the minimum expansion temperature is not lower than 110 ℃, and the maximum expansion temperature is 145-155 ℃.

Further, the first polyether polyol has a functionality of 3.6-4 and a hydroxyl value of 380-590 mgKOH/g; and/or the presence of a gas in the gas,

the second polyether polyol has a functionality of 4.7 to 5.1 and a hydroxyl value of 340-; and/or the presence of a gas in the gas,

the polyester polyol has a functionality of 2.3-2.4 and a hydroxyl value of 270-300 mgKOH/g.

Further, the polyether composition also comprises the following raw materials in parts by weight:

preferably, the catalyst comprises at least one of N, N-dimethylcyclohexylamine, triethylenediamine;

the surfactant is a polysiloxane-polyether copolymer for hard foam in a non-hydrolytic Si-C bond form;

the physical blowing agent comprises at least one of monofluorodichloroethane, 1,1,1,3, 3-pentafluoropropane, 1,1,1,3, 3-pentafluoro-n-butane, 1,1,1,2,3,3, 3-heptafluoropropane, trans-1-chloro-3, 3, 3-trifluoropropene, trans-1, 3,3, 3-tetrafluoropropene, 1,1,4,4, 4-hexafluoro-2-butene, n-butane, isobutane, cyclopentane, isopentane, n-pentane, and methyl formate;

the flame retardant comprises at least one of tris (chloroisopropyl) phosphate, tris (chloroethyl) phosphate, dimethyl methylphosphonate, diethyl ethylphosphonate and triethyl phosphate.

The invention also provides a polyurethane rigid foam, which comprises the polyether composition and isocyanate, wherein the mass ratio of the polyether composition to the isocyanate is 151.25-157.7: 85-98.

The invention also provides a preparation method of the rigid polyurethane foam, which comprises the following steps:

and mixing and foaming the polyether composition and isocyanate to obtain the rigid polyurethane foam.

Specifically, the preparation method of the polyether composition comprises the following steps:

(1) cooling the first polyether polyol, the second polyether polyol, the polyester polyol, the surfactant, the catalyst, the water and the flame retardant to below 15 ℃ to obtain a premix;

(2) and mixing the premix with a physical foaming agent and expanded microspheres for foaming at a temperature of not higher than 15 ℃.

Further, the temperature of the raw materials before mixing and foaming is controlled to be 18-20 ℃, the pressure is 140-160bar, the foaming time is 15-23min, wherein the milk cream starting time is 60-180 seconds, the foam drawing time is 240-300 seconds, the demolding time is 10-15 min, and the system temperature during mixing and foaming is not higher than the minimum expansion temperature of the expanded microspheres.

The invention also provides a composite material, and the raw materials of the composite material comprise the polyurethane hard foam.

The invention also provides a preparation method of the composite material, which comprises the following steps:

processing the polyurethane rigid foam into a required shape, coating epoxy resin glue solution on the surface, wrapping fiber cloth, and putting the fiber cloth into a mold for heating and forming;

preferably, the temperature of the heating forming is 110-160 ℃.

Compared with the prior art, the invention has the following beneficial effects:

1. the polyether composition provided by the invention is prepared by adding the expanded microspheres, selecting the polyether polyol taking pentaerythritol as an initiator or taking pentaerythritol and glycerol as a co-initiator and the polyether polyol taking sucrose and glycol as initiators or taking sucrose and glycerol as a co-initiator, and mixing the mixture with other raw materials to prepare the polyurethane rigid foam, so that the whole body has better toughness and good high-temperature expansibility, and when the fiber-coated prepreg resin is subjected to high-temperature mould pressing and curing, a proper expansion force is generated, so that the composite material can be tightly attached to a forming mould to have a full and smooth appearance, and the outer layer composite material and the core material can be tightly combined to have excellent strength.

2. The polyether polyol of the pentaerythritol initiator adopted by the invention has a good symmetrical structure, so that the roundness of the aperture of the hard bubble hole is good, the toughness is good, and the shape cannot be changed when the hard bubble hole expands at high temperature; the polyether polyol of the sucrose initiator is selected, the functionality is high, the strength of the hard foam is improved, the mechanical property is excellent, the combination of the polyester polyol has good high-temperature heat resistance and toughness, the reaction speed is better controlled during the combination of the polyether polyols, the strength of the foam reaction heat release is convenient to control by the system temperature, the system temperature is not higher than the minimum expansion temperature of the expanded microspheres, the expanded microspheres are well protected, the expansion of the expanded microspheres during the preparation of the polyurethane hard foam is prevented, the expansion of the microspheres during the subsequent preparation and molding of the composite material is guaranteed, and the temperature is raised again, so that the curing process of the subsequent composite material is achieved.

4. The components and the proportion of the catalyst, the surfactant, the physical foaming agent and the flame retardant in the polyether composition provided by the invention are limited, so that the expanded microspheres and the polyether polyol of the used specific initiator can be better highlighted.

5. The raw materials of the polyurethane rigid foam provided by the invention are low-viscosity liquid, are easy to mix uniformly to ensure that the core material of the rigid foam has uniform performance, and have good fluidity, so that each corner in a mould can be ensured to be filled even if the mould has a complex cavity structure, the problem that the core material with a complex structure cannot be manufactured by adopting a thermoplastic high-energy rubber sheet material is solved, and the manufactured product has a full and attractive appearance.

6. The invention controls the exothermic strength of the foam reaction by controlling the foaming conditions of the rigid polyurethane foam and the composition and proportion of the raw materials, so that the system temperature is not higher than the lowest expansion temperature of the expanded microspheres.

7. The rigid polyurethane foam provided by the invention has partial unreacted active hydroxyl on the surface of the water core material because the reaction index is less than 1 (the mole number of NCO groups/the mole number of OH groups) (NCO is from isoestonate, OH is from polyalcohol in a composite material and) and can react with epoxy resin at high temperature to form chemical bonds in the subsequent preparation of a composite material, and further, the bonding force between the rigid polyurethane foam and a coating material is further improved, so that the interlayer bonding force of a composite material product is high, and the strength is high.

8. The composite material provided by the invention is simple in preparation method, and due to the expansion of the expanded microspheres after 2 times of heating, the outer layer material and the rigid polyurethane foam are tightly combined, so that the obtained composite material is excellent in appearance and combination condition.

9. Compared with other traditional processes, the method has the advantages of simple process, less investment, low cost, high efficiency, contribution to reducing the production cost and improving the production efficiency and very high economic value.

Detailed Description

The following examples are provided to further understand the present invention, not to limit the scope of the present invention, but to provide the best mode, not to limit the content and the protection scope of the present invention, and any product similar or similar to the present invention, which is obtained by combining the present invention with other prior art features, falls within the protection scope of the present invention.

The examples do not show the specific experimental steps or conditions, and can be performed according to the conventional experimental steps described in the literature in the field. The reagents or instruments used are not indicated by manufacturers, and are all conventional reagent products which can be obtained commercially.

The polyether polyols of the pentaerythritol starters include polyether polyol PN400 and polyether polyol PN560, wherein:

polyether polyol PN 400: supplied by optimization chemical Co., Ltd, the product designation Puranol RF PN400, started with pentaerythritol, is prepared by addition polymerization with propylene oxide, the functionality is 4, the hydroxyl value range is 380-;

polyether polyol PN 560: supplied by the company, optica chemical Co., Ltd, the product designation Puranol RF PN560, obtained by polyaddition of pentaerythritol and glycerol co-starting with propylene oxide, has a functionality of 3.6 and a hydroxyl value in the range 535-585 mgKOH/g.

The polyether polyols of the sucrose starter include polyether polyol 8360 and polyether polyol 8238A, wherein:

polyether polyol 8360: supplied by optimization chemical Co., Ltd, product number Puranol RF8360, initiated by sucrose and glycerol, was prepared by addition polymerization with propylene oxide, with functionality of 4.7, hydroxyl value range of 340-;

polyether polyol 8238A: supplied by optimization chemical company, Inc., product number Puranol RF 8238A, obtained by polyaddition of propylene oxide starting from sucrose and diethylene glycol, has a functionality of 5.1 and a hydroxyl value in the range of 375-.

The polyether polyol used in the comparative example includes:

polyether polyol 6482: supplied by optica chemical company, Inc., under the product designation Puranol 6482, prepared by polyaddition of sorbitol starting with propylene oxide, has a functionality of 6 and a hydroxyl value of 480 mgKOH/g.

The polyester polyol is polyester polyol KH8262 which is provided by Jiangsu kang Honghong new materials Co.Ltd, the product trade name is KH8262, the polyester polyol is prepared by the esterification reaction of phthalic anhydride and alcohols such as diethylene glycol, trimethylolpropane and the like, the functionality is 2.4, and the hydroxyl value is 270-290 mgKOH/g.

The surfactant is foam stabilizer M8805, is hydrolysis-resistant polysiloxane-olefin oxide copolymer, and is provided by Jiangsu Messide chemical Co., Ltd;

isocyanate is isocyanate PM-200, NCO content is 30.5-32.0%, and functionality is 2.7, provided by Wanhua chemical group GmbH.

The catalyst comprises Polycat8,33LV and A-300, in which Polycat8 is N, N-dimethylcyclohexylamine,33LV with 33% triethylene diamine dissolved in DPG was provided by Shanghai Special chemistry (Shanghai) Co., Ltd; a-300 is a delayed gel type catalyst, an acid blocked triethylene diamine, and is provided by Michigan advanced materials (China) Co.

The expanded microspheres are of the type Expancel 551DU40 and are supplied by Acksonobel, the expansion temperature is 110-.

The physical blowing agent was commercially available monofluorodichloroethane.

The flame retardant is commercially available tris (chloroisopropyl) phosphate.

The examples do not show the specific experimental steps or conditions, and can be performed according to the conventional experimental steps described in the literature in the field. The reagents or instruments used are not indicated by manufacturers, and are all conventional reagent products which can be obtained commercially.

Example 1

This example provides a polyether composition comprising the raw materials of 30kg of polyether polyol PN560, 55kg of polyether polyol 8360, 15kg of polyester polyol KH8262, 0.05kg of water, 2kg of foam stabilizer, 0.8kg of Polycat8, and 0.4kg of33LV, 15kg of flame retardant, 30kg of foaming agent and 3kg of expanded microspheres, and the specific preparation method is as follows:

(1) weighing the raw materials, putting the other raw materials except the expanded microspheres and the foaming agent into a mixing kettle, stirring for 30min at 2000r/min, and measuring the moisture content to ensure that the raw materials are qualified to obtain a mixture;

(2) and (3) starting cooling water in the mixing kettle, cooling the mixture to below 15 ℃, adding the expanded microspheres and the foaming agent, stirring at 1500r/min for 30min, discharging and packaging to obtain the polyether composition.

This example also provides a rigid polyurethane foam, which comprises 151.25kg of the polyether composition and 90kg of isocyanate, and the preparation method comprises the following steps:

firstly, mixing other raw materials except the expanded microspheres in the polyether composition, then adding the expanded microspheres for full mixing, then adding the isocyanate and the polyether composition into a charging bucket of a low-pressure machine respectively, setting the mixing ratio of the low-pressure machine to be 60/100, controlling the material temperature to be 18-20 ℃ and the pressure to be 140-160bar during mixing and foaming, simultaneously starting stirring at the top end of the polyether composition tank, preventing the possibility of precipitation of the expanded microspheres, and uniformly mixing and foaming for 20min by the low-pressure machine to obtain the polyurethane hard foam.

Example 2

This example provides a polyether composition, which is prepared from 45kg of polyether polyol PN560, 45kg of polyether polyol 8360, 10kg of polyester polyol KH8262, 0.1kg of water, 1.5kg of foam stabilizer, 0.4kg of Polycat8, 0.3kg of a-300, 20kg of flame retardant, 25kg of foaming agent and 5kg of expanded microspheres, and its preparation method specifically includes:

(1) weighing the raw materials, putting the other raw materials except the expanded microspheres and the foaming agent into a mixing kettle, stirring for 30min at 2000r/min, and measuring the moisture content to ensure that the raw materials are qualified to obtain a mixture;

(2) and (3) starting cooling water in the mixing kettle, cooling the mixture to below 15 ℃, adding the expanded microspheres and the foaming agent, stirring at 1500r/min for 30min, discharging and packaging to obtain the polyether composition.

The embodiment also provides a polyurethane rigid foam, which comprises 152.3kg of the polyether composition and 98kg of isocyanate, and the specific preparation method is as follows:

firstly, mixing other raw materials except the expanded microspheres in the polyether composition, then adding the expanded microspheres for full mixing, then adding the isocyanate and the polyether composition into a charging bucket of a low-pressure machine respectively, setting the mixing ratio of the low-pressure machine to be 65/100, controlling the material temperature to be 18-20 ℃ and the pressure to be 140-160bar during mixing and foaming, simultaneously starting stirring at the top end of the polyether composition tank, preventing the possibility of precipitation of the expanded microspheres, and uniformly mixing and foaming for 15min by the low-pressure machine to obtain the polyurethane hard foam.

Example 3

The embodiment provides a polyether composition, which is prepared from the following raw materials, by weight, 50kg of polyether polyol PN400, 40kg of polyether polyol 8238A, 10kg of polyester polyol KH8262, 0.15kg of water, 2kg of foam stabilizer, 0.3kg of Polycat8, 0.3kg of A-300, 20kg of flame retardant, 25kg of foaming agent and 8kg of expanded microspheres, and the specific preparation method is as follows:

(1) weighing the raw materials, putting the other raw materials except the expanded microspheres and the foaming agent into a mixing kettle, stirring for 30min at 2000r/min, and measuring the moisture content to ensure that the raw materials are qualified to obtain a mixture;

(2) and (3) starting cooling water in the mixing kettle, cooling the mixture to below 15 ℃, adding the expanded microspheres and the foaming agent, stirring at 1500r/min for 30min, discharging and packaging to obtain the polyether composition.

The embodiment also provides a rigid polyurethane foam, which is prepared from 155.75kg of the polyether composition and 85kg of isocyanate by the following specific preparation method:

firstly, mixing other raw materials except the expanded microspheres in the polyether composition, then adding the expanded microspheres for full mixing, then adding the isocyanate and the polyether composition into a charging bucket of a low-pressure machine respectively, setting the mixing ratio of the low-pressure machine to be 55/100, controlling the material temperature to be 18-20 ℃ and the pressure to be 140-160bar during mixing and foaming, simultaneously starting stirring at the top end of the polyether composition tank, preventing the possibility of precipitation of the expanded microspheres, and uniformly mixing and foaming for 18min by the low-pressure machine to obtain the polyurethane hard foam.

Example 4

This example provides a polyether composition, which is prepared from 60kg of polyether polyol PN400, 35kg of polyether polyol 8238A, 5kg of polyester polyol KH8262, 0.2kg of water, 1kg of foam stabilizer, 0.3kg of Polycat8, 0.2kg of a-300, 15kg of flame retardant, 20kg of foaming agent and 6kg of expanded microspheres, and its preparation method specifically is as follows:

(1) weighing the raw materials, putting the other raw materials except the expanded microspheres and the foaming agent into a mixing kettle, stirring for 30min at 2000r/min, and measuring the moisture content to ensure that the raw materials are qualified to obtain a mixture;

(2) and (3) starting cooling water in the mixing kettle, cooling the mixture to below 15 ℃, adding the expanded microspheres and the foaming agent, stirring at 1500r/min for 30min, discharging and packaging to obtain the polyether composition.

This example also provides a rigid polyurethane foam, which is prepared from 157.7kg of the polyether composition and 87kg of isocyanate, and the preparation method comprises the following steps:

firstly, mixing other raw materials except the expanded microspheres in the polyether composition, then adding the expanded microspheres for full mixing, then adding the isocyanate and the polyether composition into a charging bucket of a low-pressure machine respectively, setting the mixing ratio of the low-pressure machine to be 55/100, controlling the material temperature to be 18-20 ℃ and the pressure to be 140-160bar during mixing and foaming, simultaneously starting stirring at the top end of the polyether composition tank, preventing the possibility of precipitation of the expanded microspheres, and uniformly mixing and foaming for 23min by the low-pressure machine to obtain the polyurethane hard foam.

Comparative example 1

This example provides a polyether composition comprising 25kg of polyether polyol PN560, 60kg of polyether polyol 8238A, 15kg of polyester polyol KH8262, 1.5kg of water, 1kg of foam stabilizer, 0.6kg of Polycat8, and 0.9kg of33LV, 15kg of flame retardant, 10kg of foaming agent and 6kg of expanded microspheres, and the specific preparation method is as follows:

(1) weighing the raw materials, putting the other raw materials except the expanded microspheres and the foaming agent into a mixing kettle, stirring for 30min at 2000r/min, and measuring the moisture content to ensure that the raw materials are qualified to obtain a mixture;

(2) and (3) starting cooling water in the mixing kettle, cooling the mixture to below 15 ℃, adding the expanded microspheres and the foaming agent, stirring at 1500r/min for 30min, discharging and packaging to obtain the polyether composition.

The comparative example also provides a rigid polyurethane foam prepared from 135kg of the polyether composition and 135kg of isocyanate, and the preparation method comprises the following steps:

firstly, mixing other raw materials except the expanded microspheres in the polyether composition, then adding the expanded microspheres for full mixing, then adding the isocyanate and the polyether composition into a charging bucket of a low-pressure machine respectively, setting the mixing ratio of the low-pressure machine to be 100/100, controlling the material temperature to be 18-20 ℃ and the pressure to be 140-160bar during mixing and foaming, simultaneously starting stirring at the top end of the polyether composition tank, preventing the possibility of precipitation of the expanded microspheres, and uniformly mixing and foaming for 20min by the low-pressure machine to obtain the polyurethane hard foam.

Comparative example 2

This comparative example differs from example 1 only in that no polyol of pentaerythritol starter is used. In this comparative example, sorbitol-initiated polyether polyol 6482 was used.

The polyether composition of this comparative example had a formulation of 30kg of polyether polyol 6482, 55kg of polyether polyol 8360, 15kg of polyester polyol KH8262, 0.05kg of water, 2kg of foam stabilizer, 0.8kg of Polycat8, 0.4kg of33LV, 15kg of flame retardant, 30kg of foaming agent and 3kg of expanded microspheres, and the specific preparation method is as follows:

(1) weighing the raw materials, putting the other raw materials except the expanded microspheres and the foaming agent into a mixing kettle, stirring for 30min at 2000r/min, and measuring the moisture content to ensure that the raw materials are qualified to obtain a mixture;

(2) and (3) starting cooling water in the mixing kettle, cooling the mixture to below 15 ℃, adding the expanded microspheres and the foaming agent, stirring at 1500r/min for 30min, discharging and packaging to obtain the polyether composition.

This comparative example also provides a rigid polyurethane foam comprising 151.25kg of the above polyether composition and 102.8kg of isocyanate, the specific preparation method being as follows:

firstly, mixing other raw materials except the expanded microspheres in the polyether composition, then adding the expanded microspheres for full mixing, then adding the isocyanate and the polyether composition into a charging bucket of a low-pressure machine respectively, setting the mixing ratio of the low-pressure machine to be 68/100, controlling the material temperature to be 18-20 ℃ and the pressure to be 140-160bar during mixing and foaming, simultaneously starting stirring at the top end of the polyether composition tank, preventing the possibility of precipitation of the expanded microspheres, and uniformly mixing and foaming for 20min by the low-pressure machine to obtain the polyurethane hard foam.

Comparative example 3

This comparative example differs from example 2 only in that no polyol is used with a sucrose starter. In this comparative example, sorbitol-initiated polyether polyol 6482 was used.

The polyether composition of the comparative example has a formulation of 45kg of polyether polyol PN560, 45kg of polyether polyol 6482, 10kg of polyester polyol KH8262, 0.1kg of water, 1.5kg of foam stabilizer, 0.4kg of Polycat8, 0.3kg of A-300, 20kg of flame retardant, 25kg of foaming agent and 5kg of expanded microspheres, and the specific preparation method is as follows:

(1) weighing the raw materials, putting the other raw materials except the expanded microspheres and the foaming agent into a mixing kettle, stirring for 30min at 2000r/min, and measuring the moisture content to ensure that the raw materials are qualified to obtain a mixture;

(2) and (3) starting cooling water in the mixing kettle, cooling the mixture to below 15 ℃, adding the expanded microspheres and the foaming agent, stirring at 1500r/min for 30min, discharging and packaging to obtain the polyether composition.

This comparative example also provides a rigid polyurethane foam made from 152.3kg of the above polyether composition and 133.42kg of isocyanate, and prepared as follows:

firstly, mixing other raw materials except the expanded microspheres in the polyether composition, then adding the expanded microspheres for full mixing, then adding the isocyanate and the polyether composition into a charging bucket of a low-pressure machine respectively, setting the mixing ratio of the low-pressure machine to be 88/100, controlling the material temperature to be 18-20 ℃ and the pressure to be 140-160bar during mixing and foaming, simultaneously starting stirring at the top end of the polyether composition tank, preventing the possibility of precipitation of the expanded microspheres, and uniformly mixing and foaming for 20min by the low-pressure machine to obtain the polyurethane hard foam.

Comparative example 4

This comparative example provides a polyether composition which differs from example 1 only in that no expanded microspheres have been added and the starting materials are 30kg of polyether polyol PN560, 55kg of polyether polyol 8360, 15kg of polyester polyol KH8262, 0.05kg of water, 2kg of foam stabilizer, 0.8kg of Polycat8, 0.4kg of33LV, 15kg flame retardant and 30kg foamThe preparation method comprises the following steps:

(1) weighing the raw materials, putting the other raw materials except the expanded microspheres and the foaming agent into a mixing kettle, stirring for 30min at 2000r/min, measuring the moisture content to be qualified, discharging and packaging to obtain the polyether composition.

The embodiment also provides a polyurethane rigid foam, the raw materials include 146.25kg of the polyether composition and 90kg of isocyanate, and the specific preparation method is as follows:

firstly, mixing other raw materials except the expanded microspheres in the polyether composition, then adding the expanded microspheres for full mixing, then adding the isocyanate and the polyether composition into a charging bucket of a low-pressure machine respectively, setting the mixing ratio of the low-pressure machine to be 61/100, controlling the material temperature to be 18-20 ℃ during mixing and foaming, simultaneously starting stirring at the top end of the polyether composition material tank, preventing the possibility of precipitation of the expanded microspheres, and uniformly mixing and foaming by the low-pressure machine to obtain the polyurethane hard foam.

Test example 1

In examples 1 to 4 and comparative example, respectively, the highest temperature of the system due to reaction heat evolution during the formation of the rigid polyurethane foam was measured, and the results are shown in Table 1:

table 1: maximum temperature of the system during foaming

As can be seen from table 1, since a large amount of reaction heat is generated in the foaming process, in the embodiment of the present invention, a large amount of reaction heat is absorbed by selecting raw materials and designing the amount of the formula, and then a specific polyether polyol is selected as an auxiliary, so that the reaction speed is slowed down to ensure that the system can release heat uniformly in the polyurethane rigid foam foaming reaction process, the maximum temperature of the system is lower than the expansion temperature of the foaming microspheres, the expansion of the expansion microspheres cannot be triggered, and the expansion microspheres can be well protected in the polyurethane rigid foam, so that the micro-expansion of the microspheres can be achieved at a high temperature of 150 ℃ in the subsequent composite material molding, and the present invention is very suitable for the subsequent composite material curing process. In contrast, in comparative example 1, because of the amount of raw materials, the heat generated from the reaction system was not absorbed in a large amount, and the temperature of the system reached the expansion temperature of the expanded microspheres, so that the expanded microspheres were prematurely expanded and failed; in comparative examples 2 and 3, polyols using no pentaerythritol starter and no sucrose starter, respectively, were used, the reaction rate was not controlled, and the system temperature reached the expansion temperature of the expanded microspheres, so that the expanded microspheres were prematurely expanded.

Test example 2

The rigid polyurethane foam materials of examples 1 to 4 and comparative examples 1 to 4 were prepared in the proportions of the examples and then in an amount of 180kg/m³The material amount is poured into a mold with the thickness of 10cmx10cmx3cm, the mold is closed and placed into a cooling table for compaction, the foaming is carried out at room temperature, the demolding is carried out for 10-15 minutes, after 24 hours of post curing, the expansion force test of 60 minutes at 150 ℃ is carried out by using a high-temperature tensile machine.

The test results are shown in table 2:

table 2 rigid polyurethane foam test results

As can be seen from the test results in Table 2, the use of high-functionality polyether with high strength and pentaerythritol polyether can ensure that the hard foam has all-directional uniform expansibility under the condition of high strength, and simultaneously, polyester also ensures that the hard foam has certain toughness when expanding, and the matching of the polyols ensures that the core material has better high temperature resistance, and also protects the hard foam from being damaged by cracking and the like in the expansion process, and simultaneously, the expansion force is more than 100N, so that the hard foam and the surface layer coating layer fiber soaking material are tightly attached to each other in the high-temperature forming process of the composite material, and a full composite material surface is formed. In contrast, in comparative examples 1 and 3, the expansion force of the foam block at the later stage of high temperature is very small because the temperature of the system rises higher during foaming and exceeds the expansion temperature of the expanded microspheres, while in comparative example 2, because pentaerythritol polyether is not present, the expansion of the foam block is not very uniform and the shape is slightly changed, meanwhile, the strength of the foam block is relatively large, and the foam block can resist the internal expansion force generated by the expanded microspheres, so that the external apparent expansion force is relatively small, and in comparative example 4, because the expanded microspheres are not added, the expansion force of the foam block at the later stage of high temperature is also very small.

Test example 3

The rigid polyurethane foam materials of examples 1 to 4 and comparative example were prepared in the proportions of the examples and then in an amount of 180kg/m³The charge amount of (A) is poured into a mold with the thickness of 20cmx15cmx10cm, the mold is closed and placed into a cooling table to be compressed, the foaming is carried out at room temperature, the demolding is carried out for 15 minutes, and after 24 hours of post curing, the compression strength and tensile strength performance tests of the examples and other comparative examples are carried out by using a universal material testing machine.

The test results are shown in table 3:

TABLE 3 mechanical Property test results of rigid polyurethane foams

As can be seen from the test results in table 3, the polyester improves the toughness of the foam, the first polyether polyol using pentaerythritol as an initiator or pentaerythritol and glycerol as co-initiators also improves the toughness of the foam, meanwhile, the sucrose polyether also improves the strength, the polyether is reasonably matched, and the toughness can be considered while the strength is ensured, so that the foam is not embrittled; the types of polyether polyols were not changed in comparative examples 1 and 4, and the differences between the properties and the examples were small, while the polyols of comparative examples 2 and 3, in which the pentaerythritol initiator and the sucrose initiator were not used, respectively, were reduced in elongation at break to different degrees, although the compressive strength and the tensile strength were similar to those of the examples of the present application.

Test example 4

The rigid polyurethane foam materials of examples 1 to 4 and comparative example were prepared in the proportions of the examples and then in an amount of 180kg/m³The amount of the charged material is poured into a mould with the thickness of 10cmx10cmx3cmIn the mould, the mould is closed and placed in a cooling table for pressing, foaming is carried out at room temperature, demoulding is carried out for 10-15 minutes, after about 15 hours, the core material is further heated in the mould for 1 hour for foaming and forming at 150 ℃, then the mould is cooled for 18 minutes for demoulding, then the core material is heated for 3 hours at 80 ℃, and the dimensional change before and after recording is as follows.

The test results are shown in table 4.

TABLE 3 polyurethane rigid foam dimensional Change test results

It can be seen from the test results in table 4 that the length-width ratio of the core material before heating in the examples is slightly smaller than that of the mold, and the mold can be easily demolded, and the core material is placed at the simulated composite material processing temperature of 150 ℃ for 1 hour to excite the expansion of the expanded microspheres, and after the temperature is raised for 3 hours at 80 ℃, the core material has a slightly larger size than that before heating under the balance effect of the self-strength of the expanded microspheres and the foam, which indicates that the core material can be tightly attached to the outer layer composite material due to the micro-expansion of the core material in the later process of the composite material, and this is the required result of the present invention. In comparative examples 1 to 3, the heat release of the early-stage foam reaction is high, the expanded microspheres are already expanded, in the subsequent high-temperature process, the foam shrinks like common polyurethane foam under the high-temperature action due to the absence of the foaming expansion action of the expanded microspheres, and in comparative example 4, the foam shrinks under the high-temperature action due to the absence of the expanded microspheres, so that the process and the product effect of the later-stage composite material are not facilitated.

Test example 5

The hard polyurethane foams of examples 1 to 4 and comparative examples were used, and carbon fiber fabrics and HR-688 and HR-660 epoxy resin glues, made by Xiamenhaole company under the model numbers FAW 450 and FAW 525, were used to prepare fiber composites by the following methods:

1) processing the polyurethane rigid foam by using a CNC (computer numerical control) machine tool until the specification is 9.8 x 9.8cm, the height is unchanged, polishing and cleaning with alcohol, brushing HR-688 glue solution, and attaching a layer of HR-660 on six surfaces;

2) coating carbon cloth, firstly adhering two surfaces, wherein the structure is 45/0/45/45(FAW is 525), then coating a peripheral structure 45/45/45(FAW is 450), placing the cloth into a 10 x3cm mould for molding at 150 ℃/1h, cooling for 10min and demoulding;

3) and (5) heating the product at 80 ℃/3h, and recording the specification change condition.

The performance was then tested as shown in table 4:

table 5 properties of the fibre composite produced:

group of	Appearance of fiber composite	Interlaminar condition of core material and composite material
			Example 1	Full and smooth	Integrated and tightly combined
Example 2	Full and smooth	Integrated and tightly combined
			Example 3	Full and smooth	Integrated and tightly combined
Example 4	Full and smooth	Integrated and tightly combined
			Comparative example 1	Surface insufficiency	The interlayer bonding is not tight and the delamination is partial
Comparative example 2	Surface insufficiency	The interlayer bonding is not tight and the delamination is partial
			Comparative example 3	Surface insufficiency	The interlayer bonding is not tight and the delamination is partial
Comparative example 4	Surface insufficiency	The interlayer bonding is not tight and the delamination is partial

As can be seen from the above table, the composite materials prepared in the examples have excellent appearance and bonding, while in the comparative examples 1 to 4, the foam core material shrinks at high temperature, so that the surface layer composite material is not subjected to expansion and extrusion of the core material, and the surface is not full, thus not only having poor appearance, but also affecting the function of the product and being unusable.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.