CN110039626B

CN110039626B - Auxiliary char-forming bio-based expansion type flame-retardant wood and manufacturing method thereof

Info

Publication number: CN110039626B
Application number: CN201910154646.8A
Authority: CN
Inventors: 姜鹏; 李路明; 陈志林; 梁善庆; 卢金汉
Original assignee: Research Institute of Wood Industry of Chinese Academy of Forestry
Current assignee: Research Institute of Wood Industry of Chinese Academy of Forestry
Priority date: 2019-03-01
Filing date: 2019-03-01
Publication date: 2020-12-11
Anticipated expiration: 2039-03-01
Also published as: CN110039626A

Abstract

Provided are an auxiliary char-forming bio-based intumescent flame retardant wood and a method for manufacturing the same, the method for manufacturing the wood comprises the following steps: soaking wood in an auxiliary carbon source and an acid gas source; drying the impregnated wood, wherein the auxiliary carbon source is any one or combination of more of graphene oxide, carboxymethyl cellulose, sodium carboxymethyl cellulose, starch, sucrose and dextrin; the acid gas source is collagen or carrageenan. The mass ratio of the acid gas source to the auxiliary carbon source is 3-6: 1.

Description

Auxiliary char-forming bio-based expansion type flame-retardant wood and manufacturing method thereof

Technical Field

The invention relates to application of a flame retardant technology in wood, in particular to auxiliary char formation bio-based expansion type flame retardant wood and a manufacturing method thereof.

Background

The combustible property of wood itself has a great limitation to its application as building materials and the like, and research on flame-retardant wood has become an important subject.

The wood has certain char forming property in the combustion process, so that the wood has flame retardant property to a certain degree, but the wood has poor char forming quality, the carbon layer has low compactness and uniformity, and the problem to be solved in the field of wood flame retardance is how to improve the char forming property of the wood.

In the prior art, wood is soaked in a three-in-one mixed solution of an auxiliary carbon source, an acid source and a gas source, the char forming amount is increased, and a uniform flame-retardant carbon frame is obtained by expansion, but the problems of compatibility of the three sources and the wood, biomass characteristics and the like are not solved, and meanwhile, in order to avoid the phenomenon of frost resistance, a condensation polymerization reaction is formed on the surface of the wood by utilizing melamine-formaldehyde prepolymer and the like, so that the process is complicated and the cost is increased.

Disclosure of Invention

In view of the above technical problems, the present invention provides a method for manufacturing an auxiliary char-forming bio-based intumescent flame retardant wood, and a novel auxiliary char-forming bio-based intumescent flame retardant wood obtained based on the method, which can realize a flame retardant wood having better char quality and without damaging the biomass characteristics of the wood itself, and a manufacturing method thereof.

According to a first aspect of the present invention, there is provided a method of manufacturing secondary char-forming bio-based intumescent fire retardant wood, comprising the steps of:

(1) soaking wood in an auxiliary carbon source and an acid gas source;

(2) the impregnated wood is dried and,

wherein the auxiliary carbon source is any one or combination of more of graphene oxide, carboxymethyl cellulose, sodium carboxymethyl cellulose, starch, sucrose and dextrin; the acid gas source is collagen or carrageenan.

In the above method, the step (1) further comprises preparing an impregnation solution including an auxiliary carbon source and an acid gas source, and impregnating the wood in the impregnation solution.

In the above method, the step (1) may include:

placing the wood in a closed impregnation treatment tank, and introducing the impregnation liquid into the treatment tank to enable the impregnation liquid to submerge the wood;

sealing the treatment tank, vacuumizing to make the tank be negative pressure, and keeping for a first specified time;

raising the air pressure in the treatment tank and keeping the air pressure for a second specified time; and

the sealed state of the treatment tank was released to obtain the impregnated wood.

In the above method, the step (1) further comprises:

sealing the treatment tank, vacuumizing to make the tank be negative pressure, and keeping for a first specified time; and

the treatment tank is released from the sealed state and is maintained for a second predetermined time.

In the above method, the step (1) may also include:

placing the wood in a closed impregnation treatment tank, sealing the treatment tank, vacuumizing the treatment tank to enable the interior of the treatment tank to be in a negative pressure state, introducing the impregnation liquid into the treatment tank by utilizing the negative pressure to enable the impregnation liquid to submerge the wood, and keeping the impregnation liquid for a first preset time;

raising the air pressure in the treatment tank and keeping the air pressure for a third specified time; and

In the above method, the same substance is used as the acid source and the gas source. The acid source and the gas source can adopt collagen or carrageenan. In this case, the mass ratio of the acid gas source to the auxiliary carbon source in the impregnation liquid is 3-6: 1.

According to a second aspect of the present invention, there is provided an auxiliary char-forming bio-based intumescent fire retardant wood made by the above method.

According to the invention, the auxiliary carbon source adopts any one or more of graphene oxide, carboxymethyl cellulose, sodium carboxymethyl cellulose, starch, sucrose and dextrin, and the substances can be extracted by natural raw materials, so that the damage of industrial products to wood is reduced. Meanwhile, in the combustion process, the substances are combined with active functional groups of the wood cell walls through chemical bonds, so that the stability is stronger, and in the thermal degradation and combustion processes, a more compact carbon frame or carbon layer is promoted to be formed through expansion in the wood microstructure.

According to the invention, a substance is used as an acid source and an air source simultaneously, so that the wood has an expansion flame-retardant function, the use of the substance as an impregnation source material is reduced, and the cost is saved.

In addition, according to the carbon source and the acid gas source adopted by the invention, the combination performance of the wood and the source material is excellent, the phenomenon of frost prevention is avoided, and the complex process and the increased cost caused by the formation of polycondensation reaction on the surface of the wood by utilizing melamine formaldehyde prepolymer and the like in the prior art are avoided.

Thus, according to the method of the present invention, a novel auxiliary char-forming intumescent flame retardant wood with biomass can be manufactured, the char-forming quality is superior and the biomass characteristic of the wood itself is not destroyed.

Drawings

FIG. 1 is a flow chart of a method of making a secondary char-forming bio-based intumescent flame retardant wood.

Fig. 2 is a flowchart of an example of a method for manufacturing the auxiliary char-forming bio-based intumescent fire retardant wood.

Fig. 3 is a flow chart of another example of a method of manufacturing the auxiliary char-forming bio-based intumescent fire retardant wood.

Fig. 4 is a flow chart of still another example of a method of manufacturing the auxiliary char-forming bio-based intumescent fire retardant wood.

Detailed Description

The application provides a new concept of flame-retardant wood, namely 'auxiliary char formation bio-based intumescent flame-retardant wood', which utilizes the char formation property of wood itself and combines other components with biomass to improve the flame-retardant performance of the wood itself and keep the biomass property of the wood, and the manufacturing process is essentially a manufacturing method of the flame-retardant wood added with an auxiliary carbon source.

Referring to fig. 1, in the above-mentioned manufacturing process of the auxiliary char-forming bio-based intumescent flame retardant wood, the following steps are included:

s100: soaking wood in an auxiliary carbon source and an acid gas source;

s200: the impregnated wood is dried and,

The term "wood" as used herein refers to lignified tissue formed by a plant capable of secondary growth.

Wood forms char layers or char frames during combustion, but the char yield is insufficient, and the quality is poor, uneven and not dense enough. According to the scheme of the invention, the carbon forming amount is increased on the basis that the wood is immersed in an auxiliary carbon source serving as a carbon forming agent to form a foam carbonization layer by the carbon source of the auxiliary wood.

The acid source is also called dehydrating agent, which plays the role of carbonization accelerant. The gas source, also called a foaming source, is used to expand the char layer to achieve uniformity.

According to the carbon source and the acid gas source adopted by the invention, the combination performance of the wood and the source material is excellent, the phenomenon of frost prevention is avoided, and the complex process and the increased cost caused by the formation of polycondensation reaction on the surface of the wood by utilizing melamine formaldehyde prepolymer and the like in the prior art are avoided.

The invention carries out the research of charring flame retardance aiming at the characteristics of natural wood, can manufacture novel auxiliary charring expansion type flame retardant wood based on bio-base, has more excellent charring quality and does not damage the biomass of the wood.

In the above step S100, for impregnation of the wood, the wood may be impregnated in the auxiliary carbon source and the acid gas source, respectively, or an impregnation solution including the auxiliary carbon source and the acid gas source may be prepared and the wood may be impregnated in the impregnation solution.

In the case where wood is impregnated with the auxiliary carbon source and the acid gas source, respectively, the present invention is carried out in two impregnation stepsWith a fourth predetermined time therebetween, e.g.24 hoursTherefore, the first-step impregnation modifier and the wood are fully reacted and combined through chemical bonds, and the loss caused by precipitation in the second-step impregnation modification process is avoided. Therefore, the impregnation process can be flexibly processed by utilizing the convenience of respectively impregnating the auxiliary carbon source and the acid gas source, for example, the material impregnated with the auxiliary carbon source is simply impregnated with the acid gas source, so that the cost is reduced and the excessive impregnation is avoided.

In the embodiment shown in fig. 2 to 4, the step S100 includes a step S101 of preparing an impregnation solution including an auxiliary carbon source and an acid gas source, and impregnating wood in the impregnation solution.

In this case, as shown in fig. 2, the step (1) may include:

s102, putting the wood into a closed impregnation treatment tank, and introducing the impregnation liquid into the treatment tank to enable the impregnation liquid to submerge the wood;

s103, the treatment tank is in a sealed state, vacuumized to enable the interior of the treatment tank to be in a negative pressure state, and kept for a first specified time;

s104, increasing the air pressure in the treatment tank and keeping the air pressure for a second specified time; and

s105, the sealed state of the treatment tank is released, and the impregnated wood is obtained.

In general, wood having a water content of, for example, 10% or less is placed in a closed-type immersion treatment tank, but the water content is not limited thereto. The introduction of the impregnation liquid containing the auxiliary carbon source and the acid gas source so that the impregnation liquid is submerged in the wood means that the wood is completely immersed in the impregnation liquid. The impregnation liquid is obtained by, for example, dissolving the auxiliary carbon source and the acid gas source in distilled water, stirring the solution sufficiently to dissolve the solution, and then leaving the solution to stand for 24 hours. The closed immersion treatment tank is closed, and vacuum is applied to maintain the negative pressure in the tank for a first predetermined time, for example, 15 to 60 minutes, for example, at a vacuum degree of-1 MPa, but the vacuum degree and the first predetermined time are not limited thereto and may be selected by those skilled in the art according to the actual circumstances. Subsequently, the gas pressure in the processing tank is increased and maintained for a second predetermined time. Here, the pressure in the processing tank can be increased by releasing the vacuum and inflating and pressurizing the tank, and the pressure is stabilized at 1.0 to 1.5MPa, and the pressure is maintained for a second predetermined time, for example, 24 hours, where the pressure and the second predetermined time are not limited herein, and those skilled in the art can select the pressure according to actual circumstances. Finally, the treatment tank is released from the closed state, and the impregnated wood is taken out, or the impregnation solution is discharged to obtain the impregnated wood.

As an alternative, referring to fig. 3, the pressure in the treatment tank may be increased by releasing the closed state of the treatment tank in step S106, wherein the pores of the wood are filled with the impregnation fluid after the pressure impregnation of the wood is performed, and the interior of the wood is still in the pressurized state after the pressure in the treatment tank is released and the atmospheric pressure is realized. In this case, the second predetermined time may be maintained, for example, for 24 hours, but the present invention is not limited thereto.

As another alternative, referring to fig. 4, as shown in step S102a, the wood may be placed in a closed impregnation treatment tank, the treatment tank is closed and vacuumized to form a negative pressure in the tank, the impregnation liquid is introduced into the treatment tank by the negative pressure to allow the impregnation liquid to pass through the wood and be maintained for a first predetermined time, and the air pressure in the treatment tank is increased in step S107 and maintained for a third predetermined time; finally, the sealing state of the treatment tank is released as shown in step S108, and the impregnated wood is obtained. In this alternative, the impregnation fluid is led to enter the treatment tank through negative pressure, which is more favorable for the impregnation fluid to initially enter the pores of the wood. Thus, the third predetermined time required for the holding can be appropriately reduced after the gas pressure in the processing tank is increased.

In the above step S200, the impregnated wood is subjected to a drying process. For example, the impregnated wood is put into a drying kiln for air drying treatment, or put into a freeze dryer for drying for 72 hours, or put into a blast drying oven after standing for 3 hours, and dried at 103 ℃, and the specific drying mode is not limited herein, and can be selected by those skilled in the art according to actual conditions.

Under the condition that wood is soaked in a soaking solution prepared by adopting the soaking solution comprising an auxiliary carbon source and an acid gas source, the mass ratio of the acid gas source to the auxiliary carbon source in the soaking solution is 3-6: 1.

The present application will be described in further detail with reference to examples. It is to be understood that the specific embodiments described herein are merely illustrative of the relevant invention and not restrictive of the invention. It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The following examples were carried out using the same wood, which was a fast-growing wood of poplar and fir wood artificial forest having a size of 100mm x 400mm x 50mm, and the modification treatment according to the present invention was carried out using the same wood, but the present invention is not necessarily limited thereto.

Example 1

Dissolving 15g of protein glue in 1000ml of graphene oxide with the concentration of 2.5mg/ml, stirring to fully dissolve, and standing for 24 hours. Completely immersing wood sample with size of 100mm 400mm 50mm into the above solution, placing in vacuum pressure impregnation tank, vacuumizing to negative pressure, maintaining pressure for 15-60min, pressurizing to 1-1.5MPa, and maintaining pressure for 24 h. And taking out a wood sample, removing surface impurities, putting the wood sample into a freezing box for freezing for 24 hours, and drying for 72 hours by using a freeze dryer to obtain the auxiliary charring bio-based intumescent flame retardant wood.

Example 2

The graphene oxide was replaced with carboxymethyl cellulose, and the rest was the same as in example 1.

Example 3

The graphene oxide was replaced with sodium carboxymethylcellulose, and the rest was the same as in example 1.

Example 4

The graphene oxide was replaced with starch, and the rest was the same as in example 1.

Example 5

The graphene oxide was replaced with sucrose, and the rest was the same as in example 1.

Example 6

The graphene oxide was replaced with dextrin, and the rest was the same as in example 1.

Example 7

Graphene oxide was replaced with carboxymethyl cellulose, and the protein gum was replaced with carrageenan, the others being the same as in example 1.

Example 8

The graphene oxide was replaced with sodium carboxymethylcellulose, the protein glue was replaced with carrageenan, and the rest were the same as in example 1.

Example 9

Graphene oxide was replaced with starch, and the protein gel was replaced with carrageenan, the other being the same as in example 1.

Example 10

The graphene oxide was replaced with sucrose, and the protein gel was replaced with carrageenan, the other being the same as in example 1.

Example 11

The graphene oxide was replaced with dextrin, the protein gel was replaced with carrageenan, and the rest were the same as in example 1.

Example 12

15g of protein was dissolved in 1000ml of graphene oxide with a concentration of 5mg/ml, and the rest was the same as in example 1.

Example 13

Graphene oxide was replaced with carboxymethyl cellulose, and the rest was the same as in example 12.

Example 14

Graphene oxide was replaced with sodium carboxymethylcellulose, and the rest was the same as in example 12.

Example 15

Graphene oxide was replaced with starch, and the rest was the same as in example 12.

Example 16

The graphene oxide was replaced with sucrose, and the rest was the same as in example 12.

Example 17

The graphene oxide was replaced with dextrin, and the rest was the same as in example 12.

Example 18

Graphene oxide was replaced with carboxymethyl cellulose, and the protein gum was replaced with carrageenan, the others being the same as in example 12.

Example 19

Graphene oxide was replaced with sodium carboxymethylcellulose, and the protein glue was replaced with carrageenan, the others being the same as in example 12.

Example 20

Graphene oxide was replaced with starch, and the protein gel was replaced with carrageenan, the other being the same as in example 12.

Example 21

The graphene oxide was replaced with sucrose, the protein gel was replaced with carrageenan, and the rest were the same as in example 12.

Example 22

Graphene oxide was replaced with dextrin, and the protein gel was replaced with carrageenan, the others being the same as in example 12.

Example 23

15g of the protein was dissolved in 1000ml of graphene oxide with a concentration of 4mg/ml, and the rest was the same as in example 23.

Example 24

Graphene oxide was replaced with carboxymethyl cellulose, and the rest was the same as in example 23.

Example 25

Graphene oxide was replaced with sodium carboxymethylcellulose, and the rest was the same as in example 23.

Example 26

Graphene oxide was replaced with starch, and the rest was the same as in example 23.

Example 27

The graphene oxide was replaced with sucrose, and the rest was the same as in example 23.

Example 28

The graphene oxide was replaced with dextrin, and the rest was the same as in example 23.

Example 29

Graphene oxide was replaced with carboxymethyl cellulose, and the protein gum was replaced with carrageenan, the others being the same as in example 23.

Example 30

Graphene oxide was replaced with sodium carboxymethylcellulose, and the protein glue was replaced with carrageenan, the others being the same as in example 23.

Example 31

Graphene oxide was replaced with starch, and the protein gel was replaced with carrageenan, the other being the same as in example 23.

Example 32

The graphene oxide was replaced with sucrose, and the protein gel was replaced with carrageenan, the other being the same as in example 23.

Example 33

Graphene oxide was replaced with dextrin, and the protein gel was replaced with carrageenan, and the rest were the same as in example 23.

The wood before modification and the wood after modification obtained in the above embodiment are subjected to a combustion experiment to obtain comparison performance results before and after wood modification, so that the wood after modification by adopting the flame retardant technology of the invention can obtain an excellent flame retardant effect by particularly soaking the wood in a soaking solution in which the mass ratio of an acid gas source to an auxiliary carbon source is 3-6: 1, and the results are specifically shown in table 1 below.

Wherein, the criteria standards of V1, V2 and no grade are GB/T2408-.

TABLE 1

From the above examples, those skilled in the art can naturally understand that the carbon source and the acid gas source can be selected from one of the materials in the above schemes or can be arbitrarily combined, and the excellent effects of the present invention can also be achieved.

Claims

1. A method for manufacturing auxiliary char forming bio-based expansion type flame retardant wood, which is characterized in that,

the method comprises the following steps:

(1) soaking wood in an auxiliary carbon source and an acid gas source;

(2) the impregnated wood is dried and,

wherein the auxiliary carbon source is any one or combination of more of carboxymethyl cellulose, sodium carboxymethyl cellulose, starch, sucrose and dextrin; the acid gas source is collagen or carrageenan,

the step (1) also comprises the steps of preparing a steeping liquor comprising the auxiliary carbon source and the acid gas source, steeping wood in the steeping liquor,

the mass ratio of the acid gas source to the auxiliary carbon source in the impregnation liquid is 3-6: 1,

thus, the auxiliary char-forming expansion type flame-retardant wood based on the bio-base is manufactured.

2. The method of claim 1,

the step (1) further comprises:

3. The method of claim 1, wherein step (1) further comprises:

4. The method of claim 1,

the step (1) further comprises:

5. An auxiliary char-forming bio-based intumescent flame retardant wood, characterized in that it is prepared by the method of any of claims 1 to 4.