Maleic anhydride / sodium silicate / furfuryl alcohol composite modified Chinese fir and preparation method and application thereof

Abstract

The invention discloses a maleic anhydride / sodium silicate / furfuryl alcohol composite modified Chinese fir and a preparation method and application thereof.The preparation method comprises the following steps that the Chinese fir is placed in a dipping device, a sodium silicate solution is added to do not leave the Chinese fir, and positive pressure is applied to conduct primary dipping treatment; adding a furfuryl alcohol-maleic anhydride compound solution to remove the cedarwood, applying positive pressure to carry out secondary dipping treatment, curing, aging and drying to obtain the maleic anhydride / sodium silicate / furfuryl alcohol compound modified cedarwood. The prepared maleic anhydride / sodium silicate / furfuryl alcohol composite modified Chinese fir has excellent mechanical properties, dimensional stability and loss resistance, can be widely applied to the high-added-value fields of buildings, solid wood furniture and the like, and has remarkable economic benefits and social benefits and good application prospects.

Description

Technical Field

[0001] The present invention belongs to the field of wood science and technology, and particularly relates to a maleic anhydride / sodium silicate / furfuryl alcohol composite modified Chinese fir and its preparation method and application. Background Art

[0002] As a major plantation tree species, Chinese fir has the characteristics of short rotation period, straight grain, and natural fragrance. The full utilization of plantation Chinese fir is of great significance for alleviating problems such as the shortage of domestic solid wood resources and high external dependence. However, the modified Chinese fir prepared by existing wood modification methods has problems such as low mechanical properties, unstable dimensions, and high leaching rate of the agent after modification. Therefore, there is an urgent need to find a preparation method for modified Chinese fir to improve its mechanical properties, dimensional stability, and anti-leaching properties. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a maleic anhydride / sodium silicate / furfuryl alcohol composite modified Chinese fir with excellent mechanical properties, dimensional stability, and anti-leaching properties, as well as its preparation method and application.

[0004] To solve the above technical problems, the present invention adopts the following technical solutions.

[0005] A preparation method of a maleic anhydride / sodium silicate / furfuryl alcohol composite modified Chinese fir, comprising the following steps:

[0006] (1) Place Chinese fir in an impregnation device, apply negative pressure to remove the air inside the Chinese fir, add sodium silicate solution to submerge the Chinese fir, apply positive pressure for a first impregnation treatment, and drain the impregnation liquid;

[0007] (2) Apply negative pressure to the impregnation device again to remove the air inside the Chinese fir, add a furfuryl alcohol-maleic anhydride compound solution to submerge the Chinese fir, apply positive pressure for a second impregnation treatment, drain the impregnation liquid, and obtain impregnated Chinese fir;

[0008] (3) Cure, age, and dry the impregnated Chinese fir to obtain a maleic anhydride / sodium silicate / furfuryl alcohol composite modified Chinese fir.

[0009] In the above preparation method, preferably, in step (1), the mass fraction of the sodium silicate solution is 20% - 30%.

[0010] In the above preparation method, preferably, in step (2), the furfuryl alcohol-maleic anhydride compound solution is formed by mixing a furfuryl alcohol solution and a maleic anhydride solution. The mass ratio of the furfuryl alcohol solution to the maleic anhydride solution is 1 - 5:1. The mass fraction of the maleic anhydride solution is 2% - 8%, and the mass fraction of the furfuryl alcohol solution is 5% - 15%.

[0011] For the above preparation method, preferably, in step (2), the mass fraction of the maleic anhydride solution is 2% - 5%.

[0012] For the above preparation method, preferably, in step (1), the specific process of applying negative pressure is: evacuating to -0.07 MPa to -0.09 MPa and maintaining for 15 min to 25 min; the specific process of the first impregnation treatment is: maintaining at a positive pressure of 0.4 MPa to 0.6 MPa for 2 h to 3 h.

[0013] For the above preparation method, preferably, in step (2), the specific process of applying negative pressure is: evacuating to -0.07 MPa to -0.09 MPa and maintaining for 15 min to 25 min; the specific process of the second impregnation treatment is: maintaining at a positive pressure of 0.4 MPa to 0.6 MPa for 2 h to 3 h.

[0014] For the above preparation method, preferably, before using the Chinese fir, the following treatment is also included: drying the Chinese fir to a moisture content of 7% - 10%.

[0015] For the above preparation method, preferably, in step (3), the curing temperature is 70°C to 100°C, the curing time is 1 h to 3 h, the aging time is 48 h to 72 h, the drying temperature is 30°C to 60°C, and the drying time is 2 days to 4 days.

[0016] As a general technical concept, the present invention also provides a maleic anhydride / sodium silicate / furfural alcohol composite modified Chinese fir prepared by the above preparation method of maleic anhydride / sodium silicate / furfural alcohol composite modified Chinese fir.

[0017] As a general technical concept, the present invention also provides an application of the above maleic anhydride / sodium silicate / furfural alcohol composite modified Chinese fir in furniture and architecture.

[0018] Compared with the prior art, the advantages of the present invention are:

[0019] The present invention discloses a preparation method of maleic anhydride / sodium silicate / furfuryl alcohol composite modified Chinese fir. Using Chinese fir as raw material, first impregnate Chinese fir with sodium silicate solution to make sodium silicate enter the interior of the wood, and then impregnate Chinese fir with a compound solution of furfuryl alcohol and maleic anhydride. On the one hand, maleic anhydride, as a curing agent for sodium silicate, can promote the polymerization of sodium silicate in the cell cavity to fill the cell cavity, and the principle is shown in formulas (1) and (2). On the other hand, maleic anhydride, as a catalyst for furfuryl alcohol, can promote the polymerization of furfuryl alcohol in the cell wall to produce a cross-linking reaction with the wood, and the principle is shown in formulas (3) to (5). Finally, a synergistically fixed composite modified Chinese fir is obtained. The maleic anhydride / sodium silicate / furfuryl alcohol composite modified Chinese fir prepared by the present invention has excellent mechanical properties, dimensional stability and anti-leaching properties, and can be widely applied to high-value-added fields such as construction and solid wood furniture, with significant economic and social benefits and good application prospects.

[0020] Specific embodiments

[0021] The following further describes the present invention in conjunction with specific preferred embodiments, but does not limit the protection scope of the present invention accordingly. The materials and instruments used in the following embodiments are all commercially available.

[0022] Example 1:

[0023] A preparation method of maleic anhydride / sodium silicate / furfuryl alcohol composite modified Chinese fir of the present invention comprises the following steps:

[0024] (1) Select fast-growing Chinese fir with regular texture, no knots, no cracks, and no decay (in accordance with the national standard GB / T 1927-2021), saw it into the standard specified size, and dry it to a moisture content of 7%-10% to obtain pretreated Chinese fir.

[0025] (2) Prepare 1000 g of sodium silicate solution (the mass fraction of this solution is 20%); place the above-mentioned pretreated Chinese fir in a container, then place the container inside an impregnation tank, evacuate to -0.08 MPa and hold the pressure for 20 min to extract the moisture and air in the wood pores; then suck in the sodium silicate solution under negative pressure to submerge the Chinese fir, after completion, unload the negative pressure, and pressurize the impregnation tank to 0.5 MPa and hold the pressure for 3 h to make the impregnating liquid fully penetrate into the interior of the wood, and after completion, relieve the pressure and drain the excess impregnating liquid.

[0026] (3) Mix the furfuryl alcohol solution and maleic anhydride solution according to a mass ratio of 5:1, with the mass fraction of the furfuryl alcohol solution being 10% and the mass fraction of the maleic anhydride solution being 2%, to prepare 1000 g of a furfuryl alcohol-maleic anhydride compound solution; place the Chinese fir in a container, then place the container inside an impregnation tank, evacuate to -0.08 MPa and maintain the pressure for 20 min to extract the moisture and air in the wood pores; then suck in the furfuryl alcohol-maleic anhydride compound solution under negative pressure to submerge the Chinese fir, unload the negative pressure after completion, and pressurize the impregnation tank to 0.5 MPa and maintain the pressure for 3 h to allow the compound solution to fully penetrate into the wood interior, unload the pressure after completion, and drain the excess impregnating liquid to obtain impregnated Chinese fir.

[0027] (4) Place the above-mentioned impregnated Chinese fir in a blast drying oven at 100 °C for curing for 2 h, then place it in a ventilated and dry place for aging for 48 h, and then put it into blast drying ovens at 40 °C and 60 °C respectively for drying for 48 h to obtain maleic anhydride / sodium silicate / furfuryl alcohol composite modified Chinese fir.

[0028] Example 2:

[0029] A kind of maleic anhydride / sodium silicate / furfuryl alcohol composite modified Chinese fir of the present invention, its preparation method is basically the same as that of the maleic anhydride / sodium silicate / furfuryl alcohol composite modified Chinese fir in Example 1, the only difference being that: in step (3), the mass fraction of the maleic anhydride solution is 5%.

[0030] Example 3:

[0031] A kind of maleic anhydride / sodium silicate / furfuryl alcohol composite modified Chinese fir of the present invention, its preparation method is basically the same as that of the maleic anhydride / sodium silicate / furfuryl alcohol composite modified Chinese fir in Example 1, the only difference being that: in step (3), the mass fraction of the maleic anhydride solution is 8%.

[0032] Comparative Example 1:

[0033] A kind of sodium silicate modified Chinese fir, its preparation method is basically the same as that of the maleic anhydride / sodium silicate / furfuryl alcohol composite modified Chinese fir in Example 1, the only difference being that: step (3) is not carried out, that is, only sodium silicate solution is used as the impregnating liquid.

[0034] Test the various properties of the maleic anhydride / sodium silicate / furfuryl alcohol composite modified Chinese fir prepared in Examples 1 to 3 and the sodium silicate modified Chinese fir prepared in Comparative Example 1, and the results are shown in Table 1.

[0035] Table 1 Performance comparison of maleic anhydride / sodium silicate / furfuryl alcohol composite modified Chinese fir in Examples 1 to 3 and sodium silicate modified Chinese fir in Comparative Example 1

[0036]

[0037] As can be seen from Table 1, compared with unmodified Chinese fir and sodium silicate modified Chinese fir prepared in Comparative Example 1, the compressive strength of maleic anhydride / sodium silicate / furfuryl alcohol composite modified Chinese fir prepared in Examples 1 to 3 is significantly improved, and the hygroscopic volume expansion rate and loss rate are significantly decreased. In addition, compared with the maleic anhydride / sodium silicate / furfuryl alcohol composite modified Chinese fir in Example 1, the compressive strength of the maleic anhydride / sodium silicate / furfuryl alcohol composite modified Chinese fir in Examples 2 and 3 is reduced. This is because the increase in maleic anhydride concentration will cause the degradation of wood components, thereby affecting the mechanical strength of the composite modified Chinese fir. It can be seen that the preparation method of the present invention uses a sodium silicate solution and a furfuryl alcohol-maleic anhydride compound solution as the impregnating solution, and maleic anhydride as the curing agent of sodium silicate and the catalyst of furfuryl alcohol, which can achieve the synergistic fixation of sodium silicate and furfuryl alcohol, and make up for the problems of poor dimensional stability and anti-loss performance caused by physical filling modification of sodium silicate.

[0038] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make many possible changes and modifications to the technical solution of the present invention by using the above-disclosed methods and technical contents, or modify it into an equivalent embodiment with equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the technical solution of the present invention still fall within the scope of the protection of the technical solution of the present invention.

Claims

1. A preparation method of maleic anhydride / sodium silicate / furfuryl alcohol composite modified Chinese fir, characterized in that, It includes the following steps: (1) Place Chinese fir in an impregnation device, apply negative pressure to remove the air inside the Chinese fir, add sodium silicate solution to submerge the Chinese fir, apply positive pressure for a primary impregnation treatment, and drain the impregnation liquid; (2) Apply negative pressure to the impregnation device again to remove the air inside the Chinese fir, add a furfuryl alcohol - maleic anhydride compound solution to submerge the Chinese fir, apply positive pressure for a secondary impregnation treatment, and drain the impregnation liquid to obtain impregnated Chinese fir; (3) Cure, age, and dry the impregnated Chinese fir to obtain maleic anhydride / sodium silicate / furfuryl alcohol composite - modified Chinese fir.

2. The preparation method of maleic anhydride / sodium silicate / furfuryl alcohol composite modified Chinese fir according to claim 1, characterized in that, In step (1), the mass fraction of the sodium silicate solution is 20% - 30%.

3. The preparation method of maleic anhydride / sodium silicate / furfuryl alcohol composite modified Chinese fir according to claim 2, wherein, In step (2), the furfuryl alcohol - maleic anhydride compound solution is formed by mixing a furfuryl alcohol solution and a maleic anhydride solution. The mass ratio of the furfuryl alcohol solution to the maleic anhydride solution is 1 - 5:

1. The mass fraction of the maleic anhydride solution is 2% - 8%, and the mass fraction of the furfuryl alcohol solution is 5% - 15%.

4. The preparation method of maleic anhydride / sodium silicate / furfuryl alcohol composite modified Chinese fir according to claim 3, characterized in that, In step (2), the mass fraction of the maleic anhydride solution is 2% - 5%.

5. The preparation method of maleic anhydride / sodium silicate / furfuryl alcohol compound modified Chinese fir according to any one of claims 1 to 4, characterized in that, In step (1), the specific process of applying negative pressure is: evacuate to - 0.07 MPa - - 0.09 MPa and hold for 15 min - 25 min; the specific process of the primary impregnation treatment is: hold at a positive pressure of 0.4 MPa - 0.6 MPa for 2 h - 3 h.

6. The preparation method of maleic anhydride / sodium silicate / furfuryl alcohol composite modified Chinese fir according to any one of claims 1 to 4, characterized in that, In step (2), the specific process of applying negative pressure is: evacuate to - 0.07 MPa - - 0.09 MPa and hold for 15 min - 25 min; the specific process of the secondary impregnation treatment is: hold at a positive pressure of 0.4 MPa - 0.6 MPa for 2 h - 3 h.

7. The preparation method of maleic anhydride / sodium silicate / furfuryl alcohol composite modified Chinese fir according to any one of claims 1 to 4, characterized in that, Before step (1), the following treatment is also included for the Chinese fir: dry the Chinese fir to a moisture content of 7% - 10%.

8. The preparation method of maleic anhydride / sodium silicate / furfuryl alcohol compound modified Chinese fir according to any one of claims 1 to 4, characterized in that, In step (3), the curing temperature is 70°C - 100°C, the curing time is 1 h - 3 h, the aging time is 48 h - 72 h, the drying temperature is 30°C - 60°C, and the drying time is 2 days - 4 days.

9. A maleic anhydride / sodium silicate / furfuryl alcohol composite - modified Chinese fir prepared by the preparation method of the maleic anhydride / sodium silicate / furfuryl alcohol composite - modified Chinese fir according to any one of claims 1 - 8.

10. An application of the maleic anhydride / sodium silicate / furfuryl alcohol composite - modified Chinese fir according to claim 9 in furniture and construction.

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