Surface modification method and device of bamboo charcoal for spinning and preparation method of nylon 6

Abstract

The invention relates to the technical field of artificial fibers, and provides a method for modifying the surface of bamboo charcoal for spinning, a modification device and a method for preparing nylon 6, comprising the following steps: placing dry bamboo charcoal powder in a closed reaction chamber, and introducing ozone; decomposing the ozone into oxygen and oxygen atoms in the reaction chamber; reacting the oxygen atoms with the carbon atoms in the bamboo charcoal to generate an intermediate: ‑COO‑; the intermediate captures a hydrogen atom from the surface of the bamboo charcoal to generate a carboxyl group ‑COOH, and obtains carboxyl-modified bamboo charcoal powder. Thus, the invention utilizes the strong oxidizing property of oxygen atoms to introduce carboxyl groups on the surface of the bamboo charcoal to obtain modified bamboo charcoal. The carboxyl groups of the modified bamboo charcoal powder are grafted onto short-chain nylon 6, thereby increasing the compatibility of bamboo charcoal particles with a nylon 6 matrix. At the same time, the agglomeration of bamboo charcoal particles is reduced, which is beneficial to the dispersion of bamboo charcoal particles in a nylon 6 matrix. The notched impact strength of the obtained nylon 6 is significantly improved, the probability of broken wires is reduced, and the problems of clogging the spinneret during spinning are avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of artificial fibers, and in particular relates to a surface modification method and a modification device of bamboo charcoal for spinning, and a preparation method of nylon 6. Background Art

[0002] Nylon is a chemical fiber synthesized from nylon 6 (also known as polyamide 6) through a melt spinning process. It has excellent wear resistance, elasticity, strength and chemical resistance, is widely used, and has broad market prospects.

[0003] Bamboo charcoal is a black porous material obtained by carbonizing bamboo under high temperature, oxygen-deficient or oxygen-free environment. It has multiple functions such as strong adsorption capacity, antibacterial and mildew-proof, far infrared emission and negative ion release. After bamboo charcoal is made into fiber, it can give fabrics multiple functions such as antibacterial, deodorizing, warming and anti-ultraviolet.

[0004] Functional bamboo charcoal fiber fabrics can be developed by adding bamboo charcoal to nylon fiber. However, as an inorganic filler, bamboo charcoal has poor compatibility with nylon 6. When directly mixed with nylon 6 and spun, it is difficult to evenly disperse into the nylon matrix, resulting in problems such as spinneret blockage and fiber breakage during spinning.

[0005] In summary, the prior art obviously has inconveniences and defects in practical use, so it is necessary to improve it. Summary of the invention

[0006] In view of the above defects, the present invention mainly provides a surface modification method of bamboo charcoal for spinning to solve the technical problem of poor compatibility between bamboo charcoal and nylon 6.

[0007] In order to solve the above problems, the present invention provides a method for surface modification of bamboo charcoal for spinning, comprising the following steps:

[0008] S1, placing dry bamboo charcoal powder into a closed reaction chamber, and injecting replacement gas to discharge air and moisture in the reaction chamber;

[0009] S2, introducing ozone into the reaction chamber; the concentration of the ozone is: 10-100 mg / L;

[0010] S3, heating the reaction chamber to a predetermined reaction temperature and maintaining the reaction time; the reaction temperature is: 20~60°C, and the reaction time is: 1~5 hours; the following reactions occur in the reaction chamber in sequence:

[0011] The ozone in the reaction chamber decomposes into oxygen and oxygen atoms;

[0012] The decomposed oxygen atoms react with the carbon atoms in the bamboo charcoal to form an intermediate: -COO-;

[0013] The intermediate -COO- captures a hydrogen atom from the surface of bamboo charcoal to generate carboxyl -COOH, and obtains carboxyl-modified bamboo charcoal powder;

[0014] S4, after the reaction is completed, a replacement gas is introduced into the reaction chamber to discharge the residual ozone.

[0015] According to the surface modification method of bamboo charcoal for spinning of the present invention, the bamboo charcoal powder in step S1 is dried at 110° C. for 12 h before being placed in the reaction chamber to remove adsorbed moisture.

[0016] According to the surface modification method of bamboo charcoal for spinning of the present invention, in steps S1 and S4, the replacement gas introduced into the reaction chamber is nitrogen.

[0017] According to the surface modification method of bamboo charcoal for spinning of the present invention, the concentration of ozone introduced into the reaction chamber in step S2 is 30-60 mg / L.

[0018] According to the surface modification method of bamboo charcoal for spinning of the present invention, in step S3, the reaction temperature in the reaction chamber is 30-50° C., and the reaction time is 2-3 h.

[0019] According to the surface modification method of bamboo charcoal for spinning of the present invention, the particle size of the modified bamboo charcoal powder does not exceed 5 μm.

[0020] A modification device for performing the surface modification method of bamboo charcoal for spinning, comprising:

[0021] An ozone reactor having a reaction chamber for containing bamboo charcoal powder;

[0022] An ozone generator connected to the ozone reactor; the ozone generator is used to prepare ozone and send the prepared ozone into the reaction chamber;

[0023] A water bath, used to heat the ozone reactor so that the reaction chamber of the ozone reactor reaches a predetermined reaction temperature and maintains a predetermined reaction time;

[0024] A gas storage cylinder is connected to the ozone reactor; the gas storage cylinder stores replacement gas and is used to transport the replacement gas into the reaction chamber of the ozone reactor.

[0025] A method for preparing nylon 6 comprises the following steps:

[0026] Z1, putting carboxyl modified bamboo charcoal powder, water and caprolactam prepared by the surface modification method of bamboo charcoal for spinning or the modification device, into a high-pressure polymerization kettle; by weight, the carboxyl modified bamboo charcoal powder is 1% to 10%, the water is 4%, and the rest is caprolactam;

[0027] Z2, at 230°C~300°C, the polymerization reaction is carried out for 10~30 hours; specifically, the polymerization reaction includes:

[0028] Caprolactam reacts with water to form aminocaproic acid;

[0029] A condensation reaction between aminocaproic acid and carboxyl occurs to generate short-chain nylon 6 and small molecule water; the short-chain nylon 6 includes dimer, trimer and tetramer;

[0030] The carboxyl-modified bamboo charcoal powder undergoes a grafting reaction with the short-chain nylon 6; the carboxyl group of the carboxyl-modified bamboo charcoal powder reacts with the amine group at the end of the short-chain nylon to form an amide bond;

[0031] Z3, after the condensation reaction is completed, the melt is extruded; after cooling, pelletizing and extraction, nylon 6 is obtained.

[0032] According to the method for preparing nylon 6 of the present invention, in step Z1, the carboxyl-modified bamboo charcoal powder is 5% to 7%; the polymerization reaction temperature of step Z2 is 250° C. to 270° C., and the reaction time is 12 to 24 h.

[0033] According to the method for preparing nylon 6 of the present invention, the extraction process of step Z3 is: extracting with hot water at 120° C. for 48 h, and then drying with hot nitrogen at 110° C. to obtain nylon 6.

[0034] In summary, the surface modification method of bamboo charcoal for spinning of the present invention utilizes the strong oxidizing property of oxygen atoms to react with carbon atoms on the surface of bamboo charcoal to generate -COO- intermediate, and then the intermediate captures a hydrogen atom on the surface of bamboo charcoal to form carboxyl -COOH to obtain modified bamboo charcoal. The present invention provides a modification device and a nylon 6 preparation method, which increases the compatibility of bamboo charcoal particles and nylon 6 matrix by grafting the carboxyl group of modified bamboo charcoal powder onto short-chain nylon 6. At the same time, due to the steric repulsion effect of the grafted chain segment, the agglomeration of bamboo charcoal particles is also reduced, which is conducive to the dispersion of bamboo charcoal particles in the nylon 6 matrix. The notched impact strength of the obtained nylon 6 composite material with modified bamboo charcoal is significantly improved, the probability of broken wire is reduced, and the problem of clogging the spinneret during spinning is avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a structural schematic diagram of the modification device of the present invention;

[0036] Figure 2 It is a schematic diagram of the principle of the surface modification method of bamboo charcoal for spinning of the present invention;

[0037] Figure 3 It is a schematic diagram of the principle of the ring-opening reaction of the method for preparing nylon 6 of the present invention;

[0038] Figure 4 It is a schematic diagram of the principle of the condensation reaction of the method for preparing nylon 6 of the present invention;

[0039] Figure 5 It is a schematic diagram of the principle of the grafting reaction of the method for preparing nylon 6 of the present invention;

[0040] In the figure: 1-ozone generator, 2-gas cylinder, 3-flow meter, 4-ozone reactor, 5-water bath, 51-water inlet pipe, 52-water outlet pipe. DETAILED DESCRIPTION

[0041] See also Figure 1 The present invention provides a method for surface modification of bamboo charcoal for spinning, comprising the following steps:

[0042] S1, placing dry bamboo charcoal powder into a sealed reaction chamber; and injecting replacement gas to discharge air and moisture in the reaction chamber;

[0043] Optionally, the bamboo charcoal powder in step S1 is dried at 110° C. for 12 h before being placed in the reaction chamber to remove adsorbed moisture;

[0044] S2, ozone (O 3 ); the ozone (O 3 ) concentration is: 10~100 mg / L;

[0045] Optionally, ozone (O) is introduced into the reaction chamber in step S2. 3 ) concentration is: 30~60 mg / L;

[0046] S3, heating the reaction chamber to a predetermined reaction temperature and maintaining the reaction time; the following reaction occurs in the reaction chamber:

[0047] In the reaction chamber, ozone (O 3 ) decomposes into oxygen (O 2 ) and oxygen atoms (O);

[0048] Combination Figure 2 , oxygen atoms (O) react with carbon atoms in bamboo charcoal to form an intermediate: -COO-;

[0049] The intermediate -COO- captures a hydrogen atom (H) from the surface of bamboo charcoal to generate carboxyl -COOH, and obtains carboxyl-modified bamboo charcoal powder;

[0050] Preferably, the reaction temperature in the reaction chamber is 20-60°C, and the reaction time is 1-5 h; during the reaction, ozone (O 3 ), to ensure the formation of carboxyl -COOH.

[0051] If the reaction temperature is too low, the amount of carboxyl-COOH generated will be small; if the reaction temperature is too high, the carboxyl-COOH will decompose. Therefore, in order to ensure that a sufficient amount of carboxyl-COOH can be generated on the surface of the bamboo charcoal powder, as a preferred solution, the reaction temperature in the reaction chamber is: 30~50℃, and the reaction time is: 2~3 h;

[0052] S4, after the reaction is completed, a replacement gas is introduced into the reaction chamber to remove the remaining ozone (O 3 )discharge.

[0053] As a preferred solution, the replacement gas is nitrogen. Specifically:

[0054] In step S1, ozone (O 3 ), nitrogen is introduced into the closed reaction chamber to discharge the air and moisture in the reaction chamber to avoid affecting the subsequent reactions.

[0055] In step S4, after the reaction is completed, nitrogen is introduced into the reaction chamber to discharge the residual ozone, so as to avoid that after the ozone is discharged, the external air directly enters the reaction chamber, causing the modified bamboo charcoal powder to absorb moisture in the air.

[0056] As an embodiment, the particle size of the modified bamboo charcoal powder of the present invention does not exceed 5 μm;

[0057] The surface modification method of bamboo charcoal for spinning of the present invention utilizes the strong oxidizing property of oxygen atoms (O) to react with carbon atoms on the surface of bamboo charcoal to generate a -COO- intermediate, and then the intermediate captures a hydrogen atom on the surface of bamboo charcoal to form a carboxyl group -COOH to obtain modified bamboo charcoal.

[0058] See also Figure 1 The present invention also provides a modification device for performing the surface modification method of bamboo charcoal for spinning, comprising:

[0059] The ozone reactor 4 has a reaction chamber for containing bamboo charcoal powder; the ozone reactor 4 is connected to the ozone generator 1;

[0060] Ozone generator 1, used to prepare ozone (O 3 ); and ozone (O 3 ) into the reaction chamber of the ozone reactor 4;

[0061] The gas cylinder 2 is connected to the ozone reactor 4; nitrogen is stored in the gas cylinder 2, and nitrogen is filled into the reaction chamber of the ozone reactor 4 before the reaction starts and after the reaction ends.

[0062] As an embodiment, the ozone generator 1 and the gas cylinder 2 are connected to the ozone reactor 4 via a flow meter 3, which is convenient for monitoring and controlling ozone (O 3 ) and nitrogen intake.

[0063] As an embodiment, the ozone reactor 4 is placed in a water bath 5; the water bath 5 has a water inlet pipe 51 and a water outlet pipe 52; heated water of a predetermined temperature is continuously circulated into the water bath 5 through the water inlet pipe 51 and the water outlet pipe 52, so that the reaction temperature in the reaction chamber of the ozone reactor 4 is constant and controllable.

[0064] The present invention provides a method for preparing nylon 6, comprising the following steps:

[0065] Z1, putting the carboxyl modified bamboo charcoal powder, water and caprolactam into a high pressure polymerization kettle; by weight, the carboxyl modified bamboo charcoal powder is 1% to 10%, water is 4%, and the rest is caprolactam;

[0066] Preferably, in step Z1, the carboxyl-modified bamboo charcoal powder is: 5% to 7%;

[0067] Z2, at 230°C~300°C, the polymerization reaction is carried out for 10~30 hours; specifically, the polymerization reaction includes:

[0068] See also Figure 3 , caprolactam reacts with water to form aminocaproic acid;

[0069] See also Figure 4 , a condensation reaction between the aminocaproic acid and the carboxyl group occurs to generate short-chain nylon 6 and small molecule water; the short-chain nylon 6 includes a dimer, a trimer, and a tetramer;

[0070] See also Figure 5 , carboxyl-modified bamboo charcoal powder undergoes grafting reaction with short-chain nylon 6; the carboxyl group of the carboxyl-modified bamboo charcoal powder reacts with the amine group at the end of the short-chain nylon 6 to form an amide bond;

[0071] Preferably, the polymerization reaction temperature of step Z2 is 250°C to 270°C, and the reaction time is 12 to 24 h.

[0072] Z3, after the condensation reaction is completed, the melt is extruded; after cooling, pelletizing and extraction, nylon 6 is obtained;

[0073] As an embodiment, the extraction process of step Z3 is: extracting with hot water at 120° C. for 48 h, and then drying with hot nitrogen at 110° C. to obtain nylon 6;

[0074] The nylon 6 preparation method of the present invention increases the compatibility of bamboo charcoal particles and nylon 6 matrix by grafting the carboxyl group of modified bamboo charcoal powder onto short-chain nylon 6. At the same time, due to the steric repulsion effect of the grafted chain segment, the agglomeration of bamboo charcoal particles is also reduced, which is conducive to the dispersion of bamboo charcoal particles in the nylon 6 matrix. The notched impact strength of the prepared nylon 6 composite material with modified bamboo charcoal is significantly improved. The nylon 6 of the present invention can be directly used for spinning to manufacture bamboo charcoal fibers, reducing the blockage of the spinneret during the spinning process and reducing the probability of broken fibers.

[0075] The inventors used the surface modification method of bamboo charcoal for spinning to prepare multiple modified bamboo charcoal powder samples. The prepared samples used the aforementioned nylon 6 preparation method to prepare multiple nylon 6 example samples;

[0076] At the same time, unmodified bamboo charcoal powder was used to prepare comparative samples using the above-mentioned nylon 6 preparation method. Notched impact strength tests were performed on each embodiment and comparative sample to verify the material performance.

[0077] Specific experimental parameters and test results are shown in Table 1. (Note: Table 1 only lists the changed parameters. The same components and steps can be found in the previous text and will not be repeated here.) From the test results, the use of modified bamboo charcoal powder to prepare nylon 6 can significantly improve the notched impact strength. This shows that the modified bamboo charcoal powder has good compatibility with nylon 6 and is well dispersed in the nylon 6 matrix, which can significantly improve the performance of the material.

[0078] .

[0079] In summary, the present invention provides a method for modifying the surface of bamboo charcoal for spinning, by utilizing the strong oxidizing property of oxygen atoms to react with carbon atoms on the surface of bamboo charcoal to generate -COO- intermediate, and then the intermediate captures a hydrogen atom on the surface of bamboo charcoal to form carboxyl -COOH, thereby obtaining modified bamboo charcoal. The present invention provides a modification device and a method for preparing nylon 6, by grafting the carboxyl group of modified bamboo charcoal powder onto short-chain nylon 6, the compatibility of bamboo charcoal particles and nylon 6 matrix is ​​increased. At the same time, due to the steric repulsion effect of the grafted chain segment, the agglomeration of bamboo charcoal particles is also reduced, which is beneficial to the dispersion of bamboo charcoal particles in the nylon 6 matrix. The notched impact strength of the obtained nylon 6 composite material with modified bamboo charcoal is significantly improved, the probability of broken wire is reduced, and the problem of clogging the spinneret during spinning is avoided.

[0080] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art may make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for preparing nylon 6, characterized in that: Including a method for modifying the surface of bamboo charcoal for spinning; The surface modification method of bamboo charcoal for spinning comprises the following steps: S1, placing dry bamboo charcoal powder into a closed reaction chamber, and injecting replacement gas to discharge air and moisture in the reaction chamber; S2, introducing ozone into the reaction chamber; The ozone concentration is: 10-100 mg / L; S3, heating the reaction chamber to a predetermined reaction temperature and maintaining the reaction time; the reaction temperature is: 20-60°C, and the reaction time is: 1-5 h; the following reactions occur in sequence in the reaction chamber: The ozone in the reaction chamber decomposes into oxygen and oxygen atoms; The decomposed oxygen atoms react with the carbon atoms in the bamboo charcoal to form an intermediate: -COO-; The intermediate -COO- captures a hydrogen atom from the surface of bamboo charcoal to generate carboxyl -COOH, and obtains carboxyl-modified bamboo charcoal powder; During the reaction, ozone is continuously introduced into the reaction chamber to ensure the generation of carboxyl - COOH; S4, after the reaction is completed, a replacement gas is introduced into the reaction chamber to discharge the residual ozone; The nylon 6 preparation method further comprises the following steps: Z1, putting carboxyl modified bamboo charcoal powder, water and caprolactam prepared by the surface modification method of bamboo charcoal for spinning into a high-pressure polymerization kettle; by weight, the carboxyl modified bamboo charcoal powder is 1% to 10%, the water is 4%, and the rest is caprolactam; Z2, at 230°C~300°C, the polymerization reaction is carried out for 10~30 hours; specifically, the polymerization reaction includes: Caprolactam reacts with water to form aminocaproic acid; A condensation reaction between aminocaproic acid and carboxyl occurs to generate short-chain nylon 6 and small molecule water; the short-chain nylon 6 includes dimer, trimer and tetramer; The carboxyl-modified bamboo charcoal powder undergoes a grafting reaction with the short-chain nylon 6; the carboxyl group of the carboxyl-modified bamboo charcoal powder reacts with the amine group at the end of the short-chain nylon to form an amide bond; Z3, after the condensation reaction is completed, the melt is extruded; after cooling, pelletizing and extraction, nylon 6 is obtained.

2. The method for preparing nylon 6 according to claim 1, characterized in that: Before being placed in the reaction chamber, the bamboo charcoal powder in step S1 is dried at 110° C. for 12 h to remove adsorbed moisture.

3. The method for preparing nylon 6 according to claim 1, characterized in that: In steps S1 and S4, the replacement gas introduced into the reaction chamber is nitrogen.

4. The method for preparing nylon 6 according to claim 1, characterized in that: The concentration of ozone introduced into the reaction chamber in step S2 is 30-60 mg / L.

5. The method for preparing nylon 6 according to claim 1, characterized in that: In the step S3, the reaction temperature in the reaction chamber is 30-50° C., and the reaction time is 2-3 h.

6. The method for preparing nylon 6 according to claim 1, characterized in that: The particle size of the modified bamboo charcoal powder does not exceed 5 μm.

7. The method for preparing nylon 6 according to any one of claims 1 to 6, characterized in that: Also included is a modification device for performing the surface modification method of the bamboo charcoal for spinning; The modification device comprises: An ozone reactor having a reaction chamber for containing bamboo charcoal powder; An ozone generator connected to the ozone reactor; the ozone generator is used to prepare ozone and send the prepared ozone into the reaction chamber; A water bath, used to heat the ozone reactor so that the reaction chamber of the ozone reactor reaches a predetermined reaction temperature and maintains a predetermined reaction time; A gas storage cylinder is connected to the ozone reactor; the gas storage cylinder stores replacement gas and is used to transport the replacement gas into the reaction chamber of the ozone reactor.

8. The method for preparing nylon 6 according to claim 1, characterized in that: In the step Z1, the carboxyl-modified bamboo charcoal powder is 5% to 7%; the polymerization reaction temperature in the step Z2 is 250° C. to 270° C., and the reaction time is 12 to 24 h.

9. The method for preparing nylon 6 according to claim 1, characterized in that: The extraction process of step Z3 is as follows: after extraction with hot water at 120°C for 48 h, drying with hot nitrogen at 110°C to obtain nylon 6.

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