阅读说明：本技术 用于聚氨酯弹性体的蓖麻油基阻燃聚醚多元醇及其制备方法 (Castor oil-based flame-retardant polyether polyol for polyurethane elastomer and preparation method thereof ) 是由 朱光宁 公维英 孙兆任 周玉波 张士虎 于 2019-09-25 设计创作，主要内容包括：本发明属于聚醚多元醇的合成技术领域,具体的涉及一种用于聚氨酯弹性体的蓖麻油基阻燃聚醚多元醇及其制备方法。以蓖麻油、芳香族起始剂和小分子起始剂为混合起始剂,与环氧烷烃聚合得到的聚醚多元醇,羟值为40～80mgKOH/g,分子量为1950～2500,25℃下粘度为1500～3000mPa·s。本发明使用蓖麻油替代部分化石能源制备出聚醚多元醇,可以减少对不可再生资源的依赖,且方法简单,使用现有的生产装置和生产工艺即可实现工业化大生产；通过向聚醚多元醇中引入苯环、溴、氯等元素或基团,可以有效提高聚醚多元醇本身的阻燃性能,且用于聚氨酯弹性体中可有效提高制品的硬度和强度等力学性能。(The invention belongs to the technical field of synthesis of polyether polyol, and particularly relates to castor oil-based flame-retardant polyether polyol for a polyurethane elastomer and a preparation method thereof. The polyether polyol is obtained by polymerizing epoxy alkane with castor oil, an aromatic initiator and a small molecular initiator which are mixed initiators, wherein the hydroxyl value is 40-80 mgKOH/g, the molecular weight is 1950-2500, and the viscosity is 1500-3000 mPa & s at 25 ℃. The method uses the castor oil to replace part of fossil energy to prepare the polyether polyol, can reduce the dependence on non-renewable resources, is simple, and can realize industrialized mass production by using the existing production device and production process; by introducing elements or groups such as benzene rings, bromine, chlorine and the like into the polyether polyol, the flame retardant property of the polyether polyol can be effectively improved, and the mechanical properties such as hardness, strength and the like of a product can be effectively improved when the polyether polyol is used in a polyurethane elastomer.)

1. A castor oil based flame retardant polyether polyol for polyurethane elastomers is characterized in that: the polyether polyol is obtained by polymerizing epoxy alkane with castor oil, an aromatic initiator and a small molecular initiator which are mixed initiators, wherein the hydroxyl value is 40-80 mgKOH/g, the molecular weight is 1950-2500, and the viscosity is 1500-3000 mPa & s at 25 ℃.

2. The castor oil-based flame retardant polyether polyol for polyurethane elastomers of claim 1, wherein: the aromatic initiator is one or more of bisphenol A, bisphenol S, tetrabromobisphenol A, tetrabromobisphenol S or tetrabromophthalic anhydride, and the mixing molar ratio of the aromatic initiator to the castor oil is 10: 1-1: 1.

3. The castor oil-based flame retardant polyether polyol for polyurethane elastomers of claim 1, wherein: the small molecular initiator is one or more of ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, 1, 4-butanediol or glycerol.

4. A method for preparing the castor oil based flame retardant polyether polyol for polyurethane elastomers of claim 1, which is characterized in that: the method comprises the following steps:

(1) adding castor oil, an aromatic initiator and a DMC catalyst into a reaction kettle, mixing, dehydrating for 1-3 hours, adding a first part of alkylene oxide to perform an initiation reaction, adding a second part of alkylene oxide to perform a first polymerization reaction after the reaction activity is opened, continuing an internal pressure reaction for 0.5-1 hour after the reaction is finished, and then vacuumizing for 20-30 min to obtain an intermediate polyether polyol;

(2) and (2) continuously adding a third part of alkylene oxide and a small molecular initiator into the intermediate polyether polyol prepared in the step (1) to perform a second polymerization reaction, heating to 135-145 ℃ after the polymerization is finished, continuously adding a fourth part of alkylene oxide, continuously performing internal pressure reaction for 0.5-1 h after the reaction is finished, and then vacuumizing for 0.5-1 h to obtain the target polyether polyol.

5. The method for preparing a castor oil-based flame retardant polyether polyol for polyurethane elastomers according to claim 4, wherein: the temperature of the first polymerization reaction and the second polymerization reaction is 110-170 ℃.

6. The method for preparing a castor oil-based flame retardant polyether polyol for polyurethane elastomers according to claim 4, wherein: the first part of alkylene oxide in the step (1) is propylene oxide, and the mass usage amount of the first part of alkylene oxide is 5-15% of the sum of castor oil and aromatic initiator; the second part of alkylene oxide is one or more of propylene oxide, ethylene oxide, butylene oxide, epichlorohydrin or trichlorobutylene oxide.

7. The method for preparing a castor oil-based flame retardant polyether polyol for polyurethane elastomers according to claim 6, wherein: the second part of alkylene oxide is a mixture of propylene oxide and epichlorohydrin, and the mixing mass ratio is 1: 2-1: 10.

8. The method for preparing a castor oil-based flame retardant polyether polyol for polyurethane elastomers according to claim 4, wherein: the molecular weight of the intermediate polyether polyol obtained in the step (1) is 600-1000; the molar ratio of the small-molecule initiator to the intermediate polyether polyol in the step (2) is 1: 1-4: 1.

9. The method for preparing a castor oil-based flame retardant polyether polyol for polyurethane elastomers according to claim 4, wherein: in the step (2), the third part of alkylene oxide is one or more of propylene oxide, ethylene oxide, butylene oxide, epichlorohydrin or trichlorobutylene oxide, and the mass of the third part of alkylene oxide is 12-13% of the total mass of the alkylene oxide added in the step (2); the fourth part of alkylene oxide is one or more of propylene oxide, ethylene oxide, butylene oxide, epichlorohydrin or trichlorobutylene oxide.

10. The method for preparing a castor oil-based flame retardant polyether polyol for polyurethane elastomers according to claim 9, wherein: in the step (2), the third part of alkylene oxide is epichlorohydrin; the fourth part of the alkylene oxide is epichlorohydrin.

Technical Field

The invention belongs to the technical field of synthesis of polyether polyol, and particularly relates to castor oil-based flame-retardant polyether polyol for a polyurethane elastomer and a preparation method thereof.

Background

With the development of science and technology and social economy, polyurethane materials have been widely used in various fields of society. Polyurethane elastomers, as a main component of polyurethane materials, have been changed from military use to dual-purpose use for military and civilian use from the 20 th century to the 80 th century, and have been an essential material for people in daily life, since the product types thereof have been rapidly increased and the production capacity thereof has been increased year by year, mainly for civilian use. However, with the continuous decrease of non-renewable resources such as petroleum and the like, the environmental pollution is increasingly intensified, and the substitution of renewable biomass resources for petroleum-based polyols becomes a topic of great interest. The castor oil has the characteristics of wide source, low cost, reproducibility, no toxicity, degradability, environmental friendliness and the like, and is widely applied to the fields of elastomers, adhesives, coatings and the like. However, the castor oil-based polyurethane material also has the disadvantages of low oxygen index, easy combustion and the like, so that flame retardant treatment is required, the castor oil-based polyurethane material generally has two forms of an additive type and a reaction type, the micromolecule flame retardant of the castor oil-based polyurethane material can migrate out of the elastomer to reduce the flame retardant property, the micromolecule flame retardant of the castor oil-based polyurethane material can influence the mechanical property of the elastomer, and the castor oil-based polyurethane material generally has the disadvantages of complex preparation process and low application prospect.

Chinese patent 201510647119.2 discloses a preparation method of castor oil acid group flame-retardant polyether polyol, which has the disadvantages of various raw materials, complex preparation steps, high manufacturing cost and unsuitability for industrial mass production. Chinese patent 201310308777.X discloses a preparation method of a castor oil based flame retardant polyol polyurethane film, which adopts sodium methoxide, triethanolamine, phosphoric acid or triphenylphosphine as a catalyst, and adopts an organic solvent method to prepare the flame retardant polyol.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: overcomes the defects of the prior art and provides castor oil based flame retardant polyether polyol for polyurethane elastomers and a preparation method thereof. The polyether polyol prepared by the method not only has the advantages of narrow molecular weight distribution, low unsaturation degree and high molecular weight, but also can be used for producing polyurethane elastomers, and can obviously improve the flame retardant property and mechanical property of the polyurethane elastomers.

The castor oil-based flame-retardant polyether polyol for the polyurethane elastomer is prepared by polymerizing castor oil, an aromatic initiator and a small molecular initiator serving as mixed initiators with alkylene oxide to obtain the polyether polyol, wherein the hydroxyl value is 40-80 mgKOH/g, the molecular weight is 1950-2500, and the viscosity is 1500-3000 mPa & s at 25 ℃.

Wherein:

the aromatic initiator is one or more of bisphenol A, bisphenol S, tetrabromobisphenol A, tetrabromobisphenol S or tetrabromophthalic anhydride, and the mixing molar ratio of the aromatic initiator to the castor oil is 10: 1-1: 1.

The micromolecule initiator is one or more of ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, 1, 4-butanediol or glycerol, and is added to adjust the functionality of the polyether polyol and play a role in reducing the viscosity of the whole system.

The mass ratio of the total amount of the used alkylene oxide to the mixed initiator is 1: 5-1: 10, preferably 1: 6-1: 7.

The preparation method of the castor oil based flame retardant polyether polyol for the polyurethane elastomer comprises the following steps:

(1) adding castor oil, an aromatic initiator and a DMC catalyst into a reaction kettle, mixing, dehydrating for 1-3 hours, adding a first part of alkylene oxide to perform an initiation reaction, adding a second part of alkylene oxide to perform a first polymerization reaction after the reaction activity is opened, continuing an internal pressure reaction for 0.5-1 hour after the reaction is finished, and then vacuumizing for 20-30 min to obtain an intermediate polyether polyol;

(2) and (2) continuously adding a third part of alkylene oxide and a small molecular initiator into the intermediate polyether polyol prepared in the step (1) to perform a second polymerization reaction, heating to 135-145 ℃ after the polymerization is finished, continuously adding a fourth part of alkylene oxide, continuously performing internal pressure reaction for 0.5-1 h after the reaction is finished, and then vacuumizing for 0.5-1 h to obtain the target polyether polyol.

Wherein:

the alkylene oxide in the step (1) accounts for 7.5-10.5% of the total mass of the alkylene oxide in the step (1) and the step (2).

The first part of the alkylene oxide accounts for 11 to 21 percent of the mass of the alkylene oxide in the step (1).

The second part of the alkylene oxide accounts for 79 to 89 percent of the mass of the alkylene oxide in the step (1).

The alkylene oxide in the step (2) accounts for 89.5-92.5% of the total mass of the alkylene oxide in the step (1) and the step (2).

The third part of the alkylene oxide accounts for 12 to 13 percent of the mass of the alkylene oxide in the step (2).

The fourth part of the alkylene oxide accounts for 87 to 88 percent of the mass of the alkylene oxide in the step (2).

The dehydration in the step (1) is carried out under the conditions that the nitrogen replacement makes the oxygen content in the kettle less than 50ppm, the temperature is 105-135 ℃ and the vacuum degree is less than-0.09 MPa.

The temperature of the first polymerization reaction and the second polymerization reaction is 110-170 ℃, and preferably 125-140 ℃.

The first part of alkylene oxide in the step (1) is propylene oxide, and the mass usage amount of the propylene oxide is 5-15%, preferably 10% of the total mass of the castor oil and the aromatic initiator.

The second part of alkylene oxide in the step (1) is one or more of propylene oxide, ethylene oxide, butylene oxide, epichlorohydrin or trichlorobutylene oxide, preferably a mixture of propylene oxide and epichlorohydrin, and the mixing mass ratio is 1: 2-1: 10, preferably 1: 5.

The molecular weight of the intermediate polyether polyol obtained in the step (1) is 600-1000.

The molar ratio of the small-molecule initiator to the intermediate polyether polyol in the step (2) is 1: 1-4: 1, and preferably 1: 1.

The third part of alkylene oxide in the step (2) is one or more of propylene oxide, ethylene oxide, butylene oxide, epichlorohydrin or trichlorobutylene oxide, preferably epichlorohydrin, and the mass of the third part of alkylene oxide is 12-13%, preferably 12.5% of the total mass of the alkylene oxide added in the step (2).

In the step (2), the fourth part of alkylene oxide is one or more of propylene oxide, ethylene oxide, butylene oxide, epichlorohydrin or trichlorobutylene oxide, preferably epichlorohydrin, and the temperature is raised to 130-145 ℃ and then the epichlorohydrin is dripped, so that the end-capping efficiency can be effectively improved.

The castor oil-based flame-retardant polyether polyol prepared by the invention is reacted with raw materials such as polyisocyanate and a chain-extending cross-linking agent to prepare the polyurethane elastomer with excellent flame-retardant property.

As a preferred technical solution, the preparation method of the castor oil based flame retardant polyether polyol for polyurethane elastomer according to the present invention comprises the following steps:

(1) adding castor oil, an aromatic initiator and a DMC catalyst into a pressure-resistant reaction kettle, mixing, performing nitrogen replacement to ensure that the oxygen content in the kettle is less than 50ppm, and dehydrating for 1-3 hours at the temperature of 105-135 ℃ and the vacuum degree of less than-0.09 MPa; and then adding a first part of alkylene oxide for initiating reaction, adding a second part of alkylene oxide for carrying out a first polymerization reaction after the reaction activity is opened, continuing the internal pressure reaction for 0.5-1 h after the reaction is finished, fully reacting the added alkylene oxide, vacuumizing for 20-30 min, and removing unreacted alkylene oxide to obtain the intermediate polyether polyol.

(2) And (2) continuously adding a third part of alkylene oxide and a small molecular initiator into the intermediate polyether polyol prepared in the step (1) to perform a second polymerization reaction, heating to 135-145 ℃ after the polymerization is finished, continuously adding a fourth part of alkylene oxide, continuously performing internal pressure reaction for 0.5-1 h after the reaction is finished, and then vacuumizing for 0.5-1 h to obtain the target polyether polyol.

The renewable biomass raw material, namely castor oil, is added into the mixed initiator selected in the step (1) to replace part of petroleum-based raw materials, so that the dependence on non-renewable resources is effectively reduced, and the method has environmental protection significance on later industrial development.

The method comprises the steps of firstly preparing the polyether polyol with low molecular weight by a step-by-step feeding mode, and then continuously reacting the polyether polyol with the micromolecule initiator and the epoxy chloropropane, so that the purpose that the micromolecule initiator and the epoxy alkane are directly catalyzed by the bimetallic catalyst to be polymerized is realized, and the important breakthrough is realized in the field of synthesizing the polyether by DMC catalysis.

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

(1) according to the preparation method of the castor oil based flame retardant polyether polyol for the polyurethane elastomer, the castor oil is used for replacing part of fossil oil energy to prepare the polyether polyol, so that the dependence on non-renewable resources can be reduced, the method is simple, and the industrial mass production can be realized by using the existing production device and production process.

(2) According to the castor oil based flame retardant polyether polyol for the polyurethane elastomer, disclosed by the invention, elements or groups such as benzene rings, bromine, chlorine and the like are introduced into the polyether polyol, so that the flame retardant property of the polyether polyol can be effectively improved, and the hardness and the strength of a product can be effectively improved when the castor oil based flame retardant polyether polyol is used in the polyurethane elastomer.

(3) The castor oil-based flame-retardant polyether polyol prepared by the method not only has the advantages of narrow molecular weight distribution, low unsaturation degree and high molecular weight, but also can obviously improve the flame retardant property and the mechanical property of the polyurethane elastomer when being used for producing the polyurethane elastomer.

Detailed Description

The present invention is further described below with reference to examples.