CN112225936A

CN112225936A - Porous aerogel, preparation method thereof and antibacterial flame-retardant PP (polypropylene) fiber containing porous aerogel

Info

Publication number: CN112225936A
Application number: CN202011048518.4A
Authority: CN
Inventors: 不公告发明人
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-09-29
Filing date: 2020-09-29
Publication date: 2021-01-15

Abstract

The invention provides a porous aerogel and a preparation method thereof, and an antibacterial flame-retardant PP fiber containing the porous aerogel, which comprises the following steps: s1, cooling the mixed aqueous solution containing NaOH and urea, adding graphene oxide into the mixed solution to obtain a graphene oxide solution, adding sodium carboxymethylcellulose into the other mixed aqueous solution containing NaOH and urea to obtain a sodium carboxymethylcellulose solution, and mixing the graphene oxide solution and the sodium carboxymethylcellulose solution to obtain a mixture; and S2, dropwise adding the mixture into liquid paraffin, adding epoxy chloropropane into the system, reacting at room temperature, neutralizing with hydrochloric acid after the reaction is finished, removing the liquid paraffin at the upper layer, repeatedly washing the target product at the lower layer, and freeze-drying to obtain the porous aerogel. The antibacterial flame-retardant PP fiber containing the porous aerogel prepared by the invention has antibacterial and flame-retardant properties, and the product has excellent mechanical properties, and the preparation method has the advantages of simple process, low cost and excellent popularization value.

Description

Porous aerogel, preparation method thereof and antibacterial flame-retardant PP (polypropylene) fiber containing porous aerogel

Technical Field

The invention relates to the technical field of PP materials, in particular to a porous aerogel and a preparation method thereof, and an antibacterial flame-retardant PP fiber containing the porous aerogel.

Background

Polypropylene is a thermoplastic resin obtained by polymerizing propylene, and is classified into isotactic polypropylene, atactic polypropylene and syndiotactic polypropylene according to the methyl arrangement position. The polypropylene has high crystallinity and regular structure, so that it has excellent mechanical performance, no toxicity, no smell, low density and other advantages, and the strength, rigidity, hardness and heat resistance are superior to those of low pressure polyethylene. Therefore, the polypropylene gradually replaces the latter and has more applications in the fields of household appliances, plastic pipes, high-transmittance materials and the like.

With the development of society, people pay more attention to the field of life and health, and polypropylene is widely applied to daily life of people, such as water cups, lunch boxes, water pipes and the like, so that the antibacterial modification of polypropylene becomes the key point of the current plastic modification.

In fire fighting and industrial and mining operations, high temperature threatens fire fighters and workers greatly, and causes death and injury accidents very easily. In daily life, there are also few cases of human injuries, deaths and property loss caused by the spread and disaster of small fire sources due to the flammability of textiles. Therefore, it is a particularly important and urgent social and practical requirement to perform flame retardant treatment on tools and household textiles. Meanwhile, bacteria on the clothes such as underwear and sweaters pose a great threat to the physical and mental health of human bodies, particularly the elderly, pregnant and lying-in women and infants, and therefore, the antibacterial requirements are put forward for fibers. The clothes made of the antibacterial fibers have good antibacterial performance and can resist the attachment of bacteria on the clothes, so that people are far away from the invasion of germs.

At present, the antibacterial agent and the flame retardant are respectively added into fiber raw materials for preparing the flame-retardant antibacterial fiber, the antibacterial agent and the flame retardant have larger difference with the fiber raw materials and have larger influence on the fiber in the fiber melting and forming process, and in addition, the addition amount of the antibacterial agent and the flame retardant in the prior art has higher requirement, if the addition amount is too large, the viscosity of a polymer is too low, and the forming and processing of the fiber are difficult.

Disclosure of Invention

The invention aims to provide a porous aerogel and a preparation method thereof, and an antibacterial flame-retardant PP fiber containing the porous aerogel.

The technical scheme of the invention is realized as follows:

the invention provides a preparation method of porous aerogel, which comprises the following steps:

s1, cooling the mixed aqueous solution containing NaOH and urea to below 5 ℃, adding graphene oxide into the mixed solution, mechanically stirring to obtain a graphene oxide solution, adding sodium carboxymethylcellulose into the other mixed aqueous solution containing NaOH and urea, mechanically stirring to obtain a sodium carboxymethylcellulose solution, and mixing the graphene oxide solution and the sodium carboxymethylcellulose solution according to a volume ratio of 1: (1-3) mixing to obtain a mixture;

s2, pouring liquid paraffin into the reactor, mechanically stirring, dropwise adding the mixture into the liquid paraffin, and mechanically stirring after dropwise adding; and then adding epoxy chloropropane into the liquid paraffin, reacting at room temperature, neutralizing with hydrochloric acid after the reaction is finished, removing the upper layer of the liquid paraffin, repeatedly washing the lower layer of the target product with distilled water and absolute ethyl alcohol to obtain hydrogel beads, and freeze-drying the hydrogel to obtain the porous aerogel.

As a further improvement of the invention, in the mixed aqueous solution containing NaOH and 5-10 wt% of urea, the mass fraction of the NaOH is 3-5 wt%, and the mass fraction of the urea is 5-10 wt%; the volume-mass ratio of the mixed aqueous solution containing NaOH and urea to the graphene oxide is (10-30): 1; the volume-mass ratio of the mixed aqueous solution containing NaOH and urea to the sodium carboxymethyl cellulose is (30-50): 1; the mass ratio of the liquid paraffin to the mixed solution to the epichlorohydrin is 100: (10-30): (5-12).

The invention further protects the porous aerogel prepared by the preparation method.

The invention further provides a preparation method of the antibacterial flame-retardant PP fiber containing the porous aerogel, which is characterized by comprising the following steps:

step one, preparing a mixed solution of an antibacterial agent and a flame retardant;

step two, preparing the porous aerogel containing the antibacterial agent and the flame retardant;

step three, preparing slow-release porous aerogel PP master batches containing the antibacterial agent and the flame retardant;

and step four, preparing the antibacterial flame-retardant PP fiber containing the porous aerogel.

As a further improvement of the invention, the first step specifically comprises the following steps: nisin and tetraphenyl (bisphenol-A) diphosphate are mixed according to a mass ratio of 1: (1-3) adding the mixture into a mixed solution of tetrahydrofuran and water after uniformly mixing, and stirring the mixture until the mixture is fully dissolved to obtain a mixed solution of the antibacterial agent and the flame retardant; the volume ratio of the tetrahydrofuran to the water in the mixed solution of the tetrahydrofuran and the water is (1-3): 1.

as a further improvement of the present invention, the second step specifically comprises: sequentially adding the antibacterial agent and flame retardant mixed solution, the porous aerogel, the coupling agent and the surfactant into a shearing disperser, heating to 50 ℃, preserving heat, performing primary shearing dispersion, then adding a stabilizer accounting for 0.1-5 wt% of the total mass of the substances, performing secondary shearing to obtain a porous aerogel suspension dispersion solution containing the antibacterial agent and the flame retardant, and volatilizing the solvent to obtain a dry porous aerogel containing the antibacterial agent and the flame retardant;

preferably, the shearing force of the first shearing dispersion is 5250-6000ips, the shearing time is 4-9min, the temperature rising rate is 3 ℃/min, the shearing force of the second shearing dispersion is 2500-3000ips, and the shearing time is 5-10 min; the coupling agent is a mixture of a silane coupling agent KH550 and a silane coupling agent KH570, the mass ratio is 5 (1-3), the surfactant is a mixture of Tween-80 and span-80, the mass ratio is 10 (1-3), and the stabilizer is a mixture of magnesium stearate and aluminum stearate, and the mass ratio is 1 (2-4).

As a further improvement of the present invention, the third step specifically comprises: adding the dried porous aerogel containing the antibacterial agent and the flame retardant into a grinding machine, adding a fat-soluble solvent, a dispersing agent and an antioxidant, and mixing and grinding to obtain a composite modifier containing the antibacterial agent and the flame retardant; adding a composite modifier containing an antibacterial agent and a flame retardant into the PP slices, melting at high temperature, keeping the melting for 10-15min, and extruding and granulating to obtain a slow-release porous aerogel PP master batch containing the antibacterial agent and the flame retardant;

preferably, the high-temperature melting temperature is 300-; the dispersing agent is selected from one of sodium polyacrylate, potassium polyacrylate and ammonium polyacrylate; the antioxidant is selected from one of 2, 4-di- (n-octylthiomethylene) -6-methylphenol, 2, 4-di (dodecylthiomethyl) -6-methylphenol, dilauryl thiodipropionate or distearyl thiodipropionate.

As a further improvement of the present invention, the step four specifically includes: carrying out melt spinning on the slow-release porous aerogel PP master batch containing the antibacterial agent and the flame retardant to obtain the antibacterial flame-retardant PP fiber containing the porous aerogel, wherein the melt spinning process parameters are as follows: the spinning temperature is 270 ℃ and 295 ℃; cooling with cross air at 28-30 deg.C; the side blowing wind speed is 0.3-0.5 m/s; the winding spinning speed is 3500 and 4000 m/min; the drafting multiplying factor is 3.0-4.0.

As a further improvement of the invention, the method specifically comprises the following steps:

step one, preparing a mixed solution of an antibacterial agent and a flame retardant: nisin and tetraphenyl (bisphenol-A) diphosphate are mixed according to a mass ratio of 1: (1-3) adding the mixture into a mixed solution of tetrahydrofuran and water after uniformly mixing, and stirring the mixture until the mixture is fully dissolved to obtain a mixed solution of the antibacterial agent and the flame retardant; the volume ratio of the tetrahydrofuran to the water in the mixed solution of the tetrahydrofuran and the water is (1-3): 1;

step two, preparing the porous aerogel containing the antibacterial agent and the flame retardant: sequentially adding 5-10 parts by weight of mixed solution of an antibacterial agent and a flame retardant, 7-12 parts by weight of porous aerogel, 1-2 parts by weight of a coupling agent and 0.5-1.5 parts by weight of a surfactant into a shearing disperser, heating to 50 ℃ at a speed of 3 ℃/min, preserving heat, performing primary shearing dispersion, wherein the shearing force is 5250-6000ips, the shearing time is 4-9min, then adding a stabilizer accounting for 0.1-5 wt% of the total mass of the substances, performing secondary shearing, the shearing force is 2500-3000ips, and the shearing time is 5-10min to obtain porous aerogel suspension dispersion liquid containing the antibacterial agent and the flame retardant, and volatilizing a solvent to obtain dry porous aerogel containing the antibacterial agent and the flame retardant;

step three, preparing the slow-release porous aerogel PP master batch containing the antibacterial agent and the flame retardant: adding 5-15 parts by weight of dried porous aerogel containing the antibacterial agent and the flame retardant into a grinding machine, adding 20-40 parts by weight of fat-soluble solvent, 1-3 parts by weight of dispersing agent and 0.5-2.5 parts by weight of antioxidant, mixing and grinding to obtain a composite modifier containing the antibacterial agent and the flame retardant; adding 5-10 parts by weight of composite modifier containing the antibacterial agent and the flame retardant into 100 parts by weight of PP slices, melting at the high temperature of 400 ℃, keeping the melting for 10-15min, and extruding and granulating to obtain slow-release porous aerogel PP master batches containing the antibacterial agent and the flame retardant;

step four, preparing the antibacterial flame-retardant PP fiber containing the porous aerogel: carrying out melt spinning on the slow-release porous aerogel PP master batch containing the antibacterial agent and the flame retardant to obtain the antibacterial flame-retardant PP fiber containing the porous aerogel, wherein the melt spinning process parameters are as follows: the spinning temperature is 270 ℃ and 295 ℃; cooling with cross air at 28-30 deg.C; the side blowing wind speed is 0.3-0.5 m/s; the winding spinning speed is 3500 and 4000 m/min; the drafting multiplying factor is 3.0-4.0.

The invention further protects the antibacterial flame-retardant PP fiber containing the porous aerogel prepared by the preparation method.

The invention has the following beneficial effects: sodium carboxymethyl cellulose is a common cellulose derivative, and is widely applied due to high solubility, biocompatibility and biodegradability, the invention adopts sodium carboxymethyl cellulose and graphene oxide to carry out mixing and coprecipitation to obtain cellulose-based aerogel, and the obtained aerogel has uniform aperture, regular size, large porosity, large specific surface area and large loading capacity of an antibacterial agent;

according to the invention, the antibacterial agent and flame retardant-containing slow-release porous aerogel is prepared by using the porous aerogel ingeniously, so that the master batch has good antibacterial and bacteriostatic properties, flame retardance and other functions, the antibacterial agent-containing porous aerogel is uniformly dispersed in the slices, and the prepared master batch further has good functions when being prepared into fibers;

nisin is a polypeptide substance produced by streptococcus lactis, which inhibits the growth and reproduction of most gram-positive bacteria, has strong inhibition effect on spores of bacillus, particularly has special effect on gram-positive bacteria producing the spores, the antibacterial mechanism is that the normal function of the cell membrane is interfered to cause the permeation of the cell membrane, nutrient loss and the reduction of the membrane potential, thereby leading the death of pathogenic bacteria and putrefying bacteria cells, tetraphenyl (bisphenol-A) diphosphate is a high-efficiency organic phosphate flame retardant, the antibacterial agent and the flame retardant are compounded and loaded on the porous aerogel, the porous aerogel has larger specific surface area and can load a large amount of antibacterial agents and flame retardants, thereby being beneficial to improving the antibacterial property and the flame retardant property of the antibacterial PP fiber, meanwhile, the mechanical property of the fiber can be synergistically improved, and the fiber has a good synergistic effect.

The antibacterial flame-retardant PP fiber containing the porous aerogel prepared by the invention has antibacterial and flame-retardant properties, and the product has excellent mechanical properties, and the preparation method has the advantages of simple process, low cost and excellent popularization value.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is an SEM image of a porous aerogel prepared in example 1 of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be 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.

Example 1 preparation of porous aerogel

S1, putting 10g of mixed aqueous solution containing 3 wt% of NaOH and 5 wt% of urea into a refrigerator, freezing to-10 ℃, adding 1g of graphene oxide into the mixed solution, mechanically stirring for 5min to obtain a graphene oxide solution, adding 1g of sodium carboxymethylcellulose into another 30g of mixed aqueous solution containing 3 wt% of NaOH and 5 wt% of urea, mechanically stirring for 1h to obtain a sodium carboxymethylcellulose solution, mixing the graphene oxide solution and the sodium carboxymethylcellulose solution according to a volume ratio of 1: 1, mixing to obtain a mixed solution;

s2, pouring 100g of liquid paraffin into a reactor, mechanically stirring for 10min, dropwise adding 10g of mixed solution into the liquid paraffin, and mechanically stirring for 10min after dropwise adding; and adding 5g of epichlorohydrin into liquid paraffin, reacting at room temperature for 1h, neutralizing with 5% hydrochloric acid after the reaction is finished, removing the upper layer of liquid paraffin, repeatedly washing the lower layer of standard product with distilled water and absolute ethyl alcohol to obtain hydrogel beads, and freeze-drying the hydrogel to obtain the porous aerogel, wherein an SEM picture of the porous aerogel is shown in figure 1, and the particle size of the porous aerogel is 200-300 nm.

Example 2 preparation of porous aerogels

S1, placing 30g of mixed aqueous solution containing 5 wt% of NaOH and 10 wt% of urea in a refrigerator, freezing to-10 ℃, adding 1g of graphene oxide into the mixed solution, mechanically stirring for 5min to obtain a graphene oxide solution, adding 1g of sodium carboxymethylcellulose into another 50g of mixed aqueous solution containing 5 wt% of NaOH and 10 wt% of urea, mechanically stirring for 2h to obtain a sodium carboxymethylcellulose solution, and mixing the graphene oxide solution and the sodium carboxymethylcellulose solution according to a volume ratio of 1:3, mixing to obtain a mixed solution;

s2, pouring 100g of liquid paraffin into a reactor, mechanically stirring for 20min, dripping 30g of mixed solution into the liquid paraffin, and mechanically stirring for 30min after dripping is finished; and adding 12g of epichlorohydrin into liquid paraffin, reacting at room temperature for 3 hours, neutralizing with 12% hydrochloric acid after the reaction is finished, removing the upper layer of liquid paraffin, repeatedly washing the lower layer of standard product with distilled water and absolute ethyl alcohol to obtain hydrogel beads, and freeze-drying the hydrogel to obtain the porous aerogel.

Example 3

S1, 20g of mixed aqueous solution containing 4 wt% of NaOH and 7 wt% of urea is placed in a refrigerator to be frozen to-10 ℃, 1g of graphene oxide is added into the mixed solution, mechanical stirring is carried out for 5min to obtain graphene oxide solution, 1g of sodium carboxymethyl cellulose is added into another 40g of mixed aqueous solution containing 4 wt% of NaOH and 7 wt% of urea, mechanical stirring is carried out for 1.5h to obtain sodium carboxymethyl cellulose solution, and the volume ratio of the graphene oxide solution to the sodium carboxymethyl cellulose solution is 1:2, mixing to obtain a mixed solution;

s2, pouring 100g of liquid paraffin into a reactor, mechanically stirring for 15min, dropwise adding 20g of mixed solution into the liquid paraffin, and mechanically stirring for 20min after dropwise adding; and adding 10g of epichlorohydrin into the liquid paraffin, reacting at room temperature for 2 hours, neutralizing with 10% hydrochloric acid after the reaction is finished, removing the upper layer of the liquid paraffin, repeatedly washing the lower layer of the standard product with distilled water and absolute ethyl alcohol to obtain hydrogel beads, and freeze-drying the hydrogel to obtain the porous aerogel.

Comparative example 1

The mixed aqueous solution contained only NaOH, and the other conditions were not changed, as compared with example 3.

S1, 20g of mixed aqueous solution containing 11 wt% of NaOH is placed into a refrigerator to be frozen to-10 ℃, 1g of graphene oxide is added into the mixed solution, the graphene oxide solution is obtained after mechanical stirring is carried out for 5min, 1g of sodium carboxymethylcellulose is added into another 40g of mixed aqueous solution containing 11 wt% of NaOH and is mechanically stirred for 1.5h to obtain sodium carboxymethylcellulose solution, and the graphene oxide solution and the sodium carboxymethylcellulose solution are mixed according to the volume ratio of 1:2, mixing to obtain a mixed solution;

Comparative example 2

Compared with example 3, the mixed aqueous solution contained only urea, and the other conditions were not changed.

S1, 20g of mixed aqueous solution containing 11 wt% of urea is placed into a refrigerator to be frozen to-10 ℃, 1g of graphene oxide is added into the mixed solution, the graphene oxide solution is obtained after mechanical stirring is carried out for 5min, 1g of sodium carboxymethyl cellulose is added into another 40g of mixed aqueous solution containing 11 wt% of urea, mechanical stirring is carried out for 1.5h, sodium carboxymethyl cellulose solution is obtained, and the volume ratio of the graphene oxide solution to the sodium carboxymethyl cellulose solution is 1:2, mixing to obtain a mixed solution;

Example 4 preparation of antibacterial flame retardant PP fiber of porous aerogel

The method comprises the following steps:

step one, preparing a mixed solution of an antibacterial agent and a flame retardant: 1g of nisin and 3g of tetraphenyl (bisphenol-A) diphosphate are uniformly mixed and then added into 20mL of mixed solution of tetrahydrofuran and water, and the mixture is stirred until the nisin and the tetraphenyl (bisphenol-A) diphosphate are fully dissolved to obtain mixed solution of an antibacterial agent and a flame retardant; the volume ratio of the tetrahydrofuran to the water in the mixed solution of the tetrahydrofuran and the water is 1: 1;

step two, preparing the porous aerogel containing the antibacterial agent and the flame retardant: sequentially adding 5g of mixed solution of the antibacterial agent and the flame retardant, 7g of the porous aerogel prepared in the embodiment 1, 1g of coupling agent and 0.5g of surfactant into a shearing disperser, heating to 50 ℃ at a speed of 3 ℃/min, preserving heat, carrying out first shearing dispersion with a shearing force of 5250ips and a shearing time of 4min, then adding a stabilizer accounting for 0.1 wt% of the total mass of the materials, carrying out second shearing with a shearing force of 2500ips and a shearing time of 5min to obtain porous aerogel suspension dispersion liquid containing the antibacterial agent and the flame retardant, and volatilizing the solvent to obtain dry porous aerogel containing the antibacterial agent and the flame retardant;

the coupling agent is a mixture of a silane coupling agent KH550 and a silane coupling agent KH570 in a mass ratio of 5:1, the surfactant is a mixture of Tween-80 and span-80 in a mass ratio of 10:1, and the stabilizer is a mixture of magnesium stearate and aluminum stearate in a mass ratio of 1: 2.

Step three, preparing the slow-release porous aerogel PP master batch containing the antibacterial agent and the flame retardant: adding 5g of dried porous aerogel containing the antibacterial agent and the flame retardant into a grinding machine, adding 20g of petroleum ether, 1g of ammonium polyacrylate and 0.5g of 2, 4-di- (n-octylthiomethylene) -6-methylphenol, mixing and grinding to obtain a composite modifier containing the antibacterial agent and the flame retardant; adding 5g of composite modifier containing the antibacterial agent and the flame retardant into 100g of PP slices, melting at the high temperature of 350 ℃, keeping the melting for 10min, and extruding and granulating to obtain slow-release porous aerogel PP master batches containing the antibacterial agent and the flame retardant;

step four, preparing the antibacterial flame-retardant PP fiber containing the porous aerogel: carrying out melt spinning on the slow-release porous aerogel PP master batch containing the antibacterial agent and the flame retardant to obtain the antibacterial flame-retardant PP fiber containing the porous aerogel, wherein the melt spinning process parameters are as follows: the spinning temperature is 270 ℃; cooling air temperature by cross air blow is 28 ℃; the side blowing wind speed is 0.3 m/s; the winding spinning speed is 3500 m/min; the draft magnification was 3.0.

Example 5 preparation of antibacterial flame retardant PP fiber of porous aerogel

The method comprises the following steps:

step one, preparing a mixed solution of an antibacterial agent and a flame retardant: 1g of nisin and 3g of tetraphenyl (bisphenol-A) diphosphate are uniformly mixed and then added into 20mL of mixed solution of tetrahydrofuran and water, and the mixture is stirred until the nisin and the tetraphenyl (bisphenol-A) diphosphate are fully dissolved to obtain mixed solution of an antibacterial agent and a flame retardant; the volume ratio of the tetrahydrofuran to the water in the mixed solution of the tetrahydrofuran and the water is 3: 1;

step two, preparing the porous aerogel containing the antibacterial agent and the flame retardant: sequentially adding 10g of mixed solution of the antibacterial agent and the flame retardant, 12g of the porous aerogel prepared in the embodiment 2, 2g of coupling agent and 1.5g of surfactant into a shearing disperser, heating to 50 ℃ at a speed of 3 ℃/min, preserving heat, performing first shearing dispersion with a shearing force of 6000ips and a shearing time of 9min, adding a stabilizer accounting for 5 wt% of the total mass of the materials, performing second shearing with a shearing force of 3000ips and a shearing time of 10min to obtain porous aerogel suspension dispersion liquid containing the antibacterial agent and the flame retardant, and volatilizing the solvent to obtain dry porous aerogel containing the antibacterial agent and the flame retardant;

the coupling agent is a mixture of a silane coupling agent KH550 and a silane coupling agent KH570 in a mass ratio of 5:3, the surfactant is a mixture of Tween-80 and span-80 in a mass ratio of 10:3, and the stabilizer is a mixture of magnesium stearate and aluminum stearate in a mass ratio of 1: 4.

Step three, preparing the slow-release porous aerogel PP master batch containing the antibacterial agent and the flame retardant: adding 15g of dried porous aerogel containing the antibacterial agent and the flame retardant into a grinding machine, adding 40g of carbon tetrachloride, 3g of ammonium polyacrylate and 2.5g of dilauryl thiodipropionate, mixing and grinding to obtain a composite modifier containing the antibacterial agent and the flame retardant; adding 10g of composite modifier containing the antibacterial agent and the flame retardant into 100g of PP slices, melting at the high temperature of 400 ℃, keeping the melting for 15min, and extruding and granulating to obtain slow-release porous aerogel PP master batches containing the antibacterial agent and the flame retardant;

step four, preparing the antibacterial flame-retardant PP fiber containing the porous aerogel: carrying out melt spinning on the slow-release porous aerogel PP master batch containing the antibacterial agent and the flame retardant to obtain the antibacterial flame-retardant PP fiber containing the porous aerogel, wherein the melt spinning process parameters are as follows: the spinning temperature is 295 ℃; side-blown cooling wind temperature is 30 ℃; the side blowing wind speed is 0.5 m/s; winding and spinning speed is 4000 m/min; the draft magnification was 4.0.

Example 6 preparation of antibacterial flame retardant PP fiber of porous aerogel

The method comprises the following steps:

step one, preparing a mixed solution of an antibacterial agent and a flame retardant: 1g of nisin and 2g of tetraphenyl (bisphenol-A) diphosphate are uniformly mixed and then added into 20mL of mixed solution of tetrahydrofuran and water, and the mixture is stirred until the mixture is fully dissolved to obtain mixed solution of an antibacterial agent and a flame retardant; the volume ratio of the tetrahydrofuran to the water in the mixed solution of the tetrahydrofuran and the water is 2: 1;

step two, preparing the porous aerogel containing the antibacterial agent and the flame retardant: sequentially adding 7g of mixed solution of the antibacterial agent and the flame retardant, 10g of the porous aerogel prepared in the embodiment 3, 1.5g of coupling agent and 1g of surfactant into a shearing disperser, heating to 50 ℃ at a speed of 3 ℃/min, preserving heat, performing first shearing dispersion with a shearing force of 5700ips and a shearing time of 6min, then adding a stabilizer accounting for 2.5 wt% of the total mass of the substances, performing second shearing with a shearing force of 2700ips and a shearing time of 7min to obtain porous aerogel suspension dispersion liquid containing the antibacterial agent and the flame retardant, and volatilizing the solvent to obtain dry porous aerogel containing the antibacterial agent and the flame retardant;

the coupling agent is a mixture of a silane coupling agent KH550 and a silane coupling agent KH570 in a mass ratio of 5:2, the surfactant is a mixture of Tween-80 and span-80 in a mass ratio of 10:2, and the stabilizer is a mixture of magnesium stearate and aluminum stearate in a mass ratio of 1: 3.

Step three, preparing the slow-release porous aerogel PP master batch containing the antibacterial agent and the flame retardant: adding 10g of dried porous aerogel containing the antibacterial agent and the flame retardant into a grinding machine, adding 30g of diethyl ether, 2g of sodium polyacrylate and 1.5g of 2, 4-bis (dodecyl-thiomethyl) -6-methylphenol, mixing and grinding to obtain a composite modifier containing the antibacterial agent and the flame retardant; adding 7g of composite modifier containing the antibacterial agent and the flame retardant into 100g of PP slices, melting at the high temperature of 370 ℃, keeping the melting for 12min, and extruding and granulating to obtain slow-release porous aerogel PP master batches containing the antibacterial agent and the flame retardant;

step four, preparing the antibacterial flame-retardant PP fiber containing the porous aerogel: carrying out melt spinning on the slow-release porous aerogel PP master batch containing the antibacterial agent and the flame retardant to obtain the antibacterial flame-retardant PP fiber containing the porous aerogel, wherein the melt spinning process parameters are as follows: the spinning temperature is 285 ℃; cooling air temperature by cross air blow is 29 ℃; the side blowing wind speed is 0.4 m/s; the winding spinning speed is 3700 m/min; the draft magnification was 3.5.

Comparative example 3

In comparison with example 6, the porous aerogel was prepared from comparative example 1, with no change in other conditions.

Comparative example 4

In comparison with example 6, the porous aerogel was prepared from comparative example 2, with no change in other conditions.

Comparative example 5

Compared with example 6, without adding nisin, all other conditions were not changed

Step one, preparing a mixed solution of an antibacterial agent and a flame retardant: uniformly mixing 3g of tetraphenyl (bisphenol-A) diphosphate, adding the mixture into 20mL of mixed solution of tetrahydrofuran and water, and stirring the mixture until the mixture is fully dissolved to obtain mixed solution of an antibacterial agent and a flame retardant; the volume ratio of the tetrahydrofuran to the water in the mixed solution of the tetrahydrofuran and the water is 2: 1.

comparative example 6

In comparison with example 6, tetraphenyl (bisphenol-A) diphosphate was not added, and other conditions were not changed.

Step one, preparing a mixed solution of an antibacterial agent and a flame retardant: uniformly mixing 3g of nisin, adding the nisin into 20mL of mixed solution of tetrahydrofuran and water, and stirring the nisin and the water until the nisin and the water are fully dissolved to obtain mixed solution of an antibacterial agent and a flame retardant; the volume ratio of the tetrahydrofuran to the water in the mixed solution of the tetrahydrofuran and the water is 2: 1.

test example 1

The obtained porous aerogels obtained in examples 1 to 3 and comparative examples 1 to 2 were subjected to test characterization by using a laser particle sizer and an ultraviolet spectrophotometer, and the particle size distribution of the porous aerogel of this example were found to be as shown in table 1:

comparing the examples, and the prior art, the following data are obtained:

TABLE 1

Group of	Particle size (nm)	Index of particle size distribution
			Example 1	245.2±0.10	0.425
Example 2	247.1±0.14	0.442
			Example 3	246.5±0.12	0.417
Comparative example 1	221.4±2.12	0.728
			Comparative example 2	274.3±1.25	0.782

As can be seen from the above table, the porous aerogel prepared by the method of the present invention has the characteristics of uniform particle size distribution, high drug loading, etc.

Test example 2

The obtained porous aerogels obtained in examples 4 to 6 and comparative examples 3 to 4 were subjected to test characterization by an ultraviolet spectrophotometer, and the drug loading of the porous aerogels of this example was found to be as shown in table 2.

TABLE 2

Group of	Drug loading (%)
		Example 4	89
Example 5	92
		Example 6	95
Comparative example 3	72
		Comparative example 4	70

Test example 3

The test index is the limiting oxygen index percent, and the sample is tested according to the experimental standard GB/T2406.2-2009. The shape of the sample is I, the length is 100mm, the width is 10mm, and the thickness is 4 mm; ignition method a, at least 15 specimens per group. The results are shown in Table 3.

TABLE 3

Group of	Limiting oxygen index (%)
		Example 4	52
Example 5	54
		Example 6	57
Comparative example 3	22
		Comparative example 4	24
Comparative example 5	2
		Comparative example 6	19

Test example 3 antibacterial property test

The antibacterial performance of the fibers prepared in the examples 4-6 and the comparative examples 3-6 is tested, and the test method refers to GB/T21510-2008 detection, and adopts a film sticking method, namely escherichia coli ATYCC 25922 and staphylococcus aureus ATCC 6538. Refer to GB21551.2-2010 "Special requirements for antibacterial materials with antibacterial, degerming and purifying functions for household and similar appliances". Detection bacteria: candida albicans ATCC 10231(Candida albicans).

The results are shown in Table 4.

TABLE 4

Test example 4 mechanical Property test

The mechanical property test of the porous silica microsphere sustained-release antibacterial PET fibers prepared in the embodiments 4-6 and the comparative examples 3-6 is carried out, and the results are shown in Table 5.

TABLE 5

As can be seen from the above table, the antibacterial flame-retardant PP fiber of the porous aerogel prepared by the invention has good mechanical properties.

Compared with example 6, the porous aerogels prepared in comparative example 1 or comparative example 2 are adopted respectively, the flame retardance, the antibacterial property and the mechanical property are obviously reduced, so that the addition of NaOH or urea in the mixed solution is not beneficial to forming better porous aerogels, the loading amount of the antibacterial agent and the flame retardant is reduced, the antibacterial property and the flame retardance are obviously reduced, and the compatibility of the aerogel prepared in comparative example 1 or comparative example 2 with PP slices is reduced due to the fact that the aerogel prepared in comparative example 1 or comparative example 2 is not regular, and the mechanical property is obviously reduced.

Compared with the example 6, the comparative example 5 and the comparative example 6 only add nisin or tetraphenyl (bisphenol-A) diphosphate, the flame retardance of the comparative example 5 is obviously reduced, the antibacterial property of the comparative example 6 is obviously reduced, and nisin and tetraphenyl (bisphenol-A) diphosphate have synergistic effect on the antibacterial property and the flame retardance of materials, the nisin is a polypeptide substance produced by the streptococcus lactis, can inhibit the growth and the reproduction of most gram-positive bacteria and has strong inhibiting effect on spores of bacillus, particularly has special effect on the spore-producing gram-positive bacteria, the antibacterial mechanism is that the normal function of cell membranes is interfered, the permeation, the nutrient flow and the membrane potential of the cell membranes are reduced, and the death of pathogenic bacteria and putrefying bacteria cells are caused, the tetraphenyl (bisphenol-A) diphosphate is a flame retardant of efficient organic phosphates, the antibacterial agent and the flame retardant are loaded on the porous aerogel in a composite mode, and a large amount of antibacterial agent and flame retardant can be loaded due to the large specific surface area of the porous aerogel, so that the antibacterial property and the flame retardant property of the antibacterial PP fiber can be improved, the mechanical property of the fiber can be improved in a synergistic mode, and the synergistic effect is good.

Compared with the prior art, sodium carboxymethyl cellulose is a common cellulose derivative, and is widely applied due to high solubility, biocompatibility and biodegradability, the cellulose-based aerogel is obtained by mixing and coprecipitating the sodium carboxymethyl cellulose and graphene oxide, and the obtained aerogel has uniform aperture, regular size, large porosity, large specific surface area and large loading capacity of an antibacterial agent;

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. A preparation method of porous aerogel is characterized by comprising the following steps:

2. The method according to claim 1, wherein in the mixed aqueous solution containing NaOH and 5-10 wt% of urea, the mass fraction of NaOH is 3-5 wt% and the mass fraction of urea is 5-10 wt%; the volume-mass ratio of the mixed aqueous solution containing NaOH and urea to the graphene oxide is (10-30): 1; the volume-mass ratio of the mixed aqueous solution containing NaOH and urea to the sodium carboxymethyl cellulose is (30-50): 1; the mass ratio of the liquid paraffin to the mixed solution to the epichlorohydrin is 100: (10-30): (5-12).

3. A porous aerogel obtained by the production method according to claim 1 or 2.

4. A preparation method of antibacterial flame-retardant PP fiber containing the porous aerogel of claim 3 is characterized by comprising the following steps:

5. The method according to claim 4, wherein the first step specifically comprises: nisin and tetraphenyl (bisphenol-A) diphosphate are mixed according to a mass ratio of 1: (1-3) adding the mixture into a mixed solution of tetrahydrofuran and water after uniformly mixing, and stirring the mixture until the mixture is fully dissolved to obtain a mixed solution of the antibacterial agent and the flame retardant; the volume ratio of the tetrahydrofuran to the water in the mixed solution of the tetrahydrofuran and the water is (1-3): 1.

6. the method according to claim 4, wherein the second step specifically comprises: sequentially adding the antibacterial agent and flame retardant mixed solution, the porous aerogel, the coupling agent and the surfactant into a shearing disperser, heating to 50 ℃, preserving heat, performing primary shearing dispersion, then adding a stabilizer accounting for 0.1-5 wt% of the total mass of the substances, performing secondary shearing to obtain a porous aerogel suspension dispersion solution containing the antibacterial agent and the flame retardant, and volatilizing the solvent to obtain a dry porous aerogel containing the antibacterial agent and the flame retardant;

7. The preparation method according to claim 4, wherein the third step specifically comprises: adding the dried porous aerogel containing the antibacterial agent and the flame retardant into a grinding machine, adding a fat-soluble solvent, a dispersing agent and an antioxidant, and mixing and grinding to obtain a composite modifier containing the antibacterial agent and the flame retardant; adding a composite modifier containing an antibacterial agent and a flame retardant into the PP slices, melting at high temperature, keeping the melting for 10-15min, and extruding and granulating to obtain a slow-release porous aerogel PP master batch containing the antibacterial agent and the flame retardant;

8. The preparation method according to claim 4, wherein the fourth step specifically comprises: carrying out melt spinning on the slow-release porous aerogel PP master batch containing the antibacterial agent and the flame retardant to obtain the antibacterial flame-retardant PP fiber containing the porous aerogel, wherein the melt spinning process parameters are as follows: the spinning temperature is 270 ℃ and 295 ℃; cooling with cross air at 28-30 deg.C; the side blowing wind speed is 0.3-0.5 m/s; the winding spinning speed is 3500 and 4000 m/min; the drafting multiplying factor is 3.0-4.0.

9. The preparation method according to claim 4, characterized by comprising the following steps:

10. An antibacterial flame-retardant PP fiber containing porous aerogel prepared by the preparation method of any one of claims 4 to 9.