CN112223464B - Wood modifier and preparation method thereof - Google Patents

Abstract

The invention discloses a wood modifier and a preparation method thereof, and relates to the technical field of chemical modification of wood. The invention discloses a wood modifier which is prepared from the following raw materials in parts by weight: 5-10 parts of triazole compound, 10-20 parts of hydroxyethyl methacrylate, 0.5-0.8 part of catalyst, 10-20 parts of ammonium dihydrogen phosphate, 20-40 parts of nonionic surfactant, 45-90 parts of polyethylene glycol and 800 parts of water, and the invention also discloses a preparation method of the wood modifier. The wood modifier provided by the invention can stabilize the size of wood treated by the wood modifier, has excellent hardness, bending strength, impact toughness and loss resistance, simultaneously has waterproofness and flame retardance, and prolongs the service life of the modified wood. The raw materials of the modifier are nontoxic and environment-friendly, and are harmless to human bodies and environment, and the application range of the modified wood is improved.

Description

Wood modifier and preparation method thereof

Technical Field

The invention belongs to the technical field of chemical modification of wood, and particularly relates to a wood modifier and a preparation method thereof.

Background

Along with the rapid development of industry, the pollution is more serious, and countries have come out a policy of limiting forest felling in succession, so that the cost required by wood import is higher and higher, and therefore China begins to grow a large number of artificial fast-growing forests such as poplar trees, fir trees, rubber trees and the like. Although the growth period of the artificial fast-growing forest is short, compared with a natural forest, the density, the physical mechanical strength and the dimensional stability of the fast-growing forest are relatively poor, and the application of the fast-growing forest in the field of high value-added wood processing is limited. How to expand the application range of the artificial fast-growing forest trees and increase the hardness and the strength of the artificial fast-growing forest trees by adopting physical or chemical means becomes a main research content in the field of wood modification.

The treatment of enhancing fast-growing forest trees can be divided into three types according to chemical reactions: the first is that the modifier fills the cell cavity, and the organic resin is used as the modifier, which can improve the strength of the wood and reduce the water absorption of the wood, but can not have hydrophobicity for a long time and has poor thermal stability; secondly, resin substances are filled in cell walls and cell cavities to be inflated, so that the dry shrinkage and wet swelling of the wood are reduced, and the method can keep the hydrophobicity of the wood for a long time; the third is the most effective way that the wood cell wall components (including lignin, cellulose and hemicellulose) chemically react with some groups in the wood modifier to form new chemical bonds, and the dimensional stability, strength, durability, etc. of the modified wood can be improved for a long time. However, wood, as a natural polymer material, has poor physical and mechanical properties and dimensional stability, and also has the defects of flammability, easy mildew and the like, thereby limiting the application and development of the wood.

Chinese patent CN104044193B discloses a resinThe wood modified by type silicate and its preparation method, use melamine, formaldehyde, urea and soluble sodium silicate as the main raw materials, use polyvinyl alcohol and diglycol as flexibilizer and stabilizer respectively and make, size stability, density, surface hardness, bending strength, bending elasticity modulus, impact toughness and wearability of the timber processed by this modifier are improved by a wide margin, give the timber the good fire-retardant function at the same time, but may remain poisonous melamine and formaldehyde in this modifier, harmful to human body and environment, and when the timber using this modifier is under the condition of high temperature, illumination or burning, it is apt to release the poisonous gas, not conform to the concept of the timber of environmental protection now. In the prior art, nanoparticles (SiO) are also used₂、TiO₂、Al₂O₃ZnO, etc.) or surface modification, and then directly spraying the modified wood or modifying the modified wood with polymer to prepare a coating, and then coating or impregnating the coating in the wood to endow the wood with super-hydrophobic self-cleaning property, but the nano particles are not uniformly dispersed in the polymer, so that the super-hydrophobic effect endowed to the wood is poor, and the wood has no sterilization, mildew prevention and weather resistance. The problems of weather resistance, super-hydrophobicity and self-cleaning can be effectively solved by utilizing surface modification of fluorine-containing polymer or fluorine-containing siloxane, but the solvent required by the coating is oil-soluble chemical substance, so that the problems of large VOC release and environmental pollution are solved.

In the prior art, wood modifier is high in toxicity, special peculiar smell, poor in anti-flow-loss capability, large in VOC release and environment pollution, complex in operation process and high in cost, or the super-hydrophobic effect is poor due to poor in-situ dispersibility of nanoparticles, or the waterproof single performance of wood can be improved, and the mutual effectiveness of multiple reagents is often influenced when the multiple reagents are compounded, and the steps and cost of wood treatment are increased, so that the development of a multifunctional (high-strength, waterproof, flame-retardant and the like) compound wood modifying reagent which is simple in operation, environment-friendly and low in cost is a necessary trend.

Disclosure of Invention

The invention aims to provide a wood modifier, which can stabilize the size of wood treated by the wood modifier, has excellent hardness, bending strength, impact toughness and loss resistance, simultaneously has water resistance and flame resistance, and prolongs the service life of the modified wood. The raw materials of the modifier are nontoxic and environment-friendly, and are harmless to human bodies and environment, and the application range of the modified wood is improved.

In order to realize the purpose of the invention, the invention provides a wood modifier which is prepared from the following raw materials in parts by weight: 5-10 parts of triazole compound, 10-20 parts of hydroxyethyl methacrylate, 0.5-0.8 part of catalyst, 10-20 parts of ammonium dihydrogen phosphate, 20-40 parts of nonionic surfactant, 45-90 parts of polyethylene glycol and 800 parts of water.

Further, the triazole compound is one or two of 3, 5-diamino-1, 2, 4-triazole, 5-methyl-3-octyl-1, 2, 4-triazole, 3-butyl-1, 2, 4-triazole, 3-ethyl-1, 2, 4-triazole and 3, 5-diisopropyl-1, 2, 4-triazole.

Further, the catalyst is n-butyl lithium.

Further, the nonionic surfactant is sucrose ester or sorbitan ester.

Further, the polyethylene glycol is one or two of PEG-200, PEG-400 or PEG-600.

The preparation method of the wood modifier comprises the following specific steps:

(1) dividing polyethylene glycol into three equal parts, and adding the polyethylene glycol in two times;

(2) adding the triazole compound, hydroxyethyl methacrylate and the first part of polyethylene glycol into a reaction kettle, uniformly stirring, adding a catalyst, stirring and reacting for 0.5-1h at room temperature, adding ammonium dihydrogen phosphate, and stirring and reacting for 2-3 h;

(3) adding a sodium hydroxide solution into the reaction kettle, adjusting the pH value to 7-8, then adding a nonionic surfactant and two parts of polyethylene glycol, and stirring for 0.5-1 h;

(4) and adding water into the reaction kettle, and uniformly stirring to obtain the wood modifier.

Further, in the step (2), the heating temperature in the stirring process after adding the ammonium dihydrogen phosphate is 50 ℃, and the stirring speed is 200-320 r/min.

Further, the stirring temperature in the step (3) is 60-80 ℃, and the stirring speed is 300-.

The invention achieves the following beneficial effects:

1. the invention takes triazole compound and hydroxyethyl methacrylate as base materials, the polymerization reaction is carried out under the action of polyethylene glycol and a catalyst to generate triazole polymer, then the triazole polymer and ammonium dihydrogen phosphate are subjected to cross-linking reaction, phosphate group and polar hydroxyl are introduced into the generated triazole blend, the triazole compound has biological activity, so that the modifier has antibacterial property, and hydrogen bonds can be formed between the phosphate group and the polar hydroxyl in the triazole blend and the hydroxyl on the wood cell wall, so that stronger interfacial interaction force is formed between the formed polymer and the wood substrate, and channels for invasion of microorganisms and moisture into the wood cell wall are reduced, thereby endowing wood with higher mechanical property, good durability and dimensional stability.

2. The triazole blend is a nitrogen-phosphorus polymer and has excellent flame retardant property, so that after the triazole blend is filled into channels of wood cell walls, stronger interfacial interaction force is formed between wood substrates, and the modified wood also has excellent flame retardant property.

3. The nonionic surfactant and the polyethylene glycol can generate synergistic action with other components in the modifier, increase the bonding force of the modifier and the wood cell wall interface, and fill channels of the wood cell wall, so that the impact resistance toughness and the strength of the wood are increased; and the polyethylene glycol can be compatible with each component in the modifier, so that the loss resistance of the modifier is improved.

4. The invention uses polyethylene glycol and water as solvents, and does not have the environmental problem caused by volatilization of organic solvents in the drying process of wood treatment.

5. The components in the modifier have excellent interface binding force with wood cell walls, and are not easy to lose, so that the modifier has excellent anti-losing performance. The loss rate of the modifier when the wood treated by the modifier is soaked in water for one month is lower than 10 percent.

6. The modifier is composed of organic matters, has excellent hydrophobicity, can reduce the water absorption of wood by filling the modifier in channels of wood cell walls, and has excellent waterproof performance.

7. The raw materials such as the triazole compound, the ammonium dihydrogen phosphate, the nonionic surfactant and the like used in the invention are nontoxic and environment-friendly, do not volatilize in the wood treatment process and the modified wood use process, do not generate the volatilization release problem of harmful substances such as formaldehyde, phenol and the like, and have no pollution to the environment, so that the environment-friendly wood modifier is provided.

8. The preparation method is simple, the cost is low, the wood modified by the wood is stable in size, and the wood modified by the wood has excellent hardness, bending strength, impact toughness, loss resistance, waterproofness and flame retardance, so that the service life of the modified wood is prolonged. The modified wood can be widely used for processing products such as floors, doors and windows, furniture, outdoor platform decks and the like, the application value of the wood of the artificial forest is greatly improved, and the wood modified wood has important significance for replacing natural forest resources with the artificial forest, relieving the contradiction between supply and demand of the wood in China and realizing sustainable development and utilization of the forest resources.

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The wood modifier and the preparation method thereof of the present invention will be described with reference to specific examples.

Example 1

A wood modifier is composed of the following raw materials in parts by weight: 5 parts of triazole compound, 20 parts of hydroxyethyl methacrylate, 0.8 part of catalyst, 20 parts of ammonium dihydrogen phosphate, 20 parts of nonionic surfactant, 90 parts of polyethylene glycol and 800 parts of water, wherein the preparation method comprises the following specific steps:

(1) dividing polyethylene glycol into three equal parts, and adding the polyethylene glycol in two times;

(2) adding a triazole compound, hydroxyethyl methacrylate and a first part of polyethylene glycol into a reaction kettle, uniformly stirring, adding a catalyst, stirring and reacting for 0.5-1h at room temperature, adding ammonium dihydrogen phosphate, heating to 50 ℃, and stirring for 2-3h at the temperature at the speed of 200-320 r/min;

(3) adding sodium hydroxide into a reaction kettle, adjusting the pH value to 7-8, then adding a nonionic surfactant and two parts of polyethylene glycol, heating to 60-80 ℃, and stirring at the speed of 300-;

(4) water is added into the reaction kettle and stirred evenly, so as to prepare the wood modifier of the embodiment.

In this example, the triazole compound was 3, 5-diamino-1, 2, 4-triazole, the catalyst was n-butyllithium, the nonionic surfactant was sucrose ester, and the polyethylene glycol was PEG-200.

Example 2

A wood modifier is composed of the following raw materials in parts by weight: 10 parts of triazole compound, 10 parts of hydroxyethyl methacrylate, 0.5 part of catalyst, 10 parts of ammonium dihydrogen phosphate, 40 parts of nonionic surfactant, 45 parts of polyethylene glycol and 300 parts of water, wherein the preparation method is the same as that in example 1, and the specific steps refer to example 1.

In the embodiment, the triazole compound is 5 parts of 5-methyl-3-octyl-1, 2, 4-triazole and 5 parts of 3-butyl-1, 2, 4-triazole, the catalyst is n-butyllithium, the nonionic surfactant is sucrose ester, and the polyethylene glycol is PEG-600.

Example 3

A wood modifier is composed of the following raw materials in parts by weight: 6 parts of triazole compound, 18 parts of hydroxyethyl methacrylate, 0.6 part of catalyst, 15 parts of ammonium dihydrogen phosphate, 30 parts of nonionic surfactant, 60 parts of polyethylene glycol and 500 parts of water, wherein the preparation method is the same as that in example 1, and the specific steps refer to example 1.

In the embodiment, the triazole compound is 3, 5-diisopropyl-1, 2, 4-triazole, the catalyst is n-butyl lithium, the nonionic surfactant is sorbitan ester, and the polyethylene glycol is 20 parts of PEG-200 and 40 parts of PEG-400.

Example 4

A wood modifier is composed of the following raw materials in parts by weight: 8 parts of triazole compound, 16 parts of hydroxyethyl methacrylate, 0.6 part of catalyst, 18 parts of ammonium dihydrogen phosphate, 28 parts of nonionic surfactant, 75 parts of polyethylene glycol and 600 parts of water, wherein the preparation method is the same as that in example 1, and the specific steps refer to example 1.

In this example, the triazole compound is 6 parts of 3, 5-diisopropyl-1, 2, 4-triazole and 2 parts of 3-ethyl-1, 2, 4-triazole, the catalyst is n-butyllithium, the nonionic surfactant is sorbitan ester, and the polyethylene glycol is PEG-400.

Comparative example 1: use Shenzhen Sanyu chemical industry Co Ltd's timber antideforming agent MCFBXJ

The application effect experiment of the wood modifier of the invention is as follows:

the wood modifying agents of the embodiments 1 to 4 of the invention are respectively adopted to modify wood, and the modification method comprises the following steps: the method comprises the steps of taking poplar 2000mm multiplied by 200mm multiplied by 25mm (longitudinal multiplied by chordwise multiplied by radial) as experimental wood, carrying out wood impregnation modification treatment in a vacuum pressurization mode, and drying to obtain the wood. Keeping the vacuum degree at-0.05 MPa for 30min, pressurizing at 1.0MPa for 2-3h, and drying to obtain modified poplar.

Comparative example 2: selecting poplar wood without modifier treatment

The modifying agents of examples 1-4 and comparative example 1 were selected, the poplar was modified according to the poplar modification method, and then the modified poplar was subjected to performance tests, such as weight gain, loss rate, anti-expansion coefficient, anti-bending strength, equilibrium moisture content, and compressive strength, as shown in table 1. Wherein the loss rate is the change rate of the loss of the modifying agent after the modified poplar is soaked in water for one month.

TABLE 1 modified poplar mechanical Properties test results after treatment of poplar with Wood modifier

	Example 1	Example 2	Example 3	Example 4	Comparative example 1	Comparative example 2
							Loss rate/%)	8.9	7.3	6.1	5.2	13.6	0
Coefficient of resistance to swelling and shrinkage /)	40.8	43.6	52.7	58.9	20.4	0
							Balance water content/%	8.3	7.7	7.1	6.5	12.5	14.5
Bending strength/%)	82.5	86.3	89.6	95.7	70.8	63.8
							Compressive strength/%	8.4	9.1	9.8	10.5	6.4	3.6

Note: the test conditions of equilibrium moisture content are 25 ℃ and 65% relative humidity.

The mechanical property detection results of the modified poplar shown in the table 1 show that the loss rate of the poplar modified by the wood modifier is lower than 8.9%, which shows that the modified poplar has good fixation in wood cells; the expansion and shrinkage resistance coefficient of the wood can reach 58.9 percent, and the wood has good dimensional stability and is not easy to deform; the equilibrium moisture content of the wood is lower than 8.3 percent, which shows that the wood has better water resistance; the bending strength and the compressive strength of the wood are greatly improved, which shows that the wood modifier can improve the strength and the toughness of the wood.

The modifying agents of the examples 1-4 and the comparative example 1 are selected, the poplar is modified according to the poplar modification method, and then the modified poplar is subjected to flame retardant property detection.

The flame retardant performance test comprises an oxygen index test and a smoke density test, wherein the oxygen index test is carried out according to GB/T2406.2-2009 'determination of combustion behavior by oxygen index method for plastics', an LFY-605 type automatic oxygen index tester is used for testing, and the specification of a used test sample is 15mm multiplied by 5mm multiplied by 3mm (length multiplied by width multiplied by thickness); smoke Density test according to GB/T8627 & 2007 Smoke Density test method for Combustion or decomposition of building materials, a JCY-2 type building material smoke Density tester is used for testing, and the specification of the used test sample is 25mm multiplied by 6mm (length multiplied by width multiplied by thickness). The results of the oxygen index and smoke density tests are shown in table 2.

TABLE 2 flame retardancy test results of modified poplar after treatment with wood modifier

The results of the tests on the flame retardant property of the modified poplar shown in Table 2 show that the drug loading of the wood treated by the wood modifier is higher than 48kg/m after the impregnation treatment³The prepared wood has higher content of flame retardant components and can ensure good flame retardance; the oxygen index of the wood treated by the wood modifier is higher than 41, and the LOI is more than or equal to 27, so that the standard of the flame-retardant ISO material is achieved; the smoke density grade SDR is lower than 22.17, and meets the requirements (SDR is less than or equal to 75) stipulated by GB/T8627 and 2007 Smoke density test method for burning or decomposing building materials. Compared with the comparative example 1 and the comparative example 2, the oxygen index and the smoke density test carbon residue rate are both improved, so that the wood treated by the wood modifier has excellent flame retardant property.

The technical features of the embodiments described above can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention.

Claims (3)

1. The wood modifier is characterized by comprising the following raw materials in parts by weight: 5-10 parts of triazole compound, 10-20 parts of hydroxyethyl methacrylate, 0.5-0.8 part of catalyst, 10-20 parts of ammonium dihydrogen phosphate, 20-40 parts of nonionic surfactant, 45-90 parts of polyethylene glycol and 800 parts of water;

the triazole compound is one or two of 3, 5-diamino-1, 2, 4-triazole, 5-methyl-3-octyl-1, 2, 4-triazole, 3-butyl-1, 2, 4-triazole, 3-ethyl-1, 2, 4-triazole and 3, 5-diisopropyl-1, 2, 4-triazole;

the catalyst is n-butyl lithium;

the preparation method of the wood modifier comprises the following specific steps:

(1) dividing polyethylene glycol into three equal parts, and adding the polyethylene glycol in two times;

(2) adding the triazole compound, hydroxyethyl methacrylate and the first part of polyethylene glycol into a reaction kettle, stirring uniformly, adding a catalyst, stirring and reacting for 0.5-1h at room temperature, adding ammonium dihydrogen phosphate, heating to 50 ℃, stirring at the speed of 200-320r/min, and stirring and reacting for 2-3 h;

(3) adding a sodium hydroxide solution into the reaction kettle, adjusting the pH value to 7-8, then adding a nonionic surfactant and two portions of polyethylene glycol, heating to 60-80 ℃, stirring at the speed of 300-;

(4) and adding water into the reaction kettle, and uniformly stirring to obtain the wood modifier.

2. The wood modifier of claim 1, wherein the nonionic surfactant is a sucrose ester or a sorbitan ester.

3. The wood modifier of claim 1, wherein the polyethylene glycol is one or two of PEG-200, PEG-400, or PEG-600.