阅读说明：本技术 低温度敏感耐高温的聚醚多元醇的制备方法 (Preparation method of low-temperature sensitive high-temperature resistant polyether polyol ) 是由 高伟伟 邵家政 李晓芳 孙露霞 杨琦 于 2020-12-28 设计创作，主要内容包括：本发明涉及一种低温度敏感耐高温的聚醚多元醇的制备方法,属于聚醚多元醇改性技术领域。本发明所述的低温度敏感耐高温的聚醚多元醇的制备方法,是以高官能度原料和小分子醇为复合起始剂,在碱类催化剂的催化作用下,与环氧烷烃进行反应,得到所述的低温度敏感耐高温的聚醚多元醇；所述高官能度原料为蔗糖、山梨醇、木糖醇或四乙烯五胺中的一种或多种；所述小分子醇为甘油、三乙二醇、二乙二醇、季戊四醇、三羟甲基丙烷、丙二醇或乙二醇中的一种或多种。本发明设计科学合理,利用得到的聚醚多元醇制得的聚氨酯泡沫不但具有稳定的泡沫结构,还具有对外界温度变化的低敏感性和耐高温性能。(The invention relates to a preparation method of low-temperature sensitive high-temperature resistant polyether polyol, belonging to the technical field of polyether polyol modification. The preparation method of the low-temperature sensitive high-temperature resistant polyether polyol takes high-functionality raw materials and small molecular alcohol as a composite initiator, and the high-functionality raw materials and the small molecular alcohol react with alkylene oxide under the catalysis of an alkali catalyst to obtain the low-temperature sensitive high-temperature resistant polyether polyol; the high-functionality raw material is one or more of sucrose, sorbitol, xylitol or tetraethylenepentamine; the small molecular alcohol is one or more of glycerol, triethylene glycol, diethylene glycol, pentaerythritol, trimethylolpropane, propylene glycol or ethylene glycol. The invention has scientific and reasonable design, and the polyurethane foam prepared by using the obtained polyether polyol not only has a stable foam structure, but also has low sensitivity and high temperature resistance to external temperature change.)

1. A preparation method of low-temperature sensitive high-temperature resistant polyether polyol is characterized by comprising the following steps: taking a high-functionality raw material and small molecular alcohol as a composite initiator, and reacting with alkylene oxide under the catalysis of an alkali catalyst to obtain the low-temperature sensitive high-temperature resistant polyether polyol;

the high-functionality raw material is one or more of sucrose, sorbitol, xylitol or tetraethylenepentamine;

the small molecular alcohol is one or more of glycerol, triethylene glycol, diethylene glycol, pentaerythritol, trimethylolpropane, propylene glycol or ethylene glycol.

2. The method for preparing a low temperature sensitive high temperature resistant polyether polyol according to claim 1, wherein: the method comprises the following steps:

(1) putting a high-functionality raw material and small molecular alcohol into a kettle, adding an alkaline catalyst, sealing the kettle, heating to 100 ℃, and performing vacuumizing dehydration to control the moisture of the material in the kettle to be lower than 0.1%;

(2) controlling the temperature in the polymerization kettle, continuously dripping propylene oxide, controlling the actual temperature of the materials to react at 90-130 ℃ in the process, controlling the pressure in the kettle at 0.1-0.4MPa at the feeding speed, finishing dripping all the first part of propylene oxide by mass, and curing for 2-3 h;

(3) controlling the temperature in the kettle at 140 ℃ below zero and 140 ℃, controlling the pressure in the kettle at-0.08 MPa to-0.09 MPa by vacuumizing, and removing unreacted propylene oxide monomers for 1-2 hours;

(4 reducing the temperature in the reaction kettle to 75-85 ℃, adding phosphoric acid and water, stirring for 1-2h, adding an adsorbent, heating to 100-.

3. The method for preparing a low temperature sensitive high temperature resistant polyether polyol according to claim 2, wherein: the alkali catalyst is solid KOH.

4. The method for preparing a low temperature sensitive high temperature resistant polyether polyol according to claim 2, wherein: the addition amount of the alkali catalyst is 0.2-0.3% of the total crude polyether obtained by the polymerization reaction.

5. The method for preparing a low temperature sensitive high temperature resistant polyether polyol according to claim 2, wherein: in the step (2), the temperature in the polymerization kettle is controlled to be 90-130 ℃.

6. The method for preparing a low temperature sensitive high temperature resistant polyether polyol according to claim 2, wherein: in the step (4), the amount of the added phosphoric acid is 0.7 percent of the mass of the total crude polyether obtained by the polymerization reaction, the amount of the added pure water is 8 percent, and the amount of the added adsorbent is 0.2 percent.

7. The method for preparing a low temperature sensitive high temperature resistant polyether polyol according to claim 2, wherein: the adsorbent is magnesium silicate.

Technical Field

The invention relates to a preparation method of low-temperature sensitive high-temperature resistant polyether polyol, belonging to the technical field of polyether polyol modification.

Background

In order to scientifically utilize energy and reduce environmental pollution, a centralized heating mode is gradually adopted in the city at present, and heat is conveyed by using a pipeline. Therefore, the heat preservation effect of the heat supply pipeline is directly related to the reasonable utilization of energy. The polyurethane foam plastic has the advantages of excellent heat insulation performance, extremely low moisture absorption and humidity resistance, convenient forming performance and the like, and is a preferred material for urban central heating and heat preservation. Due to seasonal timeliness of the use of heat supply pipelines, the temperature is about 200 ℃ when heat supply is carried out in winter, and the temperature is normal after heat supply is stopped in summer, so that common rigid polyurethane foam plastic is difficult to bear strong temperature difference change to age, deform or crack.

In general, in a sharply-heated environment, severe internal stress can cause the fracture of a cross-linked structure inside a rigid polyurethane foam, while high temperature can cause dehydration and carbonization of a foam part, further increase the rigid structure of a system, and easily cause the cracking of the foam under the condition of the existence of high temperature and high temperature difference.

Disclosure of Invention

The invention aims to provide a preparation method of low-temperature sensitive high-temperature resistant polyether polyol, which is scientific and reasonable in design, and the polyurethane foam prepared by using the obtained polyether polyol not only has a stable foam structure, but also has low sensitivity and high-temperature resistance to external temperature change.

The preparation method of the low-temperature sensitive high-temperature resistant polyether polyol takes high-functionality raw materials and small molecular alcohol as a composite initiator, and the high-functionality raw materials and the small molecular alcohol react with alkylene oxide under the catalysis of an alkali catalyst to obtain the low-temperature sensitive high-temperature resistant polyether polyol;

the high-functionality raw material is one or more of sucrose, sorbitol, xylitol or tetraethylenepentamine;

the small molecular alcohol is one or more of glycerol, triethylene glycol, diethylene glycol, pentaerythritol, trimethylolpropane, propylene glycol or ethylene glycol.

Preferably, sorbitol is an aqueous solution of sorbitol at 70% solids with 30% moisture.

Preferably, xylitol is a 75% solids aqueous xylitol solution containing 25% moisture.

The preparation method of the low-temperature sensitive high-temperature resistant polyether polyol comprises the following steps:

(1) putting a high-functionality raw material and small molecular alcohol into a kettle, adding an alkaline catalyst, sealing the kettle, heating to 100 ℃, and performing vacuumizing dehydration to control the moisture of the material in the kettle to be lower than 0.1%;

(2) controlling the temperature in the polymerization kettle at 90-130 ℃. Continuously dripping propylene oxide, controlling the actual temperature of the materials to be between 90 and 130 ℃ for reaction in the process, controlling the pressure in the kettle to be between 0.1 and 0.4MPa at the feeding speed, finishing dripping all the first part of propylene oxide by mass, and curing for 2 to 3 hours;

(3) controlling the temperature in the kettle at 140 ℃ below zero and 140 ℃, controlling the pressure in the kettle at-0.08 MPa to-0.09 MPa by vacuumizing, and removing unreacted propylene oxide monomers for 1-2 hours;

(4 reducing the temperature in the reaction kettle to 75-85 ℃, adding phosphoric acid and water, stirring for 1-2h, adding an adsorbent, heating to 100-.

Preferably, the base catalyst is solid KOH.

Preferably, the amount of the alkali catalyst added is 0.2-0.3% of the total crude polyether obtained by the polymerization reaction.

According to the invention, by adjusting the structure of polyether, macromolecules with high crosslinking degree and micromolecules with low functionality degree are reasonably combined, and the rigidity is increased by the high crosslinking degree part to stabilize the foam structure; the intermolecular internal stress is counteracted through the long-chain structure with low crosslinking degree, and the phenomenon of fracture in an environment with violent temperature change is avoided. The invention reasonably adjusts the functionality, so that the prepared rigid polyurethane foam can keep excellent high temperature resistance and size and has certain flexibility in the foaming process. The polyether polyol prepared by the invention has both structural property and functional property, the hydroxyl value is between 340 and 360mg/KOH, the viscosity is between 1500 and 4000 mpa.s/25 ℃, and the functionality is between 4 and 5.

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

(1) according to the invention, a high-functionality raw material and a small molecular alcohol compound are used as a composite initiator to obtain polyether polyol with average functionality of 4-5, and the proper functionality enables the product to have enough structural stability and excellent thermal stability without fracture;

(2) the hydroxyl value of the product obtained by the invention is between 340 and 360mgKOH/g, the viscosity is between 1500 and 4000 mpa.s/25 ℃, the proper hydroxyl value is used as the skeleton of the rigid polyurethane foam, and the proper viscosity can ensure the strength and the fluidity when in use and can keep low sensitivity to the external temperature change under the condition of high temperature resistance.

Detailed Description

The present invention is further illustrated by the following examples, which are not intended to limit the practice of the invention.

The raw materials used in the examples are all commercially available products.

Example 1

330g of xylitol aqueous solution, 95g of trimethylolpropane and 5g solid KOH are put into a reaction kettle, the kettle is sealed, the temperature is raised to 100 ℃, and the operation of vacuumizing and dehydrating is carried out to control the moisture of the materials in the kettle to be lower than 0.1 percent. Controlling the temperature in the polymerization kettle to be 102 +/-2 ℃, continuously dripping propylene oxide, controlling the actual temperature of materials to be 102 +/-2 ℃ in the process, controlling the pressure in the polymerization kettle to be less than 0.4MPa at the feeding speed, completely dripping 1350g of propylene oxide, and curing for 3 hours. Controlling the temperature in the kettle to be between 122 plus or minus 2 ℃, controlling the pressure in the kettle to be between-0.08 and-0.09 MPa by vacuumizing, and removing unreacted propylene oxide monomers for 1 hour. Reducing the temperature in the reaction kettle to 80 +/-5 ℃, adding 11.75g of phosphoric acid and 85g of water, stirring for 1h, adding 2.62g of magnesium silicate, heating to 105 +/-5 ℃, vacuumizing and dehydrating to control the pressure in the kettle to be between-0.08 and-0.09 MPa, timing for 4h, detecting that the water content is lower than 0.1%, discharging and filtering to obtain a qualified polyether polyol finished product. The polyether polyol having a hydroxyl value of 341 mg. KOH/g and a viscosity of 3050 mPa. multidot.s/25 ℃ was obtained.

Example 2

250g of cane sugar, 100g of glycerol and 4.5g of solid KOHH are put into a reaction kettle, the kettle is sealed, the temperature is raised to 100 ℃, and the operation of vacuumizing and dehydrating is carried out to control the moisture of the materials in the kettle to be lower than 0.1%. Controlling the temperature in the polymerization kettle to be 102 +/-2 ℃, continuously dripping propylene oxide, controlling the actual temperature of materials to be 102 +/-2 ℃ in the process, controlling the pressure in the polymerization kettle to be less than 0.4MPa at the feeding speed, completely dripping 1150g of propylene oxide, and curing for 3 hours. Controlling the temperature in the kettle to be 112 plus or minus 2 ℃, controlling the pressure in the kettle to be-0.08 to-0.09 MPa by vacuumizing, and removing unreacted propylene oxide monomers for 1 hour. Reducing the temperature in the reaction kettle to 80 +/-5 ℃, adding 10.57g of phosphoric acid and 75g of water, stirring for 1h, adding 2.25g of magnesium silicate, heating to 105 +/-5 ℃, vacuumizing and dehydrating to control the pressure in the kettle to be between-0.08 and-0.09 MPa, timing for 4h, detecting that the water content is lower than 0.1%, discharging and filtering to obtain a qualified polyether polyol finished product. To obtain polyether polyol with hydroxyl value of 335mg KOH/g and viscosity of 3890mpa s/25 ℃.

Example 3

428.57g of sorbitol aqueous solution, 120g of propylene glycol and 6.5g of solid KOH6 are put into a reaction kettle, the kettle is sealed, the temperature is raised to 100 ℃, and the operation of vacuumizing and dehydrating is carried out to control the moisture of materials in the kettle to be lower than 0.1%. Controlling the temperature in the polymerization kettle to be 102 +/-2 ℃, continuously dripping propylene oxide, controlling the actual temperature of materials to be 102 +/-2 ℃ in the process, controlling the pressure in the polymerization kettle to be less than 0.4MPa at the feeding speed, completely dripping 1665g of propylene oxide, and curing for 3 hours. Controlling the temperature in the kettle to be 112 plus or minus 2 ℃, controlling the pressure in the kettle to be-0.08 to-0.09 MPa by vacuumizing, and removing unreacted propylene oxide monomers for 1 hour. Reducing the temperature in the reaction kettle to 80 +/-5 ℃, adding 15.27g of phosphoric acid and 104.57g of water, stirring for 1h, adding 3.14g of magnesium silicate, heating to 105 +/-5 ℃, vacuumizing and dehydrating to control the pressure in the kettle to be-0.08 to-0.09 MPa, timing for 4h, detecting that the water content is lower than 0.1%, discharging and filtering to obtain the qualified polyether polyol finished product. A polyether polyol having a hydroxyl value of 351mg KOH/g and a viscosity of 2150mPa s/25 ℃ was obtained.

Comparative example 1

428.57g of sorbitol aqueous solution and 4.8g of solid KOH4 are put into a reaction kettle, the kettle is sealed, the temperature is raised to 100 ℃, and the vacuum pumping dehydration operation is carried out to control the moisture of materials in the kettle to be lower than 0.1 percent. Controlling the temperature in the polymerization kettle to be 102 +/-2 ℃, continuously dropwise adding propylene oxide, controlling the actual temperature of materials to be 102 +/-2 ℃ in the process, controlling the pressure in the polymerization kettle to be less than 0.4MPa at the feeding speed, completely dropwise adding 1280g of propylene oxide, and curing for 3 hours. Controlling the temperature in the kettle to be 112 plus or minus 2 ℃, controlling the pressure in the kettle to be-0.08 to-0.09 MPa by vacuumizing, and removing unreacted propylene oxide monomers for 1 hour. Reducing the temperature in the reaction kettle to 80 +/-5 ℃, adding 11.28g of phosphoric acid and 79.25g of water, stirring for 1h, adding 2.39g of magnesium silicate, heating to 105 +/-5 ℃, vacuumizing and dehydrating to control the pressure in the kettle to be-0.08 to-0.09 MPa, timing for 4h, detecting that the water content is lower than 0.1%, discharging and filtering to obtain the qualified polyether polyol finished product. The obtained polyether polyol has a hydroxyl value of 354mg KOH/g and a viscosity of 11190mpa s/25 ℃.

By combining the above examples and comparative examples, the low temperature sensitivity high temperature resistant polyether comprises the component A and the component B with the mass ratio of 1:1.2, and the components are calculated by weight parts.

The component A comprises: weighing 100 parts of polyether polyol, 1.5 parts of water, 2 parts of closed-cell silicone oil, 1 part of PC-8 catalyst and 14 parts of cyclopentane, uniformly mixing the weighed materials to obtain a product with a qualified component A, weighing A, B components according to the weight ratio of A: mixing B in a weight ratio of 1:1.2 to prepare the polyurethane thermal insulation material for the pipeline, placing the polyurethane thermal insulation material in a high-temperature oven for 1h, taking out the polyurethane thermal insulation material, placing the polyurethane thermal insulation material in a refrigerator for 1h, and repeating the steps for 3 times.

Table 1 analysis results of experimental data of examples and comparative examples