Preparation method and device of standard sample for quantitatively detecting weight gain of silk floss

Abstract

According to the standardized sample for silk weight gain detection and the preparation method of the standardized sample, the uniformity and repeatability of the silk sample are ensured by accurately controlling weight gain treatment conditions, and meanwhile special processing equipment is developed to achieve automatic and efficient sample production. Besides, the invention also relates to application and verification of the standard samples in a detection technology, including calibration of an existing detection method, internal quality control, capability verification among laboratories and development of a new detection method, and aims to improve the accuracy, efficiency and reliability of silk weight gain detection. The problems of disordered sources and unstable quality of existing standard samples are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of textile inspection and testing, and particularly relates to a method for preparing a standard sample for quantitatively detecting the weight gain of silk floss. Background Art

[0002] In the textile field, silk has become a key material for high-end textiles due to its natural advantages. To improve its physical properties, such as abrasion resistance and stiffness, the grafting weight gain technology is widely used in the post-finishing of silk. This technology adds a grafting agent to the silk fiber to form a dendritic polymer, achieving weight gain. However, the misuse of the grafting weight gain technology, especially in silk floss products, has had a negative impact on the silk quilt industry. There has been a phenomenon in the market of passing off grafted weight gain silk quilts as natural products. Therefore, accurately detecting the grafting weight gain of silk is crucial for ensuring product quality.

[0003] Existing methods for detecting the weight gain of silk floss have their own advantages and disadvantages. The colorimetric method is easy to operate, but it is inaccurate for detecting some types of silk and is susceptible to the degree of oxidation. The solubility method is intuitive, but it may be interfered by other fiber substances. The nitrogen content determination method has reliable results, but it is complex and time-consuming to operate. The liquid chromatography method has high accuracy, but it is also cumbersome and time-consuming to operate, and has high requirements for equipment and personnel. The pyrolysis-gas chromatography method and the thermal analysis method have good accuracy, but they are costly and not suitable for large-scale rapid detection. The infrared / Raman spectroscopy method is easy to operate and suitable for rapid detection, but a quantitative model needs to be established. The existing detection standard GB / T 24252—2019 "Silk Quilts" Appendices C, D, and E correspond to the colorimetric method, the solubility method, and the liquid chromatography method respectively. Appendices C and D are mainly qualitative analysis methods for silk with weight gain by the polyacrylamide grafting technology, and Appendix E is the main method for quantitative detection. Similarly, there is also the standard GB / T 32016-2015 "Determination of Amino Acids in Silk", which also uses the liquid chromatography method to determine whether silk has been grafted.

[0004] A standard sample for detection, also known as a standard reference material or a reference material, refers to a sample with one or more sufficiently homogeneous and accurately known characteristic values and is widely recognized. At present, the sources of standard samples for detecting silk weight gain are relatively limited and lack unified specifications, mainly relying on positive samples obtained in market supervision. The diversity and instability of these sources indicate that there is a certain degree of chaos in the standard samples for detecting silk weight gain. There is an urgent need to establish a standardized and reliable standard sample supply system to meet the industry's needs. Synthesizing standard samples for silk weight gain in the laboratory is a relatively controllable approach. However, the difficulty in laboratory preparation lies in achieving precise control and large-scale production while ensuring the consistency, stability, and cost-effectiveness of the samples.

[0005] Whether it is the research and improvement of the limitations of existing silk weight gain detection methods or the practical needs at the technical supervision level, high-quality standard samples for detection are urgently needed in the process of proficiency testing and inspection application of standard detection methods to ensure the accuracy and reliability of detection results. However, the scarcity of high-quality standard samples on the current market limits the proficiency testing of detection technologies and the verification of results, highlighting the urgent need to develop and provide reliable standard samples. Summary of the Invention

[0006] The purpose of this section is to outline some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section, as well as in the abstract and title of the specification of this application, to avoid obscuring the purpose of this section, the abstract, and the title. However, such simplifications or omissions shall not be used to limit the scope of the present invention.

[0007] In view of the above and / or problems existing in the prior art, the present invention is proposed.

[0008] Therefore, the purpose of the present invention is to overcome the deficiencies in the prior art and provide a method for preparing a standard sample for quantitatively detecting the weight gain of silk floss.

[0009] To solve the above technical problems, the present invention provides the following technical solution: A method for preparing a standard sample for quantitatively detecting the weight gain of silk floss, characterized in that it includes:

[0010] Degumming the silk material with a degumming agent and a silk scouring agent;

[0011] Prepare a coloring agent containing carmine and picric acid, and color the degummed silk to evaluate the degumming degree by color change to ensure complete degumming;

[0012] Graft-modify the degummed and qualified silk by coloring evaluation: Add pure water to a silk finishing machine and heat it, add a non-ionic surfactant, silk, and an initiator, then add graft monomers in three equal portions at intervals of 20 - 40 minutes. After the last addition of graft monomers, keep it warm for 20 - 60 minutes, wash the silk, dehydrate, dry, and weigh.

[0013] As a preferred embodiment of the preparation method of the present invention, wherein: the degumming agent is at least one of sodium carbonate, potassium carbonate, papain, malic acid, and trypsin.

[0014] As a preferred embodiment of the preparation method of the present invention, wherein: when preparing the coloring agent containing carmine and picric acid, the pH of the coloring agent is 8.0 - 9.0; the material ratio of carmine to picric acid is 1 g : 40 - 50 mL.

[0015] As a preferred embodiment of the preparation method of the present invention, wherein: the degumming degree is evaluated by color change, wherein the silk presenting yellow is evaluated as qualified, and the silk presenting red is evaluated as unqualified.

[0016] As a preferred embodiment of the preparation method of the present invention, wherein: pure water is added and heated in a silk finishing machine, wherein the heating temperature is 60-100 °C.

[0017] As a preferred embodiment of the preparation method of the present invention, wherein: a non-ionic surfactant, silk, and an initiator are added, wherein the concentration of the non-ionic surfactant is 4 g / L, the concentration of the initiator is 1 g / L, and the amount of silk used is 50-300 g.

[0018] As a preferred embodiment of the preparation method of the present invention, wherein: the non-ionic surfactant is at least one of AEO-9, polyethylene glycol ether, and alkyl glycoside, and the initiator is at least one of potassium persulfate, benzoyl peroxide, and azobisisobutyronitrile.

[0019] As a preferred embodiment of the preparation method of the present invention, wherein: the graft monomer is at least one of monomers such as methylacrylamide, acrylamide, acrylic acid, and its derivatives, and the amount of the graft monomer used is 240-300% o.w.f.

[0020] Another object of the present invention is to overcome the deficiencies in the prior art and provide a standard sample for quantitatively detecting the weight gain of silk floss.

[0021] Another object of the present invention is to overcome the deficiencies in the prior art and provide an application of a standard sample for quantitatively detecting the weight gain of silk floss in verifying the quantitative detection ability of the silk floss and silk amino acid content in silk quilts.

[0022] Advantages of the present invention:

[0023] By precisely controlling the weight gain treatment conditions, the present invention ensures the uniformity and repeatability of silk samples. At the same time, special processing equipment is developed to achieve automated and high-efficiency sample production, improving the accuracy, efficiency, and reliability of silk weight gain detection, and solving the problems of chaotic sources and unstable quality of existing standard samples. Description of the drawings

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for description in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings. Among them:

[0025] Figure 1It is the overall structural schematic diagram of the silk finishing machine provided by the embodiment of the present invention.

[0026] Figure 2 It is the internal schematic diagram of the silk finishing machine provided by the embodiment of the present invention.

[0027] Figure 3 It is the physical diagram of the silk finishing machine provided by the embodiment of the present invention.

[0028] Figure 4 It is the degumming result comparison diagram in Embodiment 1 of the present invention. Detailed implementation manners

[0029] To make the above objects, features and advantages of the present invention more obvious and understandable, the following detailed description of the specific implementation manners of the present invention will be given in conjunction with the embodiments of the specification.

[0030] Many specific details are set forth in the following description to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0031] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure or characteristic that can be included in at least one implementation manner of the present invention. The "in one embodiment" that appears in different places in this specification does not all refer to the same embodiment, nor is it a separate or alternative embodiment that excludes other embodiments.

[0032] The raw materials used in the present invention are shown in Table 1:

[0033] Table 1

[0034]

[0035] The instruments used in the embodiments of the present invention are shown in Table 2:

[0036] Table 2

[0037]

[0038]

[0039] The silk finishing machine used in the specific embodiment of the present invention is customized, and the structural schematic diagram is as Figures 1 - 3 shown. It includes a main body and a control device. Among them, the control device is a cylinder or a cuboid fixed on the main body. The main body includes a box body 1, a finishing barrel 2 and a heating device 4. The finishing barrel and the heating device are installed in the box body. The finishing barrel includes an inner barrel and an outer barrel. The inner barrel is rotatably installed in the outer barrel, and the surface of the outer barrel is evenly distributed with a porous perspective structure 3.

[0040] The box body includes a bottom surface and side surfaces. The bottom surface of the box body can be arranged horizontally, and the side surfaces of the box body can be barrel-shaped or cuboid-shaped surfaces fixed above the bottom surface of the box body. Among them, the bottom surface and side surfaces of the box body jointly enclose a receiving cavity with an open top. A box cover that can be flipped open can be arranged at the opening of the receiving cavity. The sorting barrel and the heating device are accommodated in the receiving cavity.

[0041] The control device includes a power supply and a control box, which are used to provide power and control the operation of the sorting machine, including heating temperature setting and rotation speed setting.

[0042] The inner barrel is used to load silk and perform sorting processing, accommodate silk and treatment liquid, and can perform centrifugal dehydration.

[0043] Specifically, silk is loaded in the inner barrel. When dehydrating, the silk in the inner barrel is in an unbalanced state at this time, resulting in the center of gravity of the inner barrel deviating from its central position. When the inner barrel rotates, a large eccentricity will be generated, which will drive the outer barrel to vibrate.

[0044] The usage method of this silk sorting machine includes the following steps:

[0045] (1) Loading pure water and heating: Load pure water in the sorting working area and heat the water to the required temperature (such as 60 - 100 °C) through the electric heating coil heating device.

[0046] (2) Adding materials: Add materials such as non-ionic surfactant, silk, and initiator to the sorting working area.

[0047] (3) Grafting modification treatment: Add graft monomers in multiple times according to the set program to perform grafting modification treatment.

[0048] (4) Cleaning and drying: After the treatment is completed, clean the silk, dehydrate, dry, and finally weigh it.

[0049] Example 1

[0050] The preparation method of a standard sample for quantitatively detecting the weight gain of silk floss in this example includes the following steps:

[0051] (1) Degumming treatment: Use Na2CO3 and refining agent to treat the mulberry silk material at a set bath ratio of 1:50 to remove the sericin component in the silk;

[0052] (2) Preparing the coloring agent: Dissolve 1 g of carmine in 10 mL of 25% ammonia water, add 20 mL of distilled water, heat in a water bath at 45 °C for 5 minutes, then cool and add 45 mL of saturated picric acid solution, adjust the pH to 8.0 - 9.0 with 5 mol / L hydrochloric acid, and finally make up the volume to 100 mL;

[0053] (3) Immerse 1 g of the degummed silk sample in 30 mL of the coloring solution, heat it in a boiling water bath for 2 minutes, and then rinse it with water multiple times. Evaluate the degree of degumming based on the color change, using the yellow silk shown in Figure 4 (b) as the standard to ensure complete degumming;

[0054] (4) Graft-modify the degummed and qualified silk in terms of coloring evaluation. According to a bath ratio of 1:100, load pure water in a silk finishing machine and heat it to 80 °C. Add 4 g / L of the non-ionic surfactant AEO-9, put in 100 g of silk, add 1 g / L of the initiator potassium persulfate, and add it in 3 equal portions 5 minutes before adding the graft monomer on average. The amount of the graft monomer methacrylamide is 270% o.w.f, and add it in 3 equal portions on average, with an addition interval of 35 minutes. After the last addition of the graft monomer, keep it warm for 30 minutes. Wash the silk with 50 °C hot water, dehydrate, dry, weigh, and calculate that the mass gain rate of the silk is 77.1%.

[0055] Example 2

[0056] The difference between this example and Example 1 is that the amount of the graft monomer methacrylamide of 270% o.w.f is replaced with the amount of the graft monomer methacrylamide of 300% o.w.f, and the rest of the steps are the same as those in Example 1. The obtained sample has a silk mass gain rate of 74.3%.

[0057] Example 3

[0058] The difference between this example and Example 1 is that the amount of the graft monomer methacrylamide of 270% o.w.f is replaced with the amount of the graft monomer methacrylamide of 240% o.w.f, and the rest of the steps are the same as those in Example 1. The obtained sample has a silk mass gain rate of 71.9%.

[0059] Comparative Example 1

[0060] The difference between this example and Example 1 is that the addition of the initiator and the graft monomer in 3 equal portions on average is replaced with a one-time addition of the initiator and the graft monomer, and the rest of the steps are the same as those in Example 1. The obtained sample has a silk mass gain rate of 12.1%.

[0061] Comparative Example 2

[0062] The difference between this example and Example 1 is that the amount of the graft monomer methacrylamide of 270% o.w.f is replaced with the amount of the graft monomer methacrylamide of 150% o.w.f, and the rest of the steps are the same as those in Example 1. The obtained sample has a silk mass gain rate of 4.6%.

[0063] It can be seen that the maximum parameter weight gain is achieved when the grafting monomer methacrylamide dosage is 270% owf; and the initiator and grafting monomer need to be added evenly in three batches to ensure a large weight gain after grafting. This is because the optimized concentration of the grafting monomer and the staged introduction of the initiator effectively reduce the self-aggregation effect of the grafting monomer and ensure uniform deposition of the initiator on the silk surface, successfully solving the problem of monomer self-aggregation during high-throughput preparation and significantly improving the grafting efficiency.

[0064] In order to determine the repeatability and stability of the process, Example 3 and Comparative Example 1 were repeatedly tested. The weight gain rate after three repetitions is shown in Table 3. It can be seen that the process steps of the embodiment of the present invention stabilize the weight gain rate after silk grafting at about 70%, ensuring the repeatability and stability of the experimental results.

[0065] Table 3

[0066] Repeated Experiment 1 Repeated Experiment 2 Repeated Experiment 3 Example 3 71.11％ 70.05％ 72.25％ Comparative Example 1 12.09％ 4.57％ 16.26％

[0067] The samples prepared in Examples 1 to 3 and Comparative Examples 1 and 2 were subjected to quantitative determination of the contents of four amino acids (test method GB / T 24252-2019 "Silk Quilt" Appendix E), and the results are shown in Table 4.

[0068] Table 4

[0069]

[0070]

[0071] The specific requirements for quantitative detection are that the standard stipulates that the total content of all amino acids in silk protein should reach more than 95%. If the content of four amino acids (serine, glycine, alanine, and tyrosine) is to be determined, the sum of the four amino acid contents should reach more than 77%. Therefore, the sum of the four amino acid contents of the positive sample should be less than 77% of that of natural silk. The one-time addition of initiator and grafting monomer or a low concentration of grafting monomer cannot significantly reduce the proportion of amino acids. Therefore, it is necessary to ensure the successful preparation of positive samples by batch operation and optimizing the concentration of grafting monomer.

[0072] In summary, the present invention successfully solved the problem of monomer self-aggregation during high-throughput preparation through process adjustment, significantly improving the grafting efficiency. The adjusted process not only increased the grafting rate but also ensured the repeatability and stability of the experimental results.

[0073] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and all of them should be covered within the scope of the present invention.

Claims

1. A method for preparing a standard sample for quantitatively detecting the weight gain of silk floss, characterized in that: Including, degumming the silk material using a degumming agent and a silk scouring agent; preparing a colorant containing carmine and picric acid, coloring the degummed silk, and evaluating the degumming degree based on color change to ensure complete degumming; performing graft modification on the degummed and qualified silk after coloring evaluation: adding pure water into a silk finishing machine and heating it, adding a nonionic surfactant, silk, and an initiator, then adding graft monomers in three equal portions with an interval of 20 - 40 min between each addition, and keeping the temperature for 20 - 60 min after the last addition of graft monomers, washing the silk, dehydrating, drying, and weighing to obtain a standard sample.

2. The preparation method according to claim 1, characterized in that: The degumming agent is at least one of sodium carbonate, potassium carbonate, papain, malic acid, and trypsin.

3. The preparation method according to claim 1, wherein: When preparing the colorant containing carmine and picric acid, the pH of the colorant is 8.0 - 9.0; the material ratio of carmine to picric acid is 1 g : 40 - 50 mL.

4. The preparation method according to claim 1, wherein: When evaluating the degumming degree based on color change, silk showing yellow is evaluated as qualified, and silk showing red is evaluated as unqualified.

5. The preparation method according to claim 1, characterized in that: When adding pure water into the silk finishing machine and heating it, the heating temperature is 60 - 100°C.

6. The preparation method according to claim 1, characterized in that: When adding a nonionic surfactant, silk, and an initiator, the concentration of the nonionic surfactant is 4 g / L, the concentration of the initiator is 1 g / L, and the amount of silk used is 50 - 300 g.

7. The preparation method according to claim 6, characterized in that: The nonionic surfactant is at least one of AEO-9, polyethylene glycol ether, and alkyl glycoside, and the initiator is at least one of potassium persulfate, benzoyl peroxide, and azobisisobutyronitrile.

8. The preparation method according to claim 1, characterized in that: The graft monomer is at least one of monomer methylacrylamide, acrylamide, acrylic acid, and its derivatives, and the amount of the graft monomer used is 240 - 300% o.w.f.

9. A standard sample for quantitatively detecting the weight gain of silk floss prepared by the preparation method according to any one of claims 1 - 8.

10. Application of the standard sample for quantitatively detecting the weight gain of silk floss according to claim 9 in the calibration of the quantitative detection ability of silk floss and silk amino acid content in silk quilts.

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