Method for preparing room temperature cured multifunctional wood modifier and method for wood modification

Abstract

The present invention relates to a method for preparing a wood modifier and a method for wood modification, and in particular, to a method for preparing a room temperature cured multifunctional wood modifier and a method for wood modification to solve the problems of high construction temperature, high toxicity, poor leaching-resistance and single function of existing wood modifiers. The method includes: step 1: weighing a hydrophobic polymer resin, an additive, a curing agent and a solvent, mixing and then stirring at room temperature to obtain a functional reagent A; step 2: weighing nanoparticles, a surface modifier and toluene, mixing and then stirring, cleaning with acetone, centrifuging, and drying to obtain a functional reagent B; step 3: adding a functional reagent C into the functional reagent A, evenly stirring, adding the functional reagent B, and performing ultrasonic processing to obtain the multifunctional wood modifier.

Claims

1. A method for preparing an ambient temperature cured multifunctional wood modifier, comprising the following steps: step 1: weighing 1%-50% of hydrophobic polymer resin, 0.1%-1% of additive, 0.1%-10% of curing agent and the balance solvent according to weight percent respectively, mixing and then stirring at an ambient temperature for at least 2 h to obtain a functional reagent A; step 2: weighing 0.1%-5% of nanoparticles, 0.1%-2% of surface modifier and the balance toluene according to weight percent respectively, mixing and then stirring for 72-76 h, cleaning with acetone, centrifuging at 8000-9000 rpm for 3-5 times, and drying at 78-82° C. for 12-14 h to obtain a functional reagent B; step 3: adding a functional reagent C into the functional reagent A, evenly stirring, adding the functional reagent B, and performing ultrasonic processing for at least 30 min to obtain the multifunctional wood modifier, wherein the weight of the functional reagent B is 0.1%-1% that of the functional reagent A, and the weight of the functional reagent C is 0.2%-2% that of the functional reagent A.

2. The method for preparing an ambient temperature cured multifunctional wood modifier according to claim 1, wherein the hydrophobic polymer resin in step 1 is fluorocarbon resin with less than 8 F atoms.

3. The method for preparing an ambient temperature cured multifunctional wood modifier according to claim 2, wherein the additive in step 1 is dibutyltin dilaurate.

4. The method for preparing an ambient temperature cured multifunctional wood modifier according to claim 3, wherein the curing agent in step 1 is aliphatic diisocyanate.

5. The method for preparing an ambient temperature cured multifunctional wood modifier according to claim 4, wherein the solvent in step 1 is a petroleum ether solvent.

6. The method for preparing an ambient temperature cured multifunctional wood modifier according to claim 5, wherein in step 2, the nanoparticles are one or a mixture of free combination of SiO.sub.2, Ag, Cu, CuO, TiO.sub.2 and ZnO at any ratio, and the nanoparticles have a particle diameter of 10-500 nm.

7. The method for preparing an ambient temperature cured multifunctional wood modifier according to claim 6, wherein the surface modifier in step 2 is polydimethyl siloxane.

8. The method for preparing an ambient temperature cured multifunctional wood modifier according to claim 6, wherein the functional reagent C in step 3 is iodopropynyl butylcarbamate.

9. The method for preparing an ambient temperature cured multifunctional wood modifier according to claim 6, wherein the ultrasonic power in step 3 is 500-550 W.

10. The method for preparing an ambient temperature cured multifunctional wood modifier according to claim 1, wherein the additive in step 1 is dibutyltin dilaurate.

11. The method for preparing an ambient temperature cured multifunctional wood modifier according to claim 10, wherein the curing agent in step 1 is aliphatic diisocyanate.

12. The method for preparing an ambient temperature cured multifunctional wood modifier according to claim 11, wherein the solvent in step 1 is a petroleum ether solvent.

13. The method for preparing an ambient temperature cured multifunctional wood modifier according to claim 12, wherein in step 2, the nanoparticles are one or a mixture of free combination of SiO.sub.2, Ag, Cu, CuO, TiO.sub.2 and ZnO at any ratio, and the nanoparticles have a particle diameter of 10-500 nm.

14. The method for preparing an ambient temperature cured multifunctional wood modifier according to claim 13, wherein the surface modifier in step 2 is polydimethylsiloxane.

15. The method for preparing an ambient temperature cured multifunctional wood modifier according to claim 13, wherein the functional reagent C in step 3 is iodopropynyl butylcarbamate.

16. The method for preparing an ambient temperature cured multifunctional wood modifier according to claim 13, wherein the ultrasonic power in step 3 is 500-550 W.

17. A method for wood modification by using the multifunctional wood modifier according to claim 1, wherein the method specifically comprises: method 1: directly spraying the multifunctional wood modifier on the surface of wood, and then standing the wood coated with the multifunctional wood modifier at the ambient temperature for 24-72 h to obtain modified wood; and method 2: adding the multifunctional wood modifier and wood into a reaction tank, keeping a pressure of 0.1-0.5 MPa for 10-30 min, impregnating the multifunctional wood modifier into the wood, and finally standing the immersed multifunctional wood at the ambient temperature for 24-72 h to obtain modified wood.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a scanning electron microscope image of the surface of modified plywood wood in Embodiment 1;

(2) FIG. 2 is a photo of a static water contact angle on the surface of the modified plywood wood in Embodiment 1;

(3) FIG. 3 is a photo of water drops on the surface of the modified plywood wood in Embodiment 1;

(4) FIG. 4 is a photo of a static water contact angle on the surface of the modified plywood wood after outdoor 90-day weathering tests in Embodiment 1;

(5) FIG. 5 is a photo of a static water contact angle on the surface of modified poplar wood in Embodiment 2;

(6) FIG. 6 is a photo of water drops on the surface of the modified poplar wood in Embodiment 2; and

(7) FIG. 7 is a photo of a static water contact angle on the surface of the modified poplar wood after outdoor 90-day weathering tests in Embodiment 2.

DETAILED DESCRIPTION

(8) The technical solution of the present invention is not limited to the specific embodiments listed below, and includes any combinations among the specific embodiments.

(9) Implementation 1: A method for preparing a room temperature cured multifunctional wood modifier according to this implementation includes the following steps:

(10) Step 1: Weighing 1%-50% of hydrophobic polymer resin, 0.1%-1% of additive, 0.1%-10% of curing agent and the balance solvent according to weight percent respectively, mixing and then stirring at room temperature for at least 2 h to obtain a functional reagent A.

(11) Step 2: Weighing 0.1%-5% of nanoparticles, 0.1%-2% of surface modifier and the balance toluene according to weight percent respectively, mixing and then stirring for 72-76 h, cleaning with acetone, centrifuging at 8000-9000 rpm for 3-5 times, and then drying at 78-82° C. for 12-14 h to obtain a functional reagent B.

(12) Step 3: Adding a functional reagent C into the functional reagent A, evenly stirring, adding the functional reagent B, and performing ultrasonic processing for at least 30 min to obtain the multifunctional wood modifier, where the weight of the functional reagent B is 0.1%-1% that of the functional reagent A, and the weight of the functional reagent C is 0.2%-2% that of the functional reagent A.

(13) Implementation 2: This implementation differs from Implementation 1 in that the hydrophobic polymer resin in step 1 is fluorocarbon resin with less than 8 F atoms. Others are the same as those in Implementation 1.

(14) The fluorocarbon resin of this implementation is purchased from Solmont Technology (Wuxi Co., Ltd. and meets the environmental protection standards of Europe, Japan and the United States.

(15) Implementation 3: This implementation differs from Implementation 1 to 2 in that the additive in step 1 is dibutyltin dilaurate. Others are the same as those in Implementation 1 or 2.

(16) The additive of this implementation has the effect of speeding-up drying.

(17) Implementation 4: This implementation differs from one of Implementations 1 to 3 in that the curing agent in step 1 is aliphatic diisocyanate. Others are the same as those in one of Implementations 1 to 3.

(18) Implementation 5: This implementation differs from one of Implementations 1 to 4 in that the solvent in step 1 is D40. Others are the same as those in one of specific Implementations 1 to 4.

(19) The D40 is a petroleum ether solvent.

(20) Implementation 6: This implementation differs from one of Implementations 1 to 5 in that the nanoparticles are one or a mixture of free combination of SiO.sub.2, Ag, Cu, CuO, TiO.sub.2 and ZnO at any ratio. Others are the same as those in Implementations 1 to 5.

(21) Implementation 7: This implementation differs from Implementation 6 in that the nanoparticles have a particle diameter of 10-500 nm. Others are the same as those in Implementations 6.

(22) Implementation 8: This implementation differs from Implementation 7 in that the surface modifier is polydimethylsiloxane. Others are the same as those in Implementation 7.

(23) Implementation 9: This implementation differs from one of Implementations 1 to 8 in that the functional reagent C in step 3 is IPBC. Others are the same as those in one of Implementations 1 to 8.

(24) Implementation 10: This implementation differs from one of Implementations 1 to 9 in that the ultrasonic power in step 3 is 500-550 W. Others are the same as those in one of Implementations 1 to 9.

(25) Implementation 11: This implementation differs from one of Implementations 1 to 10 in that the stirring in step 1 and step 2 is magnetic stirring. Others are the same as those in one of implementations 1 to 10.

(26) Implementation 12: This implementation differs from Implementation 1 in that the method for wood modification by using the foregoing multifunctional wood modifier specifically includes:

(27) method 1: directly spraying the multifunctional wood modifier on the surface of wood, and then standing the wood coated with the multifunctional wood modifier at room temperature for 24-72 h to obtain modified wood; and

(28) method 2: adding the multifunctional wood modifier and wood into a reaction tank, keeping a pressure of 0.1-0.5 MPa for 10-30 min, impregnating the multifunctional wood modifier into the wood, and finally standing the immersed multifunctional wood at room temperature for 24-72 h to obtain modified wood. Others are the same as those in Implementation 1.

(29) Embodiments of the present invention are described in details below. The following embodiments are implemented on the premise of the technical solution of the present invention, and the detailed implementation solutions and specific operation processes are given, but the protection scope of the present invention is not limited to the following embodiments.

Embodiment 1

(30) A method for preparing a room temperature cured multifunctional wood modifier according to this embodiment includes the following steps:

(31) Step 1: Weighing 10% of hydrophobic polymer resin, 0.1% of additive, 1% of curing agent and 88.9% of solvent according to weight percent respectively, mixing and then performing magnetic mixing for 2 h to obtain a functional reagent A.

(32) Step 2: Weighing 0.2% of nano-silica (100 nm), 0.2% of surface modifier and 99.6% of toluene according to weight percent respectively, mixing and then performing magnetic stirring for 72 h, cleaning with acetone, centrifuging at 8000 rpm for 3 times, and drying at 80° C. for 12 h to obtain a hydrophobically modified functional reagent B.

(33) Step 3: Adding a functional reagent C into the functional reagent A, evenly stirring, adding the functional reagent B, and performing ultrasonic processing for at least 30 min to obtain the multifunctional wood modifier, where the weight of the functional reagent B is 0.2% that of the functional reagent A, and the weight of the functional reagent C is 0.2% that of the functional reagent A.

(34) In step 1, the hydrophobic polymer resin is fluorocarbon resin with less than 8 F atoms (purchased from Solmont Technology (Wuxi) Co., Ltd. and meets the environmental protection standards of Europe, Japan and the United States); the additive is dibutyltin dilaurate which has the effect of speeding-up drying; the curing agent is aliphatic diisocyanate, and the solvent is D40 (a petroleum ether solvent).

(35) The surface modifier in step 2 is polydimethylsiloxane.

(36) The functional reagent C in step 3 is IPBC.

(37) A method for wood modification includes:

(38) directly spraying the obtained target multifunctional wood modifier on the surface of plywood with a spraying amount of 50 g/m.sup.2, and then air-drying at room temperature for 48 h to obtain super waterproof; oleophobic, bactericidal, mildew-proof and weatherproof multifunctional wood.

(39) The cross section of the modified wood shows obvious micro-nano hierarchical structure, and the cell wall is provided with nanoscale silicon-containing compounds (as shown in FIG. 1). The water contact angle on surface can reach 156.6° (as shown in FIG. 2) and the rolling angle is 10°. Macroscopically, water drops on the surface of plywood form an approximate spherical shape (as shown in FIG. 3). The hexadecane contact angle reaches 91.5°, the rolling angle is 18°, the alcohol contact angle is 77°, and the rolling angle is 29.5°. The wood treated with the foregoing hydrophobic polymer resin only is taken as a control. The water contact angle of the control modified wood is 122°, the rolling angle is less than or equal to 30°, the hexadecane contact angle is 73°, and the rolling angle is 30°; the alcohol contact angle is 65°, and the rolling angle is 30°.

(40) The weight loss rate of the modified wood decayed by brown rot fungi is reduced by 88.4% compared with that of untreated wood, and there is no obvious mildew on the wood surface (Aspergillus niger), indicating that the sterilization and mildew resistance of the modified wood have been significantly improved.

(41) Leaching-resistance test: Wood treated with the modifier of this embodiment was compared with wood treated with IPBC only. A wood block was placed on a triangular flask with a funnel, and a spray vehicle was used to simulate rainfall, with rainfall time of 6 h and rainfall set at 10 mm. The triangular flask was used to collect simulated rainfall. The amount of IPBC in the collected artificial rainfall was measured by using a fluorescence meter, and the chemical dosage under scouring was calculated. The sample was compared with the wood sample treated with IPBC only, and the leaching-resistance property was improved by 82.22%.

(42) The wood block treated with the functional reagents and the control test block treated with D40 solution of IPBC were weighed before and after the treatments, and the chemical loading capacity was calculated. Parallel experiments were conducted for 6 times to obtain an average IPBC loading capacity of 016% in treated wood (the weight of IPBC in per gram of wood—the chemical loading capacity was calculated according to the formula of the functional reagent) and an average IPBC loading capacity of 0.12% in control wood (the weight of IPBC in per gram of wood). After scouring experiments, liquid was collected, the usage amount for the treated wood was 485 ml, and the usage amount for the control wood was 498 ml. According to fluorescence measurement, the amount of ODBC contained in the liquid flushed out from the treated wood was about 0.01% on average, and thus the anti-leaching rate was calculated to be 9175% based on the amount of the chemical remaining in the wood. According to fluorescence measurement, it can be seen that the amount of IPBC contained in the liquid flushed out from the control wood was about 0.10% on average, and thus the anti-leaching rate was calculated to be 16.67% based on the amount of the chemical remaining in the wood. Finally, the anti-leaching rate of the treated wood was compared with that of the control wood, and it was calculated that the leaching-resistance property of the treated wood was increased by 82.22%.

(43) After 90 days of weathering tests in an outdoor environment, the treated wood and the control wood were exposed outdoors on the sunny side for the test time from April 1 to July 1, and the surface weathering stability was judged by testing surface contact angles before and after the weathering test. The weather resistance effect was judged by observing wood surface morphology (texture color, surface roughness, etc.). The water contact angle of the cross section of the wood could still reach 151° (as shown in FIG. 4), and the wood surface had no obvious color change, while the untreated wood surface as the control had obvious grooves, cracks and light gray color, indicating that the weather resistance of the modified wood was obviously improved.

Embodiment 2

(44) A method for preparing a room temperature cured multifunctional wood modifier according to this embodiment includes the following steps:

(45) Step 1: Weighing 15% of hydrophobic polymer resin, 0.2% of additive, 1.5% of curing agent and 83.3% of solvent according to weight percent respectively, mixing and then performing magnetic mixing for 2 h or more to obtain a functional reagent A.

(46) Step 2: Weighing 0.1% of nanoparticles, 0.4% of surface modifier and 99.5% of toluene according to weight percent respectively, mixing and then performing magnetic stirring for 72 h, cleaning with acetone, centrifuging at 8000 rpm for 3 times, and drying at 80° C. for 12 h to obtain a hydrophobically modified functional reagent B.

(47) Step 3: Adding a functional reagent C into the functional reagent A, evenly stirring, adding the functional reagent B, and performing ultrasonic processing for at least 30 min to obtain the multifunctional wood modifier, where the weight of the functional reagent B is 0.1% that of the functional reagent A, and the weight of the functional reagent C is 0.3% that of the functional reagent A.

(48) In step 1, the hydrophobic polymer resin is fluorocarbon resin with less than 8 F atoms (purchased from Solmont Technology (Wuxi) Co., Ltd. and meets the environmental protection standards of Europe, Japan and the United States); the additive is dibutyltin dilaurate which has the effect of speeding-up drying; the curing agent is aliphatic diisocyanate, and the solvent is D40 (a petroleum ether solvent).

(49) The nanoparticles in step 2 are a mixture of 100 nm SiO.sub.2 and 100 am TiO.sub.2 in a weight ratio of 2:1. The surface modifier is polydimethylsiloxane.

(50) The functional reagent C in step 3 is IPBC.

(51) A method for wood modification includes:

(52) Impregnating the multifunctional wood modifier into solid poplar wood by an air pressure of 0.5 MPa, keeping the pressure for 30 min, releasing the pressure and then standing for 72 h at normal temperature and normal pressure to obtain the superhydrophobic, oleophobic, bactericidal, mildew-proof and weatherproof multifunctional wood.

(53) The cross section of the modified wood shows obvious micro-nano hierarchical structure, and the cell wall is provided with nanoscale silicon-containing compounds. The water contact angle on surface can reach 157.7° (as shown in FIG. 5) and the rolling angle is 9°. Macroscopically, water drops on the surface of poplar form an approximate spherical shape (in FIG. 6). The hexadecane contact angle reaches 93°, the rolling angle is 17°, the alcohol contact angle is 78°, and the rolling angle is 28°. The wood treated with the foregoing hydrophobic polymer resin only is taken as a control. The water contact angle of the control modified wood is 122°, the rolling angle is less than or equal to 30°, the hexadecane contact angle is 73°, and the rolling angle is 30°; the alcohol contact angle is 65°, and the rolling angle is 30°.

(54) The weight loss rate of the modified wood decayed by brown rot fungi is reduced by 91.3% compared with that of untreated wood, and there is no obvious mildew on the wood surface (Aspergillus niger), indicating that the sterilization and mildew resistance of the modified wood have been significantly improved.

(55) Leaching-resistance test: Wood treated with the modifier of this embodiment was compared with wood treated with IPBC only. A wood block was placed on a triangular flask with a funnel, and a spray vehicle was used to simulate rainfall, with rainfall time of 6 h and rainfall set at 10 mm. The triangular flask was used to collect simulated rainfall. The amount of BSF in the collected artificial rainfall was measured by using a fluorescence meter, and the chemical dosage under scouring was calculated. The sample was compared with the wood sample treated with IPBC only, and the leaching-resistance property was improved by 88.33%.

(56) The wood block treated with the functional reagents and the control test block treated with D40 solution of IPBC were weighed before and after the treatments, and the chemical loading capacity was calculated. Parallel experiments were conducted for 6 times to obtain an average IPBC loading capacity of 0.21% in treated wood (the weight of IPBC in per gram of wood—the chemical loading capacity was calculated according to the formula of the functional reagent) and an average IPBC loading capacity of 0.18% in control wood (the weight of IPBC in per gram of wood). After the scouring experiments, liquid was collected, the usage amount for the treated wood was 523 ml, and the usage amount for the control wood was 539 ml. According to fluorescence measurement, the amount of IPBC contained in the liquid flushed out from the treated wood was about 0.01% on average, and thus the anti-leaching rate was calculated to be 95.24% based on the amount of the chemical remaining in the wood. According to fluorescence measurement, it can be seen that the amount of IPBC contained in the liquid flushed out from the control wood was about 0.16% on average, and thus the anti-leaching rate was calculated to be 11.11% based on the amount of the chemical remaining in the wood. Finally, the anti-leaching rate of the treated wood was compared with that of the control wood, and it was calculated that the anti-leaching property of the treated wood was increased by 88.33%.

(57) After 90 days of weathering tests in an outdoor environment, the treated wood and the control wood were exposed outdoors on the sunny side for the test time from April 1 to July 1, and the surface weathering stability was judged by testing surface contact angles before and after the weathering test. The weather resistance effect was judged by observing wood surface morphology (texture color, surface roughness, etc.). The water contact angle of the cross section of the wood could still reach 152° (as shown in FIG. 7), and the wood surface had no obvious color change, while the untreated wood surface as the control had obvious grooves, cracks and light gray color, indicating that the weather resistance of the modified wood was obviously improved.