阅读说明：本技术 一种阻燃硬质聚氨酯泡沫的制备方法 (Preparation method of flame-retardant rigid polyurethane foam ) 是由 闫云君 薄广旭 许小玲 何鑫 李凯 汪建华 田小可 万谦 于 2019-10-21 设计创作，主要内容包括：本发明属于阻燃材料领域,更具体地,涉及一种阻燃硬质聚氨酯泡沫的制备方法。将FRC-6、含有羟基的多元醇与含有环氧基团的长链烷烃混合,加入催化剂,在一定温度下使得长链烷烃的环氧基团发生开环接枝反应,获得开环产物；将获得的开环产物与FRC-6、添加型阻燃剂混合,在催化剂、表面活性剂、发泡剂存在条件下,在搅拌条件下与异氰酸酯反应,制得阻燃硬质聚氨酯泡沫。本发明使用了一种添加型阻燃剂和两种反应型阻燃剂,提高了阻燃材料的阻燃性能。最终简单测试结果表明,长×宽×高为8cm×8cm×1cm的泡沫在火焰温度为1300℃的高温喷枪下燃烧可达2分钟以上,且燃烧面与背面温度差在700℃以上。(The invention belongs to the field of flame-retardant materials, and particularly relates to a preparation method of flame-retardant rigid polyurethane foam. Mixing FRC-6, polyhydric alcohol containing hydroxyl and long-chain alkane containing epoxy groups, adding a catalyst, and performing ring-opening grafting reaction on the epoxy groups of the long-chain alkane at a certain temperature to obtain a ring-opening product; mixing the obtained ring-opening product with FRC-6 and an additive flame retardant, and reacting with isocyanate under stirring in the presence of a catalyst, a surfactant and a foaming agent to obtain the flame-retardant rigid polyurethane foam. The invention uses an additive flame retardant and two reactive flame retardants, thereby improving the flame retardant property of the flame retardant material. The final simple test results show that the foam with length x width x height of 8cm x 1cm can burn for more than 2 minutes under a high-temperature spray gun with the flame temperature of 1300 ℃, and the temperature difference between the combustion surface and the back surface is more than 700 ℃.)

1. The preparation method of the flame-retardant rigid polyurethane foam is characterized by comprising the following steps:

(1) mixing FRC-6, polyhydric alcohol containing hydroxyl, long-chain alkane containing epoxy group and organic solvent, adding catalyst to make the epoxy group of the long-chain alkane, FRC-6 and the polyhydric alcohol containing hydroxyl generate ring-opening grafting reaction to obtain a ring-opening product; wherein FRC-6 and a hydroxyl group-containing polyol are used as ring-opening agents;

(2) and (2) mixing the ring-opening product obtained in the step (1) with FRC-6 and an additive flame retardant, and reacting with isocyanate under stirring in the presence of a catalyst, a surfactant and a foaming agent to obtain the flame-retardant rigid polyurethane foam.

2. The method according to claim 1, wherein the long-chain alkane has not less than 10 carbon atoms.

3. The method according to claim 1 or 2, wherein the ratio of the total amount of the FRC-6 and the hydroxyl group in the hydroxyl group-containing polyol to the amount of the epoxy group-containing substance of the long-chain alkane having an epoxy group in step (1) is 3 to 10: 1.

4. The method according to claim 1, wherein the organic solvent in the step (1) is dichloromethane or acetone; the catalyst is fluoroboric acid.

5. The method according to claim 1, wherein the temperature of the ring-opening grafting reaction in the step (1) is 40 to 80 ℃ and the reaction time is 0.5 to 3 hours.

6. The method of claim 1, wherein the blowing agent of step (2) is water.

7. The method of claim 6, wherein the molar ratio of the total amount of the blowing agent, the ring-opening product and the hydroxyl group contained in FRC-6 in step (2) to the isocyanate group is 1:1 to 1: 1.5.

8. The method of claim 1, wherein the additive-type flame retardant of step (2) is aluminum hydroxide; the adding amount of the aluminum hydroxide is 160% of the mass of the isocyanate.

9. The application of the illegal cooking oil biodiesel is characterized in that the illegal cooking oil biodiesel is processed by taking illegal cooking oil as a raw material and is used for preparing flame-retardant rigid polyurethane foam.

10. Use according to claim 9, characterized in that it comprises the following steps:

(1) mixing FRC-6, polyhydric alcohol containing hydroxyl, long-chain alkane containing epoxy group and organic solvent, adding catalyst to make the epoxy group of the long-chain alkane, FRC-6 and the polyhydric alcohol containing hydroxyl generate ring-opening grafting reaction to obtain a ring-opening product; wherein FRC-6 and a hydroxyl group-containing polyol are used as ring-opening agents; the long-chain alkane containing the epoxy group is prepared by epoxidizing a carbon-carbon double bond of long-chain alkane containing an unsaturated carbon-carbon double bond; the long-chain alkane containing unsaturated carbon-carbon double bonds is biodiesel processed by taking illegal cooking oil as a raw material;

(2) and (2) mixing the ring-opening product obtained in the step (1) with FRC-6 and an additive flame retardant, and reacting with isocyanate under stirring in the presence of a catalyst, a surfactant and a foaming agent to obtain the flame-retardant rigid polyurethane foam.

Technical Field

The invention belongs to the field of flame-retardant materials, and particularly relates to a preparation method of flame-retardant rigid polyurethane foam.

Background

Rigid polyurethane foams are high molecular weight polymers having urethane linkages formed from polyols and isocyanates under the combined action of blowing agents, catalysts, foam stabilizers and the like. Along with the rapid development of economic society and high-rise forestation, rigid polyurethane foam which is a main product for building energy conservation is widely applied to high-rise buildings. However, the traditional rigid polyurethane foam is mostly prepared from fossil raw materials, is very easy to ignite and is easy to cause fire. Therefore, the development and use of rigid polyurethane foam having flame retardant properties is imminent.

At present, polyol used by flame-retardant rigid polyurethane foam is mainly derived from fossil raw materials, and the flame-retardant modes of the polyol are two types, namely additive flame-retardant rigid polyurethane foam and reactive flame-retardant rigid polyurethane foam. Although the additive type flame-retardant rigid polyurethane foam has simple process and low cost, the flame-retardant effect is not durable enough; the reactive flame-retardant rigid polyurethane foam has good flame-retardant stability, but has higher cost and complex production process.

Disclosure of Invention

Aiming at the defects or improvement requirements of the prior art, the invention provides a preparation method of flame-retardant rigid polyurethane foam, which comprises the steps of adopting a reaction type flame retardant with flame retardant property to carry out ring opening on long-chain alkane containing an epoxy group to obtain polyol with flame retardant property, and then further mixing the polyol with the reaction type flame retardant and another additive type flame retardant for foaming to prepare the flame-retardant rigid polyurethane foam.

To achieve the above objects, according to one aspect of the present invention, there is provided a method for preparing a flame retardant rigid polyurethane foam, comprising the steps of:

(1) mixing FRC-6, polyhydric alcohol containing hydroxyl, long-chain alkane containing epoxy group and organic solvent, adding catalyst, and performing ring-opening grafting reaction on the epoxy group of the long-chain alkane, FRC-6 and the polyhydric alcohol containing hydroxyl at a certain temperature to obtain a ring-opening product; wherein FRC-6 and a hydroxyl group-containing polyol are used as ring-opening agents;

(2) and (2) mixing the ring-opening product obtained in the step (1) with FRC-6 and an additive flame retardant, and reacting with isocyanate under stirring in the presence of a catalyst, a surfactant and a foaming agent to obtain the flame-retardant rigid polyurethane foam.

Preferably, the long-chain alkane contains no less than 10 carbon atoms.

Preferably, the ratio of the total amount of the FRC-6 and hydroxyl in the hydroxyl-containing polyol to the amount of epoxy groups in the epoxy-containing long-chain alkane in the step (1) is 3-10: 1.

Preferably, the ratio of the total mass of the FRC-6 and hydroxyl groups in the hydroxyl group-containing polyol to the mass of epoxide groups of the long-chain alkane containing epoxide groups is 7.5: 1.

Preferably, the organic solvent in step (1) is dichloromethane or acetone; the catalyst is fluoroboric acid.

Preferably, the temperature of the ring-opening grafting reaction in the step (1) is 40-80 ℃, and the reaction time is 0.5-3 hours.

Preferably, the catalyst in the step (2) is triethylamine or stannous octoate; the surfactant is silicone oil.

Preferably, the foaming agent of step (2) is water.

Preferably, the molar ratio of the total amount of the foaming agent, the ring-opening product and hydroxyl contained in FRC-6 in the step (2) to the isocyanate group is 1: 1-1: 1.5.

Preferably, the molar ratio of the total amount of blowing agent, ring-opening product and hydroxyl groups contained in FRC-6 to isocyanate groups is 1: 1.3.

Preferably, the additive flame retardant of step (2) is aluminum hydroxide; the adding amount of the aluminum hydroxide is 160% of the mass of the isocyanate.

Preferably, the additive flame retardant of step (2) is aluminum hydroxide; the addition amount of the aluminum hydroxide is 140% by mass of the isocyanate.

According to another aspect of the invention, the application of the illegal cooking oil biodiesel is provided, and the illegal cooking oil biodiesel is processed by taking illegal cooking oil as a raw material and is used for preparing flame-retardant rigid polyurethane foam.

Preferably, the application comprises the following steps:

(1) mixing FRC-6, polyhydric alcohol containing hydroxyl, long-chain alkane containing epoxy group and organic solvent, adding catalyst, and performing ring-opening grafting reaction on the epoxy group of the long-chain alkane, FRC-6 and the polyhydric alcohol containing hydroxyl at a certain temperature to obtain a ring-opening product; wherein FRC-6 and a hydroxyl group-containing polyol are used as ring-opening agents; the long-chain alkane containing the epoxy group is prepared by epoxidizing a carbon-carbon double bond of long-chain alkane containing an unsaturated carbon-carbon double bond; the long-chain alkane containing unsaturated carbon-carbon double bonds is biodiesel processed by taking illegal cooking oil as a raw material;

(2) and (2) mixing the ring-opening product obtained in the step (1) with FRC-6 and an additive flame retardant, and reacting with isocyanate under stirring in the presence of a catalyst, a surfactant and a foaming agent to obtain the flame-retardant rigid polyurethane foam.

In general, compared with the prior art, the above technical solution contemplated by the present invention can achieve the following beneficial effects:

(1) according to the invention, the commercial flame retardant FRC-6 with low price and wide source is subjected to long-chain alkane modification, and meanwhile, the FRC-6 is used as a ring-opening agent of the long-chain alkane containing an epoxy group, so that the polyol with flame retardant property is obtained and used as a soft segment of the hard polyurethane foam. Mixing with hard segment FRC-6 as polyurethane foam and additive flame retardant to foam to obtain the hard polyurethane foam.

(2) In the process of preparing the flame-retardant rigid polyurethane foam, the invention uses an additive flame retardant and two reaction flame retardants, improves the flame retardant property of the flame-retardant material, and improves the mechanical property and smoke suppression property to a certain extent. The final simple test results show that the foam with length x width x height of 8cm x 1cm can burn for more than 2 minutes under a high-temperature spray gun with the flame temperature of 1300 ℃, and the temperature difference between the combustion surface and the back surface is more than 700 ℃.

(3) The invention alleviates the brittleness problem of hard polyurethane foam by introducing hydroxyl-containing alkyl long chain.

(4) The invention can adopt the illegal cooking oil derivative-illegal cooking oil biodiesel as the initial raw material, has rich sources, saves energy, protects environment and can reduce environmental pollution; the initial raw material uses the polyol prepared by an epoxy ring-opening method as the flame-retardant polyol which is a ring-opening product, and the flame-retardant polyol can be used for preparing rigid polyurethane foam and can improve the flame-retardant property of the rigid polyurethane foam.

(5) According to the invention, the cheap and effective additive type flame retardant aluminum hydroxide, the flame-retardant illegal cooking oil biodiesel polyol and the reactive flame retardant with phosphorus-nitrogen synergistic flame retardance are used, and the three flame retardants are synergistic, so that the flame retardance and various physical and chemical properties of the hard polyurethane foam are improved, and the hard polyurethane foam can be used in the fields of buildings, automobiles, aerospace and the like.

Drawings

FIG. 1 is an infrared spectrum of a illegal cooking oil biodiesel (GOB), an epoxy illegal cooking oil biodiesel (EGOB), a flame retardant illegal cooking oil biodiesel polyol (FRPGOB);

FIG. 2 is an appearance diagram of flame-retardant rigid polyurethane foams prepared in example 2 and comparative examples 1 to 3;

FIG. 3 is the oxygen limit of the flame retardant rigid polyurethane foam prepared in example 2 and comparative examples 1 to 3;

FIG. 4 is a scanning electron microscope image of flame-retardant rigid polyurethane foams prepared in example 2 and comparative examples 1 to 3;

FIG. 5 is a TG curve of example 2 and comparative examples 1 to 3;

FIG. 6 is a graph of the combustion side and back side temperature of the flame retardant rigid polyurethane foam prepared in example 2.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

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

(1) mixing FRC-6, polyhydric alcohol containing hydroxyl, long-chain alkane containing epoxy group and organic solvent, adding catalyst, and performing ring-opening grafting reaction on the epoxy group of the long-chain alkane at a certain temperature to obtain a ring-opening product; wherein FRC-6 and a hydroxyl group-containing polyol are used as ring-opening agents;

(2) and (2) mixing the ring-opening product obtained in the step (1) with FRC-6 and an additive flame retardant, and reacting with isocyanate under stirring in the presence of a catalyst, a surfactant and a foaming agent to obtain the flame-retardant rigid polyurethane foam.

In some embodiments, the long-chain alkane containing epoxy groups of the present invention may be any of various long-chain alkanes containing epoxy groups. The long-chain alkane generally has a carbon number of not less than 10. The long-chain alkane containing an epoxy group plays a role in the present invention as a raw material for preparing a long-chain alkane having a hydroxyl group.

The long-chain alkane containing the epoxy group can also be long-chain alkane containing the epoxy group, which is prepared by epoxidizing long-chain alkane containing unsaturated carbon-carbon double bonds. For example, in some embodiments, the long-chain alkane containing unsaturated carbon-carbon double bonds is various oils, including biodiesel, castor oil, soybean oil, rapeseed oil, Chinese tallow kernel oil, and the like.

In some embodiments, the long-chain alkane containing unsaturated carbon-carbon double bonds is prepared from biodiesel prepared by processing waste oil as a raw material.

According to the invention, FRC-6 is used as a ring-opening agent of long-chain alkane containing an epoxy group, FRC-6 is used as a commercial flame retardant, and the long-chain alkane is connected with the FRC-6 through a ring-opening grafting reaction, so that the long-chain alkane has a certain flame retardant property. In the prepared rigid polyurethane foam, the flame retardant property is improved, and the brittleness is reduced.

Besides FRC-6, other polyol micromolecules containing hydroxyl, such as glycerol, glycol and the like are introduced to be used as ring-opening agents of long-chain alkanes containing epoxy groups at the same time, because the hydroxyl of the FRC-6 has a large steric hindrance effect, and the glycerol, the glycol and the like are used as the ring-opening agents and are also grafted on the long-chain alkanes containing the epoxy groups. The purpose is to increase the ring opening rate of long-chain alkane of epoxy group.

The invention mixes the ring-opening product obtained in the step (1) with FRC-6 and additive flame retardant to prepare the flame-retardant rigid polyurethane foam. Here FRC-6 is used as a flame retardant in commercial rigid polyurethane foams, as a hard stage in rigid polyurethane foams. And the ring-opening product long-chain alkane modified FRC-6 is used as a soft segment of the hard polyurethane foam. The two are used cooperatively to prepare the hard polyurethane foam with better flame retardant property and mechanical property.

The additive flame retardant can be a conventional additive flame retardant, such as aluminum hydroxide, the flame-retardant rigid polyurethane foam is prepared by uniformly blending two reactive phosphorus-nitrogen-containing intumescent flame retardants (FRC-6 and illegal cooking oil biodiesel flame-retardant polyol) and one additive flame retardant, and the intumescent reactive flame retardant and the additive flame retardant are mutually synergistic to jointly reduce harmful smoke generated by combustion of the rigid polyurethane foam and enhance the flame retardant property and mechanical property of the rigid polyurethane foam.

The intumescent reactive flame retardant participates in chemical reaction in the formation process of foam, and finally grafted to macromolecules forming the foam to play a role of a flame retardant. And when the foam burns, the foam expands volumetrically to form an expanded carbon remnant layer. Most of the conventional intumescent reactive flame retardants contain phosphorus, nitrogen and other elements. The additive flame retardant is also called as a blending flame retardant, is uniformly dispersed in the foam only in a physical blending mode in the preparation process of the foam, and plays a flame retardant role by utilizing the high temperature resistance of the additive flame retardant. The expansion type reaction flame retardant used in the invention is FRC-6 and swill-cooked dirty oil biodiesel flame retardant polyol (long-chain alkane containing hydroxyl), FRC-6 is taken as a hard section in hard polyurethane foam to improve the hardness of the foam, and the long-chain alkane containing hydroxyl is taken as a soft section in the hard polyurethane foam to adjust the flexibility of the foam; the cheap additive flame retardant with good flame retardant effect is aluminum hydroxide. During combustion, rigid polyurethane foam prepared by using FRC-6 and illegal cooking oil biodiesel flame-retardant polyol as an intumescent reaction type flame retardant expands to form a residual carbon layer which is not easy to drip, and part of additive type flame retardant is also remained in the residual carbon layer. When the aluminum hydroxide serving as the additive flame retardant is heated, the aluminum hydroxide absorbs heat and decomposes water vapor, so that combustion smoke is reduced, heat is taken away, and the surface temperature of foam is reduced; the residual carbon layer has more pores and lower heat conductivity coefficient, prevents the surface temperature of the foam from continuously propagating to the inside, and plays a role in flame retardance. In the experiment, the prepared foam is relatively fragile and poor in mechanical property only by using FRC-6 and aluminum hydroxide; the flame retardant properties of the foams prepared using only FRC-6 and long chain alkanes containing hydroxyl groups are not particularly desirable; only using long-chain alkane containing hydroxyl group and aluminum hydroxide, the foam prepared was not shaped. The three flame retardants are simultaneously used according to the proportion, the mechanical property and the flame retardance of the prepared rigid polyurethane foam can reach the best, and the flame retardant temperature can reach 1300 ℃.

The invention also provides application of the illegal cooking oil biodiesel, which is processed by taking the illegal cooking oil as a raw material and is used for preparing the flame-retardant rigid polyurethane foam.

In some embodiments, the application comprises the following steps:

(1) mixing FRC-6, polyhydric alcohol containing hydroxyl, long-chain alkane containing epoxy group and organic solvent, adding catalyst, and performing ring-opening grafting reaction on the epoxy group of the long-chain alkane, FRC-6 and the polyhydric alcohol containing hydroxyl at a certain temperature to obtain a ring-opening product; wherein FRC-6 and a hydroxyl group-containing polyol are used as ring-opening agents; the long-chain alkane containing the epoxy group is prepared by epoxidizing a carbon-carbon double bond of long-chain alkane containing an unsaturated carbon-carbon double bond; the long-chain alkane containing unsaturated carbon-carbon double bonds is biodiesel processed by taking illegal cooking oil as a raw material;

(2) and (2) mixing the ring-opening product obtained in the step (1) with FRC-6 and an additive flame retardant, and reacting with isocyanate under stirring in the presence of a catalyst, a surfactant and a foaming agent to obtain the flame-retardant rigid polyurethane foam.

In some embodiments, the ratio of the total amount of the FRC-6 and hydroxyl groups in the hydroxyl group-containing polyol to the amount of the epoxy groups in the epoxy group-containing long-chain alkane in step (1) is 3-10: 1, preferably 7.5: 1.

In some embodiments, the catalyst of step (1) is fluoroboric acid.

In some embodiments, an organic solvent is further added to the system in step (1), and the organic solvent is dichloromethane or acetone.

In some embodiments, the temperature of the ring-opening grafting reaction in the step (1) is 65-75 ℃, and the reaction time is 45-55 min.

In some embodiments, the catalyst in step (2) is triethylamine or stannous octoate, etc. The surfactant is silicone oil.

In some embodiments, the blowing agent of step (2) is water.

In some embodiments, the molar ratio of the total amount of the blowing agent water, the ring-opening product and hydroxyl groups contained in FRC-6 to the isocyanate groups is 1: 1.2-1: 1.4, preferably 1: 1.3. Experiments prove that the rigid polyurethane foam molded in the range has better mechanical property.

In a preferred embodiment, the additive flame retardant in the step (2) is aluminum hydroxide; the addition amount of the aluminum hydroxide is 160%, preferably 140% of the mass of the isocyanate.

The following are examples: