Model and method for evaluating degradation capability of microorganisms on hydroxyl-terminated polybutadiene
Through the comprehensive degradation rate model, gel permeation chromatography was used to evaluate the degradation performance of microorganisms on end hydroxyl polybutadiene, which solved the problem of large errors in the prior art and achieved accurate evaluation of the degradation performance of microorganisms.
Patent Information
- Application Number
- CN202411178393.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-27
- Publication Date
- 2024-12-20
AI Technical Summary
The prior art is difficult to effectively evaluate the degradation performance of microorganisms on end hydroxyl polybutadiene, especially due to the wide molecular weight distribution range and large errors in the weight loss method, it is impossible to accurately reflect the degradation performance of microorganisms.
The comprehensive degradation rate model was used to detect the number average molecular weight and weight average molecular weight before and after degradation by gel permeation chromatography. Combined with the peak area of the degradation product, the comprehensive degradation rate D was calculated, which was divided into excellent, qualified, general and poor grades, and evaluated microorganisms. degradation ability.
The error of the weight loss method is effectively avoided, and the molecular weight and abundance of different degradation products are comprehensively considered, the average molecular weight of the degradation products is accurately reflected, and the degradation performance of microorganisms is objectively evaluated.
Smart Images
Figure SMS_1 
Figure SMS_32 
Figure SMS_45
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of microbial degradation, and particularly relates to a model and a method for evaluating the degradation ability of microorganisms on terminal hydroxyl polybutadiene. Background Art
[0002] Hydroxyl-terminated polybutadiene (HTPB), also known as HTPB, is a type of telechelic liquid rubber that can be used as a structural material for the production of cast elastomers and automobile tires. Hydroxyl-terminated polybutadiene is mainly used as an adhesive for solid rocket propellants. However, with the upgrading of weapons and ammunition, after the scrapped propellants are recycled for energetic materials, the remaining adhesive system is mainly treated by landfilling and incineration, which poses environmental pollution and other problems. Microbial degradation is a low-carbon, environmentally friendly, and low-cost treatment method, and has good application prospects in the degradation process of waste hydroxyl-terminated polybutadiene adhesive systems. However, the molecular weight distribution range of hydroxyl-terminated polybutadiene is relatively wide, and the number average molecular weight is generally between 2000 and 12000 g / mol. The weight loss method has a large error and cannot effectively evaluate the degradation performance of microorganisms. Therefore, it is necessary to develop a method suitable for evaluating the degradation performance of microorganisms on hydroxyl-terminated polybutadiene. Summary of the invention
[0003] In view of the problems existing in the prior art, the object of the present invention is to provide a model and method for evaluating the degradation ability of microorganisms on terminal hydroxyl polybutadiene.
[0004] In order to achieve the above object, the present invention adopts the following technical solution:
[0005] A model for evaluating the degradation ability of microorganisms on terminal hydroxyl polybutadiene, the model is a comprehensive degradation rate model, specifically:
[0006] Comprehensive degradation rate D = D n ×40%+D w ×60%
[0007] Among them, the D n and D w Calculated by the following formula:
[0008]
[0009] Where:
[0010] M n0 is the number average molecular weight of HTPB before degradation;
[0011] is the average number average molecular weight of all degradation products, i.e., the total number average molecular weight of degradation products;
[0012] M w0 is the weight average molecular weight of HTPB before degradation;
[0013] is the average weight-average molecular weight of all degradation products, that is, the total weight-average molecular weight of degradation products.
[0014] Based on the above scheme, the total number average molecular weight of the degradation product
[0015] in,
[0016] i is the degradation product number;
[0017] S i is the peak area of degradation product i;
[0018] Mn i is the number average molecular weight of degradation product i.
[0019] Based on the above scheme, the total weight average molecular weight of the degradation product
[0020] in,
[0021] i is the degradation product number;
[0022] S i is the peak area of degradation product i;
[0023] M i is the weight average molecular weight of degradation product i.
[0024] Based on the above scheme, when D ≥ 60%, the degradation efficiency is excellent;
[0025] When 60%>D≥30%, the degradation efficiency is qualified;
[0026] When 30%>D≥10%, the degradation efficiency is general;
[0027] When D < 10%, the degradation efficiency is poor.
[0028] A method for evaluating the ability of microorganisms to degrade terminal hydroxyl polybutadiene, characterized by using the above-mentioned model.
[0029] Based on the above scheme, before evaluation, gel permeation chromatography was used to detect the number average molecular weight M of the hydroxy-terminated polybutadiene before degradation. n0 and weight average molecular weight M w0 ;
[0030] Afterwards, microorganisms were used to degrade the terminal hydroxyl polybutadiene, and the degraded solution was extracted with an equal volume of solvent. The extract was filtered through a 0.45 μm microporous filter membrane. After the solvent was evaporated, gel permeation chromatography was used to obtain the number average molecular weight, weight average molecular weight and peak area of the degradation product. The peak area corresponding to the product was normalized to obtain the percentage of each peak, and then the product of the number average molecular weight of each peak and the peak area percentage was summed to obtain the total number average molecular weight of the degradation product. The product of the weight average molecular weight of each peak and the peak area percentage is summed to obtain the total weight average molecular weight of the degradation product. According to the obtained and Calculate D n and D w The comprehensive degradation rate D was further calculated, and the degradation ability of microorganisms on terminal hydroxyl polybutadiene was evaluated based on the comprehensive degradation rate D.
[0031] Based on the above scheme, the solvent used for extraction is at least one of dichloromethane and n-hexane.
[0032] On the basis of the above scheme, the method for microbial degradation of hydroxy-terminated polybutadiene is as follows:
[0033] The microbial liquid is inoculated into a liquid culture medium containing terminal hydroxyl polybutadiene at an inoculation rate of 2% to 10% (v / v), and aerobically cultured at 25 to 35° C. and 120 to 200 rpm for 5 to 30 days to obtain a degraded solution.
[0034] Based on the above scheme, in the liquid culture medium containing terminal hydroxyl polybutadiene, the final concentration of terminal hydroxyl polybutadiene is 0.5 g / L to 2 g / L.
[0035] Based on the above scheme, the concentration of the microorganism in the microbial solution is 1×10 8 ~10 9 cfu / mL.
[0036] Advantages of the technical solution of the present invention
[0037] Compared with the existing methods, the present invention effectively avoids the errors of the weight loss method during operation. The calculation method of the degradation rate used comprehensively considers the molecular weight and abundance ratio of different degradation products. At the same time, the calculation method of the data molecular weight and the weight-average molecular weight can more accurately reflect the average molecular weight of the degradation products and objectively evaluate the degradation performance of microorganisms. DETAILED DESCRIPTION
[0038] The terms used in the present invention, unless otherwise specified, generally have the meanings commonly understood by those of ordinary skill in the art. The present invention will be further described in detail below in conjunction with specific examples and with reference to data. The following examples are intended to illustrate the present invention and are not intended to limit the scope of the present invention in any way.
[0039] The experimental methods in the following examples, unless otherwise specified, are all conventional methods, and are performed according to the techniques or conditions described in the literature in the field or according to the product instructions. The experimental materials, reagents, drugs, etc. used in the following examples, unless otherwise specified, can all be purchased through general channels.
[0040] In the following examples, the culture medium used is as follows:
[0041] LB medium: yeast powder 5.0 g / L, peptone 10.0 g / L, sodium chloride 10.0 g / L, pH 7.0.
[0042] Inorganic salt medium: K 2 HPO 4 1g / L, NaCl 1g / L, FeSO 4 7H 2 O 0.02g / L, MgSO 4 7H 2 O0.2g / L, CaCl 2 0.01g / L, pH is 7.0.
[0043] Fermentation medium 1: glucose 5g / L, peptone 5g / L, K 2 HPO 4 1g / L, NaCl 1g / L, FeSO 4 7H 2 O0.02g / L, MgSO 4 7H 2 O 0.2g / L, CaCl 2 0.01g / L, pH is 7.0.
[0044] Fermentation medium 2: sucrose 5g / L, peptone 5g / L, K 2 HPO 4 1g / L, NaCl 1g / L, FeSO 4 7H 2 O0.02g / L, MgSO 4 7H 2 O 0.2g / L, CaCl 2 0.01g / L, pH is 7.0.
[0045] Example 1
[0046] Based on the model in this application, this application provides a specific implementation scheme of a method for evaluating the ability of microorganisms to degrade terminal hydroxyl polybutadiene, the steps are as follows:
[0047] (1) Gel permeation chromatography was used to measure the number average molecular weight M of the hydroxy-terminated polybutadiene before degradation. n0 and weight average molecular weight M w0 ;
[0048] (2) The terminal hydroxyl polybutadiene is degraded by using microorganisms, and the degraded solution is extracted by using an equal volume of solvent. The extract is filtered through a 0.45 μm microporous filter membrane. After the solvent is evaporated, gel permeation chromatography is used to obtain the number average molecular weight, weight average molecular weight and peak area of the degradation product. The peak area corresponding to the product is normalized to obtain the percentage of each peak, and then the product of the number average molecular weight of each peak and the peak area percentage is summed to obtain the total number average molecular weight of the degradation product. The product of the weight average molecular weight of each peak and the peak area percentage is summed to obtain the total weight average molecular weight of the degradation product. The calculation formula is as follows:
[0049] Total number average molecular weight of degradation products
[0050] in,
[0051] i is the degradation product number;
[0052] S i is the peak area of degradation product i;
[0053] Mn i is the number average molecular weight of degradation product i.
[0054] Total weight average molecular weight of degradation products
[0055] in,
[0056] i is the degradation product number;
[0057] S i is the peak area of degradation product i;
[0058] M i is the weight average molecular weight of degradation product i.
[0059] (3) Based on the obtained and Calculate D n and D w , the calculation formula is as follows:
[0060] Number average degradation rate
[0061] Weight average degradation rate
[0062] Where:
[0063] M n0 is the number average molecular weight of HTPB before degradation;
[0064] is the average number average molecular weight of all degradation products, i.e., the total number average molecular weight of degradation products;
[0065] M w0 is the weight average molecular weight of HTPB before degradation;
[0066] is the average weight-average molecular weight of all degradation products, that is, the total weight-average molecular weight of degradation products.
[0067] (4) Calculate the comprehensive degradation rate D, and evaluate the degradation ability of microorganisms on terminal hydroxyl polybutadiene based on the comprehensive degradation rate D. Due to the different calculation methods of number average molecular weight and weight average molecular weight, the calculation of number average molecular weight focuses on the effect of molecular quantity on the whole, and the low molecular weight part contributes more to the average molecular weight. The calculation of weight average molecular weight is based on the effect of molecular weight on the whole, and the high molecular weight part contributes more to the average molecular weight. Compared with the number average degradation rate D n , weight average degradation rate D w It can better reflect the degree of degradation at the molecular weight level. Therefore, when comprehensively evaluating the degradation of HTPB by microorganisms, the focus is on the weight-average degradation rate D w , while taking into account the number average degradation rate D n , the comprehensive degradation rate D is calculated according to the following formula:
[0068] Comprehensive degradation rate D = D n ×40%+D w ×60%
[0069] When D≥60%, the degradation efficiency is excellent; when 60%>D≥30%, the degradation efficiency is qualified; when 30%>D≥10%, the degradation efficiency is general; when D<10%, the degradation efficiency is poor.
[0070] Example 2
[0071] The present application provides an implementation scheme for evaluating the ability of Altererythrobacter to degrade terminal hydroxyl polybutadiene. The Altererythrobacter used is Altererythrobacter N1. The Altererythrobacter N1 (Altererythrobacter sp.) is deposited in the General Microbiological Center of the China Microbiological Culture Collection Administration Committee with the number CGMCC NO.23607, the deposited name is Altererythrobacter sp., the deposited time is October 15, 2021, and the deposited address is No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing. The activation method is: a single colony of Altererythrobacter N1 is picked from a low-temperature preserved slope, and activated with LB medium at 35°C and 150 rpm for 24 hours to a bacterial concentration of 1×10 8 ~10 9 cfu / mL.
[0072] The steps of the evaluation method are as follows:
[0073] (1) Gel permeation chromatography was used to measure the number average molecular weight M of the hydroxy-terminated polybutadiene before degradation. n0 and weight average molecular weight M w0 , the solvent was tetrahydrofuran, the injection concentration was 5 mg / mL, and the running time was 30 min.
[0074] (2) Weigh 0.05 g of hydroxy-terminated polybutadiene in a 250 mL conical flask, add an appropriate amount of dichloromethane to dissolve it, evaporate the solvent in a fume hood, and spread HTPB evenly on the bottom of the flask; add inorganic salt culture medium to make the final HTPB content 0.5 g / L, sterilize with high-pressure steam at 121°C for 20 min; cool to room temperature after sterilization, and inoculate the activated Erythrobacter alternifolia liquid (cell concentration 1×10 8 ~10 9 cfu / mL), and cultured aerobically in an air bath constant temperature oscillator at 35°C and 150rpm for 15 days; on the 15th day after inoculation, an equal volume of dichloromethane was added to the culture solution for extraction, and the extract was filtered through a 0.45μm microporous filter membrane. After the solvent was evaporated, the degradation products were detected by gel permeation chromatography to obtain the chromatogram and molecular weight distribution of the degradation products. The solvent was tetrahydrofuran, the injection concentration was 5mg / mL, and the running time was 30 minutes; the total number average molecular weight of the degradation products was calculated according to the following formula: and total weight average molecular weight
[0075] Total number average molecular weight of degradation products
[0076] Total weight average molecular weight of degradation products
[0077] in,
[0078] i is the degradation product number;
[0079] S i is the peak area of degradation product i;
[0080] Mn i is the number average molecular weight of degradation product i;
[0081] M i is the weight average molecular weight of degradation product i;
[0082] is the average number average molecular weight of all degradation products, i.e., the total number average molecular weight of degradation products;
[0083] is the average weight-average molecular weight of all degradation products, that is, the total weight-average molecular weight of degradation products.
[0084] (3) Combine the M obtained in step (1) n0 and M w0 And the one obtained in step (2) and The number average degradation rate D was calculated according to the following formula: n And weight average degradation rate D w :
[0085] Number average degradation rate
[0086] Weight average degradation rate
[0087] in,
[0088] M n0 is the number average molecular weight of HTPB before degradation;
[0089] is the average number average molecular weight of all degradation products, i.e., the total number average molecular weight of degradation products;
[0090] M w0 is the weight average molecular weight of HTPB before degradation;
[0091] is the average weight-average molecular weight of all degradation products, i.e., the total weight-average molecular weight of degradation products;
[0092] D n is the number average degradation rate;
[0093] D w is the weight average degradation rate;
[0094] (4) The number average degradation rate D obtained by step (3) n And weight average degradation rate D w, the comprehensive degradation rate D is calculated according to the following formula:
[0095] Comprehensive degradation rate D = D n ×40%+D w ×60%
[0096] The results are shown in Table 1:
[0097] Table 1 Degradation rate of HTPB by Erythrobacterium alternifolium
[0098]
[0099] As shown in Table 1, the number average molecular weight (Mn) of the original HTPB is 9523 g / mol, and the weight average molecular weight (Mw) is 22364 g / mol. After HTPB is degraded by the strain, two degradation products are produced, and the molecular weight of the degradation products is lower than that of the initial HTPB molecular weight. The number average molecular weight of degradation product 1 is 9168 g / mol, and the weight average molecular weight is 20089 g / mol. The number average molecular weight of degradation product 2 is 619 g / mol, and the weight average molecular weight is 751 g / mol. The number average degradation rate is 41.43%, the weight average degradation rate is 46.48%, and the comprehensive degradation rate is 44.47%. The degradation grade is good, indicating that Erythrobacter alternifolius can grow and reproduce with HTPB as the only carbon source under inorganic conditions, and can degrade HTPB to produce small molecular weight compounds.
[0100] Example 3
[0101] The present application provides a specific implementation scheme of a method for evaluating the degradation ability of Enterobacter quasihormaechei on terminal hydroxyl polybutadiene. The Enterobacter quasihormaechei used is screened by the laboratory. The activation method of the Enterobacter quasihormaechei strain is as follows: a single colony of Enterobacter quasihormaechei is picked from a low-temperature preserved slant, and activated with LB medium at 35°C and 150 rpm for 48 hours until the bacterial cell concentration is 1×10 8 ~10 9 cfu / mL.
[0102] The steps of the evaluation method are as follows:
[0103] (1) Gel permeation chromatography was used to measure the number average molecular weight M of the hydroxy-terminated polybutadiene before degradation. n0 and weight average molecular weight M w0 , the solvent was tetrahydrofuran, the injection concentration was 5 mg / mL, and the running time was 30 min.
[0104] (2) Weigh 0.05 g of hydroxy-terminated polybutadiene in a 250 mL conical flask, add an appropriate amount of dichloromethane to dissolve it, evaporate the solvent in a fume hood, and spread the HTPB evenly on the bottom of the flask; add fermentation medium 1 to make the final HTPB content 0.5 g / L, and sterilize it with high-pressure steam at 121°C for 20 min; after sterilization, cool it to room temperature, and inoculate it with activated Enterobacter quasicorum at a 6% (v / v) inoculum (bacterial concentration 1×10 8 ~10 9 cfu / mL), and cultured aerobically in an air bath constant temperature oscillator at 35°C and 150rpm for 15 days; on the 15th day after inoculation, an equal volume of dichloromethane was added to the culture solution for extraction, and the extract was filtered through a 0.45μm microporous filter membrane. After the solvent was evaporated, the degradation products were detected by gel permeation chromatography to obtain the chromatogram and molecular weight distribution of the degradation products. The solvent was tetrahydrofuran, the injection concentration was 5mg / mL, and the running time was 30 minutes; the total number average molecular weight of the degradation products was calculated according to the following formula: and total weight average molecular weight
[0105] Total number average molecular weight of degradation products
[0106] Total weight average molecular weight of degradation products
[0107] in,
[0108] i is the degradation product number;
[0109] S i is the peak area of degradation product i;
[0110] Mn i is the number average molecular weight of degradation product i;
[0111] M i is the weight average molecular weight of degradation product i;
[0112] is the average number average molecular weight of all degradation products, i.e., the total number average molecular weight of degradation products;
[0113] is the average weight-average molecular weight of all degradation products, that is, the total weight-average molecular weight of degradation products.
[0114] (3) Combine the M obtained in step (1) n0 and M w0 And the one obtained in step (2) and The number average degradation rate D was calculated according to the following formula: n And weight average degradation rate D w :
[0115] Number average degradation rate
[0116] Weight average degradation rate
[0117] in,
[0118] M n0 is the number average molecular weight of HTPB before degradation;
[0119] is the average number average molecular weight of all degradation products, i.e., the total number average molecular weight of degradation products;
[0120] M w0 is the weight average molecular weight of HTPB before degradation;
[0121] is the average weight-average molecular weight of all degradation products, i.e., the total weight-average molecular weight of degradation products;
[0122] D n is the number average degradation rate;
[0123] D w is the weight average degradation rate;
[0124] (4) The number average degradation rate D obtained in step (3) n And weight average degradation rate D w , the comprehensive degradation rate D is calculated according to the following formula:
[0125] Comprehensive degradation rate D = D n ×40%+D w ×60%
[0126] The results are shown in Table 2:
[0127] Table 2 Degradation rate of HTPB by Enterobacter quasiperithi
[0128]
[0129] As shown in Table 2, the number average molecular weight (Mn) of the original HTPB is 9523 g / mol, and the weight average molecular weight (Mw) is 22364 g / mol. After HTPB is degraded by the strain, two degradation products are produced, and the molecular weight is lower than that of the initial HTPB molecular weight. The number average molecular weight of degradation product 1 is 8967 g / mol, and the weight average molecular weight is 21523 g / mol. The number average molecular weight of degradation product 2 is 598 g / mol, and the weight average molecular weight is 723 g / mol. The number average degradation rate is 49.78%, the weight average degradation rate is 50.26%, the comprehensive degradation rate is 50.07%, and the degradation grade is good, which proves that the Enterobacter quasi-Hossleri has a strong degradation ability for HTPB.
[0130] Example 4
[0131] The present application provides a specific implementation scheme of a method for evaluating the degradation ability of Pseudomonas stutzeri on terminal hydroxyl polybutadiene. The Enterobacter quasi-Hossleri used is screened by the laboratory. The activation method of the Pseudomonas stutzeri is as follows: a single colony of Pseudomonas stutzeri is picked from a low-temperature preserved slant, and activated with LB medium at 35°C and 150rpm for 24h to a bacterial cell concentration of 1×10 8 ~10 9 cfu / mL.
[0132] The steps of the evaluation method are as follows:
[0133] (1) Gel permeation chromatography was used to measure the number average molecular weight M of the hydroxy-terminated polybutadiene before degradation. n0 and weight average molecular weight M w0 , the solvent was tetrahydrofuran, the injection concentration was 5 mg / mL, and the running time was 30 min.
[0134] (2) Weigh 0.05 g of hydroxy-terminated polybutadiene in a 250 mL conical flask, add an appropriate amount of dichloromethane to dissolve it, evaporate the solvent in a fume hood, and spread HTPB evenly on the bottom of the flask; add fermentation medium 2 to make the final HTPB content 0.5 g / L, and sterilize with high-pressure steam at 121°C for 20 min; after sterilization, cool to room temperature, and inoculate the activated Pseudomonas stutzeri culture liquid (cell concentration 1×10 8 ~10 9 cfu / mL), and cultured aerobically in an air bath constant temperature oscillator at 35°C and 150rpm for 15 days; on the 15th day after inoculation, an equal volume of dichloromethane was added to the culture solution for extraction, and the extract was filtered through a 0.45μm microporous filter membrane. After the solvent was evaporated, the degradation products were detected by gel permeation chromatography to obtain the chromatogram and molecular weight distribution of the degradation products. The solvent was tetrahydrofuran, the injection concentration was 5mg / mL, and the running time was 30 minutes; the total number average molecular weight of the degradation products was calculated according to the following formula: and total weight average molecular weight
[0135] Total number average molecular weight of degradation products
[0136] Total weight average molecular weight of degradation products
[0137] in,
[0138] i is the degradation product number;
[0139] S iis the peak area of degradation product i;
[0140] Mn i is the number average molecular weight of degradation product i;
[0141] M i is the weight average molecular weight of degradation product i;
[0142] is the average number average molecular weight of all degradation products, i.e., the total number average molecular weight of degradation products;
[0143] is the average weight-average molecular weight of all degradation products, that is, the total weight-average molecular weight of degradation products.
[0144] (3) Combine the M obtained in step (1) n0 and M w0 And the one obtained in step (2) and The number average degradation rate D was calculated according to the following formula: n And weight average degradation rate D w :
[0145] Number average degradation rate
[0146] Weight average degradation rate
[0147] in,
[0148] M n0 is the number average molecular weight of HTPB before degradation;
[0149] is the average number average molecular weight of all degradation products, i.e., the total number average molecular weight of degradation products;
[0150] M w0 is the weight average molecular weight of HTPB before degradation;
[0151] is the average weight-average molecular weight of all degradation products, i.e., the total weight-average molecular weight of degradation products;
[0152] D n is the number average degradation rate;
[0153] D w is the weight average degradation rate;
[0154] (4) The number average degradation rate D obtained by step (3) n And weight average degradation rate D w , the comprehensive degradation rate D is calculated according to the following formula:
[0155] Comprehensive degradation rate D = Dn ×40%+D w ×60%
[0156] The results are shown in Table 3:
[0157] Table 3 Degradation rate of HTPB by Pseudomonas stutzeri
[0158]
[0159] It can be seen from Table 3 that the number average molecular weight of the original HTPB is 9523g / mol, and the weight average molecular weight is 22364g / mol. After HTPB is degraded by the strain, two degradation products are produced, and the molecular weight of the degradation products is lower than that of the initial HTPB molecular weight. The number average molecular weight of degradation product 1 is 10399g / mol, and the weight average molecular weight is 26845g / mol. The number average molecular weight of degradation product 2 is 618g / mol, and the weight average molecular weight is 752g / mol. The number average degradation rate is 62.70%, the weight average degradation rate is 61.64%, and the comprehensive degradation rate is 62.06%. The degradation grade is excellent, which proves that the Pseudomonas stutzeri strain has a strong degradation ability for HTPB, can use organic nutrition to grow and reproduce, and degrade HTPB at the same time.
[0160] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.
Claims
1. A model for evaluating the degradation ability of microorganisms to hydroxy-terminated polybutadiene, characterized in that: The model is a comprehensive degradation rate model, specifically: Comprehensive degradation rate D = D n ×40%+D w ×60% Among them, the D n and D w Calculated by the following formula: Where: M n0 is the number average molecular weight of HTPB before degradation; is the average number average molecular weight of all degradation products, i.e., the total number average molecular weight of degradation products; M w0 is the weight average molecular weight of HTPB before degradation; is the average weight-average molecular weight of all degradation products, that is, the total weight-average molecular weight of degradation products.
2. The model for evaluating the degradation ability of microorganisms to hydroxy-terminated polybutadiene according to claim 1, characterized in that: The total number average molecular weight of the degradation products in, i is the degradation product number; S i is the peak area of degradation product i; Mn i is the number average molecular weight of degradation product i.
3. The model for evaluating the degradation ability of microorganisms to hydroxy-terminated polybutadiene according to claim 1, characterized in that: The total weight average molecular weight of the degradation product in, i is the degradation product number; S i is the peak area of degradation product i; M i is the weight average molecular weight of degradation product i.
4. The model for evaluating the degradation ability of microorganisms to hydroxy-terminated polybutadiene according to claim 1, characterized in that: When D ≥ 60%, the degradation efficiency is excellent; When 60%>D≥30%, the degradation efficiency is qualified; When 30%>D≥10%, the degradation efficiency is general; When D < 10%, the degradation efficiency is poor.
5. A method for evaluating the ability of microorganisms to degrade hydroxy-terminated polybutadiene, characterized in that: Use the model described in any one of claims 1 to 4.
6. The method for evaluating the degradation ability of microorganisms to hydroxy-terminated polybutadiene according to claim 5, characterized in that: Before evaluation, gel permeation chromatography was used to detect the number average molecular weight M of the hydroxy-terminated polybutadiene before degradation. n0 and weight average molecular weight M w0 ; Afterwards, the terminal hydroxyl polybutadiene was degraded by microorganisms, and the degraded solution was extracted by an equal volume of solvent. The extract was filtered through a 0.45 μm microporous filter membrane. After the solvent was evaporated, the number average molecular weight, weight average molecular weight and peak area of the degradation product were obtained by gel permeation chromatography. The peak area corresponding to the product was normalized to obtain the percentage of each peak, and then the product of the number average molecular weight of each peak and the peak area percentage was summed to obtain the total number average molecular weight Mn of the degradation product; the product of the weight average molecular weight of each peak and the peak area percentage was summed to obtain the total weight average molecular weight Mw of the degradation product, and D was calculated based on the obtained Mn and Mw. n and D w The comprehensive degradation rate D was further calculated, and the degradation ability of microorganisms on terminal hydroxyl polybutadiene was evaluated based on the comprehensive degradation rate D.
7. The method for evaluating the degradation ability of microorganisms to hydroxy-terminated polybutadiene according to claim 6, characterized in that: The solvent used for extraction is at least one of dichloromethane and n-hexane.
8. The method for evaluating the degradation ability of microorganisms to hydroxy-terminated polybutadiene according to claim 6, characterized in that: The method of microbial degradation of hydroxy-terminated polybutadiene is as follows: The microbial liquid is inoculated into a liquid culture medium containing terminal hydroxyl polybutadiene at an inoculation rate of 2% to 10% (v / v), and aerobically cultured at 25 to 35° C. and 120 to 200 rpm for 5 to 30 days to obtain a degraded solution.
9. The method for evaluating the degradation ability of microorganisms to hydroxy-terminated polybutadiene according to claim 8, characterized in that: In the liquid culture medium containing terminal hydroxyl polybutadiene, the final concentration of terminal hydroxyl polybutadiene is 0.5 g / L to 2 g / L.
10. The method for evaluating the degradation ability of microorganisms to hydroxy-terminated polybutadiene according to claim 8, characterized in that: The bacterial concentration in the microbial solution is 1×10 8 ~10 9 cfu / mL.