Synthetic color number testing device for butanediol and adipic acid

Abstract

The utility model relates to a synthetic color number testing device for butanediol and adipic acid, which comprises a four-neck flask, a heating jacket, a temperature detection unit, a stirring unit, a condensing component, a receiving bottle and a spectrophotometer, wherein the four-neck flask is used for esterification reaction of butanediol and adipic acid; the temperature detection unit is arranged at a first interface of the four-neck flask; the stirring unit is arranged at the second interface of the four-neck flask; the condensation assembly is arranged at a third interface of the four-neck flask and is used for cooling a reaction product of the four-neck flask; the receiving bottle is connected with the condensation assembly and is used for receiving the reaction waste liquid cooled by the condensation assembly; the spectrophotometer is arranged on one side of the receiving bottle and is used for detecting the color number of the reaction liquid in the four-neck flask. Compared with the prior art, the BDO impurity content and the product color value can be accurately correlated, and key technical support is provided for polymer-grade BDO quality control and high-end production.

Description

Technical Field

[0001] The utility model relates to the technical field of chemical detection, in particular to a synthetic color number testing device for butanediol and adipic acid. Background Art

[0002] 1,4-Butanediol (BDO) is a core raw material or chain extender in the production of materials such as polybutylene terephthalate (PBT), polyurethane (PU), thermoplastic polyurethane elastomer (TPU), and biodegradable plastic PBAT. For example, in the synthesis of PBT, BDO needs to undergo an esterification reaction with terephthalic acid to form a prepolymer, and its purity directly affects the mechanical properties (such as tensile strength and heat resistance) and appearance characteristics (such as color) of PBT. Similarly, in the production of PU and TPU, impurities in BDO may interfere with the formation of carbamate groups, resulting in defects in the polymer chain structure, which in turn affects the elasticity, wear resistance and color stability of the material.

[0003] In the prior art, there are many experimental devices for the synthesis reaction and testing of organic compounds. For example, CN219002004U discloses a nitrogen dehydration experimental device for polyol components of polyurethane adhesives, which includes components such as a four-necked flask, a stirring device, a nitrogen inlet pipeline, a thermometer and a condensation system, and is used for the dehydration experiment of polyol components. CN214735623U discloses an esterification reaction experimental device for preparing biodiesel, which consists of a reagent bottle, a peristaltic pump, a four-necked flask, an electric heating jacket, a stirring device, a distillation column, a distillation head and a condenser, and is used for the esterification reaction experiment of biodiesel. CN212246951U discloses an experimental device for preparing biodiesel by esterification reaction of waste oils and fats, which includes components such as a reagent bottle, a peristaltic pump, an electric heating jacket, a four-necked flask, a distillation head, a thermocouple, a condenser, a receiving bottle, a thermometer and a stirrer. In addition, CN220125532U discloses a simple distillation column device for laboratory use, which includes components such as a heating jacket, a material bottle, a straight condenser, a spherical condenser and a collecting bottle, and is used for laboratory distillation operations. CN214735625U discloses an ester exchange reaction experimental device for preparing biodiesel, which includes components such as a reagent bottle, a peristaltic pump, a four-necked flask, an electric heating jacket, a thermocouple, a water separator and a condenser.

[0004] The current national standards for BDO testing focus on conventional indicators (such as purity, moisture, and acidity), mainly using traditional methods such as gas chromatography and Karl Fischer method. However, these methods have the following defects:

[0005] Unable to capture key trace impurities: Trace amounts of nitrogen-containing, sulfur-containing compounds or specific organic small molecules (such as aldehydes and ketones as byproducts) in BDO may trigger side reactions (such as the generation of chromophores) during downstream polymerization, significantly deteriorating the color value of the product (such as yellowing of PBT and decreased transparency of PU). The detection limit of such impurities exceeds the coverage of conventional methods.

[0006] Lack of correlation verification with downstream reactions: Existing tests only evaluate the physical and chemical properties of BDO in isolation, and do not simulate the impact of actual polymerization conditions (such as high-temperature esterification reactions) on impurities, resulting in the inability of test results to accurately predict the applicability of BDO in actual production.

[0007] As high-end application fields (such as electronic packaging and medical devices) have higher requirements for material performance, downstream customers have set higher standards for BDO impurity control. For example, in the production of TPU medical catheters, a slight deviation in the color value of the material may cause biocompatibility risks; in automotive-grade PBT materials, unstable color will directly affect the appearance quality grade. However, the existing testing system is difficult to meet the following requirements:

[0008] Rapid screening of polymer-grade BDO: Traditional methods require multiple rounds of experiments to verify the applicability of BDO, which takes several weeks and is costly, and there is an urgent need to develop new detection technologies to solve this problem.

[0009] Quantify the dynamic impact of impurities on color value: It is impossible to directly correlate the BDO impurity content with the color number of downstream products through test data, which makes quality traceability and process optimization difficult. It is urgent to develop new testing technologies to solve this problem. Utility Model Content

[0010] The purpose of the utility model is to overcome the defects of the above-mentioned prior art and provide a synthetic color number testing device for butanediol and adipic acid, which can accurately correlate the impurity content of BDO with the product color value, and provide key technical support for the quality control and high-end production of polymerization-grade BDO.

[0011] The purpose of the utility model can be achieved through the following technical solutions:

[0012] The utility model provides a synthetic color number testing device for butanediol and adipic acid, comprising a four-necked flask, a heating jacket, a temperature detection unit, a stirring unit, a condensation component, a receiving bottle, and a spectrophotometer, wherein specifically:

[0013] A four-necked flask is used for the esterification reaction of butanediol and adipic acid;

[0014] A heating jacket is arranged at the bottom of the four-necked flask;

[0015] The temperature detection unit is arranged at the first interface of the four-necked flask, and is used to detect the temperature of the liquid in the four-necked flask;

[0016] The stirring unit is arranged at the second interface of the four-necked flask;

[0017] The condensation component is arranged at the third interface of the four-necked flask, and is used to cool the reaction product of the four-necked flask;

[0018] The receiving bottle is connected to the condensation assembly and is used to receive the reaction waste liquid after the condensation assembly is cooled;

[0019] The spectrophotometer is arranged on one side of the four-necked flask and is used to detect the color number of the reaction liquid in the four-necked flask.

[0020] Furthermore, the heating jacket is an electric heating jacket, and the heating jacket matches the four-necked flask.

[0021] Furthermore, the temperature detection unit is an electronic thermometer or a thermocouple.

[0022] Furthermore, the stirring unit includes a stirring motor disposed at the second interface of the four-necked flask and a stirring paddle connected to an output end of the stirring motor.

[0023] Furthermore, the condensation assembly includes a spherical condenser and a straight tube condenser that are connected to each other.

[0024] Furthermore, one end of the spherical condenser is connected to the third interface of the four-necked flask, the other end of the spherical condenser is connected to one end of the straight tube condenser, and the other end of the straight tube condenser is connected to the receiving bottle.

[0025] Furthermore, the condensation path in the spherical condenser is oriented obliquely upward, and the condensation path in the straight tube condenser is oriented obliquely downward.

[0026] Furthermore, the model of the spectrophotometer is 3nh CR-10.

[0027] Furthermore, the four-necked flask is made of transparent glass.

[0028] Furthermore, the synthetic color number testing device of butanediol and adipic acid also includes a temperature controller, and the temperature controller is electrically connected to the temperature detection unit and the heating sleeve respectively.

[0029] Compared with the prior art, the utility model has the following beneficial effects:

[0030] The utility model can quickly evaluate the polymerization applicability of BDO by constructing a standardized esterification reaction simulation system (four-necked flask, segmented condensation component) and a high-precision real-time color number detection unit (spectrophotometer), which significantly improves the efficiency compared with the traditional multi-day experimental verification method; it can accurately correlate the BDO impurity content with the product color value, and provide key technical support for the quality control of polymerization-grade BDO and high-end production (such as electronic-grade materials). The spectrophotometer can measure the reflectivity or transmittance of the sample at different wavelengths to obtain the color information of the sample. By measuring the transmission of the liquid sample, the spectrophotometer can accurately analyze the color characteristics of the sample and compare it with the platinum-cobalt color number standard to obtain the platinum-cobalt color number value of the sample. Compared with the traditional visual colorimetry method, the spectrophotometer has higher precision and accuracy, can avoid the subjectivity and error of human eye judgment, and can also improve the measurement efficiency, and can provide more detailed color data. Compared with the traditional platinum-cobalt colorimeter, it solves the problems of colorimetric cell cracking at high temperature and colorimetric cell difficult to clean after cooling. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The utility model is a schematic diagram of the structure of the synthetic color number testing device of butanediol and adipic acid.

[0032] In the figure: 0. four-necked flask, 1. heating jacket, 2. temperature detection unit, 3. stirring unit, 4. spherical condenser, 5. straight tube condenser, 6. receiving flask, 8. temperature controller, 10. spectrophotometer. DETAILED DESCRIPTION

[0033] Based on the in-depth study of BDO synthesis process and downstream applications, this utility model innovatively proposes synthetic color number as the core indicator of BDO quality control. This indicator simulates the actual working conditions of BDO in esterification reaction (such as the reaction system of butanediol and adipic acid), quantifies the chromaticity change of the reaction product, and indirectly reflects the type and content of impurities in BDO. Its technical logic is:

[0034] Impurity-color value correlation mechanism: Color-forming impurities in BDO (such as conjugated olefins and metal ion complexes) will catalyze side reactions during high-temperature reactions to generate color-developing substances (such as quinone compounds), resulting in an increase in the color number of the reaction solution.

[0035] By integrating a standardized esterification reaction apparatus (such as a four-necked flask, a controllable temperature heating system) with a color detection unit (such as a spectrophotometer), rapid performance evaluation of BDO in a simulated polymerization environment can be achieved, providing a direct basis for quality control.

[0036] The following is a detailed description of the present invention in conjunction with the accompanying drawings and specific embodiments. Component models, material names, connection structures, control methods, algorithms and other features not clearly described in this technical solution are all considered to be common technical features disclosed in the prior art.

[0037] Example 1

[0038] The synthetic color number testing device of butanediol and adipic acid in this embodiment includes a four-necked flask 0, a heating jacket 1, a temperature detection unit 2, a stirring unit 3, a condensation assembly, a receiving bottle 6, and a spectrophotometer 10, wherein the specific Figure 1 .

[0039] Four-necked flask 0 is used for esterification reaction of butanediol and adipic acid;

[0040] The heating jacket 1 is arranged at the bottom of the four-necked flask 0;

[0041] The temperature detection unit 2 is arranged at the first interface of the four-necked flask 0, and is used to detect the temperature of the liquid in the four-necked flask 0;

[0042] The stirring unit 3 is arranged at the second interface of the four-necked flask 0;

[0043] The condensation component is arranged at the third interface of the four-necked flask 0, and is used to cool the reaction product of the four-necked flask 0;

[0044] The receiving bottle 6 is connected to the condensation assembly and is used to receive the reaction waste liquid after the condensation assembly is cooled;

[0045] The spectrophotometer 10 is disposed on one side of the four-necked flask 0 and is used to detect the color number of the reaction liquid in the four-necked flask 0 .

[0046] The heating jacket 1 is an electric heating jacket, and the heating jacket 1 matches the four-necked flask 0. The temperature detection unit 2 is an electronic thermometer or a thermocouple.

[0047] The stirring unit 3 includes a stirring motor disposed at the second interface of the four-necked flask 0 and a stirring paddle connected to the output end of the stirring motor.

[0048] The condensation assembly includes a spherical condenser 4 and a straight tube condenser 5 connected to each other. One end of the spherical condenser 4 is connected to the third interface of the four-necked flask 0, the other end of the spherical condenser 4 is connected to one end of the straight tube condenser 5, and the other end of the straight tube condenser 5 is connected to the receiving bottle 6. The condensation path in the spherical condenser 4 is in an oblique upward direction, and the condensation path in the straight tube condenser 5 is in an oblique downward direction.

[0049] The model of the spectrophotometer 10 is 3nh CR-10.

[0050] When selecting the specific type, the four-necked flask 0 is made of transparent glass.

[0051] The synthetic color number testing device of butanediol and adipic acid further comprises a thermostat 8, which is electrically connected to the temperature detection unit 2 and the heating jacket 1. The thermostat 8 in the utility model is used to control the power of the heating jacket 1 based on a preset temperature. The specific model of the thermostat 8 and the circuit connection with the temperature detection unit 2 and the heating jacket 1 are well known to those skilled in the art and will not be described in detail here.

[0052] The synthetic color number testing device of butanediol and adipic acid in the utility model comprises the following steps in the specific use process:

[0053] Install the reaction unit:

[0054] Fix the four-necked flask 0 in the heating jacket 1, and ensure that the bottom of the flask fits tightly against the inner wall of the heating jacket.

[0055] A temperature detection unit 2 (such as a K-type thermocouple) is installed through the first interface of the four-necked flask, and the probe is inserted into a depth of about 2 / 3 below the liquid surface.

[0056] The stirring unit 3 is installed on the second interface, that is, the stirring paddle is installed, and the stirring paddle is adjusted to the center of the flask to ensure that the paddle is immersed in the reaction liquid.

[0057] Connect the condensing components:

[0058] The inlet end of the spherical condenser 4 is connected to the third interface of the four-necked flask, and the condensation path is oriented obliquely upward.

[0059] The outlet end of the spherical condenser 4 is connected to the straight tube condenser 5 , the condensation path is slanting downward, and the end is connected to the receiving bottle 6 .

[0060] Pass cooling water into the condensation assembly (flow rate 1.5 L / min, water temperature ≤15°C).

[0061] Detection unit calibration:

[0062] Turn on the spectrophotometer 10 (model 3nh CR-10), perform black and white calibration, and select the appropriate color space.

[0063] Use standard color solution such as (ASTM D1500 standard solution) to calibrate the colorimeter and ensure that the error is ≤ 0.1 color unit.

[0064] Feeding and reaction start-up

[0065] Raw materials added:

[0066] Add butanediol (100.0 ± 0.5 g) and adipic acid (150.0 ± 0.5 g) into four-necked flask 0.

[0067] A catalyst (such as tetrabutyl titanate, 0.05 wt%) was added when necessary.

[0068] Parameter settings:

[0069] Turn on the thermostat 8 and set the target reaction temperature to 160±1°C.

[0070] Start stirring unit 3 and adjust the speed to 200±10 rpm.

[0071] Heating and reaction monitoring:

[0072] Turn on the heating jacket 1, raise the temperature to the target temperature at a rate of 10°C / min, and maintain the reaction time for 2 hours.

[0073] The temperature fluctuation is monitored in real time by the thermostat 8, and the heating power is automatically adjusted (PID control mode).

[0074] Product liquid receiving:

[0075] The reaction product generated by the reaction flows into the receiving bottle 6 after being cooled by the condensation component.

[0076] After the reaction is completed, the heating jacket 1 is turned off and the mixture is naturally cooled to below 80°C.

[0077] Online color measurement:

[0078] Ensure that the four-necked flask 0 is placed in a position where the spectrophotometer 10 can detect, and ensure that the detection window is aligned with the optical fiber probe.

[0079] Start the automatic detection mode of the spectrophotometer and record the color value of the reaction solution (output the result according to the ASTM D1500 standard).

[0080] Data Records:

[0081] Export color data and temperature curve to the user's PC (via USB interface or wireless transmission).

[0082] Disassemble the device, clean the four-necked flask 0, condenser and receiving flask with ethanol and deionized water in turn, and dry them for later use.

[0083] Color number determination standard:

[0084] If the color number value is ≤10.0 (platinum-cobalt color scale), BDO is determined to be suitable for polymer-grade products;

[0085] If the color number value is greater than 10.0, further analysis of the impurity components (such as GC-MS testing) is required and the BDO production process is optimized.

[0086] The above description of the embodiments is to facilitate the understanding and use of the utility model by those skilled in the art. It is obvious that those familiar with the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the utility model is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the utility model without departing from the scope of the utility model should be within the scope of protection of the utility model.

Claims

1. A synthetic color number testing device for butanediol and adipic acid, characterized in that: include: A four-necked flask (0) for esterification of butanediol and adipic acid; A heating jacket (1) is arranged at the bottom of the four-necked flask (0); A temperature detection unit (2), arranged at a first interface of the four-necked flask (0), and used to detect the temperature of the liquid in the four-necked flask (0); A stirring unit (3) is provided at the second interface of the four-necked flask (0); A condensation component, arranged at the third interface of the four-necked flask (0), and used for cooling the reaction product in the four-necked flask (0); A receiving bottle (6), connected to the condensation assembly, and used to receive the reaction waste liquid after the condensation assembly is cooled; The spectrophotometer (10) is arranged on one side of the four-necked flask (0) and is used to detect the color number of the reaction liquid in the four-necked flask (0).

2. A synthetic color number testing device for butanediol and adipic acid according to claim 1, characterized in that: The heating jacket (1) is an electric heating jacket, and the heating jacket (1) matches the four-necked flask (0).

3. The synthetic color number testing device of butanediol and adipic acid according to claim 1, characterized in that: The temperature detection unit (2) is an electronic thermometer or a thermocouple.

4. The synthetic color number testing device of butanediol and adipic acid according to claim 1, characterized in that: The stirring unit (3) comprises a stirring motor arranged at the second interface of the four-necked flask (0) and a stirring paddle connected to the output end of the stirring motor.

5. The synthetic color number testing device of butanediol and adipic acid according to claim 1, characterized in that: The condensation assembly comprises a spherical condensation tube (4) and a straight tube condensation tube (5) which are connected to each other.

6. A synthetic color number testing device for butanediol and adipic acid according to claim 5, characterized in that: One end of the spherical condenser (4) is connected to the third interface of the four-necked flask (0), the other end of the spherical condenser (4) is connected to one end of the straight tube condenser (5), and the other end of the straight tube condenser (5) is connected to the receiving bottle (6).

7. A synthetic color number testing device for butanediol and adipic acid according to claim 5, characterized in that: The condensation path in the spherical condenser (4) is oriented obliquely upward, and the condensation path in the straight tube condenser (5) is oriented obliquely downward.

8. The synthetic color number testing device of butanediol and adipic acid according to claim 1, characterized in that: The model of the spectrophotometer (10) is 3nh CR-10.

9. The synthetic color number testing device of butanediol and adipic acid according to claim 1, characterized in that: The four-necked flask (0) is made of transparent glass.

10. The synthetic color number testing device of butanediol and adipic acid according to claim 1, characterized in that: The synthetic color number testing device of butanediol and adipic acid further comprises a temperature controller (8), wherein the temperature controller (8) is electrically connected to the temperature detection unit (2) and the heating jacket (1), respectively.

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