Detection method of PC content in PC / ABS alloy material

Abstract

The present invention provides a method for detecting PC content in a PC / ABS alloy material, comprising: (i) pre-processing a standard sample; (ii) performing infrared spectrum test on the standard sample; (iii) establishing a standard curve; (iv) performing infrared spectrum test on the sample to be tested; (v) determining the PC content in the sample to be tested: using OMNIC software to calibrate the infrared absorption spectrum of the sample to be tested at a wave number of 1700 cm ‑1 ~1840 cm ‑1 (2) according to the corrected peak area of ​​the sample to be tested, the PC content in the sample to be tested is calculated according to the standard curve established in step (iii). The detection method has good linear coefficient and stability, is relatively accurate in quantification, and is simple and convenient to operate.

Description

Technical Field

[0001] The invention relates to the field of chemical analysis and detection, and in particular to a method for detecting PC content in a PC / ABS alloy material. Background Art

[0002] PC / ABS alloy combines the excellent properties of PC (polycarbonate) and ABS (acrylonitrile-butadiene-styrene copolymer). On the one hand, it improves the heat resistance and tensile strength of ABS, and on the other hand, it reduces the melt viscosity of PC, improves processing performance, and reduces the sensitivity of product internal stress and impact strength to product thickness.

[0003] PC / ABS alloy materials have a balanced comprehensive performance and are moderately priced, so they have developed very rapidly. After Borg-Warner developed the first PC / ABS alloy material in the mid-1960s, many large companies in the world also competed to develop new varieties of PC / ABS alloys, such as flame retardant, electroplated, UV stabilized and glass fiber reinforced, etc. These PC / ABS alloy materials have been widely used in the automotive field, such as making dashboards, bumpers, radiator grilles, body panels, interior and exterior trims, rear spoilers, wheel covers, etc.

[0004] PC / ABS alloy material has the comprehensive characteristics of both PC and ABS, but the ratio or content of PC directly affects the thermal stability of PC / ABS alloy material. There is no specific detection method for the detection of PC content in PC / ABS alloy material at present, both internationally and domestically. Therefore, it is urgent to develop a detection method for PC content in PC / ABS alloy material. Summary of the invention

[0005] In view of the above technical problems, the present invention provides a method for detecting the PC content in a PC / ABS alloy material to solve the problem that there is no clear or specific method in the prior art to detect the PC content in a PC / ABS alloy material.

[0006] To achieve the above object, the present invention provides a method for detecting the PC content in a PC / ABS alloy material, the method comprising the following steps:

[0007] (I) Pre-treatment of standard samples

[0008] (1) taking a plurality of qualified PC / ABS alloy materials with known PC contents as a plurality of standard samples, drying the standard samples, and performing tabletting on the dried standard samples;

[0009] (II) Infrared spectrum test of standard samples

[0010] (1) performing infrared spectrum testing on a plurality of the standard samples according to preset equipment parameters;

[0011] (2) performing smoothing processing on the infrared absorption spectrum of the standard sample;

[0012] (3) performing baseline correction on the infrared absorption spectrum of the standard sample;

[0013] (III) Establishing a standard curve

[0014] (1) The infrared absorption spectrum of each standard sample after correction was analyzed using OMNIC software with a wave number of 1700 cm -1 ~1840cm -1 The peak area of ​​the range is calculated to obtain the corrected peak area; a standard curve is drawn based on the corrected peak area of ​​the standard sample and the PC content in the standard sample;

[0015] (IV) Infrared spectrum test of the sample to be tested

[0016] (1) Perform infrared spectrum test on the sample to be tested according to the preset equipment parameters;

[0017] (2) performing smoothing processing on the infrared absorption spectrum of the sample to be tested;

[0018] (3) performing baseline correction on the infrared absorption spectrum of the sample to be tested;

[0019] (V) Determination of PC content in the sample to be tested

[0020] (1) The wave number of the infrared absorption spectrum of the sample to be tested after correction using OMNIC software is 1700cm -1 ~1840cm -1 Calculate the peak area of ​​the sample to be tested to obtain the corrected peak area of ​​the sample;

[0021] (2) Calculate the PC content in the sample according to the corrected peak area of ​​the sample according to the standard curve established in step (iii).

[0022] Preferably, the PC contents in the plurality of standard samples are 30%, 45%, 65%, 75.25% and 100%, respectively.

[0023] Preferably, in step (ii), performing baseline correction on the infrared absorption spectrum of the standard sample comprises: performing spectral preprocessing and spectral region selection on the infrared absorption spectrum of the standard sample to obtain a 1700cm -1 ~1840cm -1The characteristic spectrum information of PC content in the range is obtained and compared with the PC content of the standard sample for correction.

[0024] Preferably, it also includes determining the 1700cm -1 ~1840cm -1 Whether the characteristic peak intensity of the range conforms to the rule of the PC content in the multiple standard samples from small to large, and whether to further calibrate the infrared absorption spectrum of the standard sample is determined based on the judgment result.

[0025] Preferably, in step (i), the standard sample is heated and dried in an infrared oven at a temperature of 70° C. for 1 h.

[0026] Preferably, in step (i), the standard sample is tableted using an infrared tablet press, wherein the pressure range is 2MPa to 3MPa, and the surface of the pressed sheet is smooth and free of cracks.

[0027] Preferably, in step (ii), each standard sample is scanned N times at different locations, N is greater than 2, and the average spectral data of the N times is taken as the obtained spectral data.

[0028] Preferably, step (iii) further comprises obtaining a linear regression equation based on the standard curve, wherein the regression equation is y=-1.179x 2 +2.914x-0.158, where x is the mass percentage of PC in the sample to be tested, and y is the mass percentage of 1700cm in the sample to be tested. -1 ~1840cm -1 The corrected peak area range, where the linear coefficient of the standard curve is R 2 Greater than or equal to 0.996.

[0029] Preferably, in step (iii), the corrected peak areas used in drawing the calibration curve are all average values ​​of three parallel tests.

[0030] Preferably, the infrared spectrometer used in the infrared spectrum test is the ThermoFisher Nicolet Is10 FT-IR spectrometer produced by Thermo Fisher Scientific, USA, which is a mid-infrared spectrometer with a scanning range of 650cm -1 ~4000cm -1 , the scanning method is attenuated total reflection accessory method.

[0031] Compared with the prior art, the method for detecting the PC content in the PC / ABS alloy material of the present invention has good linear relationship and stability when detecting the PC content in the PC / ABS alloy material through reasonable method step design and optimization of infrared spectrum test parameters, and the quantitative method is relatively accurate, and the operation is simple and convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 This is an example of a normal infrared absorption spectrum of a standard sample in the present invention;

[0034] Figure 2a is the infrared absorption spectrum of the first point of the standard sample in the present invention (expressed in absorbance);

[0035] Figure 2b is the infrared absorption spectrum of the second point of the standard sample in the present invention (expressed in absorbance);

[0036] Figure 2c is the infrared absorption spectrum of the third point of the standard sample in the present invention (expressed in absorbance);

[0037] Figure 3 is a schematic diagram of a fitting curve of the infrared absorption spectrum of the standard sample in the present invention;

[0038] Figure 4a is the infrared absorption spectrum of the first point of the sample to be tested in the present invention (expressed in absorbance);

[0039] Figure 4b is an infrared absorption spectrum of the second point of the sample to be tested in the present invention (expressed in absorbance);

[0040] Figure 4c It is the infrared absorption spectrum of the third point of the sample to be tested in the present invention (expressed in absorbance). DETAILED DESCRIPTION

[0041] In order to provide a further understanding of the purpose, structure, features, and functions of the present invention, the following detailed description is given in conjunction with the embodiments.

[0042] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0043] The present invention provides a method for detecting PC content in a PC / ABS alloy material, the detection method comprising the following steps:

[0044] (I) Pre-treatment of standard samples

[0045] (1) taking a plurality of qualified PC / ABS alloy materials with known PC contents as a plurality of standard samples, drying the plurality of standard samples, and performing tablet pressing on the dried standard samples; wherein the standard samples are heated and dried in an infrared oven at a temperature of 70° C. for 1 hour; the standard samples are tablet pressed using an infrared tablet press, wherein the pressure range is 2 MPa to 3 MPa, and the surface of the pressed thin slices is smooth and free of cracks;

[0046] (II) Infrared spectrum test of standard samples

[0047] (1) performing Fourier transform infrared spectroscopy test on a plurality of the standard samples according to preset equipment parameters; wherein each standard sample is scanned N times at different locations, N being greater than 2, and taking the average spectral data of the N times as the obtained spectral data;

[0048] (2) performing smoothing processing on the infrared absorption spectrum of the standard sample;

[0049] (3) Baseline correction is performed on the infrared absorption spectrum of the standard sample; the spectrum after baseline correction can effectively eliminate the baseline drift of the spectrum, which is beneficial to improving the accuracy of the predicted value.

[0050] (III) Establishing a standard curve

[0051] (1) The infrared absorption spectrum of each standard sample after correction was analyzed using OMNIC software with a wave number of 1700 cm -1 ~1840cm -1 The peak area of ​​the range is calculated to obtain the corrected peak area; a standard curve is drawn with the corrected peak area of ​​the standard sample and the PC content in the standard sample, and a linear regression equation is calculated; wherein the corrected peak areas used in drawing the calibration curve are all the average values ​​of three parallel tests.

[0052] (IV) Infrared spectrum test of the sample to be tested

[0053] (1) Perform Fourier transform infrared spectroscopy test on the sample to be tested according to the preset equipment parameters;

[0054] (2) performing smoothing processing on the infrared absorption spectrum of the sample to be tested;

[0055] (3) performing baseline correction on the infrared absorption spectrum of the sample to be tested;

[0056] (V) Determination of PC content in the sample to be tested

[0057] (1) The wave number of the infrared absorption spectrum of the sample to be tested after correction using OMNIC software is 1700cm -1 ~1840cm -1 Calculate the peak area of ​​the sample to be tested to obtain the corrected peak area of ​​the sample;

[0058] (2) According to the corrected peak area of ​​the sample to be tested, the PC content in the sample to be tested is calculated according to the calibration curve established in step (iii).

[0059] The PC contents in the above-mentioned multiple standard samples are, for example, 30%, 45%, 65%, 75.25%, and 100%, respectively. However, the present invention is not limited thereto, and the number of standard samples can be more, as long as the PC contents with different contents are sufficient to draw a standard curve.

[0060] In the step (ii), the baseline correction of the infrared absorption spectrum of the standard sample includes: performing spectral preprocessing and spectral region selection on the infrared absorption spectrum of the standard sample to obtain a 1700cm -1 ~1840cm -1 The PC content characteristic spectrum information of the range is compared with the PC content of the standard sample and the calibration is performed. Moreover, step (ii) also includes determining the 1700cm -1 ~1840cm -1 Whether the characteristic peak intensity of the range conforms to the rule of the PC content in the multiple standard samples from small to large, and whether to further calibrate the infrared absorption spectrum of the standard sample is determined based on the judgment result.

[0061] Preferred examples of the present invention are listed below to help further understand the present invention. The protection scope of the present invention is not limited to these preferred examples.

[0062] Example 1

[0063] This embodiment provides a method for detecting the PC content in a PC / ABS alloy material, comprising the following steps:

[0064] (I) Pre-treatment of standard samples

[0065] (1) Take five PC / ABS alloy materials with known PC contents as standard samples, where the PC contents in the standard samples are 30%, 45%, 65%, 75.25%, and 100%, respectively. Place the standard samples in an infrared oven and bake at 70°C for one hour to remove moisture. Then press them into thin sheets using an infrared tablet press at a pressure range of 2MPa to 3MPa. The pressed sheets must have a smooth surface without cracks. The movements during tableting must be slow and gentle, and PE gloves or cotton gloves must be worn throughout the process.

[0066] (II) Infrared spectrum test of standard samples

[0067] (1) Perform Fourier transform infrared spectroscopy test on standard samples according to preset equipment parameters; wherein each standard sample is tested at 3 points;

[0068] (2) performing smoothing processing on the infrared absorption spectrum of the standard sample;

[0069] (3) Baseline correction is performed on the infrared absorption spectrum of the standard sample. Specifically, spectrum preprocessing and spectrum region selection are performed on the infrared absorption spectrum of the standard sample to obtain a 1700 cm -1 ~1840cm -1 The PC content characteristic spectrum information of the range is compared with the PC content of the standard sample and the calibration is performed; and the 1700cm -1 ~1840cm -1 Whether the intensity of the characteristic peaks in the range conforms to the rule of the PC content in the various standard samples from small to large. If not, retesting is required. In addition, there should be a certain distance between each characteristic peak. If the two peaks are too close, retesting is required.

[0070] Among them, the instrument models used in this embodiment are as follows:

[0071] Fourier transform infrared spectrometer (FT-IR): Thermo Fisher NicoletIs10 FT-IR spectrometer produced by Thermo Fisher Scientific, USA, mid-infrared spectrometer; infrared oven: HW-3A, infrared tablet press: YP-2, among which FT-IR parameter selection: instrument components: SMART iTR Basic, detector: MCT / A, beam splitter: KBr, gain: 8.0, resolution: 4, aperture: medium resolution, scanning range: 650cm -1 ~4000cm -1 , Scanning method: attenuated total reflection attachment method (ATR method).

[0072] (III) Establishing a standard curve

[0073] (1) The infrared absorption spectrum of each standard sample after correction was analyzed using OMNIC software with a wave number of 1700 cm -1 ~1840cm -1 The peak area of ​​the range is calculated to obtain the corrected peak area; the standard curve is drawn with the corrected peak area of ​​the standard sample and the PC content in the standard sample. Moreover, in this embodiment, the corrected peak area used in drawing the calibration curve is the average value of three parallel tests. Figure 1-2c , Figure 1 This is an example of a normal infrared absorption spectrum of a standard sample in the present invention; Figure 2a is the infrared absorption spectrum of the first point of the standard sample in the present invention (expressed in absorbance); Figure 2b is the infrared absorption spectrum of the second point of the standard sample in the present invention (expressed in absorbance); Figure 2c It is the infrared absorption spectrum of the third point of the standard sample in the present invention (expressed in absorbance).

[0074] In addition, when establishing the standard curve, the linear regression equation can also be directly calculated, y = -1.179x 2 +2.914x-0.158, where x is the mass percentage of PC in the sample to be tested, and y is the mass percentage of 1700cm in the sample to be tested. -1 ~1840cm -1 The corrected peak area range, where the linear coefficient of the standard curve is R 2 Greater than or equal to 0.996, see Figure 3 , Figure 3 It is a schematic diagram of the fitting curve of the infrared absorption spectrum of the standard sample in the present invention.

[0075] Table 1 below shows the results of the repeatability collection and analysis of standard samples.

[0076] Table 1 Standard sample repeatability collection and analysis results

[0077] PC content (%) Corrected peak area 1 Corrected peak area 2 Corrected peak area 3 Average corrected peak area 30 0.6283 0.6283 0.6283 0.6283 45 0.8806 0.8806 0.8806 0.8806 65 1.3334 1.1415 1.2316 1.2355 75.25 1.4565 1.3644 1.3644 1.3951 100 1.5649 1.5649 1.5726 1.5675

[0078] It can be seen from Table 1 that the infrared absorption spectrum lines of the same sample collected at different times basically overlap. When the infrared absorption spectrum curves collected three times for the same sample are quantitatively calculated, the similarity is above 0.99.

[0079] (IV) Infrared spectrum test of the sample to be tested

[0080] (1) Perform Fourier transform infrared spectroscopy test on the sample to be tested according to the preset equipment parameters; each sample test surface is tested three times at different points;

[0081] (2) performing smoothing processing on the infrared absorption spectrum of the sample to be tested;

[0082] (3) Baseline correction is performed on the infrared absorption spectrum of the sample to be tested, and the corrected infrared absorption spectrum is used to test the PC content in the PC / ABS alloy material. Figure 4a-4c , Figure 4a is the infrared absorption spectrum of the first point of the sample to be tested in the present invention (expressed in absorbance); Figure 4b is an infrared absorption spectrum of the second point of the sample to be tested in the present invention (expressed in absorbance); Figure 4c It is the infrared absorption spectrum of the third point of the sample to be tested in the present invention (expressed in absorbance).

[0083] (V) Determination of PC content in the sample to be tested

[0084] (1) The wave number of the infrared absorption spectrum of the sample to be tested after correction using OMNIC software is 1700cm -1 ~1840cm -1 Calculate the peak area of ​​the sample to be tested to obtain the corrected peak area of ​​the sample;

[0085] (2) According to the corrected peak area of ​​the sample to be tested, Figure 4a-4c As shown, they are 0.8311, 0.8361, and 0.8336, respectively. The PC content in the sample to be tested is calculated according to the calibration curve established in step (iii), and the average value of the PC content in the sample to be tested is 39%.

[0086] In summary, the method for detecting the PC content in the PC / ABS alloy material of the present invention is designed through reasonable method steps and optimization of infrared spectrum test parameters, so that the detection method has good linear relationship and stability when detecting the PC content in the PC / ABS alloy material, is more accurate in quantitative determination, and is simple and convenient to operate.

[0087] The present invention has been described by the above-mentioned relevant embodiments, but the above-mentioned embodiments are only examples for implementing the present invention. In addition, the technical features involved in the different embodiments of the present invention described above can be combined with each other as long as they do not conflict with each other. It must be pointed out that the disclosed embodiments do not limit the scope of the present invention. On the contrary, changes and modifications made without departing from the spirit and scope of the present invention are all within the scope of patent protection of the present invention.

Claims

1. A method for detecting PC content in PC / ABS alloy material, characterized in that: The detection method comprises the following steps:

1. Pretreatment of standard samples (1) taking a plurality of qualified PC / ABS alloy materials with known PC contents as a plurality of standard samples, drying the standard samples, and performing tabletting on the dried standard samples; In the step (i), the standard sample is pressed into tablets using an infrared tablet press, wherein the pressure range is 2MPa to 3MPa, and the surface of the pressed sheet is smooth and free of cracks; (II) Infrared spectrum test of standard samples (1) performing infrared spectrum testing on a plurality of the standard samples according to preset equipment parameters; (2) performing smoothing processing on the infrared absorption spectrum of the standard sample; (3) performing baseline correction on the infrared absorption spectrum of the standard sample; In the step (ii), performing baseline correction on the infrared absorption spectrum of the standard sample comprises: The infrared absorption spectrum of the standard sample was subjected to spectral preprocessing and spectral region selection to obtain 1700cm -1 ~1840cm -1 The PC content characteristic spectrum information of the range is compared with the PC content of the standard sample for correction; Also includes the 1700cm -1 ~ 1840 cm -1 Whether the characteristic peak intensity of the range conforms to the rule of the PC content in the plurality of standard samples from small to large, and whether to further calibrate the infrared absorption spectrum of the standard sample according to the judgment result; 3. Establishing a standard curve (1) The wave number of the corrected infrared absorption spectrum of each standard sample is 1700 cm-1 using OMNIC software. -1 ~ 1840 cm -1 The peak area of ​​the range is calculated to obtain the corrected peak area; a standard curve is drawn based on the corrected peak area of ​​the standard sample and the PC content in the standard sample; (IV) Infrared spectrum test of the sample to be tested (1) Perform infrared spectrum test on the sample to be tested according to the preset equipment parameters; (2) Smoothing the infrared absorption spectrum of the sample to be tested; (3) performing baseline correction on the infrared absorption spectrum of the sample to be tested; 5. Determination of PC content in the sample to be tested (1) The wave number of the infrared absorption spectrum of the sample to be tested after correction using OMNIC software is 1700cm -1 ~1840 cm -1 Calculate the peak area of ​​the sample to be tested to obtain the corrected peak area of ​​the sample; (2) Calculate the PC content in the sample according to the corrected peak area of ​​the sample and the standard curve established in step (iii).

2. The method for detecting PC content in PC / ABS alloy material according to claim 1, characterized in that: The PC contents in the multiple standard samples are 30%, 45%, 65%, 75.25% and 100% respectively.

3. The method for detecting PC content in PC / ABS alloy material according to claim 1, characterized in that: In step (i), the standard sample is heated and dried in an infrared oven at a temperature of 70° C. for 1 h.

4. The method for detecting PC content in PC / ABS alloy material according to claim 1, characterized in that: In step (ii), each standard sample is scanned N times at different locations, where N is greater than 2, and the average spectral data of the N times is taken as the obtained spectral data.

5. The method for detecting PC content in PC / ABS alloy material according to claim 1, characterized in that: Step (iii) also includes obtaining a linear regression equation based on the standard curve, wherein the regression equation is y = -1.179x 2 +2 .914x-0.158, where x is the mass percentage of PC in the sample to be tested, and y is the 1700cm -1 ~ 1840 cm -1 The corrected peak area range, where the linear coefficient of the standard curve is R 2 Greater than or equal to 0.

996.

6. The method for detecting PC content in PC / ABS alloy material according to claim 1, characterized in that: In step (iii), the corrected peak areas used in drawing the calibration curve are all average values ​​of three parallel tests.

7. The method for detecting PC content in PC / ABS alloy material according to claim 1, characterized in that: The infrared spectrometer used in the infrared spectrum test is the Thermo Fisher Nicolet Is10 FT-IR spectrometer produced by Thermo Fisher Scientific, USA, which is a mid-infrared spectrometer with a scanning range of 650 cm -1 ~ 4000cm -1 , the scanning method is attenuated total reflection accessory method.

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