KR102599477B1 - Polymer polyols by recycling rigid urethane foams and a method of manufacturing the same - Google Patents

Abstract

The present invention provides a method for producing recycled polymer polyol. The present invention includes the first step of obtaining a primary liquefied depolymerization product by performing a glycolysis reaction by adding 50 to 150 parts by weight of glycol to 100 parts by weight of rigid polyurethane foam scrap collected from rigid polyurethane foam products; 50 to 150 parts by weight of the isocyanate component is added to 100 parts by weight of the first liquefied depolymerization obtained in the first step, and a relatively highly reactive compound is reacted with the isocyanate component, resulting in a relatively highly reactive compound. A second step of gradually exhausting to obtain a secondary liquefied depolymerization product with uniform reactivity; A third step of obtaining a recycled polymer polyol by adding and mixing 25 to 150 parts by weight of the secondary liquefied depolymerization obtained in the second step with respect to 100 parts by weight of the new polyol; It includes.

Description

Rigid urethane foam recycling polymer polyol and its manufacturing method {Polymer polyols by recycling rigid urethane foams and a method of manufacturing the same}

The present invention relates to a recycled polymer polyol and a method for producing the same, and more specifically, to obtain a depolymerized product through glycolysis using scraps of rigid urethane foam, and to process the depolymerized product again to produce urethane in a conventional manner. It relates to a recycled polymer polyol that can stably and efficiently produce high-quality rigid polyurethane foam products even when undergoing reaction or urea reaction and a method for producing the same.

Today, appropriate treatment technology for various wastes generated after use has emerged as a very important task in terms of protecting the global environment for the future of humanity. In the case of polyurethane, hard polyurethane foam scraps, which were most commonly used as insulation in waste refrigerators, are generally recovered at home appliance recycling centers, and soft polyurethane foam scraps are recovered from car seats or bed mattresses. It is known that these amounts amount to approximately 40,000 tons per year based on domestic standards, and most of them are incinerated. This is because most polyurethane products are cross-linked polymers with a network structure, making recycling through physical melting difficult. However, polyurethane generates fatal amounts of hydrogen cyanide and carbon monoxide when burned, so extreme caution is required when operating incineration facilities. (Reference: McKenna and Hull, Fire Science Reviews , 5, 3 (2016))

Rigid polyurethane foam has excellent insulation performance and mechanical strength and is used in the manufacture of refrigerator insulation, freezer and refrigerated container insulation, and building insulation. Used rigid polyurethane foam scrap can be recycled by chemically processing it to produce polyol that can be used to manufacture polyurethane foam insulation.

Rigid polyurethane foam, which is used as a variety of insulation materials, is based on a chemically cross-linked structure, so it is not easy to recycle after use. Therefore, glycol is commonly added to solid polyurethane scrap to liquefy it through a depolymerization reaction through glycolysis at around 200°C. If necessary, recycled polyol is produced through a denaturation process and used again as a raw material for manufacturing polyurethane foam. The reaction involved in the depolymerization process of urethane and urea groups through glycolysis can be shown in Figures 1 and 2 [Reference 1, Reference 2].

If the recycled polyol contains primary amines and secondary amines generated in the glycolysis reaction and these are involved in the reaction, it becomes difficult to control the reaction in the manufacturing process due to high reactivity when used to manufacture polyurethane foam. Therefore, mixing with new polyol is inevitable, and increasing the recycled polyol content is limited. Therefore, in order to control the high reactivity due to these amine compounds, it is possible to convert them into hydroxyl groups by adding a compound such as propylene oxide or ethylene oxide, but it requires a high-pressure reactor [Reference 2]. Meanwhile, compounds with an epoxy group can be used for the same purpose, but they have the disadvantage of being less economical [Reference 3]. Therefore, the problem of high reactivity due to amine compounds contained in the depolymerization product through glycolysis must be solved when using recycled polyol to produce urethane.

In the refrigerator manufacturing process that uses rigid polyurethane foam as an insulating material and the insulating foam manufacturing process such as building board or sandwich panel, the internal temperature rises to over 150℃ due to the high heat of reaction [4]. In the manufacture of such rigid polyurethane foam insulation, when rapid cooling occurs, residual stress occurs and deformation occurs due to differences in cooling rates depending on the area, so securing an appropriate cooling time is required to prevent this. Meanwhile, in the manufacturing process of rigid polyurethane foam insulation, auxiliary foaming agents such as low-boiling hydrocarbons, methyl formate, and hydrogen fluoride compounds are used to reduce heat generation. Nevertheless, there is an advantage in improving productivity if the calorific value can be lowered, so improvement in calorific value control technology is necessary.

As a result, when recycling technology for polyurethane scrap is applied today, there is a disadvantage that it is difficult to obtain high-quality polyurethane foam products unless the urethane reaction process is precisely controlled due to the generally high reactivity of recycled polyol. Therefore, there is a need to find ways to lower the reactivity of recycled polyol.

In addition, when isocyanate is reacted with recycled polyol and water used in the production of rigid polyurethane foam insulation, high-temperature heat is inevitably generated, and a cooling process is essential, which has the disadvantage of causing shrinkage of the product. Therefore, even in the process of manufacturing polyurethane foam insulation using recycled polyol, there is a great demand for the development of technology that can reduce the calorific value.

U.S. Patent No. 5,300,530 “Process for modifying the glycolysis reaction product of polyurethane scrap”;

J. Borda, G. Pasztor, and M. Zsuga, “Glycolysis of polyurethane foams and elastomers,” Polymer Degradation and Stability, 68, 419-422 (2000); M.G. Kim, S. H. Kim, J. H. Chun, and Y. S. Lee, “Deamination of MDA in the Recycled Polyol Obtained from the Glycolyiiis of Waste MDI Based Polyurethane Foam” International Journal of Safety, 4, 14-17 (2005); R. E. Welte, “Calculation and measurement of reaction temperatures in rigid polyurethane and isocyanurate foams” Journal of cellular plastics, 5, 351 (1984); V. Zhao and G. J. Suppes, “Computational study on reaction enthalpies of urethane-forming reactions,” Polymer Engineering and Science, 1421 (2015).

The present invention is intended to solve the problems of the prior art, by obtaining a depolymerization product through glycolysis using scraps of rigid urethane foam and processing the depolymerization product again to produce a urethane reaction or urea reaction in a conventional manner. The purpose is to provide a recycled polymer polyol and a manufacturing method thereof that can stably and efficiently manufacture high-quality rigid polyurethane foam products even when the reaction proceeds.

The present invention includes the first step of obtaining a primary liquefied depolymerization product by performing a glycolysis reaction by adding 50 to 150 parts by weight of depolymerized polyol to 100 parts by weight of rigid polyurethane foam scrap collected from rigid polyurethane foam products;

50 to 150 parts by weight of the isocyanate component is added to 100 parts by weight of the first liquefied depolymerization obtained in the first step and stirred to cause a relatively highly reactive compound to react with the isocyanate component. As a result, a relatively reactive compound is reacted with the isocyanate component. A second step in which high compounds are gradually consumed to obtain a secondary liquefied depolymerization product with uniform reactivity;

A third step of obtaining a recycled polymer polyol by adding and mixing 25 to 100 parts by weight of the secondary liquefied depolymerization obtained in the second step with respect to 100 parts by weight of the new polyol; It includes.

The present invention targets rigid polyurethane foam scraps, performs a depolymerization reaction on the rigid polyurethane foam scraps to obtain a primary liquefied depolymerization product, and the components of the primary liquefied depolymerization product have different reactivity and are relatively Recognizing that highly reactive substances and relatively normal reactive substances are mixed together, by exhausting the highly reactive substances in advance before actually proceeding with the urethane reaction or urea reaction of the depolymerization in the dispersed phase, the urethane reaction or Its technical feature is to allow the urea reaction to proceed smoothly. Examples of the relatively highly reactive compound include compounds derived from the rigid polyurethane foam scrap and having a primary amine group, a secondary amine group, or a primary hydroxyl group.

By realizing these technical features, the present invention can obtain a polymer polyol compound by chemically treating the highly reactive amine compound inevitably generated in the depolymerization reaction of hard polyurethane foam scrap in advance, and combining the polymer polyol compound and the new polyol. By mixing, recycled polyol can be obtained, and when the recycled polyol is later used again to manufacture urethane foam, the problem of difficulty in controlling reactivity can be solved.

It is generally desirable to use a polyol used in the production of rigid polyurethane foam with a hydroxyl value of about 400 mgKOH/g. In this case, about 2 phr of water, which generates carbon dioxide, is added to 100 polyols by weight, and the amount of isocyanate added is defined as Index 100, which is the amount required to achieve 100% reaction stoichiometrically. It is recommended to add the Index value above 100. desirable. Under these conditions, when Polymeric Methylene Diphenyl Diisocyanate (MDI) with an NCO content of 31% by weight is used as an isocyanate, the amount of MDI required by polyol in the mixture in which 2 parts by weight of water is added to 100 parts by weight of polyol is 104 parts by weight, The MDI required by water is 30 parts by weight, which is 78% and 22% in percentage, respectively. And the heat of reaction between isocyanate and polyol or water and amine is about 85 kJ/eq. If we assume the specific heat of the reactants to be about 2 J/g without considering the cooling effect due to vaporization of the auxiliary blowing agent, this theoretically entails a temperature rise of 178°C. This calculation is in accordance with measurements of exothermic temperature rise in the literature and It's at a similar level. Therefore, when using the above-described polymer polyol (polymer content: 50%), the reaction with isocyanate by polyol already includes a dispersed phase formed of polymer, so when manufacturing rigid polyurethane foam using polymer polyol, the calorific value generated by polyol This can be reduced by up to 50%, so heat generation due to reaction in the process can be reduced by up to 37%, and temperature rise can also be greatly reduced.

The rigid polyurethane foam recycled polymer polyol produced by the present invention, unlike existing recycled polyols, has recycled components present in a dispersed phase cross-linked to the new polyol, so its reactivity is not as fast as in the past and can be easily controlled. There is an advantage.

In addition, the rigid polyurethane foam recycled polymer polyol produced by the present invention exists with a reduced content of reactive components within the polyol unit mass, so when using it to manufacture a rigid polyurethane foam insulation material, it naturally The heat of reaction is reduced, which reduces the temperature rise, so the cooling process can proceed more easily, which also has the advantage of improving productivity.

Figure 1 is a reaction scheme in which, when the urethane group of polyurethane is depolymerized by glycolysis, the polymer chain is cut and depolymerized into hydroxyl groups and secondary amines,
Figure 2 is a reaction scheme in which, when the urea group of polyurethane is depolymerized by glycolysis, the polymer chain is cut and depolymerized into primary amine, hydroxyl group, and secondary amine,
Figure 3 schematically shows the polymer polyol obtained by dispersing the depolymerized product formed by breaking the polymer chain through glycolysis of polyurethane into a new polyol while mixing it with isocyanate and proceeding with the reaction.

Hereinafter, the present invention will be described in more detail and detail. It is clear that the specific numerical values or specific examples provided in the present invention are preferred embodiments of the present invention, and are only intended to explain the technical idea of the present invention in more detail, and the present invention is not limited thereto. In addition, in the specification of the present invention, detailed description of parts that are known in the technical field and can be easily created by those skilled in the art will be omitted.

The present invention includes a first step of obtaining a primary liquefied depolymerization product by performing a glycolysis reaction by adding 50 to 150 parts by weight of depolymerization polyol to 100 parts by weight of rigid polyurethane foam scrap collected from rigid polyurethane foam products, there is. Hard polyurethane scrap is generated during the dismantling process of used refrigerator products and various building insulation products, and their raw material compositions are chemically similar in that the main raw materials are polyol and polyisocyanate. . For the sake of explanation, the present invention uses used refrigerator insulation scrap as a specific example, but various rigid polyurethane foams and elastic materials can also be chemically treated using the same principle.

In the present invention, hard polyurethane scrap is depolymerized through glycolysis reaction by adding polyol in the range of 140 to 240 ° C. Examples of the hard polyurethane scrap include refrigerator insulation scrap, building insulation scrap, and sandwich panel insulation scrap. The polyol is added to depolymerize the hard polyurethane scrap, and is one selected from the group consisting of ethylene glycol, propylene glycol, dipropylene glycol, low molecular weight ether polyol, low molecular weight ester polyol, and copolymerized polyol. Two or more can be mixed and used.

In consideration of convenience of explanation, the present invention will be described by selecting and using the hard polyurethane scrap as refrigerator insulation scrap, and in the case of the polyol, propylene glycol is selected from glycol compounds. This depolymerization reaction proceeds as a glycolysis reaction in the range of 140 to 240°C, and this process may involve reactions such as hydrolysis and thermal decomposition. Additionally, organometallic catalysts and antioxidants can be added for effective reactions.

This glycolysis reaction is shown in a representative chemical equation in Figures 1 and 2.

In the present invention, when the depolymerization reaction of the first step is completed, a first liquefied depolymerization product of hard polyurethane scrap is obtained. This first liquefied depolymerization product is composed of polyol, amine compound derived from isocyanate, and residual glycol, and these are usually observed uniformly. At this time, since the isocyanate is derived from the hard polyurethane scrap, it can be seen that the amine compound is ultimately derived from the scrap of waste rigid polyurethane foam. The amine compound is more reactive than other components, so if it remains as is, it acts as a realistic obstacle that makes it difficult to normally control the urethane reaction or urea reaction that will proceed later. In the present invention, the amine compound may be referred to as a highly reactive compound.

In the present invention, as a second step, 50 to 150 parts by weight of an isocyanate compound is added and mixed with 100 parts by weight of the first liquefied depolymerization obtained in the previous step to obtain a secondary liquefied depolymerization. At this time, it is preferable to add and mix the isocyanate compound so that it can stoichiometrically react with 50% or more of active hydrogen.

In the present invention, the reason for adding isocyanate to the first liquefied depolymerization is that, firstly, the highly reactive components present in the first liquefied depolymerization react preferentially and remain dispersed rather than dissolved in the new polyol. , Second, in a situation where the first liquefied depolymer reacts with isocyanate to form a polymer and is dispersed in the new polyol, this is to maintain the reactivity of the new polyol when used as a polyol for producing polyurethane foam. Third, Ultimately, in the reaction process for manufacturing rigid polyurethane insulation, a small amount participates in the reaction as much as the fraction present as a polymer in polyol, thereby reducing heat generation and temperature rise due to reaction in the urethane insulation foam manufacturing process, making cooling easier and improving productivity. This is because it has suitable characteristics.

In the present invention, the isocyanate component may be an isocyanate component used in this technical field. For example, it is preferable to use polyisocyanate containing toluene diisocyanate (TDI), 4,4-phenyl methane diisocyanate (MDI), or polymeric MDI.

According to the present invention, when isocyanate is added stoichiometrically to 50% or less with respect to 100 parts by weight of the first liquefied depolymerization, there is a very high possibility that an uncrosslinked composition will exist in the second liquefied depolymerization. As a result, This is undesirable because there is a risk that it may dissolve in the new polyol to be added in the next step.

In the present invention, the isocyanate addition reaction can be carried out at 25 to 120°C. At this time, the hard polyurethane scrap used as the starting material undergoes glycolysis to exist as various depolymers, and among them, the relatively highly reactive compound reacts with the isocyanate added in the second step, so the highly reactive compound It is gradually converted into a new reactant.

In the present invention, when comparing the secondary liquefied depolymerization obtained in the second step with the primary liquefied depolymerized product obtained in the first step, the highly reactive compound contained in the secondary liquefied depolymerization It can be seen that the composition ratio is lower and exists in smaller quantities compared to the composition ratio of the highly reactive compound contained in the first liquefied depolymerization.

In the present invention, in the third step, 25 to 100 parts by weight of the secondary liquefied depolymerization obtained in the second step is added to 100 parts by weight of the new polyol and mixed to obtain a recycled polymer polyol. If the secondary liquefied depolymerization is included in an amount of 25 parts by weight or less based on 100 parts by weight of the new polyol, the recycling rate is low and thus undesirable, and if it is included in more than 100 parts by weight, it becomes difficult for the new polyol to maintain a continuous phase, and the new material It does not exhibit polyol reactivity, making it undesirable. In this case, the recycled polymer polyol exists in a form in which polyurethane-urea particles obtained from depolymerization are uniformly dispersed in the new polyol.

Figure 3 conceptually illustrates the appearance of this recycled polymer polyol.

In order to explain the technical features more clearly, the present invention clearly distinguishes between the second step and the third step. However, in actual work, the order of these steps is not strictly distinguished, and they are carried out simultaneously with each other. It can be implemented. However, the stoichiometric input amount or input ratio does not change.

In the present invention, the material obtained in this way is named recycled polymer polyol, but considering its practical characteristics, it can be named hard polyurethane dispersed polymer polyol.

In the present invention, the rigid polyurethane dispersed polymer polyol obtained in this way can be used to produce rigid polyurethane foam products through urethane and urea formation reaction in a conventional manner.

In this case, highly reactive substances are almost absent or present in relatively very small amounts in the rigid polyurethane dispersed polymer polyol according to the present invention. Therefore, when the final product is manufactured through a urethane reaction or a urea reaction, the manufacturing process is easy to control because it shows a stable reaction, and the subsequent cooling process can be simplified or simplified because the exothermic reaction occurs relatively less.

Hereinafter, the present invention will be described in more detail by examples.

<< Example 1 >>

200 grams of pulverized polyurethane foam scrap generated during the dismantling process of a used refrigerator was divided and added to 100 grams of propylene glycol (molecular weight: 76 g/mol) in a 1 liter reactor maintained at 200°C.

When solid scrap is added to propylene glycol, liquefaction proceeds through glycolysis at a very rapid rate. In general, equilibrium is reached after 4 hours of reaction, and through this, the first liquid glycolysis depolymerization product is obtained. The hydroxyl value of the first liquid depolymerization was 480 mgKOH/g, and the viscosity at 25°C was 10,000 cps.

<< Example 2 >>

In Example 1, the rest was carried out in the same manner as in Example 1, except that 200 grams of the pulverized polyurethane foam scrap was used and 200 grams of the propylene glycol was used.

As a result, the hydroxyl value of the first liquid depolymerization was 720 mgKOH/g, and the viscosity at 25°C was 6,000 cps.

<< Example 3 >>

In Example 1, the rest was carried out in the same manner as in Example 1, except that 100 grams of the pulverized polyurethane foam scrap was used and 150 grams of the propylene glycol was used.

As a result, the hydroxyl value of the first liquid depolymerization was 870 mgKOH/g, and the viscosity at 25°C was 3,000 cps.

<< Example 4 >>

50 grams of the depolymerization obtained in Example 1 and 25 grams of TDI were mixed, and 300 grams of glycerin/sugar type polyether polyol with a hydroxyl value of 490 was added, divided into three times and stirred.

After the final injection was completed, the hard polyurethane foam scrap was reacted with TDI, and the resulting polymer was dispersed in the new polyol to obtain a colloidal recycled polymer polyol. The hydroxyl value of the obtained recycled polymer polyol was 390 mgKOH/g, the viscosity was 2,000 cps, and the average volume particle size of the dispersed polymer was 0.8 micron.

<< Example 5 >>

Except that in Example 4, 112.5 grams of the glycerin/sugar type polyether polyol having a hydroxyl value of 490 was used, the rest was carried out in the same manner as in Example 4.

The hydroxyl value of the obtained recycled polymer polyol was 290 mgKOH/g, the viscosity was 4,000 cps, and the average particle size of the dispersed phase polymer was 1.0 micron.

<< Example 6 >>

Except that in Example 4, 75 grams of the glycerin/sugar type polyether polyol having a hydroxyl value of 490 was used, the rest was carried out in the same manner as in Example 4.

The hydroxyl value of the obtained recycled polymer polyol was 243 mgKOH/g, the viscosity was 7,000 cps, and the average volume particle size of the dispersed polymer was 1.1 micron.

Below, the purpose was to examine whether rigid polyurethane foam can be manufactured using the recycled polymer polyol obtained by the manufacturing method of the present invention and the change in internal heating temperature during the manufacturing process.

<< Example of commercialization application >>

To manufacture rigid polyurethane foam using the rigid polyurethane dispersed polymer polyol obtained in Example 4, the composition shown in <Table 1> below was used.

As confirmed in <Table 1> below, the additive composition was applied in the same ratio as the raw material composition of conventional polyurethane foam.

The new polyol, recycled polymer polyol, and additives shown in <Table 1> were weighed at 25°C, added to the reaction cup, and mixed with a high-speed stirrer at 2000 rpm for 1 minute. After adding polymeric diphenyl methane diisocyanate in a quantity determined by the composition to the mixture, it was further mixed for 10 seconds with a high-speed stirrer, and then introduced into a box made of wood measuring 400 , cream time, gel time, and tack free time were measured during the reaction process, and the internal temperature rise was observed using a thermometer.

Raw material mixing ratio for manufacturing rigid polyurethane foam using recycled polymer polyol of the present invention
sample name Composition ratio (parts by weight) A - 0 A-25 A-50 A-75 A - 100 Polyol part New polyol (JOP-0585) 100.0 75.0 50.0 25.0 0 Recycled polymer polyol 0 25.0 50.0 75.0 100.0 antiseptic B-8462 2.0 2.0 2.0 2.0 2.0 Catalyst(1) HEX CEM-977 0.3 0.3 0.3 0.3 0.3 Catalyst (2) PC-8 3.0 3.0 3.0 3.0 3.0 flame retardant TCPP 15.0 15.0 15.0 15.0 15.0 Foaming agent (1) Water 2.0 2.0 2.0 2.0 2.0 Foaming agent (2) Cyclopentane 20.0 20.0 20.0 20.0 20.0 Isocyanate part NCO Index 120 120 120 120 120

Polyurethane reaction was performed based on the raw material samples with each composition ratio shown in Table 1, and the reactivity data and maximum internal temperature rise measured during the manufacturing process were measured, and the results are shown in the table below. 2 > is presented.

This examines whether the product manufactured by the method of the present invention shows a certain degree of difference compared to the product manufactured by the conventional method, and ultimately determines whether its suitability as a polyurethane foam can be recognized. It was for evaluation.

Reactivity of rigid polyurethane foam applied with recycled polymer polyol of the present invention characteristic A - 0 A-25 A-50 A-75 A - 100 Cream time(sec) 12 12 11 10 10 Gel time(sec) 80 79 78 76 75 Tack free time(sec) 125 124 122 121 120 Internal maximum temperature (℃) 160 150 140 130 120

As confirmed in Table 2 above, in the polyurethane foam manufacturing process, reactivity tended to become slightly faster with the addition of hard polyurethane dispersed polymer polyol, but it was not at a level that was problematic. In addition, the internal temperature rise due to heat generation was greatly reduced depending on the amount of recycled polymer polyol added according to the present invention, thereby shortening the cooling time, and the advantage of contributing to improved productivity was confirmed.

In conclusion, the disadvantage was that it was difficult to control due to the fast reactivity observed when applying to hard polyurethane foam scrap in the conventional method, but in the case of the new method according to the present invention, when applied to hard polyurethane foam scrap, It was confirmed that the problem could be overcome.

Moreover, it was empirically confirmed that the new method according to the present invention can be directly applied at work sites in practice, has the advantage of increasing productivity, and that the performance of the final product is not inferior to that of existing products.

Although the recycled polymer polyol and its production method according to the present invention have been specifically presented above, this is only specified in the process of explaining the embodiments of the present invention, and all features of the present invention are limited to apply only to the items mentioned above. It should not be interpreted as such.

In addition, anyone skilled in the art will be able to make various modifications and imitations based on the contents of the specification of the present invention, but it will be clear that these are not beyond the scope of the present invention.

Claims (6)

A first step of obtaining a primary liquefied depolymerization product by performing a glycolysis reaction by adding 50 to 150 parts by weight of polyol to 100 parts by weight of rigid polyurethane foam scrap collected from rigid polyurethane foam products;
50 to 150 parts by weight of the isocyanate component is added to 100 parts by weight of the first liquefied depolymerization obtained in the first step, and the relatively highly reactive compound is reacted with the isocyanate component. As a result, the highly reactive compound is gradually A second step of obtaining a secondary liquefied depolymerization product whose reactivity is uniformized by exhaustion;
A third step of obtaining a recycled polymer polyol by adding and mixing 25 to 100 parts by weight of the secondary liquefied depolymerization obtained in the second step with respect to 100 parts by weight of the new polyol; In the method for producing recycled polymer polyol containing,
The isocyanate is,
First, the highly reactive components present in the first liquefied depolymerization react preferentially and remain dispersed without being dissolved in the new polyol,
Second, the first liquefied depolymer reacts with isocyanate to form a polymer to maintain the reactivity of the new polyol,
Third, in the reaction process for manufacturing rigid polyurethane insulation, a small portion of polyol participates in the reaction as much as the polymer fraction, thereby reducing heat generation and temperature rise due to the reaction and making cooling easier.
Characterized by a method for producing recycled polymer polyol.
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