WO2013166782A1

WO2013166782A1 - Preparation method of homopolymerized n-vinyl butyl lactam iodine with effective iodide content of 20%

Info

Publication number: WO2013166782A1
Application number: PCT/CN2012/079056
Authority: WO
Inventors: 王宇; 刘薇; 陈占
Original assignee: 上海宇昂生物科技有限公司
Priority date: 2012-05-10
Filing date: 2012-07-23
Publication date: 2013-11-14
Also published as: CN102643377B; CN102643377A

Abstract

A preparation method of homopolymerized N-vinyl butyl lactam iodine with an effective iodide content of 20%, comprises: using an N-vinyl butyl lactam iodine homopolymer and iodine with the particle size being small than 850 μm as raw materials, the mass ratio of the N-vinyl butyl lactam iodine homopolymer to the iodine with the particle size being small than 850 μm being 7:3-5:5; meanwhile, with the amount of the raw materials being the reference, adding an additive of 0.01%-5% by weight; stirring at the temperature of 50-100°C for reaction for 5-20 hours in a segmented preparation manner. The additive may be sodium citrate, sodium chloride, or sodium acetate.

Description

Method for preparing homopolymerized N-vinyl butyrolactam iodine with 20% effective iodine content

The invention relates to the technical field of compound preparation, in particular to the technical field of preparation of homopolymerized N-vinyl butyrolactam iodine, and specifically relates to a method for preparing homopolymeric N-vinyl butyrolactam iodine having a 20% effective iodine content. Background technique

The homopolymerized N-ethylglycolyl lactam iodine is a yellow-brown to reddish-brown amorphous powder formed by the hydrogen bonding and other external forces in the complexation of N-ethylglycolyl lactam homopolymer with iodine. An amorphous complex iodine is a kind of iodophor (Cui Yingde, Yi Guobin, Liao Lewen. Synthesis and application of polyvinylpyrrolidone [M]. Science Press, 2001, 2:161). It is an excellent disinfectant, and the 1990 edition of the Pharmacopoeia in China began to be included. Can maintain a long time of bactericidal power, is a strong disinfectant (G & SMED ICAL LTD (US). Infection fighting composition for topical application [P]. US5137718 1992: 5), for viruses, bacteria, fungi and Mold spores have a strong killing effect and are approved by the Chinese Pharmacopoeia as a disinfectant for human body. N-Ethylbutyrolactam homopolymer is a nonionic surfactant, which has no antibacterial effect itself, but can improve the solubility of iodine, and help to improve the wetting and penetrating ability of iodine solution to objects, so that effective iodine The affinity for the cell membrane is enhanced, and the effective iodine can be directly introduced into the cell membrane and cytoplasm of the bacteria, and the bacteria are immediately killed within a few seconds, thereby enhancing the bactericidal ability of iodine, and the N-vinyl butyrolactam iodine also has It is easily soluble in water and has no irritation, allergies and poisoning to skin and mucous membranes. Moreover, the homopolymerized N-vinyl butylamide iodine can be used not only as an aqueous solution but also in a solid form in some special cases. This makes the homopolymerized N-vinyl butyrolactam iodine widely used in various fields of sterilization and disinfection, expands the use range of iodine, and is widely used in hospital disinfection at home and abroad.

The effective iodine content of homopoly N-vinyl butyrolactone iodine powder currently on the market and the effective iodine content specified in the Pharmacopoeia are both 9%-12%, however, the homopolymeric N-vinyl butyrolactam with higher effective iodine content Iodine shows good advantages both in terms of application and storage, especially in terms of market profit, using homogeneous N-vinyl butyrolactam iodine with an effective iodine content of 10% and 20% homopolymerized N- Vinyl butyrolactam iodine to prepare homopoly N-vinyl butyrolactam iodine disinfectant of the same specification, and the effective iodine of 20% homopolymerized N-vinyl butyrolactam iodine greatly reduces the cost of the disinfectant. It also proves its market operability.

Therefore, it is desirable to provide a process for the preparation of homopolymeric N-vinyl butyrolactam iodine having a 20% effective iodine content. Summary of the invention

It is an object of the present invention to overcome the above-mentioned shortcomings of the prior art and to provide a homopolymeric N-ethylene having an effective iodine content of 20%. The preparation method of butyl iodide iodine, the preparation method of the homopolymerized N-vinyl butyrolactone iodine with 20% effective iodine content is ingeniously designed, and the preparation of the homopolymer N-vinyl butyrolactam iodine is effective. The iodine content is 20%, and it also has high stability and photo-bactericidal performance, which is suitable for large-scale popularization and application.

In order to achieve the above object, a 20% effective iodine content homopolymeric N-vinyl butyrolactam iodine preparation method of the present invention is characterized in that N-vinyl butyrolactam homopolymer and 850 μ ηι particle size or less The iodine is a raw material, wherein the mass ratio of the Ν-vinyl butyrolactam homopolymer to the iodine below the 850 μm particle size is 7:3 to 5:5, and 0.01 is added based on the amount of the raw material. %~5.0% by weight of the auxiliary agent, the fractional preparation method is stirred at a temperature of 50-100 ° C for 5-20 hours.

The auxiliaries may be any suitable auxiliaries. Preferably, the auxiliaries are sodium citrate, sodium chloride or sodium acetate. The N-vinyl butyrolactam homopolymer, the iodine having a particle diameter of 850 μm or less, the auxiliary agent, the temperature, and the stirring reaction time may be selected from the above range, preferably, The Ν-ethylglycolyl lactam homopolymer is 68 g, the iodine of the 850 μηη particle size is 32 g, the amount of the auxiliary agent is 0.46 g, the temperature is 60 ° C, the stirring The reaction time was 17 hours.

The segmented preparation method refers to first reacting an excess amount of N-ethylglycolide lactam homopolymer, a small amount of iodine and an auxiliary agent for a period of time, and then adding a certain amount of iodine and a small amount of auxiliary agent. The excess homo-N-vinyl butyrolactam in the reactants is further reacted with iodine, and may of course be divided into three or more segments. More preferably, the fractional preparation method is to firstly apply 68 g of the N. a vinyl butyrolactam homopolymer, 22 g of the 850 μm particle size iodine and 0.35 g of the auxiliary agent were stirred at 60 ° C for 8 hours, after which 10 g of the above-mentioned 850 μm particle size were further added. The auxin and the promoter of O.lg were continuously stirred at 60 ° C for 9 hours.

The N-vinyl butyrolactam homopolymer, the iodine having a particle diameter of 850 μm or less, the auxiliary agent, the temperature, and the stirring reaction time may be selected from the above range, preferably, The Ν-ethylglycolyl lactam homopolymer is 62 g, the iodine of the 550 μηη particle size is 38 g, the amount of the auxiliary agent is 2.6 g, the temperature is 75 ° C, the stirring The reaction time was 19 hours.

The segmented preparation method refers to first reacting an excess amount of N-ethylglycolide lactam homopolymer, a small amount of iodine and an auxiliary agent for a period of time, and then adding a certain amount of iodine and a small amount of auxiliary agent. The excess homo- N-vinyl butyrolactam in the reactants is further reacted with iodine, and may of course be divided into three or more segments. More preferably, the fractional preparation method is to firstly 62g the N a vinyl butyrolactam homopolymer, 20 g of the 550 μm particle size iodine and 1.4 g of the auxiliary agent were stirred at 75 ° C for 11 hours, after which 18 g of the 550 μm particle size were added. Iodine and 1.2 g of the above-mentioned auxiliary agent were further stirred at 75 ° C for 8 hours.

The N-vinyl butyrolactam homopolymer, the iodine having a particle diameter of 850 μm or less, the auxiliary agent, the temperature, and the stirring reaction time may be selected from the above range, preferably, The Ν-ethylglycolyl lactam homopolymer is 70 g, the iodine of the 750 μηη particle size is 30 g, the amount of the auxiliary agent is 0.2 g, the temperature is 97 ° C, the stirring The reaction time is 19 hour.

The segmented preparation method refers to first reacting an excess amount of N-ethylglycolide lactam homopolymer, a small amount of iodine and an auxiliary agent for a period of time, and then adding a certain amount of iodine and a small amount of auxiliary agent. The excess homo-N-vinyl butyrolactam in the reactants is further reacted with iodine, and may of course be divided into three or more segments. More preferably, the fractional preparation method is to firstly apply 70 g of the N. - vinyl butyrolactam homopolymer, 30 g of the 750 μm particle size iodine and 0.15 g of the auxiliary agent were stirred at 97 ° C for 13 hours, after which 5 g of the above-mentioned 750 μηη particle size were added. Iodine and 0.5 g of the auxiliary were further stirred at 97 ° C for 6 hours.

The beneficial effects of the present invention are specifically as follows: The preparation method of the 20% effective iodine content homopolymer N-vinyl butyrolactam iodine of the present invention is an N-vinyl butyrolactam homopolymer and an iodine having a particle diameter of 850 μm or less The raw material, wherein the mass ratio of the Ν-vinyl butyrolactam homopolymer to the iodine below the 850 μηη particle size is 7:3 to 5:5, and 0.01% is added based on the amount of the raw material. 5.0% by weight of the auxiliary agent, the fractional preparation method is stirred at a temperature of 50-100 ° C for 5-20 hours, thereby obtaining a homopolymerized N-ethylglycolyl lactam iodine effective iodine The content is more than 20%, the design is ingenious, the preparation of the single, and also has high stability and optical bactericidal performance, suitable for large-scale promotion and application. DRAWINGS

Figure 1 is a graph showing the effect of reaction temperature on effective iodine content.

Figure 2 is a graph showing the effect of additive addition on reaction time.

Figure 3 is a graph showing the effect of the addition of an adjuvant on the effective iodine content.

Figure 4 is a graph showing the effect of particle size of iodine on effective iodine content. detailed description

In order to more clearly understand the technical content of the present invention, the following embodiments are specifically described.

1.1 Experimental materials

Table 1 Main raw materials

Name Specifications Manufacturer

Homopolymerization N-vinyl butyrolactam Pharmaceutical grade Shanghai Yuang Chemical Technology Development Co., Ltd. Sodium citrate Analytical pure Sinopharm Chemical Reagent Co., Ltd.

Distilled water

Shike Dai Shike Sodium Acid Analysis Pure Sinopharm Chemical Reagent Co., Ltd.

Starch indicator liquid homemade 1.2 Experimental equipment

250 ml three-necked flask, HH-WO thermostatic oil bath, S312 electric mixer, FA2004 analytical balance, conical flask, lO mLl pipette, basic burette.

1.3 Determination of effective iodine content

The effective iodine concentration of the sample can be determined by referring to the Chinese Pharmacopoeia (Chinese Pharmacopoeia. Part 2 [S]. 2005: 823) method. In this experiment, the effective iodine content was measured by the United States Pharmacopoeia: Weigh the sample about lg, accurately weigh it in a beaker, add some water to stir it, dissolve it, transfer it to a 100 mL volumetric flask, and accurately measure the sample solution with a pipette. 20 mL 2 parts into the iodine measuring flask, titrated with sodium thiosulfate standard titration solution (0.1 mol/L), add appropriate amount of starch indicator when it is light yellow, continue to drop with sodium thiosulfate until the blue disappears, record The volume of sodium thiosulfate used was used and the effective iodine content of the sample was calculated.

The effective iodine content in the sample is expressed in mass fraction (%):

(" ₂ ) x l2.69 _÷ 1000

w =— ― x lOO

m where:

Vi - volume of sample consumption sodium thiosulfate standard solution in milliliters (mL);

V ₂ - the volume of the sodium thiosulfate standard solution consumed in the blank test, in milliliters (mL);

m __ The mass of the sample taken, in grams (g).

2 Results and discussion

2.1 The effect of total iodine on effective iodine

The maximum effective iodine content of homopolymerized N-vinyl butyrolactam is limited by solubility. In order to reduce the total iodine content and reduce the cost of the product, it is necessary to find a reasonable ratio of homopolymeric N-vinyl butyrolactam to iodine.

Table 2: Effect of total iodine on effective iodine

Item Total Iodine Effective Effective Content

1 20% 15.35%

2 24% 17.32%

3 26% 18.91%

4 30% 20.82%

5 35% 21.05%

6 50% 20.88% It can be seen from the data in Table 2 that the effective iodine content in the homopolymerized N-vinyl butyrolactam iodine increases with the increase of the amount of iodine in a certain range, and the value tends to be stable after reaching a certain content. The reason may be that the number of terminal groups of the homopolymerized N-ethylglycolyl lactam molecular chain limits the amount of iodine complexed by it. The total amount of iodine in the homo- N-vinyl butyrolactam iodine raw material having an effective iodine content of 20% is preferably 30% to 50%.

2.2 Effect of temperature on effective iodine content

N-vinyl butyrolactam homopolymer and iodine can be complexed at room temperature, but the time required at different temperatures is different, and the effective iodine content of the final product is also different. The general reaction temperature is controlled at 45-100 ° C. . The effect of the study temperature on the effective iodine content of the product is shown in Figure 1 when the mass fraction of homopolymerized N-vinyl butyrolamide is 70%, the mass fraction of iodine is 30%, and the same auxiliaries are reacted for 6 hours.

As can be seen from the data in Figure 1, 70 ° C is the optimum temperature for the preparation of homopolymerized N-vinyl butyrolactam iodine; meanwhile, under the same conditions, the effective iodine content of N-vinyl butyrolactam iodine The increase in temperature first increases and then decreases. This is mainly because the increase of temperature is beneficial to increase the number of activated molecules of the reactants, thereby accelerating the frequency of intermolecular collisions and allowing the reactants to fully react; however, the reaction rate is too high, and the peak of effective iodine content during the reaction is peaked. It was greatly advanced, and as the reaction time prolonged, the complex bond between the homopolymerized N-vinyl butyrolactam and iodine gradually broke, and the effective iodine content rapidly decreased.

2.3 Effect of adding additives on effective iodine content

Take the mass fraction of homopolymerized N-vinyl butyrolactam 70%, the mass fraction of iodine is 30%, and react at 70 °C. Add the auxiliaries to the reaction time by adding additives such as sodium citrate (Fig. 2) And the effect of effective iodine content (Figure 3): As can be seen from Figure 2 and Figure 3, the addition of citrate and other additives can greatly shorten the reaction time, and can also effectively increase the maximum effective iodine content in the reaction, which is the most The amount added is 1.0% of the raw material. The addition of additives such as sodium citrate acts as a grinding aid, which promotes the contact between iodine and homopolymerized N-vinyl butyrolactam to exacerbate the internal friction, thereby causing an increase in the reaction rate, a sufficient complexation reaction, and further reaction. The time is reduced and the effective iodine content is increased.

2.4 The effect of raw material treatment on effective iodine content

The mass fraction of N-vinyl butyrolactam was 70%, the mass fraction of iodine was 30%, and the reaction was carried out at 70 °C for 12 hours. The effect of iodine with different particle sizes on the effective iodine content of the product was studied, as shown in Fig. 4.

The reaction of homopolymeric N-vinyl butyrolactam and iodine is essentially a solid-solid reaction and a gas-solid reaction of iodine with homopolymeric N-vinyl butyrolactam. After the particle size treatment of the raw material iodine, the contact surface of the iodine with the homopolymerized N-vinyl butyrolactam can be greatly improved, thereby increasing the reaction rate and the effective iodine content to reduce the reaction time and the quality influencing factors during the reaction. This is mainly because of the strong oxidizing property of iodine. If the reaction time is too long, iodine will cause some oxidation of N-vinyl butyrolactam to break the molecular chain, which will affect the progress of the complexation reaction. The processing is indispensable, can be obtained from Figure 4. Real.

Effect of 2.5-stage preparation process on effective iodine content

Segmented preparation: firstly use an excess of homopolyvinylbutyrolactam with a small amount of iodine, complexed with sodium chloride and other auxiliaries to form a homogenous N- with a lower effective iodine content (12% - 18%). Vinyl butyrolactam iodine, and then add a certain amount of iodine and a small amount of sodium chloride and other additives, so that the excess homopolymerized N-vinyl butyrolactam in the reactants continues to react with iodine to prepare high effective iodine. Content (more than 20%) of homopolymeric N-vinyl butyrolactam iodine.

Compared with the traditional one-time preparation process, the method has a higher effective iodine content of homopolymerized N-ethylglycolyl lactam iodine, generally more than 20%. The reasons may be: On the one hand, the complexation performance of iodine is very good, and it is easy to prepare 8%-12% effective iodine content of homopolymeric N-vinyl butyrolactam under normal conditions; however, due to homopolymerization of N-ethylene The limited number of end groups of the chitin lactam and the large steric hindrance between the groups on the molecular chain make it difficult to achieve theoretically sufficient complexation with iodine. This is why traditional processes cannot produce high levels of homopolymerized N-ethylglycolyl lactam iodine. On the other hand, this segmented preparation process overcomes the deactivation of homopolymerized N-vinyl butyrolactam by temperature and oxidative denaturation of iodine during prolonged reaction. The complexation process of homopolymerized N-vinyl butyrolactam with iodine is a typical exothermic reaction. During the reaction, more heat is released, which will increase the temperature of the reaction system in a shorter period of time, resulting in homopolymerization of N-ethylene. The partial deactivation of the butyrolactam is inactivated; and by the fractional preparation, since the "reaction point" is less in the whole process, the generated heat is relatively small and can be released relatively quickly, and at the same time, the addition of additives such as sodium chloride The steric hindrance of each group of the homopolymeric N-vinyl butyrolactam molecular chain is effectively reduced, thereby greatly increasing the degree of complexation, and a homogenous N-vinyl butyrolactam iodine having a higher effective iodine content is prepared.

3 Conclusion

With a ratio of homopolymerized N-vinyl butyrolactam to iodine of 7:3 to 5:5, a set of practical high productivity and operation was developed by adjusting the reaction temperature, additives and iodine particle size. Mild conditions, low cost, the production process of 20% effective iodine content homopolymerization of N-vinyl butyrolactam by solid phase heating method: the mass fraction of homopolymerized N-vinyl butyrolactam is 50%~70%, The mass fraction of iodine below 850μηι particle size is 50%~30%, the amount of auxiliary agent is 0.01%~5.0% of the amount of raw materials, and the homopolymerization is prepared by the stirring method of segmentation method at 50°C~100°C. The effective iodine content of N-vinyl butyrolactam iodine is above 20%. The invention will be more specifically illustrated by the following examples, but the invention is not limited by these examples. In the following, "% by weight" is only expressed as "%" unless otherwise stated.

Example 1

Weighed 60g of homo-N-vinyl butyrolactam K30 produced by Shanghai Yuang Chemical Technology Development Co., Ltd., 22g of iodine with a particle size of 850μηηι, 0.35g of sodium citrate was added to a 500ml three-necked flask, and the stirring paddle was inserted at a low speed. Stirring to mix the raw materials Stir well, then put in a 50 ° C oil bath and stir to heat the reaction for 8 hours, then add 18g of iodine with a particle size of 850 μm and O.lg sodium citrate, continue to heat and stir the reaction for 9 hours, then cool and sieve to be effective Homogeneous N-vinyl butyrolactam oxime having an iodine content of 21.11%.

Comparative example 1 :

The same operation as in Example 1 was carried out except that sodium citrate was not added, and as a result, the effective iodine content was found to be 15.72%. Example 2:

Weigh 50g of homopolymerized N-vinyl butyrolactam K30 produced by Shanghai Yuang Chemical Technology Development Co., Ltd., 25g of iodine with a particle size of 550 μm, add 2.6g of sodium acetate to a 500ml three-necked flask, and insert a stirring paddle for low-speed stirring. The raw materials were uniformly mixed, and then heated in a 75 ° C oil bath for 11 hours with stirring. Then, 25 g of iodine having a particle diameter of 550 μm and 2.4 g of sodium acetate were added, and the mixture was further heated and stirred for 9 hours, and then cooled and sieved. The effective iodine content is 21.63% of homopoly N-vinyl butyrolactam iodine.

Comparative example 2:

The same operation as in Example 2 was carried out except that iodine having an unpulverized iodine (particle diameter of more than 1500 μm) was used instead of iodine having a particle diameter of 550 μm, and as a result, an effective iodine content of 16.22% was detected. Example 3

Weighed 70g of homopolymerized N-vinyl butyrolactam K30 produced by Shanghai Yuang Chemical Technology Development Co., Ltd., 25g of iodine with a particle size of 750 μm, 0.005g of sodium chloride was added to a 500ml three-necked flask, and inserted into the stirring paddle at low speed. Stir the raw materials evenly, then put them in a 100'C oil bath and heat them for 3 hours. Then add 5 g of iodine with a particle size of 750 μm and 0.005 g of sodium chloride. Continue to stir the reaction for 2 hours, then cool and sieve. That is, a homopolymeric N-vinyl butyrolactam having an effective iodine content of 20.05% is obtained.

Comparative example 3:

Weighed 70g of homopolymerized N-vinyl butyrolactam K30 produced by Shanghai Yuang Chemical Technology Development Co., Ltd., 30g of iodine with a particle size of 750μm, and added O.lg sodium acetate to a 500ml three-necked flask. The raw materials were uniformly mixed by stirring, and then stirred and heated in a 100 ° C oil bath for 5 hours, and cooled to obtain an effective iodine content of 17.83% of homopolymer N-vinyl butyrolactam. In the invention, the raw material N-vinyl butyrolactam homopolymer and the iodine mass ratio after particle size selection treatment are 7:3~5:5, and 0.01%~5.0% by weight of the auxiliary agent is added based on the amount of the raw material. (sodium citrate, sodium chloride, sodium acetate), the fractional preparation method is stirred at 50-100 ° C for about 5-20 hours to obtain a homogenous N-vinyl butyl with high effective iodine content. Lactam iodine powder.

In summary, the preparation method of the 20% effective iodine content of the homopolymerized N-ethylglycolyl lactam iodine of the invention is ingeniously designed, and the prepared iodine has an effective iodine content of the homopolymerized N-vinyl butyrolactam. 20%, it also has high stability and spectral sterilization performance, suitable for large-scale promotion and application.

In this specification, the invention has been described with reference to specific embodiments thereof. However, it will be apparent that various modifications and changes can be made without departing from the spirit and scope of the invention. Accordingly, the specification and figures are to be regarded as illustrative and not limiting.

Claims

Rights request

1. A method for preparing homopolymerized N-vinylbutyrolactam iodine with 20% effective iodine content, which is characterized in that N-vinylbutyrolactam homopolymer and iodine with a particle size of less than 850 μm are used as the preparation method. Raw materials, wherein the mass ratio of the N-vinyl butyrolactam homopolymer and the iodine with a particle size below 850 μm is 7:3~5:5, and at the same time, 0.01%~5.0 is added based on the amount of raw materials. % weight percentage of additives, adopt a staged preparation method, stir and react for 5-20 hours at a temperature of 50-100°C.

2. The preparation method of homopolymerized N-vinylbutyrolactam iodine with 20% available iodine content according to claim 1, wherein the auxiliary agent is sodium citrate, sodium chloride or sodium acetate.

3. The preparation method of homopolymerized N-vinylbutyrolactam iodine with 20% available iodine content according to claim 1, characterized in that the N-vinylbutyrolactam homopolymer is 68g, so The iodine with a particle size of 850 μm is 32g, the amount of the auxiliary agent is 0.46g, the temperature is 60°C, and the stirring reaction time is 17 hours.

4. The preparation method of homopolymerized N-vinylbutyrolactam iodine with 20% available iodine content according to claim 3, characterized in that, the segmented preparation method is to first prepare 68g of the N-vinylbutyrolactam iodine Butyrolactam homopolymer, 22g of the iodine with a particle size of 850 μm and 0.35g of the auxiliary were stirred and reacted at 60°C for 8 hours, and then 10g of the iodine with a particle size of 850 μm and O were added. .lg of the auxiliary agent was stirred and reacted at 60 C for 9 hours.

5. The preparation method of homopolymerized N-vinylbutyrolactam iodine with 20% available iodine content according to claim 1, wherein the N-vinylbutyrolactam homopolymer is 62g, so The iodine with a particle size of 550 μm is 38g, the amount of the auxiliary agent is 2.6g, the temperature is 75°C, and the stirring reaction time is 19 hours.

6. The preparation method of homopolymerized N-vinylbutyrolactam iodine with 20% available iodine content according to claim 5, characterized in that, the segmented preparation method is to first prepare 62g of the N-vinylbutyrolactam iodine Butyrolactam homopolymer, 20g of the iodine with a particle size of 550 μm and 1.4g of the auxiliary were stirred and reacted at 75°C for 11 hours, and then 18g of the iodine with a particle size of 550 μm and 1.2 g were added. g The auxiliary agent was continued to stir and react at 75 C for 8 hours.

7. The preparation method of homopolymerized N-vinylbutyrolactam iodine with 20% available iodine content according to claim 1, wherein the N-vinylbutyrolactam homopolymer is 70g, so The iodine with a particle size of 750 μm is 30g, the amount of the auxiliary agent is 0.2g, the temperature is 97°C, and the stirring reaction time is 19 hours.

8. The preparation method of homopolymerized N-vinylbutyrolactam iodine with 20% available iodine content according to claim 7, characterized in that, the segmented preparation method is to first prepare 70g of the N-vinylbutyrolactam iodine Butyrolactam homopolymer, 30g of the iodine with a particle size of 750 μm and 0.15g of the auxiliary were stirred and reacted at 97°C for 13 hours, and then 5g of the iodine with a particle size of 750 μm and 0.5 g were added. g The auxiliary agent was continued to stir for 6 hours at 97°C.