KR20200038729A - Method for producing biopolyol from lignocellulosic biomass and method for producing biopolyurethane using thereof - Google Patents

Abstract

The present invention relates to a method for preparing biopolyol, the method comprising a first liquefaction reaction of a lignocellulosic biomass in the presence of an acid catalyst, followed by a second liquefaction reaction in the presence of a base catalyst, a biopolyol prepared by the method, a method for preparing biopolyurethane using the same, and biopolyurethane prepared thereby. The preparation method according to the present invention may prepare biopolyol with a low molecular weight and a low viscosity through a two-step liquefaction process, and the biopolyol prepared by the method has a low acid number, thereby producing biopolyurethane with improved material properties by using the biopolyol.

Description

{Method for producing biopolyol from lignocellulosic biomass and method for producing biopolyurethane using thereof}

The present invention is a method for producing a biopolyol comprising the first liquefaction reaction of a wood-based biomass in the presence of an acid catalyst, followed by a second liquefaction reaction in the presence of a base catalyst, the biopolyol prepared by the method, the biopolyol It relates to a method for producing bio-polyurethane using and bio-polyurethane produced by the above method.

Environmental pollution such as global warming is emerging as an international problem due to carbon dioxide emitted from petroleum or oil-derived products. To solve this problem, interest in biomass resources that can replace petroleum resources is increasing. In particular, lignin, the second-generation wood-based biomass, which has advantages such as a very abundant amount, low price, and biodegradability, is most frequently studied as a bioresource that can replace petroleum-derived products.

In particular, biopolyol production from lignin is a field that has attracted attention in the polyurethane industry. Polyurethane is used in various fields in the form of foams, elastomers, adhesives, and coatings used in furniture, architecture, and transportation. Above all, polyurethane foam is an industrial material that is most frequently applied as a heat insulator, lightweight material, or complementary material depending on its properties of rigidity and softness. Although polyurethane is widely used in the plastics industry because of its excellent mechanical properties, it is generally made from petroleum-derived polyols, and thus has many problems to be improved environmentally and economically. Accordingly, research is underway to produce biopolyols from bio resources through liquefaction reactions and convert them into products of high added value.

Liquefaction is a method for decomposing large molecules of lignin into small monomers by using polyhydric alcohol as a solvent together with a catalyst. In general, many acid catalyst liquefaction reactions have been studied to lower the viscosity of the polyol and improve the liquefaction efficiency. However, the acid catalytic liquefaction has the disadvantage of deteriorating physical properties when synthesized as bioplastics in the future because it produces a polyol having a high acid number.

Thus, the present inventors were studying to produce a polyol having a low acid value, and the primary biopolyol generated from the acid catalytic liquefaction reaction of the empty fruit bunch lignin, the second-generation biomass of woody wood, was secondarily used as a base catalyst. A biopolyol having a low molecular weight and a low viscosity in which the acid compound is removed through a two-step acid-base catalyst liquefaction process of decomposition was prepared, and the present invention was confirmed to be able to produce biopolyurethane having improved physical properties using the same. Was completed.

An object of the present invention is to provide a method for producing biopolyol derived from wood-based biomass.

Another object of the present invention is to provide a method for producing biopolyurethane using the biopolyol.

Another object of the present invention is to provide a biopolyurethane prepared by the above method.

In order to achieve the above object,

The present invention comprises the steps of synthesizing a primary biopolyol by primary liquefaction reaction of a wood-based biomass and an acid catalyst in a reaction solvent (step 1); And neutralizing the mixed solution obtained in step 1, and then adding a base catalyst to synthesize a secondary biopolyol by performing a secondary liquefaction reaction (step 2); Gives

In addition, the present invention comprises the steps of synthesizing a primary biopolyol by primary liquefaction reaction of a wood-based biomass and an acid catalyst in a reaction solvent (step 1); Neutralizing the mixture obtained in step 1, and then adding a base catalyst to synthesize a secondary biopolyol by secondary liquefaction (step 2); And synthesizing the biopolyurethane by polymerizing the secondary biopolyol with diisocyanate (step 3).

Furthermore, the present invention provides a biopolyurethane produced by the above manufacturing method.

The manufacturing method according to the present invention is a low molecular weight and low viscosity through a two-step liquefaction process in which the primary biopolyol produced by liquefying the wood-based biomass with an acid catalyst is secondarily liquefied using a base catalyst. It is possible to produce a biopolyol of, and since the biopolyol produced by the above method has a low acid number, there is an effect of producing biopolyurethane with improved physical properties using the biopolyol.

), 점도(viscosity,

) 및 산가(acid number,

).
도 2는 본 발명의 2차 액화반응에서의 반응 시간(time)에 따른 실시예 1-2(10min), 실시예 1-3(30 min), 실시예 1-1(60min), 실시예 1-4(120 min) 및 실시예 1-5(180 min)에 대한 분자량, 점도 및 수산가를 나타낸 그래프이다: (a) 분자량(molecular weight, ◇) 및 점도(viscosity, ◆), (b) 수산가(hydroxyl number, ●).
도 3은 본 발명의 2차 액화반응에서의 염기 촉매 첨가량(base catalyst loading)에 따른 실시예 1-6(0.5 wt%), 실시예 1-1(1 wt%), 실시예 1-7(2 wt%) 및 실시예 1-8(3 wt%)에 대한 분자량, 점도 및 수산가를 나타낸 그래프이다: (a) 분자량(molecular weight, ◇) 및 점도(viscosity, ◆), (b) 수산가(hydroxyl number, ●).
도 4는 본 발명의 2차 액화반응에서의 반응 온도(temperature)에 따른 실시예 1-9(110℃), 실시예 1-10(130℃), 실시예 1-11(150℃), 실시예 1-12(170℃) 및 실시예 1-7(190℃)에 대한 분자량, 점도 및 수산가를 나타낸 그래프이다: (a) 분자량(molecular weight, ◇) 및 점도(viscosity, ◆), (b) 수산가(hydroxyl number, ●).
도 5는 본 발명의 실시예 2의 EFB 리그닌 바이오 매스 유래의 바이오폴리우레탄 폼(Biopolyurethane foam)과 석유 유래 폴리우레탄 폼(Petroleum-derived polyurethane foam)의 TGA 곡선을 나타낸 그래프이다.Figure 1 shows the molecular weight, viscosity and acid value for Comparative Example 1 (polyol-A), Comparative Example 2 (polyol-AA) and Example 1-1 (polyol-AB) according to the type of secondary liquefaction catalyst of the present invention. The graph is shown: molecular weight (molecular weight,

), Viscosity (viscosity,

) And acid number,

).
Figure 2 is the reaction time (time) in the second liquefaction reaction of the present invention Example 1-2 (10min), Example 1-3 (30 min), Example 1-1 (60min), Example 1 It is a graph showing molecular weight, viscosity and hydroxyl value for -4 (120 min) and Examples 1-5 (180 min): (a) molecular weight (◇) and viscosity (viscosity, ◆), (b) hydroxyl value (hydroxyl number, ●).
FIG. 3 shows Example 1-6 (0.5 wt%), Example 1-1 (1 wt%), and Example 1-7 (Base catalyst loading) in the second liquefaction reaction of the present invention. 2 wt%) and Examples 1-8 (3 wt%) are graphs showing molecular weight, viscosity and hydroxyl value: (a) molecular weight (◇) and viscosity (viscosity, ◆), (b) hydroxyl value ( hydroxyl number, ●).
FIG. 4 shows Examples 1-9 (110 ° C.), Examples 1-10 (130 ° C.), and Examples 1-11 (150 ° C.), carried out according to the reaction temperature in the second liquefaction reaction of the present invention. It is a graph showing the molecular weight, viscosity and hydroxyl value for Examples 1-12 (170 ° C) and Examples 1-7 (190 ° C): (a) molecular weight (◇) and viscosity (viscosity, ◆), (b ) Hydroxyl number (hydroxyl number, ●).
5 is a graph showing the TGA curve of EFB lignin biomass-derived biopolyurethane foam and petroleum-derived polyurethane foam (Petroleum-derived polyurethane foam) of Example 2 of the present invention.

Hereinafter, the present invention will be described in detail.

Biopolyol  Manufacturing method

The present invention comprises the steps of synthesizing a primary biopolyol by primary liquefaction reaction of a wood-based biomass and an acid catalyst in a reaction solvent (step 1); And

Neutralizing the mixture obtained in step 1, and then adding a base catalyst to synthesize a secondary biopolyol by secondary liquefaction (step 2);

It provides a method for producing a bio-polyol derived from wood-based biomass comprising a.

The term "biopolyol" of the present invention means a polyol produced using biological raw materials that are not pure chemical synthesis. In the present invention, the biopolyol may be interpreted as a polyol produced using a woody biomass.

The term "polyol" of the present invention is a general term for a polymer compound having a hydroxyl group, and generally an initiator such as a polyfunctional alcohol or aromatic amine having two or more hydroxyl groups or amine groups in the molecule, and propylene oxide or ethylene oxide as appropriate conditions. It means a compound obtained by reacting under. The polyol is known as a synthetic raw material of polyurethane, and according to its chemical properties, it is divided into polyether polyol and polyester polyol.

In the manufacturing method according to the present invention, the wood-based biomass of step 1 may be EFB lignin (Empty Fruit Bunches lignin) biomass. The wood-based biomass of step 1 may be 5 to 15% by weight based on the total weight of the reaction solvent, and preferably 8 to 12% by weight.

In the manufacturing method according to the present invention, the reaction solvent of step 1 and step 2 may be one or more solvents among polyethylene glycol and glycerol, preferably polyethylene glycol and glycerol It may be to use this mixed solvent. The polyethylene glycol and glycerol may be mixed in a weight ratio of 5: 5 to 9: 1, and may preferably be mixed in a weight ratio of 5: 5 to 7: 3. In the present invention, the solvent in which the polyethylene glycol and glycerol are mixed may be used to increase the liquefaction efficiency by accelerating the liquefaction reaction of the wood-based biomass and suppressing the recondensation reaction.

In the production method according to the present invention, the polyethylene glycol is not particularly limited as long as the biopolyol of the present invention can be prepared, but preferably PEG 300 (poly ethylene glycol 300, MW: 285 to 315 g / mol) You can.

In the production method according to the present invention, the acid catalyst of step 1 may be selected from the group consisting of sulfuric acid, aqueous sulfuric acid solution, hydrochloric acid and aqueous hydrochloric acid, but is not limited thereto. Preferably it may be sulfuric acid or an aqueous sulfuric acid solution.

In the manufacturing method according to the present invention, the first liquefaction reaction of step 1 may be performed at 150 to 210 ° C. for 5 to 180 minutes by adding an acid catalyst to 0.5 to 5% by weight based on the total weight of the reaction solvent, preferably It may be performed by adding 0.5 to 1.5% by weight at 180 to 200 ° C for 30 to 120 minutes, and more preferably by adding 0.8 to 1.2% by weight at 185 to 195 ° C for 40 to 80 minutes. have.

In the production method according to the present invention, the base catalyst of step 2 may be selected from the group consisting of sodium hydroxide and potassium hydroxide, but is not limited thereto. It may preferably be sodium hydroxide.

The present inventors in the process of secondary liquefaction of the primary biopolyol produced by the primary liquefaction reaction of the wood-based biomass, the effect on the properties of the biopolyol product according to the amount of base catalyst, reaction temperature and reaction time The reaction conditions were optimized by analysis.

In the production method according to the present invention, the addition amount of the base catalyst in step 2 may be 0.5 to 3% by weight based on the total weight of the reaction solvent, preferably 1.5 to 2.5% by weight, more preferably It may be from 1.8 to 2.2% by weight, even more preferably from 1.9 to 2.1% by weight.

In the manufacturing method according to the present invention, the second liquefaction reaction of step 2 may be performed at 110 to 190 ° C for 10 to 180 minutes, and preferably performed at 115 to 145 ° C for 35 to 115 minutes. It may be, more preferably, it may be performed at 120 to 140 ° C for 45 to 90 minutes, and even more preferably, it may be performed at 125 to 135 ° C for 50 to 70 minutes.

In the manufacturing method according to the present invention, the step of neutralizing the mixed solution of step 2 neutralizes the mixed solution (reaction solution) containing the primary biopolyol in which the first liquefaction reaction is completed, thereby removing the acid compound, and the first liquefaction reaction It may be to include a process for removing the unreacted residue (residue) that is not reacted by.

The manufacturing method according to the present invention can provide a biopolyol having a low molecular weight and viscosity by liquefying the primary biopolyol produced from the primary liquefaction reaction using an acid catalyst using a base catalyst.

That is, in the two-step liquefaction process of performing a base catalyst liquefaction after the acid catalyst liquefaction, the ether bond of the lignin monomer is first decomposed using an acid catalyst and the base compound is used as the second catalyst. It is a method of decomposing not only chemical bonds of lignin monomers, such as ether bonds, but also methoxyl groups. The lower the molecular weight and the viscosity of the polyol, the easier it is to process the polymer, so these two properties are important factors in the application of the polymer. On the other hand, it was confirmed through the experimental example of the present invention that the biopolyol production method of the present invention is a suitable method for producing high-performance plastics.

Specifically, the present inventors produced a low molecular weight biopolyol from which the acid compound was removed through the two-step liquefaction process according to the present invention, and through GPC analysis, viscosity, and hydroxyl number measurement, 2 The conditions of the reaction temperature, reaction time and base catalyst addition amount for the secondary liquefaction reaction were optimized (see Experimental Examples 3 to 5), and the resulting biopolyol was compared to the biopolyol produced by the one-step acid catalyst liquefaction process. It was confirmed that the acid value as well as the molecular weight and viscosity were low (see Experimental Example 2).

Biopolyurethane  Manufacturing method

In addition, the present invention comprises the steps of synthesizing a primary biopolyol by primary liquefaction reaction of a wood-based biomass and an acid catalyst in a reaction solvent (step 1);

Neutralizing the mixture obtained in step 1, and then adding a base catalyst to synthesize a secondary biopolyol by secondary liquefaction (step 2); And

It provides a method for producing a bio-polyurethane comprising a; step of synthesizing the bio-polyurethane by polymerizing the secondary bio-polyol and diisocyanate (step 3).

In the manufacturing method according to the present invention, the polyurethane may be a polyurethane foam (foam).

In the manufacturing method according to the present invention, the diisocyanate may be p-MDI (polymeric diphenylmethane diisocyanate).

In the production method according to the present invention, the polymerization reaction in step 3 is a step in which a crosslinking reaction proceeds between an NCO group present in diisocyanate and a hydroxyl group included in the secondary biopolyol obtained from the secondary liquefaction process in step 2.

Since a method for preparing polyurethane by reacting a polyol with diisocyanate is already known, the biopolyol produced by the method provided in the present invention can also be used for the production of polyurethane. At this time, the conditions for reacting the biopolyol and diisocyanate may be used as it is in a known polyurethane manufacturing process or may be used with some modifications.

Furthermore, the present invention provides a biopolyurethane produced by the biopolyurethane production method.

The present inventors synthesized biopolyurethane foams using biopolyol and p-MDI produced under the optimum conditions according to the present invention, and bio-according to the present invention through FT-IR and TGA, compressive strength, and density analysis. It was confirmed that the polyurethane foam has the potential to be used as a high value-added bioplastic (Experimental Example 6).

The bio-polyurethane according to the present invention is a high-value-added bioplastic produced from a low-value biomass, and can provide a reduction effect of the use of petroleum-derived raw materials, which are conventional polyurethane materials.

Hereinafter, the present invention will be described in more detail by the following examples. However, the following examples are only illustrative of the present invention, and the contents of the present invention are not limited by the following examples.

< Example  1> EFB  Lignin's two-step acid-base catalytic liquefaction

Step 1: acid catalyst liquefaction (first liquefaction)

EFB lignin (Empty Fruit Bunches lignin) biomass was liquefied by stirring at 200 rpm under mild temperature (130-210 ° C) and atmospheric pressure conditions using a 500 mL three-neck reactor and a mantle for heating. At this time, the EFB lignin biomass is a wood-based biomass, and the EFB lignin residue (residue) from the enzyme saccharification process of the empty fruit bunch (EFB) lignocellulose biomass provided by Daejeon Chemical Research Institute was used. , The main composition of the EFB lignin residue was 49.7% lignin, 22.1% cellulose and 2.7% hemicellulose.

After 50 g of the reaction solvent was added to the reactor, the liquefied EFB lignin was added under the condition of adding 10% by weight of biomass to the solvent weight. Biomass was introduced into the reactor. In the case of the reaction solvent, polyethylene glycol 300 (PEG300) and glycerol (glycerol) were used by mixing in a weight ratio of 6: 4. After pre-heating the reaction solution in the reactor for 1 hour, 98% sulfuric acid catalyst was slowly added under the condition of adding 1% by weight of acid catalyst relative to the total weight of the reaction solvent. Thereafter, the acid catalyst was liquefied (1st liquefaction) at a temperature of 190 ° C for 1 hour. After completion of the reaction, the primary liquefaction reaction was terminated by lowering the temperature to room temperature using cold water to obtain a primary biopolyol.

Step 2: Base catalyst liquefaction (secondary liquefaction)

The mixed solution (reaction solution) containing the primary biopolyol obtained in step 1 was neutralized using a 1N sodium hydroxide (NaOH) solution in consideration of the acid value. Thereafter, for separation and purification, acetone and filter paper were used to remove unresolved residue, and acetone was evaporated from the mixed solution, followed by a base catalyst liquefaction process (secondary liquefaction process).

The mixed solution containing the primary biopolyol having been neutralized and separated and purified was liquefied in the same manner as in step 1, but a second catalyst was used by adding a sodium hydroxide (NaOH) catalyst, which is a base catalyst, instead of a sulfuric acid catalyst. The base catalyst liquefaction (secondary liquefaction) was performed by changing the time (minutes), the amount of catalyst addition (% by weight based on the total weight of the reaction solvent in step 1) and the reaction temperature (° C) as shown in Table 1 below.

Example 1-1 1-2 1-3 1-4 1-5 1-6 1-7 1-8 1-9 1-10 1-11 1-12 Reaction time (minutes) 60 10 30 120 180 60 60 60 60 60 60 60 Catalyst amount (% by weight) One One One One One 0.5 2 3 2 2 2 2 Reaction temperature (℃) 190 190 190 190 190 190 190 190 110 130 150 170

After the base catalytic liquefaction reaction (secondary liquefaction reaction) is completed, the heating mantle is removed to lower the temperature to room temperature to terminate the reaction, thereby ending EFB lignin, the second-generation biomass. The resulting biopolyol (Examples 1-1 to 1-13) was obtained.

< Comparative example  1> EFB  Lignin's one step acid catalyst liquefaction

Step 2 of Example 1 was omitted, and only the acid catalyst liquefaction reaction (first liquefaction reaction) of Step 1 was performed to obtain biopolyol of Comparative Example 1.

< Comparative example  2> EFB  Lignin's two-step acid-acid catalytic liquefaction

2 in the same manner as in Example 1-1, except that in step 2 of Example 1, the catalyst for the secondary liquefaction reaction was 98% sulfuric acid, which is the same acid catalyst as the primary liquefaction reaction, instead of the sodium hydroxide as the base catalyst. A biopolyol of Comparative Example 2 was obtained by performing a two-step liquefaction reaction.

< Experimental example  1> Biopolyol  Characteristic measurement method

1-1. Measurement of molecular weight and viscosity of biopolyol

The molecular weight (molecular weight, g / mol) of the biopolyol derived from EFB lignin biomass was measured using a gel permeation chromatography instrument. At this time, the analysis solvent was N, N-dimethylformamide (99.8%), and the injection content of the solvent was 50 μl, and the flow rate was set to 1 ml per minute.

The viscosity (viscosity, cP) of the EFB lignin biomass-derived biopolyol was measured at 60 rpm using a Brookfield laboratory viscometer instrument.

1-2. Biopolyol Mountain  And fisheries value measurement

The acid number (mg KOH / g) of the biopolyol derived from EFB lignin biomass was analyzed according to ASTM D4662-08 standard. 2 g of each biopolyol was dissolved in 50 mL ethanol, and titrated to pH 8.0 with 0.1 N aqueous sodium hydroxide solution. For accurate measurement, all samples were measured twice and the average was calculated as the acid value.

The hydroxyl value (hydroxyl number, mg KOH / g) of the biopolyol derived from EFB lignin biomass was analyzed according to ASTM D4274-05D standard. 25 mL of an esterification reagent was added to 1 g of each biopolyol, and the esterification reaction was performed while stirring at 100 ° C for 15 minutes. After cooling to room temperature, it was titrated to pH 8.0 using 0.5 N aqueous sodium hydroxide solution. For accurate measurement, all samples were measured twice and the average was calculated as the hydroxyl value.

< Experimental example  2> Depending on the type of secondary liquefaction catalyst Biopolyol  Characteristic evaluation

Example 1-1 (after the primary acid catalyst liquefaction reaction) to investigate the repolymerization reaction and decomposition reaction of the biopolyol derived from EFB lignin biomass according to the type of catalyst for the secondary liquefaction reaction of step 2 of Example 1 Biopolyol of the second liquefaction reaction using sodium hydroxide catalyst), Comparative Example 1 (primary acid catalyst liquefaction reaction and no secondary liquefaction reaction) and Comparative Example 2 (primary acid catalyst liquefaction reaction and secondary liquefaction reaction using sulfuric acid catalyst) The molecular weight, viscosity, and acid value for were measured and compared. At this time, the molecular weight, viscosity and acid value were measured by the methods of Experimental Examples 1-1 and 1-2, and the results are shown in Table 2 and FIG. 1 below.

Polyol properties Comparative Example 1
(polyol-A) Comparative Example 2
(polyol-AA) Example 1-1
(polyol-AB) Molecular weight (g / mol) 15161 15811 7178 Viscosity (cP) 2635 ± 4 3514 ± 4 691 Acid value (mg KOH / g) 5.08 10.51 ND

), 점도(viscosity,

) 및 산가(acid number,

).Figure 1 shows the molecular weight, viscosity and acid value for Comparative Example 1 (polyol-A), Comparative Example 2 (polyol-AA) and Example 1-1 (polyol-AB) according to the type of secondary liquefaction catalyst of the present invention. The graph is shown: molecular weight (molecular weight,

), Viscosity (viscosity,

) And acid number,

).

As shown in Table 2 and Figure 1, the biopolyol (polyol-AA) of Comparative Example 2 using sulfuric acid as a catalyst for the second liquefaction reaction is a one-step liquefaction reaction due to the repolymerization reaction (second liquefaction reaction is not performed) The molecular weight of the biopolyol (polyol-A) obtained in Comparative Example 1 was increased from 15161 g / mol to 15811 g / mol, and the viscosity also increased from 2635 cP to 3514 cP.

On the other hand, in the case of the biopolyol (polyol-AB) of Example 1-1 using sodium hydroxide as a catalyst for the second liquefaction reaction, it was confirmed that the molecular weight was lowered to 7178 g / mol and the viscosity was 691 cP. It was found that the molecular weight reduction by the sodium hydroxide catalyst is a phenomenon in which the bonds of lignin monomers such as methoxy groups and C-O-C bonds are cleaved by necleophilic functional groups such as hydroxyl groups.

On the other hand, the acid value of the biopolyol (polyol-A) of Comparative Example 1 was confirmed to be 5.08 mg KOH / g, and the biopolyol (polyol-AA) of Comparative Example 2 showed a high acid value of 10.51 mg KOH / g, but was carried out. In the case of the biopolyol of Example 1-1 (polyol-AB), the acid value appears to be 0, confirming that it is possible to prepare a biopolyol suitable for biopolyurethane production when performing a two-step liquefaction reaction of an acid catalyst-base catalyst. Did. In general, the high acid value of the polyol induces hydrolysis of the polyurethane and has a disadvantage of inhibiting physical properties.

From the above results, it was confirmed that the basic catalyst, sodium hydroxide, is a suitable catalyst as a catalyst for the second liquefaction reaction.

< Experimental example  3> Second liquefaction reaction Biopolyol  Characteristic evaluation

Process time is an important factor in evaluating economic efficiency in the production process. Therefore, in order to optimize the reaction time of the second liquefaction reaction, after undergoing a neutralization process and a separation and purification process on the primary biopolyol produced by the acid catalyst liquefaction of step 1, the amount of base catalyst added is 1 weight based on the total weight of the reaction solvent % And the reaction temperature was fixed at 190 ° C, and the molecular weight, viscosity, and hydroxyl value of the biopolyol derived from the EFB lignin biomass of Examples 1-1 to 1-5 synthesized by varying the reaction time were measured and compared. At this time, the molecular weight, viscosity and hydroxyl value were measured by the methods of Experimental Examples 1-1 and 1-2.

Figure 2 is the reaction time (time) in the second liquefaction reaction of the present invention Example 1-2 (10min), Example 1-3 (30 min), Example 1-1 (60min), Example 1 Graph showing molecular weight, viscosity and hydroxyl value for -4 (120 min) and Examples 1-5 (180 min): (a) molecular weight (◇) and viscosity (viscosity, ◆), (b) hydroxyl value (hydroxyl number, ●).

As a result, as shown in FIG. 2 (a), as the reaction time increased from 10 minutes (min) to 60 minutes, the molecular weight decreased from 8692 g / mol to 7178 g / mol, and after that time, the repolymerization reaction was performed. By little by little. In the case of viscosity, it decreased from 795 cP to 691 cP with a decrease in molecular weight as the reaction time increased from 10 minutes to 60 minutes. This is because the polymer compounds present in the biopolyol produced by the acid catalytic liquefaction reaction (primary liquefaction reaction) are divided into various low molecular weight elements such as phenolic compounds and polyhydroxy polyols. After a reaction time of 60 minutes, the viscosity increased with increasing molecular weight by C-C bond and repolymerization of the decomposed lignin derivatives.

On the other hand, as shown in Figure 2 (b), the hydroxyl value of the biopolyol showed a value between 765.76 to 810.64 mg KOH / g. Theoretically, the hydroxyl value of the biopolyol is the highest in the biopolyol produced in the 60 minutes when the most decomposition occurred due to the polyhydroxy group generated by the active decomposition reaction of ether bonds between lignin units. It was expected, but as a result of the measurement of the hydroxyl value, it was confirmed that the hydroxyl value of the biopolyol of Example 1-1 produced under the condition that the reaction time of the second liquefaction reaction was 60 minutes was slightly lower than that of other biopolyols. This is a phenomenon caused by the influence of different functional groups. Since the appropriate hydroxyl value for preparing the polyurethane is 300 to 800 mg KOH / g, it was confirmed that the biopolyol obtained under the conditions of Example 1-1 was suitable for biopolyurethane synthesis.

Based on the above results, 60 minutes of Example 1-1 having the lowest molecular weight and viscosity value was selected as the optimal reaction time for the second liquefaction reaction.

< Experimental example  4> Second Liquefaction Base Catalytic  Follow Biopolyol  Characteristic evaluation

In order to optimize the amount of the base catalyst added in the second liquefaction reaction, after the neutralization process and the separation and purification process were performed on the primary biopolyol produced by the acid catalyst liquefaction in step 1, the reaction time was adjusted to the optimum condition in Experimental Example 3. It was fixed to the confirmed 60 minutes, the reaction temperature was fixed to 190 ℃, sodium hydroxide catalyst addition amount (% by weight relative to the total weight of the reaction solvent) synthesized Example 1-1 and Examples 1-6 to 1-8 The molecular weight, viscosity and hydroxyl value of the biopolyol derived from the EFB lignin biomass were measured and compared. At this time, the molecular weight, viscosity and hydroxyl value were measured by the methods of Experimental Examples 1-1 and 1-2.

FIG. 3 shows Examples 1-6 (0.5 wt%), Examples 1-1 (1 wt%), and Examples 1-7 (Base catalyst loading) in the second liquefaction reaction of the present invention. 2 wt%) and Examples 1-8 (3 wt%) are graphs showing molecular weight, viscosity and hydroxyl value: (a) molecular weight (◇) and viscosity (viscosity, ◆), (b) hydroxyl value ( hydroxyl number, ●).

As a result, as shown in FIG. 3 (a), as the amount of the base catalyst (sodium hydroxide) added to the reaction solvent weight increased from 0.5% to 1% by weight, the molecular weight and viscosity of the produced biopolyol did not show a large change, As the amount of the base catalyst added increased from 1% by weight to 2% by weight based on the weight of the solvent, the molecular weight decreased rapidly from 7178 g / mol to 5328 g / mol. The decrease in molecular weight is due to the increased catalytic activity of inducing the decomposition reaction of lignin units as the content of sodium hydroxide increases from 1% by weight to 2% by weight relative to the weight of the solvent. On the other hand, when the amount of the base catalyst added increased from 2% by weight to 3% by weight relative to the weight of the solvent, the molecular weight was again increased. Next, the viscosity increased from 688 cP to 2741 cP as the base catalyst content increased from 0.5 to 3% by weight relative to the solvent weight. This follows the general theory that the viscosity of the material increases as the amount of base catalyst increases. As a result, it was found that adding 2% by weight of sodium hydroxide relative to the weight of the solvent was suitable for producing a low molecular weight polyol.

On the other hand, as shown in Figure 3 (b), as a result of measuring the hydroxyl value of the bio-polyols, when the base catalyst addition amount increased from 0.5% to 3% by weight, the hydroxyl value from 726.49 mg KOH / g to 791.01 mg KOH / g Increased. This is because hydroxyl groups are introduced with active decomposition of lignin units and an increase in sodium hydroxide content. When the amount of the base catalyst added to the weight of the solvent was 2% by weight, the hydroxyl value of the biopolyol of Example 1-7 was 779.79 mg KOH / g, and this value is suitable for polyurethane production as mentioned in Experimental Example 3 above. It was confirmed that it was fisheries.

Therefore, based on the above results, the optimum catalyst amount condition was selected to be 2% by weight based on the weight of the reaction solvent, as in Example 1-7, based on the lowest molecular weight.

< Experimental example  5> Second liquefaction reaction according to the reaction temperature Biopolyol  Characteristic evaluation

In order to optimize the reaction temperature in the second liquefaction reaction, after undergoing a neutralization process and a separation and purification process on the primary biopolyol produced by the acid catalyst liquefaction in step 1, the reaction time and the amount of the base catalyst are added in Experimental Example 3, respectively. And fixed to 60 minutes and 2% by weight identified as the optimum condition in 4, the reaction temperature of the synthesized Example 1-7 and Examples 1-9 to 1-12 of the EFB lignin biomass-derived biopolyol of The molecular weight, viscosity and hydroxyl value were measured and compared. At this time, the molecular weight, viscosity and hydroxyl value were measured by the methods of Experimental Examples 1-1 and 1-2.

FIG. 4 shows Examples 1-9 (110 ° C.), Examples 1-10 (130 ° C.), Examples 1-11 (150 ° C.), and implementation according to the reaction temperature in the second liquefaction reaction of the present invention. It is a graph showing molecular weight, viscosity and hydroxyl value for Examples 1-12 (170 ° C) and Examples 1-7 (190 ° C): (a) molecular weight (◇) and viscosity (viscosity, ◆), (b ) Hydroxyl number (hydroxyl number, ●).

As a result, as shown in FIG. 4 (a), when the reaction temperature was reduced from 190 ° C to 130 ° C, the molecular weight of the biopolyol decreased from 5328 g / mol to 4724 g / mol. This is because as the reaction temperature decreases, depolymerization of the polyphenol compounds predominates. The viscosity was found to be the lowest biopolyol of Example 1-10 obtained by performing a second liquefaction reaction at a reaction temperature of 130 ° C.

On the other hand, as shown in Figure 4 (b), as a result of measuring the hydroxyl value of each biopolyol, it was confirmed that the hydroxyl value is generally increased as the molecular weight decreases. This is because it follows the decomposition mechanism of the two-step acid-base catalyst liquefaction reaction as mentioned in the above experimental examples. In addition, it was confirmed that the biopolyols of Examples 1-10 obtained at a reaction temperature of 130 ° C. were close to the hydroxyl value range suitable for polyurethane production.

Based on the above results, the optimum reaction temperature for the second liquefaction reaction was selected as 130 ° C of Examples 1-10, which produced biopolyol having a molecular weight of 4724 g / mol and a viscosity of 1144 cP.

< Example  2> Bio polyurethane synthesis

In order to synthesize bio-polyurethane, the optimum conditions of the second liquefaction reaction confirmed through Experimental Examples 2 to 5 (reaction time 60 minutes, base catalyst addition amount 2% by weight and reaction temperature of 130 ° C) were produced in Examples 1-10. A biopolyol derived from EFB lignin was mixed with a pre-resin mix in a weight ratio of 0.1: 0.9 to prepare a mixture and reacted with diisocyanate. As the diisocyanate, p-MDI (polymeric diphenylmethane diisocyanate) was used. After adding 2 g of a biopolyol (Example 1-10) and a pre-resin mix mixture to a 100 mL beaker, the diisocyanate was added in a weight ratio of 1: 1 to the biopolyol and pre-resin mix mixture, and 900 rpm at 60 ° C. And react for 20-25 seconds with strong stirring.

After the biopolyurethane foam was foamed, the final product was stored at room temperature for about 1 hour. Thereafter, the product was cured in a drying oven at 105 ° C. for 12 hours to recover the final biopolyurethane foam product.

< Experimental example  6> Bio polyurethane  Foam characterization

Using the biopolyol of Examples 1-10 produced under the optimum conditions according to the present invention, the properties of the biopolyurethane foam synthesized in Example 2 were analyzed using FT-IR and TGA, compressive strength and density equipment. .

6-1. Bio polyurethane  Thermal properties of foam

In order to evaluate the thermal properties of the biopolyurethane foam of Example 2 and the petroleum-derived polyurethane foam, thermogravimetric analysis (TGA) was performed.

Specifically, the biopolyurethane foam of Example 2 and the petroleum-derived polyurethane foam (Petroleum-derived polyurethane foam) samples of 30 mg each were added to the TGA platinum pan, respectively, and nitrogen gas was used as atmospheric gas at 20 mL per minute. It was put in, and the temperature was increased from 30 ° C to 750 ° C at 30 ° C per minute, and the weight according to the temperature change was measured. The thermal stability of the two polyurethane foams was compared based on 10% weight loss temperature (T _d10 ) compared to the initial weight of each sample and 50% weight loss temperature (T _d50 ) compared to the initial weight.

5 is a graph showing the TGA curve of EFB lignin biomass-derived biopolyurethane foam and petroleum-derived polyurethane foam (Petroleum-derived polyurethane foam) of Example 2 of the present invention.

As a result, as shown in Fig. 5, the petroleum-derived polyurethane foam exhibited a T _d10 value of 295 ° C and a T _d50 value of 351 ° C. On the other hand, the biopolyurethane foam of Example 2 according to the present invention exhibited a T _d10 value of 287 ° C and a T _d50 value of 339 ° C. Since their thermal stability is very similar, excellent thermal stability of the biopolyurethane foam has been demonstrated.

6-2. Bio polyurethane  Mechanical properties of foam

To evaluate the mechanical properties of the biopolyurethane foam of Example 2 and the petroleum-derived polyurethane foam, compressive strength (at 10% strain, kPa) and density (kg /) of the two polyurethane foams m ³ ) was measured.

The compressive strength was measured using a universal testing machine according to the test method of KS M ISO 844, and the density was measured using a vernier caliper (MITUTOYO, Japan) and Chemical Balance (HANSUNG, Korea) according to the test method of KS M ISO 845. Density was calculated by measuring size and weight, respectively, and the results are shown in Table 3 below.

Compressive strength
(at 10% strain) (kPa) density
(kg / m ³ ) Polyurethane foam derived from petroleum resources 94 25.04 Biopolyurethane foam of Example 2 99 24.85

Compressive strength and density are important factors that affect the properties of rigid polyurethane foams as insulators. As shown in Table 3, the compressive strength and density of the petroleum-derived polyurethane foam were 94 kPa and 25.04 kg / m ³ , respectively. On the other hand, the biopolyurethane foam of Example 2 had a compressive strength of 99 kPa and a density of 24.85 kg / m ³ . This means that the superior compressive strength of biopolyurethane foam can be maintained even when petroleum resources are replaced with biomass resources. In addition, it was confirmed that the biopolyurethane foam of Example 2 prepared according to the present invention has a higher compressive strength than the conventional petroleum-derived polyurethane foam, and thus has better mechanical properties.

Based on the results above, it was confirmed that a high value-added biopolyurethane foam was successfully produced from low value added biomass resources.

So far, the present invention has been focused on the preferred embodiments. Those skilled in the art to which the present invention pertains will understand that the present invention may be implemented in a modified form without departing from the essential characteristics of the present invention. Therefore, the disclosed embodiments should be considered in terms of explanation, not limitation. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the equivalent range should be interpreted as being included in the present invention.

Claims (11)

Synthesizing a primary biopolyol by performing a primary liquefaction reaction of a wood-based biomass and an acid catalyst in a reaction solvent (step 1); And
Neutralizing the mixture obtained in step 1, and then adding a base catalyst to synthesize a secondary biopolyol by secondary liquefaction (step 2);
Method of producing a wood-based biomass-derived biopolyol comprising a.
According to claim 1,
The method of manufacturing the wood-based biomass of step 1 is EFB lignin (Empty Fruit Bunches lignin) biomass.
According to claim 1,
The method for producing wood-based biomass in step 1 is characterized in that 5 to 15% by weight based on the total weight of the reaction solvent.
According to claim 1,
The reaction solvent of the step 1 and step 2 is a polyethylene glycol (poly ethylene glycol) and glycerol (glycerol) at least one of the production method characterized in that it uses a solvent.
According to claim 1,
The production method of the acid catalyst of step 1 is selected from the group consisting of sulfuric acid, aqueous sulfuric acid solution, hydrochloric acid and aqueous hydrochloric acid.
According to claim 1,
The first liquefaction reaction of step 1 is an acid catalyst is added to 0.5 to 5% by weight based on the total weight of the reaction solvent is carried out for 5 to 180 minutes at 150 to 210 ℃.
According to claim 1,
The base catalyst of step 2 is selected from the group consisting of sodium hydroxide and potassium hydroxide.
According to claim 1,
The production method characterized in that the addition amount of the base catalyst in step 2 is 0.5 to 3% by weight based on the total weight of the reaction solvent.
According to claim 1,
The second liquefaction reaction in step 2 is carried out for 10 to 180 minutes at 110 to 190 ° C.
Synthesizing a primary biopolyol by performing a primary liquefaction reaction of a wood-based biomass and an acid catalyst in a reaction solvent (step 1);
Neutralizing the mixture obtained in step 1, and then adding a base catalyst to synthesize a secondary biopolyol by secondary liquefaction (step 2); And
Synthesis of the second biopolyol and diisocyanate to synthesize a biopolyurethane (step 3); a method for producing a biopolyurethane comprising a.
Bio-polyurethane produced by the manufacturing method according to claim 10.

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