A method for determining the root inhibitor content of prepreg in coiled material

Abstract

The present invention relates to a method for determining the root inhibitor content of a prepreg in a coil, the method comprising the following steps: melting the coil and the coating material therein in two closed containers respectively, volatilizing the root inhibitor, taking the volatiles in the two closed containers for detection, obtaining the root inhibitor content in the coil and the coating material, calculating the difference between the two, and obtaining the root inhibitor content of the prepreg in the coil. The method of the present invention has a simple processing method, does not require the use of organic solvents, and avoids the harm of organic solvent volatilization to experimental personnel and the environment.

Description

Technical Field

[0001] The invention relates to the technical field of determining the content of a root inhibitor, and in particular to a method for determining the content of a root inhibitor in a prepreg in a coil. Background Art

[0002] The root inhibitor content needs to be accurately tested.

[0003] CN104267115A discloses a method for determining the content of a chemical root inhibitor in a root puncture resistant material, wherein the root puncture resistant material is an asphalt root puncture resistant material or a polymer modified asphalt root puncture resistant material; the method comprises the following steps: extracting the chemical root inhibitor in the root puncture resistant material to be tested with a first organic solvent to obtain a sample solution; preparing a blank solution with the first organic solvent; diluting a chemical root inhibitor standard product with the first organic solvent to a set concentration to obtain a standard solution; performing a chromatographic test on the standard solution to obtain a chromatographic peak area corresponding to the chemical root inhibitor in the standard solution; and taking the chromatographic peak area corresponding to the chemical root inhibitor in the standard solution as the longitudinal axis. Coordinate, draw a standard working curve with the mass of the injected chemical root inhibitor as the horizontal coordinate; under the same test conditions as the standard solution, perform chromatographic tests on the sample solution and the blank solution respectively, and obtain the chromatographic peak area corresponding to the chemical root inhibitor in the sample solution and the chromatographic peak area corresponding to the blank solution; calculate the concentration of the chemical root inhibitor in the sample solution according to the slope of the standard working curve, the area of ​​the chromatographic peak corresponding to the chemical root inhibitor in the sample solution and the area of ​​the chromatographic peak corresponding to the blank solution, and obtain the content of the chemical root inhibitor in the root penetration resistant material to be tested according to the concentration of the chemical root inhibitor in the sample solution.

[0004] The existing methods and standards for detecting root inhibitors include T / CBMF 49-2019T / CWA 301-2019. The method steps are to use methyl tert-butyl ether and methanol to extract the root inhibitor in the sample under ultrasonic action in turn, and use high performance liquid chromatography to test, and use retention time for qualitative analysis and external standard method for quantitative analysis. This method is for asphalt coating samples.

[0005] In the prior art, the prepreg of the coil base cannot be directly separated after being compounded with other rubber materials, and the prepreg cannot be extracted separately as a sample for testing. Therefore, the root inhibitor content of the prepreg compounded with the coil base cannot be determined. In addition, the current method has many pretreatment steps, the errors introduced by equipment and personnel factors are large, and a large amount of organic solvents are consumed, which is easy to cause harm to the experimenters and the environment.

[0006] In summary, it is crucial to develop a simple method to determine the root inhibitor content of prepreg in coils. Summary of the invention

[0007] In view of the deficiencies in the prior art, the object of the present invention is to provide a method for determining the root inhibitor content of prepreg in a coiled material. The method is simple in processing, does not require the use of organic solvents, and avoids the harm of organic solvent volatilization to experimenters and the environment.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] The present invention provides a method for determining the content of a root inhibitor in a prepreg in a coil, the method comprising the following steps:

[0010] The coil and the coating material therein are melted in two closed containers respectively to volatilize the root inhibitor, and the volatiles in the two closed containers are taken for detection to obtain the root inhibitor content in the coil and the coating material. The difference between the two is calculated to obtain the root inhibitor content of the prepreg in the coil.

[0011] When the method of the present invention determines the root inhibitor content of the prepreg in the coil, the prepreg is not directly extracted as a sample, but the root inhibitor content of the coil product and the coating material is detected respectively. The root inhibitor content of the prepreg can be obtained by calculation. The processing method is simple, and no organic solvent is needed, which avoids the harm of the volatilization of organic solvents to the experimenters and the environment.

[0012] In the present invention, the coiled material is composed of a base and a coating covering the surface thereof, the base includes prepreg, and the difference in root inhibitor content between the coiled material and the coating is the root inhibitor content in the base, that is, the root inhibitor content in the prepreg.

[0013] Preferably, before melting the coiled material and the coating material therein in two closed containers respectively, the method further comprises: judging whether the coating material in the coiled material is completely taken out.

[0014] Preferably, the step of judging whether all the coating material in the coil is taken out further comprises:

[0015] (1) Using a utility knife, remove the coating material that does not contact the base of the coil, so that the base is not exposed at all, extract the soluble matter therein, and obtain the mass fraction of the soluble matter;

[0016] (2) Use a scraper to completely scrape off the coating material in the coil until the upper and lower surfaces of the base are exposed, extract the soluble matter in the coating material, and obtain the mass fraction of the soluble matter;

[0017] (3) Compare the mass fractions of soluble matter in steps (1) and (2). If the two are equal, all coating materials in the coil have been removed and the next step of the test can be carried out.

[0018] If the two are not equal, it indicates that prepreg is mixed in the coating material. Resample and test until the two are equal to obtain the entire coating material without prepreg.

[0019] In the present invention, a judgment standard for preparing the coating material sample is added, that is, the mass fraction of the soluble matter of the entire coating material scraped off is compared with the mass fraction of the soluble matter of the coating material not contacting the tire base, and the value should be consistent. This standard can further increase the accuracy of the test results, and the operation is simple and is conducive to the expansion of industrial operation.

[0020] Preferably, the extraction of soluble matter in step (1) and step (2) is carried out in accordance with GB / T 328.26-2007.

[0021] Preferably, the step of taking volatiles from two sealed containers for testing to obtain the root inhibitor content in the coil and the coating material further comprises:

[0022] The volatiles per unit volume are obtained respectively;

[0023] Detecting the volatile matter per unit volume to obtain the content of the root inhibitor per unit volume;

[0024] The content of root inhibitor in coiled material and coating material is obtained according to the content of root inhibitor in unit volume.

[0025] Preferably, the step of obtaining the content of the root inhibitor in the coil and the coating material according to the content of the root inhibitor in the unit volume also includes:

[0026] Obtain coil size and closed container volume;

[0027] The content of root inhibitor in the coil and coating material is obtained according to the coil size, the volume of the closed container and the content of root inhibitor per unit volume.

[0028] Preferably, the melting method is heating, and the heating temperature is 180-220°C, such as 190°C, 200°C, 210°C, etc.

[0029] Preferably, the heating time is 50-70 min, such as 55 min, 60 min, 65 min, etc.

[0030] Preferably, the device for detecting the content of the root inhibitor includes a gas chromatograph.

[0031] Preferably, the chromatographic separation column of the gas chromatograph is non-polar, and the filler comprises polysiloxane;

[0032] The injection port temperature is 205-215°C, such as 206°C, 208°C, 210°C, 212°C, 214°C, etc.;

[0033] The detector temperature is 250-270°C, such as 255°C, 260°C, 265°C, etc.;

[0034] The column flow rate is 0.5-1.5 mL / min, for example, 0.6 mL / min, 0.8 mL / min, 1 mL / min, 1.2 mL / min, 1.4 mL / min, etc.;

[0035] The hydrogen flow rate is 30-50 mL / min, such as 35 mL / min, 40 mL / min, 45 mL / min, etc.;

[0036] The air flow rate is 350-450 mL / min, such as 360 mL / min, 380 mL / min, 400 mL / min, 420 mL / min, 440 mL / min, etc.

[0037] The tail gas flow rate is 30-50 mL / min, such as 35 mL / min, 40 mL / min, 45 mL / min, etc.

[0038] The initial temperature of the column oven is 50-70°C (e.g. 55°C, 60°C, 65°C, etc.), maintained for 1-10 min (e.g. 2 min, 4 min, 6 min, 8 min, etc.), increased to 240-260°C (e.g. 245°C, 250°C, 255°C, etc.) at a rate of 5-25°C / min (e.g. 10°C / min, 15°C / min, 20°C / min, etc.), maintained for 5-15 min (e.g. 6 min, 8 min, 10 min, 12 min, 14 min, etc.).

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] (1) When the method of the present invention is used to determine the content of the root inhibitor in the prepreg in the coil, the processing method is simple. The content of the root inhibitor in the prepreg is obtained by measuring the content of the root inhibitor in the coating material and the coil, without extracting the prepreg.

[0041] (2) When the method of the present invention is used to determine the root inhibitor content of the prepreg in the coil, no organic solvent is needed, thereby avoiding the harm caused by the volatilization of the organic solvent to the experimenter and the environment. DETAILED DESCRIPTION

[0042] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0043] In some embodiments of the present invention, the method for determining the root inhibitor content of the prepreg in the coil specifically comprises the following steps:

[0044] The coil and the coating material therein are melted in two closed containers respectively to volatilize the root inhibitor, and the volatiles in the two closed containers are taken for detection to obtain the root inhibitor content in the coil and the coating material. The difference between the two is calculated to obtain the root inhibitor content of the prepreg in the coil.

[0045] When the method of the present invention is used to determine the root inhibitor content of the prepreg in the coil, the processing method is simple. The content of the root inhibitor in the prepreg is obtained by the content of the root inhibitor in the coating material and the coil, and there is no need to extract the prepreg; there is no need to use organic solvents, which avoids the harm of organic solvent volatilization to experimenters and the environment.

[0046] In the present invention, the coiled material is composed of a base and a coating covering the surface thereof, the base includes prepreg, and the difference in root inhibitor content between the coiled material and the coating is the root inhibitor content in the base, that is, the root inhibitor content in the prepreg.

[0047] In some embodiments of the present invention, before melting the coil and the coating material therein in two closed containers respectively, the process further includes: determining whether all the coating material in the coil is taken out.

[0048] In some embodiments of the present invention, the method of determining whether the coating material in the coil is completely removed specifically comprises the following steps:

[0049] (1) Using a utility knife, remove the coating material that does not contact the base of the coil, so that the base is not exposed at all, extract the soluble matter therein, and obtain the mass fraction of the soluble matter;

[0050] (2) Use a scraper to completely scrape off the coating material in the coil until the upper and lower surfaces of the base are exposed, extract the soluble matter in the coating material, and obtain the mass fraction of the soluble matter;

[0051] (3) Compare the mass fractions of soluble matter in steps (1) and (2). If the two are equal, all coating materials in the coil have been removed and the next step of the test can be carried out.

[0052] If the two are not equal, it indicates that prepreg is mixed in the coating material. Resample and test until the two are equal to obtain the entire coating material without prepreg.

[0053] In the present invention, a judgment standard for preparing coating samples is added, that is, the mass fraction of soluble matter in the entire coating removed by shoveling is compared with the mass fraction of soluble matter in the coating not contacting the tire base, and the values ​​should be consistent. This standard is conducive to the expansion of industrial operation.

[0054] Exemplarily, the step of judging whether all the coating material in the coil is taken out specifically comprises the following steps:

[0055] (1) Select a coil specimen with a mass of m1, use a utility knife to remove the coating material that does not contact the base, so that the base is not exposed at all. Weigh the coating material to obtain a mass of m2, extract the soluble matter, and obtain a mass fraction of the soluble matter = m3 / m2;

[0056] (2) Use a scraper to completely scrape off the coating material in the coil until the upper and lower surfaces of the base are exposed. The total coating material mass is m4. Accurately weigh the coating material with a mass of m4 / 2 (the remaining coating material is for standby use) and extract the soluble matter of the coating material, the mass of which is m5. The mass fraction of the soluble matter is obtained = 2×m5 / m4;

[0057] (3) Compare the mass fractions of soluble matter in steps (1) and (2). If the two are equal, all coating materials in the coil have been removed and the next step of the test can be carried out.

[0058] If the two are not equal, it indicates that prepreg is mixed in the coating material. Resample and test until the two are equal to obtain the entire coating material without prepreg.

[0059] In some embodiments of the present invention, the extraction of soluble matter in step (1) and step (2) is performed in accordance with GB / T328.26-2007.

[0060] In some embodiments of the present invention, the step of obtaining the content of the root inhibitor in the coil and the coating material according to the content of the root inhibitor in the unit volume is first performed as follows:

[0061] Obtain coil size and closed container volume;

[0062] The content of root inhibitor in the coil and coating material is obtained according to the coil size, the volume of the closed container and the content of root inhibitor per unit volume.

[0063] Exemplarily, the size of the coil specimen is 50 mm × 20 mm, the mass is m1, the volume of the sealed container is V, and the volatiles in the 1 mL sample bottles in the sealed container are collected as test samples to determine the content of root inhibitor in the material and the coating material.

[0064] In some embodiments of the present invention, the step of taking volatiles from two sealed containers for testing to obtain the root inhibitor content in the coil and the coating material further comprises:

[0065] The volatiles per unit volume are obtained respectively;

[0066] Detecting the volatile matter per unit volume to obtain the content of the root inhibitor per unit volume;

[0067] The content of root inhibitor in coiled material and coating material is obtained according to the content of root inhibitor in unit volume.

[0068] For example, the coating material in the coil is taken out, and the same coil and coating material are placed in two closed containers respectively, so that the coil and coating material are melted, and the root inhibitor volatilizes. 1 mL of volatiles in the coil and coating material are collected and tested to obtain the root inhibitor content w1 of the coating material and the root inhibitor content w2 of the coil per unit area. The root inhibitor content w of the prepreg can be calculated by the formula:

[0069] The root inhibitor content w of the prepreg = the root inhibitor content w2 of the coil - the root inhibitor content w1 of the coating material.

[0070] In some embodiments of the present invention, the melting method is heating, and the heating temperature is 180-220°C, such as 190°C, 200°C, 210°C, etc.

[0071] In some embodiments of the present invention, the heating time is 50-70 min, such as 55 min, 60 min, 65 min, etc.

[0072] In some embodiments of the present invention, the device for detecting the content of the root inhibitor includes a gas chromatograph.

[0073] In some embodiments of the present invention, the chromatographic separation column of the gas chromatograph is non-polar, and the filler comprises polysiloxane;

[0074] The injection port temperature is 205-215°C, such as 206°C, 208°C, 210°C, 212°C, 214°C, etc.;

[0075] The detector temperature is 250-270°C, such as 255°C, 260°C, 265°C, etc.;

[0076] The column flow rate is 0.5-1.5 mL / min, for example, 0.6 mL / min, 0.8 mL / min, 1 mL / min, 1.2 mL / min, 1.4 mL / min, etc.;

[0077] The hydrogen flow rate is 30-50 mL / min, such as 35 mL / min, 40 mL / min, 45 mL / min, etc.;

[0078] The air flow rate is 350-450 mL / min, for example, 360 mL / min, 380 mL / min, 400 mL / min, 420 mL / min, 440 mL / min, etc.;

[0079] The tail gas flow rate is 30-50 mL / min, such as 35 mL / min, 40 mL / min, 45 mL / min, etc.

[0080] The initial temperature of the column oven is 50-70°C (e.g. 55°C, 60°C, 65°C, etc.), maintained for 1-10 min (e.g. 2 min, 4 min, 6 min, 8 min, etc.), increased to 240-260°C (e.g. 245°C, 250°C, 255°C, etc.) at a rate of 5-25°C / min (e.g. 10°C / min, 15°C / min, 20°C / min, etc.), maintained for 5-15 min (e.g. 6 min, 8 min, 10 min, 12 min, 14 min, etc.).

[0081] Specifically, the method for determining the root inhibitor content of the prepreg in the coiled material of the present invention comprises the following steps:

[0082] (1) Cut a 50 mm × 20 mm coil specimen and weigh its mass m1.

[0083] (2) Use a utility knife to remove the coating material on the surface of the coiled material that does not contact the base. At this time, the base is completely exposed. Weigh the mass of the coating material as m2. Extract the soluble matter of the coating material according to the steps of GB / T 328.26-2007, and the mass of the soluble matter is m3. The mass fraction of the soluble matter = m3 / m2.

[0084] (3) Use a spatula to completely scrape off the coating material on the upper and lower surfaces of the coil until the upper and lower surfaces of the base are exposed, and the total coating material of the coil specimen is obtained, with a mass of m4. Accurately weigh the coating material with a mass of m4 / 2 for testing (the remaining coating material is for standby use). Similarly, extract the soluble matter of the coating material according to the steps of GB / T 328.26-2007, and obtain the soluble matter mass m5. The mass fraction of the total soluble matter of the coating material = 2×m5 / m4.

[0085] (4) Compare the soluble mass fractions obtained in step (2) and step (3). If the two values ​​are equal, it indicates that all the coating materials of the coil specimen have been removed and the next test can be carried out. If the two values ​​are not equal, it indicates that part of the prepreg is mixed in the total coating material, and the specimen needs to be cut again for testing.

[0086] (5) Place the remaining coating material prepared in step (3) into a 20 mL sample bottle and seal it with a PTFE lid. Similarly, cut the 25 mm × 20 mm coil specimen into the smallest possible shape, place it into a 20 mL sample bottle and seal it with a PTFE lid. Place the two sample bottles in an oil bath set at 200°C for 60 minutes to melt the rubber and volatilize the root inhibitor in the rubber.

[0087] (6) Use a syringe to absorb the volatiles in the sample bottles of 1 mL, and inject them into the gas chromatograph (refer to the gas chromatograph detection parameters after debugging in the notes) for analysis and detection. The retention time is used for qualitative analysis and the peak area is used for quantitative analysis. The root inhibitor content w1 of the coating material and the root inhibitor content w2 of the coil per unit area are obtained.

[0088] Among them, the gas chromatography detection parameters that can be used to detect root inhibitors after debugging are:

[0089] Chromatographic separation column: non-polar, filled with (5% phenyl)-methyl polysiloxane;

[0090] Inlet temperature: 210°C;

[0091] Detector temperature: 260°C;

[0092] Column flow rate: 1 mL / min;

[0093] Hydrogen flow rate: 40mL / min;

[0094] Air flow rate: 400mL / min;

[0095] Make-up gas flow rate: 40mL / min;

[0096] Column oven heating process: initial temperature 60°C, hold for 5 min, then heat to 250°C at a rate of 20°C / min and hold for 10 min.

[0097] (7) The root inhibitor content w of the prepreg can be calculated by the formula:

[0098] The root inhibitor content w of the prepreg = the root inhibitor content w2 of the coil - the root inhibitor content w1 of the coating material.

[0099] The testing method of the present invention has the following advantages over the existing testing methods:

[0100] 1. No need to use organic solvents to avoid the harm of organic solvent volatilization to human body and environment;

[0101] 2. The processing method is simple. The content of the root inhibitor in the prepreg can be obtained by measuring the content of the root inhibitor in the coating material and the coil, without extracting the prepreg.

[0102] The present invention illustrates the detailed method of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed method, that is, it does not mean that the present invention must rely on the above-mentioned detailed method to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for determining the root inhibitor content of prepreg in a coil, characterized in that: The method comprises the following steps: The coil and the coating material therein are melted in two closed containers respectively to volatilize the root inhibitor, and the volatiles in the two closed containers are taken for detection to obtain the root inhibitor content in the coil and the coating material, and the difference between the two is calculated to obtain the root inhibitor content of the prepreg in the coil; The melting method is heating, and the heating temperature is 180-220°C; Before melting the coil and the coating material therein in two closed containers respectively, the method further includes: judging whether all the coating material in the coil is taken out; The method of judging whether the coating material in the coil is completely removed also includes the following steps: (1) Use a utility knife to remove the coating material that does not contact the base of the coil. At this time, the base is completely not exposed. Extract the soluble matter and obtain the mass fraction of the soluble matter. (2) Use a scraper to completely scrape off the coating material in the coil until the upper and lower surfaces of the base are exposed, extract the soluble matter in the coating material, and obtain the mass fraction of the soluble matter; (3) Compare the mass fractions of soluble matter in steps (1) and (2). If the two are equal, all coating materials in the coil have been removed and the next test can be carried out. If the two are not equal, it indicates that the coating material is mixed with prepreg. Resample and test until the two are equal to obtain the entire coating material without prepreg. The extraction of soluble matter in step (1) and step (2) is carried out in accordance with GB / T 328.26-2007; The equipment for detecting the content of the root inhibitor is a gas chromatograph; The chromatographic separation column of the gas chromatograph is non-polar and the filler is 5% phenyl-methyl polysiloxane; The injection port temperature is 205-215°C; Detector temperature is 250-270°C; Column flow rate is 0.5-1.5 mL / min; The hydrogen flow rate is 30-50 mL / min; Air flow rate is 350-450 mL / min; The tail gas flow rate is 30-50 mL / min; The initial temperature of the column oven is 50-70°C, maintained for 1-10 min, then raised to 240-260°C at 5-25°C / min, and maintained for 5-15 min.

2. The method according to claim 1, characterized in that The volatiles in the two sealed containers are tested to obtain the root inhibitor content in the coil and the coating material, and the content of the root inhibitor in the coil and the coating material also includes: The volatiles per unit volume are obtained respectively; Detecting the volatile matter per unit volume to obtain the content of the root inhibitor per unit volume; The content of root inhibitor in coiled material and coating material is obtained according to the content of root inhibitor in unit volume.

3. The method according to claim 2, characterized in that The method of obtaining the content of the root inhibitor in the coil and the coating material according to the content of the root inhibitor in the unit volume also includes: Obtain coil size and closed container volume; The content of root inhibitor in the coil and coating material is obtained according to the coil size, the volume of the closed container and the content of root inhibitor per unit volume.

4. The method according to claim 1, characterized in that The heating time is 50-70 minutes.