Preparation method of low-ring antibacterial modified silicone oil

Abstract

The invention discloses a preparation method of low-ring-body antibacterial modified silicone oil, which comprises the following steps: taking polyether amine and epoxy-terminated silicone oil as starting raw materials, fully reacting in a solvent environment to obtain polyether silicone oil terminated by double-end epoxy groups, then adding oligomeric chitosan obtained after degradation and acidification, and reacting to obtain the low-ring-body antibacterial modified silicone oil. The method has the advantages of high operability, energy conservation, low cost and the like, and is suitable for industrial production; meanwhile, the prepared low-ring antibacterial modified silicone oil has the advantages of good antibacterial property, strong washability, good hydrophilicity and biodegradability, and can be used for addition of daily chemical products and post-treatment of textile fabrics.

Description

Technical Field

[0001] The invention belongs to the technical field of antibacterial material preparation, and in particular relates to a method for preparing low-cyclic antibacterial modified silicone oil. Background Art

[0002] Textiles are very easy to breed bacteria and are an important source of disease transmission, so the antibacterial finishing of textiles is extremely important. Antibacterial textiles can prevent fabrics from being contaminated by microorganisms, prevent infectious diseases, ensure human safety and health and wear comfort, reduce cross-infection in public environments, and have certain health care functions. Antibacterial textiles have a wide range of applications, such as home textiles, underwear, sportswear, interior decorations, hospitals, food processing and pharmaceutical work clothes, patient gowns, packaging materials, etc.

[0003] There are two main ways to treat textiles with antibacterial agents. One is to directly treat the fabric fibers with antibacterial substances and attach the antibacterial substances to the fabric surface by sedimentation. For example, Chinese patent CN201410164116.9 uses chitosan and titanium dioxide as antibacterial raw materials to treat wool fabrics. The treated fabrics have antibacterial effects, but chitosan is not tightly bound to the fabric and is easy to wash off. The second is to synthesize a finishing agent with antibacterial effects and then finish the fabric. For example, Chinese patent CN116640314A uses long-chain alkylamines and end-epoxy polyether silicone oils to synthesize quaternary ammonium silicone oils under acidic conditions, and then combines the silicone oil with the fabric through fabric finishing to obtain a fabric with antibacterial properties.

[0004] Commonly used antibacterial substances are divided into non-bio-based and bio-based. Non-bio-based antibacterial materials include organic compounds (such as quaternary ammonium salt compounds, polydimethyl hexaguanidine, etc.) and metal-based materials (such as silver, zinc, titanium and its oxides and salts, etc.), and bio-based antibacterial materials include chitosan, tea polyphenols, menthol, betaine, etc. With the increasing attention paid by the international community to environmental protection, biodegradable antibacterial materials have become the focus of attention. Chitosan is very suitable for use as an antibacterial material for fabrics due to its biodegradability, bio-friendliness, easy accessibility, antibacterial properties and reactivity.

[0005] Chinese patent CN118110032A discloses a chitosan composite antibacterial fabric, its preparation method and application, wherein the chitosan fiber / fabric is obtained by immersing the fabric in a chitosan acetic acid solution, followed by shaking and drying. The above-mentioned immersion steps are then repeated, and then the fabric is transferred to a sulfate / phosphate aqueous solution, washed with deionized water and dried to obtain the target fabric. The chitosan coating layer with different hydrophilicity meets the antibacterial, cell activity, hemolysis and coagulation performance requirements of the fabric, while retaining the original shape, air permeability and flexibility of the fabric. However, since the chitosan is coated on the surface of the fabric by deposition and drying, the bonding is not tight and the washability is poor.

[0006] Chinese patent CN105088774B discloses a method for preparing a long-lasting antibacterial fabric, which uses a "messenger" technology to complex nanosilver with chitosan and control the isoelectric point of the system to make the nanosilver complex and deposit on the fiber, so that the nanosilver is enriched on the surface of the fabric in large quantities, achieving the purpose of making the fabric long-lasting antibacterial. However, the biological safety of nanosilver is worrying, and the high cost also affects the promotion and application of this technology.

[0007] Chinese patent CN118087113A discloses an antibacterial yarn and a preparation method thereof, wherein a metal material modified by an epoxy silane coupling agent is first loaded onto wool by padding / magnetron sputtering, and then dopamine, chitosan, acrylic acid and a cross-linking agent are uniformly mixed to obtain a chitosan mixed solution, which is then impregnated with silver-loaded wool and then taken out for rolling and drying, and then immersed in a mixture of isohexanediol and dipropylene glycol for reaction, followed by washing and drying, to obtain chitosan silver-loaded wool and bamboo fiber for treatment to obtain antibacterial yarn. This preparation method has complicated processing steps, and the cost of dopamine is very high, which is not conducive to industrial production.

[0008] Therefore, it is necessary to develop an antibacterial substance that can improve washability, reduce costs and simplify the process while ensuring good antibacterial effects. Summary of the invention

[0009] In view of the above technical problems, the present invention provides a method for preparing low-cyclic antibacterial modified silicone oil, which uses polyether amine and terminal epoxy silicone oil to prepare epoxy group-terminated polyether silicone oil, and then mixes and reacts with cationic oligochitosan to obtain low-cyclic antibacterial modified silicone oil. After using it for fabric treatment, the antibacterial effect and washability of the fabric can be improved, and it has the advantages of low cost and simple process, and is suitable for industrial production.

[0010] In order to achieve the above object, the present invention provides a method for preparing low-cyclic antibacterial modified silicone oil, comprising the following steps: (1) dissolving polyether amine and epoxy-terminated silicone oil in a solvent, and reacting to obtain epoxy-terminated polyether silicone oil; (2) Chitosan is dissolved in acid, and an oxidant is added to react to obtain oligomeric chitosan; (3) dissolving oligomolecular chitosan in acid to obtain cationic oligomolecular chitosan; (4) placing the cationic oligosaccharide chitosan in the polyether silicone oil obtained in step (1) to react and obtain low-ring antibacterial modified silicone oil.

[0011] Preferably, the molar ratio of the polyetheramine to the epoxy-terminated silicone oil in step (1) is 1:1.8-2.5.

[0012] Further preferably, the molar ratio of the polyetheramine to the epoxy-terminated silicone oil is 1:2.0-2.2.

[0013] Further preferably, the polyetheramine is a linear molecular structure with -NH2 groups at both ends of the chain segment and a polyether chain segment in the middle, and the molecular weight is 200-3000; further preferably, the molecular weight is 200-1000.

[0014] More preferably, the epoxy-terminated silicone oil is a linear polysiloxane segment terminated with double-end epoxy groups, with a volatile matter of less than 0.5% and a molecular weight of 400-40,000; and even more preferably, the molecular weight is 4,000-20,000.

[0015] Preferably, the solvent in step (1) is one or more of diethylene glycol butyl ether, dipropylene glycol butyl ether and isohexanediol.

[0016] Preferably, the reaction temperature in step (1) is 40-125° C., and an inert gas is used for protection during the reaction.

[0017] Further preferably, the reaction temperature is 70-90° C., and the inert gas is nitrogen.

[0018] Preferably, the mass ratio of chitosan, acid and oxidant in step (2) is 1:3:0.08; and the reaction temperature is 45-70°C.

[0019] Further preferably, the acid is one or more of glacial acetic acid, carbonic acid, and propionic acid, with a pH of 5.0-6.5 and a mass fraction of 3-5%; further preferably, the pH is 6.0-6.0.

[0020] Further preferably, the deacetylation degree of the chitosan is greater than 90%.

[0021] More preferably, the deacetylation degree of the chitosan is ≥95%.

[0022] More preferably, the oxidant is hydrogen peroxide.

[0023] Preferably, the molecular weight of the oligochitosan in step (2) is 2000-8000.

[0024] Preferably, the mass ratio of the oligochitosan to the acid in step (3) is 2:1.

[0025] Preferably, the dissolution time in step (3) is 1-12 hours.

[0026] More preferably, the acid is one or more of glacial acetic acid, carbonic acid, and propionic acid, and the pH is less than 5.0.

[0027] Preferably, the reaction temperature in step (4) is 30-100°C, and the reaction time is 1-8h; more preferably, the reaction temperature is 30-60°C.

[0028] The beneficial effects of the present invention are: 1. By controlling the ratio of polyetheramine and epoxy silicone oil to react, epoxy-terminated polyether silicone oil is obtained, which has a polyether siloxane segment in the middle of the double-end epoxy group. On the one hand, the double-end reaction activity is retained, and on the other hand, the amino group in the middle of the segment is conducive to combining with the groups on the surface of the fabric. After the epoxy-terminated polyether silicone oil is reacted with oligomolecular chitosan, the presence of the polyether segment and the oligomolecular chitosan makes the silicone oil more hydrophilic and convenient to use. At the same time, chitosan, as a biological macromolecule, is used as an antibacterial modifier and has biodegradable properties.

[0029] 2. By controlling the pH value of the acid used in the two acidifications, the different conditions required for the depolymerization and cationization of chitosan can be met. The free amino groups in chitosan can react with the H + The reaction generates -NH 3+ When the pH value is between 5.0 and 6.5, the ionic strength of the solution is low, the chitosan molecular chain is unfolded due to the repulsion of the positive charge, and the number of attack sites of active oxidative groups increases, which is conducive to the degradation reaction. When the pH value is less than 5.0, a large amount of -NH 3+ At this time, most of the system is acetylamino, and its steric hindrance effect will hinder hydrogen peroxide from attacking the β-glycosidic bond and avoid degradation.

[0030] 3. Using degraded oligochitosan as a reaction monomer, firstly, compared with chitosan, oligochitosan has better solubility and is easier to produce and operate; secondly, reducing the molecular weight of chitosan is conducive to its connection to the polysiloxane chain segment through reaction; thirdly, for chitosan, as the molecular weight decreases, its antibacterial ability is improved.

[0031] 4. The present invention adopts polyetheramine and ultra-low volatile end-epoxy silicone oil to prepare low-cyclic antibacterial modified silicone oil by ring-opening condensation. Compared with the traditional copolymerization method of synthesizing silicone oil and then removing low-boiling products at high temperature / long time, the reaction is carried out at a lower temperature throughout the process to effectively retain the amino activity. The polyether segment in the system also makes the product more hydrophilic, the emulsification process is more convenient, and the treated fabric is more skin-friendly. At the same time, the product meets the current international standards for low-cyclic silicone products, and the product can be applied in a wider range of fields. DETAILED DESCRIPTION

[0032] The technical solution of the present invention is further explained below in conjunction with specific embodiments. It is worth noting that the following embodiments are only preferred embodiments of the present invention and should not be construed as limiting the present invention. The protection scope of the present invention shall be subject to the contents recorded in the claims. Any modification or replacement made by a person skilled in the art to the technical solution of the present invention without creative work shall fall within the protection scope of the present invention.

[0033] The parts involved in the following examples are all parts by mass.

[0034] Example 1 Preparation of low-ring end epoxy polyether silicone oil (1) 100 parts of terminal epoxy silicone oil (molecular weight 2000) and 22.5 parts of polyetheramine ED900 (the molar ratio of polyetheramine to terminal epoxy silicone oil is 1:2) are mixed and dissolved in 30 parts of diethylene glycol monobutyl ether to obtain a mixed solution; (2) The mixed solution was then protected by nitrogen at normal pressure, heated to 80°C with stirring, and condensed and refluxed for 3 hours to obtain epoxy-terminated polyether silicone oil; the yield was 98.90% and the viscosity was 118 cp.

[0035] Example 2 (1) 100 parts of terminal epoxy silicone oil (molecular weight 8000) and 5.6 parts of polyetheramine ED900 (the molar ratio of polyetheramine to terminal epoxy silicone oil is 1:2) are mixed and dissolved in 30 parts of dipropylene glycol butyl ether to obtain a mixed solution; (2) The mixed solution was then protected by nitrogen at normal pressure, heated to 80°C with stirring, and condensed and refluxed for 3 hours to obtain epoxy-terminated polyether silicone oil; the yield was 98.82% and the viscosity was 292 cp.

[0036] Example 3 (1) 100 parts of terminal epoxy silicone oil (molecular weight 20,000) and 2.3 parts of polyetheramine ED900 (the molar ratio of polyetheramine to terminal epoxy silicone oil is 1:2) are mixed and dissolved in 30 parts of isohexanediol to obtain a mixed solution; (2) The mixed solution was then protected by nitrogen at normal pressure, heated to 80°C with stirring, and condensed under reflux for 3 hours to obtain epoxy-terminated polyether silicone oil; the yield was 99.16% and the viscosity was 1600cp.

[0037] Example 4 Preparation of oligomeric chitosan (1) Dissolve 1 part of chitosan (95% deacetylation degree) in 3 parts of aqueous solution prepared with glacial acetic acid (pH = 5.5) and stir until completely dissolved; (2) placing the solution obtained in step (1) in a reactor, heating it to 50°C, then adding 5 parts of hydrogen peroxide (w=0.02), and stirring slowly and evenly to react for 6 hours; (3) The solution after the reaction was filtered and dried to obtain a light yellow oligosaccharide product with a weight average molecular weight of 6.2x10 3 , molecular weight distribution coefficient is 2.23.

[0038] Example 5 The method and steps are the same as those in Example 4, except that the temperature in step (2) is changed to 80°C to prepare a red oligosaccharide product with a weight average molecular weight of 5.6x10 3 , distribution coefficient 2.38.

[0039] Example 6 The method and steps are the same as those in Example 4, except that the amount of hydrogen peroxide in step (2) is changed to 8 parts, and a light yellow oligosaccharide product with a weight average molecular weight of 5.8x10 3 , distribution coefficient 2.12.

[0040] Example 7 The method and steps are the same as those in Example 4, except that the temperature in step (2) is changed to 80°C and the amount of hydrogen peroxide is changed to 8 parts to prepare a yellow oligosaccharide product with a weight average molecular weight of 5.6x10 3 , distribution coefficient 2.14.

[0041] Example 8 (1) Dissolve 1 part of chitosan (92% deacetylation degree) in 3 parts of a carbonic acid aqueous solution (pH = 6.0) and stir until completely dissolved; (2) placing the solution obtained in step (1) in a reactor, heating it to 65°C, then adding 5 parts of hydrogen peroxide (w=0.02), and stirring slowly and evenly to react for 6 hours; (3) The solution after the reaction was filtered and dried to obtain a light yellow oligosaccharide product with a weight average molecular weight of 6.8×10 3 , molecular weight distribution coefficient is 2.54.

[0042] Example 9 (1) Dissolve 1 part of chitosan (98% deacetylation degree) in 3 parts of aqueous solution prepared with propionic acid (pH = 6.0) and stir until completely dissolved; (2) placing the solution obtained in step (1) in a reactor, heating it to 50°C, then adding 5 parts of hydrogen peroxide (w=0.02), and stirring slowly and evenly to react for 6 hours; (3) The solution after the reaction was filtered and dried to obtain a light yellow oligosaccharide product with a weight average molecular weight of 5.2×10 3 , molecular weight distribution coefficient is 2.28.

[0043] Example 10 Preparation of low-cyclic antibacterial modified silicone oil (1) The oligomolecular chitosan prepared in Example 6 was placed in a glacial acetic acid solution (pH = 4.5), stirred and acidified for 1 h to obtain a cationic oligomolecular chitosan; (2) Under nitrogen protection, the epoxy-terminated polyether silicone oil prepared in Example 2 was placed in a reactor, heated to 50° C. and stirred, and the cationic oligosaccharide chitosan prepared in step (1) was added while stirring. The reaction was continued for 8 h to obtain low-ring antibacterial modified silicone oil.

[0044] Embodiment 11 The method and steps are the same as those of Example 10, except that the epoxy-terminated polyether silicone oil is changed to that prepared in Example 2 to obtain a low-ring antibacterial modified silicone oil.

[0045] Example 12 The method and steps are the same as those of Example 10, except that the epoxy-terminated polyether silicone oil is changed to that prepared by Example 3, thereby obtaining a low-ring antibacterial modified silicone oil.

[0046] Embodiment 13 The method and steps are the same as those of Example 10, except that the glacial acetic acid solution in step (1) is replaced by a propionic acid solution with a pH value of 4, and the acidification time is changed to 5 h; the reaction temperature in step (2) is changed to 30° C., and a low-cyclic antibacterial modified silicone oil is prepared.

[0047] Embodiment 14 The method and steps are the same as those in Example 10, except that the glacial acetic acid solution in step (1) is replaced by a carbonic acid solution with a pH value of 3, and the acidification time is changed to 12 hours; the reaction temperature in step (2) is 100° C. and the reaction time is 1 hour, thereby preparing a low-cyclic antibacterial modified silicone oil.

[0048] Comparative Example 1 (1) Place chitosan in a glacial acetic acid solution (pH = 4.5), stir and acidify for 1 hour to obtain cationic chitosan; (2) Under nitrogen protection, the epoxy-terminated polyether silicone oil prepared in Example 2 was placed in a reactor, heated to 50° C. and stirred, and the cationic chitosan prepared in step (1) was added while stirring. The reaction was continued for 8 h to obtain the modified silicone oil.

[0049] Comparative Example 2 Under nitrogen protection, the epoxy-terminated polyether silicone oil prepared in Example 2 was placed in a reactor, heated to 50° C. and stirred, and the oligomolecular chitosan prepared in Example 4 was added while stirring, and the reaction was continued for 8 hours to obtain modified silicone oil.

[0050] Comparative Example 3 (1) 100 parts of epoxy-terminated silicone oil (molecular weight 8000, volatile matter>1%) and 8.4 parts of polyetheramine ED900 were mixed and dissolved in 30 parts of diethylene glycol monobutyl ether to obtain a mixed solution; (2) The mixed solution was then protected by nitrogen at normal pressure, heated to 80°C with stirring, and condensed and refluxed for 3 hours to obtain epoxy-terminated polyether silicone oil; the yield was 98.46% and the viscosity was 254 cp; (3) The oligomolecular chitosan prepared in Example 6 was placed in a glacial acetic acid solution (pH = 4.5), stirred and acidified for 1 h to obtain a cationic oligomolecular chitosan; (4) Under nitrogen protection, the epoxy-terminated polyether silicone oil prepared in step (2) is placed in a reactor, the temperature is raised to 50° C. and stirred, and the cationic oligosaccharide prepared in step (1) is added while stirring. The reaction is continued for 8 hours to obtain the modified silicone oil.

[0051] Comparative Example 4 The method and steps are the same as those of Comparative Example 3, except that the molecular weight of the epoxy-terminated silicone oil is changed to 20,000, and the amount of polyetheramine ED900 is changed to 1.1 parts, and the modified silicone oil is prepared with a yield of 99.08% and a viscosity of 1527 cp.

[0052] Example 15 Emulsification Application (1) The modified silicone oils prepared in the above examples and comparative examples were tested for their ring body content by gas chromatography. The results are shown in Table 1. (2) Take the modified silicone oil prepared in the above examples and comparative examples, and the epoxy-terminated polyether silicone oil prepared in the above examples, add glacial acetic acid to stir and emulsify, and gradually add water during the stirring and emulsification process until the appearance of the emulsion is uniform and stable; the amount of glacial acetic acid used is 2wt% of the solid content of the emulsion (3) The cotton cloths were immersed in the emulsions obtained in step (1) for 5 minutes, and then the excess water was squeezed out. The cotton cloths were dried in a dryer at 165° C. for 1 minute. After being left at room temperature for half an hour, the hand feel of the cotton cloths was tested. The hand feel test items were softness and smoothness. The results are shown in Table 2. (4) The cotton cloth obtained in step (3) was tested for antibacterial effect according to the national standard of the People's Republic of China GB / T 20944.3-2008. The results are shown in Table 3. Table 1 Ring body content of modified silicone oil

[0053] Table 2 Application feel of silicone oil

[0054] Note: The hand feel evaluation is divided into 1-5 levels, with 5 being the best and 1 being the worst.

[0055] Table 3 Antibacterial properties of silicone oil

[0056] It can be seen from Table 1 that the contents of D4, D5 and D6 in the low-cyclic antibacterial modified silicone oil products prepared in Examples 10-14 and Comparative Examples 1, 2 and 4 are all less than 1000 ppm, which is in compliance with relevant international laws and regulations; while the cyclic content of the modified silicone oil prepared in Comparative Example 3 obviously exceeds the limit, indicating that the volatile matter of the selected terminal epoxy silicone oil has a very obvious effect on the cyclic bodies in the system.

[0057] It can be seen from Table 2 that for epoxy-terminated polyether silicone oil, the greater the viscosity, the better the smoothness and the worse the softness of the treated cotton cloth, while the feel of the cotton cloth treated with low-ring antibacterial modified silicone oil does not change much. This is because under the conditions of nitrogen protection and low-temperature reaction, the amino group in the system is not destroyed, and the siloxane segment can still be attached to the fabric surface. At the same time, the hydroxyl groups contained in chitosan can also enhance the adhesion to the surface of the cotton fabric; and the feel of the cotton cloth treated with the modified silicone oil prepared in Example 14 is reduced. This is because part of the amino group is destroyed when the treatment is carried out at high temperature. At the same time, the feel of the cotton cloth treated with the modified silicone oil prepared in Comparative Example 4 is significantly reduced. This is because the proportion of polyetheramine is too low, resulting in fewer amino groups on the product, and the effect of adhesion to the fabric surface cannot be achieved.

[0058] As shown in Table 3, the epoxy-terminated polyether silicone oil prepared from polyetheramine and epoxy-terminated silicone oil does not have antibacterial properties, while the untreated chitosan has antibacterial properties, but poor washing resistance, and the antibacterial properties are significantly reduced after washing; the cotton cloth treated with the low-ring antibacterial modified silicone oil prepared in Examples 10-12 has a higher antibacterial rate than the untreated chitosan, and has good washing resistance, which is because the antibacterial properties of chitosan are affected by molecular weight, and the larger the molecular weight, the worse the antibacterial properties. In addition, the washing resistance of the cotton cloth treated with the low-ring antibacterial modified silicone oil prepared in Examples 10-12 decreases successively, which is because as the molecular weight of the epoxy-terminated polyether silicone oil increases, the reaction activity decreases, and part of the chitosan fails to be connected to the siloxane main chain, and the adhesion effect with the fabric is poor, and it is easy to fall off during washing. The antibacterial properties of the cotton cloth treated with modified silicone oil prepared in Comparative Example 1 decreased before and after washing, which is because the undegraded chitosan molecules are large, the antibacterial properties are poor, and it is difficult to graft to the siloxane segment; while the cotton cloth treated with modified silicone oil in Comparative Example 2 has good antibacterial properties before washing, and the antibacterial properties decrease significantly after washing, which is because the unacidified oligomeric chitosan is difficult to graft to the siloxane main chain and is easy to fall off during the washing process. The washing resistance of the cotton cloth treated with modified silicone oil in Comparative Examples 3 and 4 has decreased, among which the decrease in Comparative Example 3 is due to the excessive participation of amino groups in the system in the end-capping, which makes it difficult for the oligomeric chitosan to react, while the decrease in Comparative Example 4 is due to the large molecular weight of epoxy silicone oil and the small amount of polyetheramine, which makes it difficult for the oligomeric chitosan to react to the siloxane segment and part of the silicone oil is also difficult to adhere to the fabric, which ultimately leads to a decrease in washing resistance.

Claims

1. A method for preparing a low-cyclic antibacterial modified silicone oil, characterized in that: The steps include: (1) dissolving polyether amine and epoxy-terminated silicone oil in a solvent, and reacting to obtain epoxy-terminated polyether silicone oil; (2) Chitosan is dissolved in acid, and an oxidant is added to react to obtain oligomeric chitosan; (3) dissolving oligomolecular chitosan in acid to obtain cationic oligomolecular chitosan; (4) placing the cationic oligosaccharide chitosan in the polyether silicone oil obtained in step (1) to react and obtain low-ring antibacterial modified silicone oil.

2. The method for preparing a low-cyclic antibacterial modified silicone oil according to claim 1, characterized in that: The molar ratio of the polyetheramine to the epoxy-terminated silicone oil in step (1) is 1:1.8-2.5; and the solvent is one or more of diethylene glycol butyl ether, dipropylene glycol butyl ether and isohexanediol.

3. The method for preparing a low-cyclic antibacterial modified silicone oil according to claim 2, characterized in that: The polyetheramine is a linear molecular structure with -NH2 groups at both ends of the chain segment and a polyether chain segment in the middle, with a molecular weight of 200-3000; the terminal epoxy silicone oil is a linear polysiloxane chain segment terminated by double-end epoxy groups, with a volatile matter of less than 0.5% and a molecular weight of 400-40000.

4. The method for preparing a low-cyclic antibacterial modified silicone oil according to claim 1, characterized in that: The reaction temperature in step (1) is 40-125°C, and an inert gas is used for protection during the reaction.

5. The method for preparing a low-cyclic antibacterial modified silicone oil according to claim 1, characterized in that: The mass ratio of chitosan, acid and oxidant in step (2) is 1:3:0.08; and the reaction temperature is 45-70°C.

6. The method for preparing a low-cyclic antibacterial modified silicone oil according to claim 5, characterized in that: The acid is one or more of glacial acetic acid, carbonic acid, and propionic acid, and the pH value is 5.0-6.5; and the oxidant is hydrogen peroxide.

7. The method for preparing a low-cyclic antibacterial modified silicone oil according to claim 1, characterized in that: The molecular weight of the oligochitosan described in step (2) is 2000-8000.

8. The method for preparing a low-cyclic antibacterial modified silicone oil according to claim 1, characterized in that: The mass ratio of the oligochitosan to the acid in step (3) is 2:1; and the dissolution time is 1-12 hours.

9. The method for preparing a low-cyclic antibacterial modified silicone oil according to claim 8, characterized in that: The acid is one or more of glacial acetic acid, carbonic acid, and propionic acid, and the pH value is less than 5.

0.

10. The method for preparing a low-cyclic antibacterial modified silicone oil according to claim 1, characterized in that: The reaction temperature in step (4) is 30-100°C and the reaction time is 1-8h.

Images