Preparation method and use method of glycosamine phosphorus-based wood modifier

Abstract

The invention discloses a preparation method and a use method of a glycosamine phosphorus-based wood modifier, and belongs to the field of material processing. The problems that in existing wood modification treatment, the interaction force between a modification agent and wood is insufficient, impregnation is uneven, the flame retardant property is poor, and toxic and harmful substances are generated in the production process of the modification agent are solved. The preparation method comprises the following steps: 1, preparing a flame retardant precursor; 2, preparing a crude product of the flame retardant; and 3, cleaning. The use method comprises the following steps: adding the glycosamine phosphorus-based wood modifier and the catalyst into water for dissolving to obtain a modifier aqueous solution, dipping wood in the modifier aqueous solution, then taking out and drying, and finally heating for reaction. The preparation method is used for preparing and using the glycosamine phosphorus-based wood modifier.

Description

Technical Field

[0001] The invention belongs to the field of material processing. Background Art

[0002] As a natural renewable material, wood has excellent properties such as earthquake resistance, sound insulation, thermal insulation, etc. It is the only renewable and reusable building material. It has an important impact on alleviating climate warming and is in line with the current green, environmentally friendly and sustainable development route. Modification of wood can improve its flame retardancy, mechanical strength, dimensional stability, etc. However, most of the raw materials of wood modifiers currently rely on petrochemical raw materials, and are modified by physical filling of cell cavities. The interface bonding between the modifier and the wood is weak, the impregnation is uneven, the flame retardancy is poor, and toxic and harmful substances are produced during the use and production process. Summary of the invention

[0003] The present invention aims to solve the problems of insufficient interaction between the modification agent and the wood, uneven impregnation, poor flame retardancy, and generation of toxic and harmful substances during the production process of the modification agent in the existing wood modification treatment, and further provides a preparation method of a glucosamine phosphorus-based wood modifier and a use method thereof.

[0004] A method for preparing a sugar amine phosphorus-based wood modifier is carried out according to the following steps:

[0005] 1. Preparation of flame retardant precursor:

[0006] The natural green biomolecule containing aldehyde groups and the nitrogen-containing element modifier are dissolved in distilled water, and then heated to react to obtain a flame retardant precursor;

[0007] 2. Preparation of crude flame retardant product:

[0008] At a temperature of 100°C to 130°C, a modifier having a PO bond is added to a flame retardant precursor, heated and stirred to dissolve, then cooled to 40°C to 80°C, and formaldehyde solution is added and stirred to mix evenly at a temperature of 40°C to 80°C, then heated to 115°C to 135°C, and heated and stirred for 3h to 7h at a temperature of 115°C to 135°C, and then urea is added at a temperature of 115°C to 135°C, and finally heated and stirred for 0.5h to 2h at a temperature of 120°C to 140°C to obtain a crude flame retardant product;

[0009] 3. Cleaning:

[0010] The crude flame retardant product is rotary evaporated and washed to obtain the glycosylamine phosphorus-based wood modifier.

[0011] A method for using a glucosamine phosphorus-based wood modifier is carried out according to the following steps:

[0012] The glycosylamine phosphate-based wood modifier and a catalyst are added to water to dissolve to obtain a modifier aqueous solution, the wood is immersed in the modifier aqueous solution, then taken out and dried, and finally heated for reaction to obtain wood treated with the glycosylamine phosphate-based wood modifier.

[0013] The beneficial effects of the present invention are:

[0014] The present invention modifies natural biomass molecules with substances containing elements such as nitrogen and phosphorus to prepare a water-soluble glucosamine phosphorus-based wood modifier, and undergoes a grafting reaction with wood under certain conditions to form a strong chemical bond, thereby improving the green and environmentally friendly flame retardancy, mechanical properties and color aesthetics of the wood.

[0015] The sugar amine phosphorus-based wood modifier of the present invention can be evenly impregnated into the cell wall and a grafting reaction occurs, and the impregnation is uniform. The flame retardant effect of the wood modified by impregnation is significantly improved, which is specifically manifested in that the limiting oxygen index is significantly improved. In Example 3, the limiting oxygen index can reach 39.6. According to the UL-94 grade standard of GB / T2408-2021, it is significantly improved, up to the V0 level. The experiment of suppressing the continuous combustion of the sample after two 10s ignitions shows that when the concentration of the impregnated modifier reaches 20w% or more, the heat source is withdrawn 10s after the sample is ignited, and the flame on the surface of the sample will quickly extinguish and form a dense carbon layer. The heat release rate (HRR) and total heat release rate (THR) of the wood modified by the sugar amine phosphorus-based wood modifier of the present invention are significantly reduced compared with the unmodified wood. In Example 2, the HRR and THR of the wood sample treated with flame retardant treatment are respectively reduced from 141.33W / g and 12.82MJ / g before treatment to 72.05W / g and 7.56MJ / g, respectively, which are reduced by 50.98% and 60.10%, and the residual carbon rate is increased from 14.0% to 39.3%. In addition, the pyrolysis temperature of the wood modified with flame retardant treatment is significantly lower, which indicates that the modifier plays a role in promoting carbonization, and the dense carbon layer formed protects the wood from further combustion, so the wood treated with flame retardant treatment has a higher residual carbon rate.

[0016] In addition to the significant improvement in flame retardancy, the mechanical properties of wood modified with glycosylamine phosphate-based wood modifiers are also greatly improved. After comparing the tensile curves with those of untreated wood, the maximum fracture stress of the treated wood increased from 35.7MPa to 50.0MPa, and the fracture strain increased from 0.99% to 1.14%. The toughness of the wood modified with glycosylamine phosphate-based wood modifiers is improved.

[0017] Since the natural substances in the modifier undergo caramelization reaction at high temperature, the wood modified by the glycosaminoglycan phosphorus-based wood modifier CNPam has a caramelized smell, and the color is deepened and the texture is more obvious. It is more pleasing to the eye in terms of appearance and smell. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The microstructure of wood treated with the glycosylamine phosphorus-based wood modifier prepared in Example 1, a) is a cross section, b) is a longitudinal section, and c) is a surface energy spectrum scanning result;

[0019] Figure 2 This is a test chart of the vertical burning grade of wood treated with the glucosamine phosphorus-based wood modifier prepared in Examples 1 to 3;

[0020] Figure 3 Heat release rate (HRR) and total heat release rate (THR) measured by microcalorimeter (MCC) of untreated wood and wood treated with the glucosamine phosphorus-based wood modifier prepared in Example 2;

[0021] Figure 4 The thermal degradation process of the combustion of the samples in the thermogravimetric analysis of the untreated wood and the wood treated with the glucosamine phosphorus-based wood modifier prepared in Example 2;

[0022] Figure 5 The tensile curves of mechanical properties of untreated wood and wood treated with the glucosamine phosphorus-based wood modifier prepared in Example 2;

[0023] Figure 6 It is a visual picture of untreated wood and wood treated with the glucosamine phosphate-based wood modifier prepared in Example 2. DETAILED DESCRIPTION

[0024] Specific implementation method 1: This implementation method is a method for preparing a sugar amine phosphorus-based wood modifier, which is carried out according to the following steps:

[0025] 1. Preparation of flame retardant precursor:

[0026] The natural green biomolecule containing aldehyde groups and the nitrogen-containing element modifier are dissolved in distilled water, and then heated to react to obtain a flame retardant precursor;

[0027] 2. Preparation of crude flame retardant product:

[0028] At a temperature of 100°C to 130°C, a modifier having a PO bond is added to a flame retardant precursor, heated and stirred to dissolve, then cooled to 40°C to 80°C, and formaldehyde solution is added and stirred to mix evenly at a temperature of 40°C to 80°C, then heated to 115°C to 135°C, and heated and stirred for 3h to 7h at a temperature of 115°C to 135°C, and then urea is added at a temperature of 115°C to 135°C, and finally heated and stirred for 0.5h to 2h at a temperature of 120°C to 140°C to obtain a crude flame retardant product;

[0029] 3. Cleaning:

[0030] The crude flame retardant product is rotary evaporated and washed to obtain the glycosylamine phosphorus-based wood modifier.

[0031] The beneficial effects of this specific implementation are:

[0032] This specific implementation method uses substances containing elements such as nitrogen and phosphorus to modify natural biomass molecules to prepare a water-soluble glucosamine phosphorus-based wood modifier, and undergoes a grafting reaction with wood under certain conditions to form a strong chemical bond, thereby improving the green and environmentally friendly flame retardancy, mechanical properties and color aesthetics of the wood.

[0033] The sugar amine phosphorus-based wood modifier of this specific embodiment can be evenly impregnated into the cell wall and a grafting reaction occurs, and the impregnation is uniform. The flame retardant effect of the wood modified by impregnation is significantly improved, which is specifically manifested in a significant increase in the limiting oxygen index. The limiting oxygen index in Example 3 can reach 39.6. According to the UL-94 grade standard of GB / T2408-2021, it is significantly improved, up to the V0 level. The experiment of suppressing the continuous combustion of the sample after two 10s ignitions shows that when the concentration of the impregnated modifier reaches 20w% or more, the heat source is withdrawn 10s after the sample is ignited, and the flame on the surface of the sample will quickly extinguish and form a dense carbon layer. The heat release rate (HRR) and total heat release rate (THR) of the wood modified by the glucosamine phosphorus-based wood modifier in this specific embodiment are significantly lower than those of the unmodified wood. In Example 2, the HRR and THR of the wood sample treated with flame retardant decreased from 141.33W / g and 12.82MJ / g before treatment to 72.05W / g and 7.56MJ / g, respectively, which decreased by 50.98% and 60.10%, respectively, and the residual carbon rate increased from 14.0% to 39.3%. In addition, the pyrolysis temperature of the wood modified with flame retardant is significantly lower, which indicates that the modifier plays a role in promoting carbonization, and the dense carbon layer formed protects the wood from further combustion, so the wood treated with flame retardant has a higher residual carbon rate.

[0034] In addition to the significant improvement in flame retardancy, the mechanical properties of wood modified with glycosylamine phosphate-based wood modifiers are also greatly improved. After comparing the tensile curves with those of untreated wood, the maximum fracture stress of the treated wood increased from 35.7MPa to 50.0MPa, and the fracture strain increased from 0.99% to 1.14%. The toughness of the wood modified with glycosylamine phosphate-based wood modifiers is improved.

[0035] Since the natural substances in the modifier undergo caramelization reaction at high temperature, the wood modified by the glycosaminoglycan phosphorus-based wood modifier CNPam has a caramelized smell, and the color is deepened and the texture is more obvious. It is more pleasing to the eye in terms of appearance and smell.

[0036] Specific implementation method 2: This implementation method is different from specific implementation method 1 in that: the natural green biological molecules containing aldehyde groups described in step 1 are one or a combination of starch, sucrose, maltose, corn sugar, xylan, trehalose and cellulose derivatives; the nitrogen-containing element modifier described in step 1 is one or a combination of 2-methylaminopyrimidine, 1-ethylamino-2-propanol, 3-dimethylaminopropylamine, aminoanthracene, 3-aminophenol, 2-aminopurine, 2-aminothiazole, tetraethylenepentamine, aminoquinoline, 3-aminopyridazine, 1-aminopiperidine and 3-aminoindazole; the modifier with PO bond described in step 2 is one or a combination of isopropyl phosphite, potassium dihydrogen phosphite, sodium phosphite, phosphorous acid, chloroquine phosphate, methyl phosphate and histamine phosphate. Others are the same as specific implementation method 1.

[0037] Specific embodiment 3: This embodiment is different from specific embodiment 1 or 2 in that: the mass ratio of the natural green biological molecules containing aldehyde groups to the nitrogen-containing element modifier described in step 1 is 1:(0.5-3); the mass ratio of the natural green biological molecules containing aldehyde groups to distilled water described in step 1 is 1:(1-5). Others are the same as specific embodiment 1 or 2.

[0038] Specific embodiment 4: This embodiment differs from specific embodiments 1 to 3 in that the heating reaction described in step 1 is specifically carried out at a reaction temperature of 100° C. to 130° C. for 0.5 h to 4 h. The rest is the same as specific embodiments 1 to 3.

[0039] Specific embodiment 5: This embodiment is different from specific embodiments 1 to 4 in that: the mass ratio of the modifier with PO bond described in step 2 to the nitrogen-containing modifier described in step 1 is (1.5-3):1; the mass ratio of the formaldehyde solution described in step 2 to the nitrogen-containing modifier described in step 1 is (1.5-3):1; the concentration of the formaldehyde solution described in step 2 is 10wt%-50wt%; the mass ratio of urea described in step 2 to the modifier with PO bond is (1-5):1. Others are the same as specific embodiments 1 to 4.

[0040] Specific implementation method 6: This implementation method is different from specific implementation methods 1 to 5 in that the stirring speed in step 2 is 100 r / min to 800 r / min. The rest is the same as specific implementation methods 1 to 5.

[0041] Specific embodiment seven: This embodiment is a method for using a sugar amine phosphorus-based wood modifier, which is carried out according to the following steps:

[0042] The glycosylamine phosphate-based wood modifier and a catalyst are added to water to dissolve to obtain a modifier aqueous solution, the wood is immersed in the modifier aqueous solution, then taken out and dried, and finally heated for reaction to obtain wood treated with the glycosylamine phosphate-based wood modifier.

[0043] Specific embodiment eight: This embodiment differs from specific embodiment seven in that: the wood is basswood, poplar, ash, fir, willow, two-winged bean, beech, balsa, oak, birch, pine, camphor, teak, nanmu, elm, mahogany or cottonwood; the catalyst is one of dicyandiamide, cyanamide, melamine cyanurate, ethyl acetamidocyanate and 1-tert-butyl-3-ethylaminocyanoacetate or a combination of several thereof. Others are the same as specific embodiment seven.

[0044] Specific embodiment 9: This embodiment differs from specific embodiment 7 or 8 in that the mass ratio of the sugar amine phosphorus-based wood modifier to the catalyst is 1:(0.05-0.1); the mass ratio of the sugar amine phosphorus-based wood modifier to water is 1:(3-30). Others are the same as specific embodiment 7 or 8.

[0045] Specific embodiment 10: This embodiment is different from any one of specific embodiments 7 to 9 in that: the impregnation is atmospheric pressure impregnation, vacuum impregnation or vacuum pressure impregnation; the vacuum degree of the vacuum impregnation is 0.09MPa to 0.25MPa; the vacuum degree of the vacuum pressure impregnation is 0.09MPa to 0.25MPa, and the pressure is 0.1MPa to 0.3MPa; the impregnation time is 3h to 10h; the heating reaction is specifically under the condition of a reaction temperature of 160°C to 190°C, and the reaction time is 0.2h to 2h. The rest is the same as specific embodiments 7 to 9.

[0046] The following examples are used to verify the beneficial effects of the present invention:

[0047] Embodiment 1:

[0048] A method for preparing a sugar amine phosphorus-based wood modifier is carried out according to the following steps:

[0049] 1. Preparation of flame retardant precursor:

[0050] The natural green biomolecule containing aldehyde group and the nitrogen-containing element modifier are dissolved in distilled water, and then reacted at a reaction temperature of 120°C for 1 hour to obtain a flame retardant precursor;

[0051] The natural green biological molecule containing aldehyde groups is corn sugar; the nitrogen-containing element modifier is tetraethylenepentamine;

[0052] The mass ratio of the natural green biological molecules containing aldehyde groups to the nitrogen-containing element modifier is 1:2; the mass ratio of the natural green biological molecules containing aldehyde groups to distilled water is 1:2;

[0053] 2. Preparation of crude flame retardant product:

[0054] At a temperature of 120°C and a rotation speed of 500 r / min, a modifier having a PO bond is added to a flame retardant precursor, heated and stirred for 5 minutes, then cooled to 60°C, and a formaldehyde solution is added and stirred to mix evenly at a temperature of 60°C and a rotation speed of 500 r / min, then heated to 120°C, and heated and stirred for 6 hours at a temperature of 120°C and a rotation speed of 500 r / min, and then urea is added at a temperature of 120°C and a rotation speed of 500 r / min, and finally heated and stirred for 1 hour at a temperature of 130°C and a rotation speed of 500 r / min to obtain a crude flame retardant product;

[0055] The modifier having a PO bond is phosphorous acid;

[0056] The mass ratio of the modifier having a PO bond to the nitrogen-containing modifier in step one is 1.5:1; the mass ratio of the formaldehyde solution to the nitrogen-containing modifier in step one is 1.5:1; the concentration of the formaldehyde solution is 37wt%; the mass ratio of the urea to the modifier having a PO bond is 2:1;

[0057] 3. Cleaning:

[0058] The crude flame retardant product was rotary evaporated and washed with anhydrous ethanol to obtain a glycosylamine phosphorus-based wood modifier.

[0059] The method for using the above-mentioned sugar amine phosphorus-based wood modifier is carried out according to the following steps:

[0060] Adding a glycosylamine phosphorus-based wood modifier and dicyandiamide into water to dissolve, to obtain a modifier aqueous solution, placing wood in the modifier aqueous solution, vacuum impregnating for 3 hours under a vacuum degree of 0.10 MPa, then taking it out, and drying it in air for 12 hours, and finally reacting it at a temperature of 180° C. for 0.5 hours to obtain wood treated with the glycosylamine phosphorus-based wood modifier;

[0061] The wood is a basswood veneer with a length×width×height=10cm×10cm×1cm;

[0062] The mass ratio of the sugar amine phosphorus-based wood modifier to dicyandiamide is 1:0.05; the mass ratio of the sugar amine phosphorus-based wood modifier to water is 1:10.

[0063] Embodiment 2:

[0064] A method for preparing a sugar amine phosphorus-based wood modifier is carried out according to the following steps:

[0065] 1. Preparation of flame retardant precursor:

[0066] The natural green biomolecule containing aldehyde group and the nitrogen-containing element modifier are dissolved in distilled water, and then reacted at a reaction temperature of 125°C for 1 hour to obtain a flame retardant precursor;

[0067] The natural green biological molecule containing aldehyde groups is corn sugar; the nitrogen-containing element modifier is tetraethylenepentamine;

[0068] The mass ratio of the natural green biological molecules containing aldehyde groups to the nitrogen-containing element modifier is 1:1; the mass ratio of the natural green biological molecules containing aldehyde groups to distilled water is 1:1;

[0069] 2. Preparation of crude flame retardant product:

[0070] At a temperature of 125°C and a rotation speed of 300 r / min, a modifier having a PO bond is added to a flame retardant precursor, heated and stirred for 10 minutes, then cooled to 50°C, and a formaldehyde solution is added and stirred to mix evenly at a temperature of 50°C and a rotation speed of 300 r / min, then heated to 125°C, and heated and stirred for 5 hours at a temperature of 125°C and a rotation speed of 300 r / min, and then urea is added at a temperature of 125°C and a rotation speed of 300 r / min, and finally heated and stirred for 1 hour at a temperature of 130°C and a rotation speed of 300 r / min to obtain a crude flame retardant product;

[0071] The modifier having a PO bond is phosphorous acid;

[0072] The mass ratio of the modifier having a PO bond to the nitrogen-containing modifier in step one is 2:1; the mass ratio of the formaldehyde solution to the nitrogen-containing modifier in step one is 2:1; the concentration of the formaldehyde solution is 37wt%; the mass ratio of urea to the modifier having a PO bond is 3:1;

[0073] 3. Cleaning:

[0074] The crude flame retardant product was rotary evaporated and washed with anhydrous ethanol to obtain a glycosylamine phosphorus-based wood modifier.

[0075] The method for using the above-mentioned sugar amine phosphorus-based wood modifier is carried out according to the following steps:

[0076] Adding a glycosylamine phosphorus-based wood modifier and dicyandiamide into water to dissolve, to obtain a modifier aqueous solution, placing wood in the modifier aqueous solution, vacuum impregnating for 3 hours under a vacuum degree of 0.15 MPa, then taking it out, and drying it in air for 24 hours, and finally reacting it at a temperature of 180° C. for 15 minutes to obtain wood treated with the glycosylamine phosphorus-based wood modifier;

[0077] The wood is a basswood veneer with a length×width×height=10cm×10cm×1cm;

[0078] The mass ratio of the sugar amine phosphorus-based wood modifier to dicyandiamide is 1:0.06; the mass ratio of the sugar amine phosphorus-based wood modifier to water is 1:4.

[0079] Embodiment three:

[0080] A method for preparing a sugar amine phosphorus-based wood modifier is carried out according to the following steps:

[0081] 1. Preparation of flame retardant precursor:

[0082] The natural green biomolecule containing aldehyde group and the nitrogen-containing element modifier are dissolved in distilled water, and then reacted at a reaction temperature of 130°C for 1 hour to obtain a flame retardant precursor;

[0083] The natural green biological molecule containing aldehyde groups is corn sugar; the nitrogen-containing element modifier is tetraethylenepentamine;

[0084] The mass ratio of the natural green biological molecules containing aldehyde groups to the nitrogen-containing element modifier is 1:2; the mass ratio of the natural green biological molecules containing aldehyde groups to distilled water is 1:3;

[0085] 2. Preparation of crude flame retardant product:

[0086] At a temperature of 130°C and a rotation speed of 400 r / min, a modifier having a PO bond is added to a flame retardant precursor, heated and stirred for 10 minutes, then cooled to 50°C, and formaldehyde solution is added and stirred to mix evenly at a temperature of 50°C and a rotation speed of 400 r / min, then heated to 130°C, and heated and stirred for 4 hours at a temperature of 130°C and a rotation speed of 400 r / min, and then urea is added at a temperature of 130°C and a rotation speed of 400 r / min, and finally heated and stirred for 1 hour at a temperature of 135°C and a rotation speed of 400 r / min to obtain a crude flame retardant product;

[0087] The mass ratio of the modifier having a PO bond to the nitrogen-containing modifier in step one is 3:1; the mass ratio of the formaldehyde solution to the nitrogen-containing modifier in step one is 2:1; the concentration of the formaldehyde solution is 37wt%; the mass ratio of the urea to the modifier having a PO bond is 4:1;

[0088] The modifier having a PO bond is phosphorous acid;

[0089] 3. Cleaning:

[0090] The crude flame retardant product was rotary evaporated and washed with anhydrous ethanol to obtain a glycosylamine phosphorus-based wood modifier.

[0091] The method for using the above-mentioned sugar amine phosphorus-based wood modifier is carried out according to the following steps:

[0092] Adding a glycosylamine phosphorus-based wood modifier and dicyandiamide into water to dissolve, to obtain a modifier aqueous solution, placing wood in the modifier aqueous solution, immersing for 8 hours at normal pressure, then taking it out, and drying it in air for 24 hours, and finally reacting it at a temperature of 160° C. for 20 minutes to obtain wood treated with the glycosylamine phosphorus-based wood modifier;

[0093] The wood is a basswood veneer with a length×width×height=10cm×10cm×1cm;

[0094] The mass ratio of the sugar amine phosphorus-based wood modifier to dicyandiamide is 1:0.1; the mass ratio of the sugar amine phosphorus-based wood modifier to water is 1:3.

[0095] Figure 1 The microstructure of wood treated with the glycosaminoglycan-based wood modifier prepared in Example 1, a) is a cross section, b) is a longitudinal section, and c) is a surface spectrum scan result; from Figures a) and b), it can be seen that a large amount of modifiers exist in the wood cell cavity, and the spectrum scan result of the modified wood surface c) shows that a large amount of N and P elements exist in the wood cell wall, indicating that the glycosaminoglycan-based wood modifier already exists in the cell wall in large quantities. It can be seen that the glycosaminoglycan-based wood modifier prepared in the example can be evenly impregnated into the cell wall and undergo a grafting reaction, thereby improving the impregnation efficiency in the wood.

[0096] According to GB / T 2406.2-2009 and GB / T 2408-2021 standards, the limiting oxygen index and combustion grade of the wood treated with the glucosamine phosphate-based wood modifier prepared in Examples 1 to 3 were tested, and the test results are shown in Table 1.

[0097] Table 1: Weight gain rate, limiting oxygen index and combustion grade of wood treated with the glycosylamine phosphorus-based wood modifier prepared in Examples 1 to 3

[0098]

[0099] It can be seen from the table that the flame retardant effect of the wood modified by impregnation is significantly improved, which is specifically manifested in that the limiting oxygen index is significantly improved. In Example 3, the limiting oxygen index can reach 39.6. According to the UL-94 grade standard of GB / T2408-2021, it is significantly improved, up to V0 level.

[0100] Figure 2 The vertical burning grade test diagram of wood treated with the sugar amine phosphorus-based wood modifier prepared in Examples 1 to 3. The experiment of inhibiting the continuous combustion of the sample after two 10s ignitions shows that when the concentration of the impregnated modifier reaches 20w% and above (Examples 2 and 3), the flame on the surface of the sample will be extinguished quickly and a dense carbon layer will be formed after the heat source is withdrawn 10s after the sample is ignited. After the flame is extinguished, the sample is ignited again, and no obvious flame appears on the surface of the sample.

[0101] Figure 3 The heat release rate (HRR) and total heat release rate (THR) measured by the microcalorimeter (MCC) of untreated wood and wood treated with the glucosamine phosphorus-based wood modifier prepared in Example 2. As can be seen from the figure, the heat release rate (HRR) and total heat release rate (THR) of the wood treated with the glucosamine phosphorus-based wood modifier prepared in Example 2 are significantly lower than those of the unmodified wood. The HRR and THR of the flame-retardant treated wood sample in Example 2 are reduced from 141.33 W / g and 12.82 MJ / g before treatment to 72.05 W / g and 7.56 MJ / g, respectively, down by 50.98% and 60.10%, respectively.

[0102] Figure 4 The thermal degradation process of the untreated wood and the wood treated with the glycosylamine phosphorus-based wood modifier prepared in Example 2 during the thermogravimetric analysis of the sample combustion. As can be seen from the figure, the temperature T at which the mass loss of the wood modified in Example 2 is 5% compared with the unmodified wood is 5％ The temperature T at which the decomposition rate is fastest decreases from 265°C to 187°C. max The temperature dropped from 367℃ to 296℃, and the final carbon residue rate increased from 14.0% to 39.3%. This shows that the pyrolysis temperature of the flame-retardant modified wood is significantly lower. The modifier promotes carbonization, and the dense carbon layer formed protects the wood from further combustion. Therefore, the flame-retardant treated wood has a higher carbon residue rate.

[0103] The mechanical properties test is carried out according to GB / T 1040.3-2006 standard. Figure 5The tensile curves of mechanical properties of untreated wood and wood treated with the glycosylamine phosphate-based wood modifier prepared in Example 2 are shown in the figure. As can be seen from the figure, the wood modified with the glycosylamine phosphate-based wood modifier has a significant improvement in flame retardancy and mechanical properties. After comparing and analyzing the tensile curves with the untreated wood, the maximum fracture stress of the treated wood increased from 35.7MPa to 50.0MPa, and the fracture strain increased from 0.99% to 1.14%. The toughness of the wood modified with the glycosylamine phosphate-based wood modifier is improved.

[0104] Figure 6 This is a visual picture of untreated wood and wood treated with the glucosamine phosphate-based wood modifier prepared in Example 2; as can be seen from the figure, after treatment with the modifier, the color of the wood becomes darker, the texture becomes more obvious, and the color is beautiful.

Claims

1. A method for preparing a sugar amine phosphorus-based wood modifier, characterized in that It is carried out in the following steps:

1. Preparation of flame retardant precursor: The natural green biomolecule containing aldehyde groups and the nitrogen-containing element modifier are dissolved in distilled water, and then heated to react to obtain a flame retardant precursor; 2. Preparation of crude flame retardant product: At a temperature of 100°C to 130°C, a modifier having a PO bond is added to a flame retardant precursor, heated and stirred to dissolve, then cooled to 40°C to 80°C, and formaldehyde solution is added and stirred to mix evenly at a temperature of 40°C to 80°C, then heated to 115°C to 135°C, and heated and stirred for 3h to 7h at a temperature of 115°C to 135°C, and then urea is added at a temperature of 115°C to 135°C, and finally heated and stirred for 0.5h to 2h at a temperature of 120°C to 140°C to obtain a crude flame retardant product; 3. Cleaning: The crude flame retardant product is rotary evaporated and washed to obtain the glycosylamine phosphorus-based wood modifier.

2. The method for preparing a sugar amine phosphorus-based wood modifier according to claim 1, characterized in that The natural green biological molecule containing aldehyde groups described in step one is one of starch, sucrose, maltose, corn sugar, xylan, trehalose and cellulose derivatives, or a combination of several thereof; the nitrogen-containing element modifier described in step one is one of 2-methylaminopyrimidine, 1-ethylamino-2-propanol, 3-dimethylaminopropylamine, aminoanthracene, 3-aminophenol, 2-aminopurine, 2-aminothiazole, tetraethylenepentamine, aminoquinolines, 3-aminopyridazine, 1-aminopiperidine and 3-aminoindazole, or a combination of several thereof; the modifier with PO bond described in step two is one of isopropyl phosphite, potassium dihydrogen phosphite, sodium phosphite, phosphorous acid, chloroquine phosphate, methyl phosphate and histamine phosphate, or a combination of several thereof.

3. The method for preparing a sugar amine phosphorus-based wood modifier according to claim 1, characterized in that The mass ratio of the natural green biological molecules containing aldehyde groups described in step 1 to the nitrogen-containing element modifier is 1:(0.5-3); the mass ratio of the natural green biological molecules containing aldehyde groups described in step 1 to distilled water is 1:(1-5).

4. The method for preparing a sugar amine phosphorus-based wood modifier according to claim 1, characterized in that The heating reaction described in step 1 is specifically carried out at a reaction temperature of 100° C. to 130° C. for 0.5 h to 4 h.

5. The method for preparing a sugar amine phosphorus-based wood modifier according to claim 1, characterized in that The mass ratio of the modifier having a PO bond described in step 2 to the nitrogen-containing modifier described in step 1 is (1.5-3):1; the mass ratio of the formaldehyde solution described in step 2 to the nitrogen-containing modifier described in step 1 is (1.5-3):1; the concentration of the formaldehyde solution described in step 2 is 10wt%-50wt%; the mass ratio of urea described in step 2 to the modifier having a PO bond is (1-5):

1.

6. The method for preparing a sugar amine phosphorus-based wood modifier according to claim 1, characterized in that The stirring speed in step 2 is 100 r / min to 800 r / min.

7. A method for using a sugar amine phosphorus-based wood modifier prepared as claimed in claim 1, characterized in that It is carried out in the following steps: The glycosylamine phosphate-based wood modifier and a catalyst are added to water to dissolve to obtain a modifier aqueous solution, the wood is immersed in the modifier aqueous solution, then taken out and dried, and finally heated for reaction to obtain wood treated with the glycosylamine phosphate-based wood modifier.

8. The method for using a sugar amine phosphorus-based wood modifier according to claim 7, characterized in that The wood is basswood, poplar, ash, fir, willow, beech, balsa, oak, birch, pine, camphor, teak, nanmu, elm, mahogany or cottonwood; the catalyst is one of dicyandiamide, cyanamide, melamine cyanurate, ethyl acetamidocyanate and 1-tert-butyl-3-ethylcyanamide or a combination of several thereof.

9. The method for using a sugar amine phosphorus-based wood modifier according to claim 7, characterized in that The mass ratio of the sugar amine phosphorus-based wood modifier to the catalyst is 1:(0.05-0.1); the mass ratio of the sugar amine phosphorus-based wood modifier to water is 1:(3-30).

10. The method for using a sugar amine phosphorus-based wood modifier according to claim 7, characterized in that The impregnation is atmospheric pressure impregnation, vacuum impregnation or vacuum pressure impregnation; the vacuum degree of the vacuum impregnation is 0.09MPa~0.25MPa; the vacuum degree of the vacuum pressure impregnation is 0.09MPa~0.25MPa, and the pressure is 0.1MPa~0.3MPa; the impregnation time is 3h~10h; the heating reaction is specifically carried out at a reaction temperature of 160℃~190℃ for 0.2h~2h.

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