CN-121994860-A - Polymer solution phase diagram rapid test method integrating test data and theoretical model

CN121994860ACN 121994860 ACN121994860 ACN 121994860ACN-121994860-A

Abstract

The invention belongs to the technical field of polymer physical characterization and basic research, and relates to a polymer solution phase diagram rapid test method for fusing test data and a theoretical model. The method is further based on a polymer solution phase diagram universality mathematical model, and comprises the steps of polymer solution sample preparation, phase transition temperature measurement, experimental result fusion theoretical model and polymer solution phase diagram drawing. The method can greatly shorten the mapping period of the polymer solution phase diagram and realize the rapid drawing of the high-quality polymer solution phase diagram.

Inventors

ZHANG JIAHUI
LI JUAN
ZHANG LONGGUI
ZHENG JUNPENG
QIAO JINLIANG
DU WENJIE
GONG XIANGJUN
LUO CHUNXIA
WU QI

Assignees

中国石油化工股份有限公司
中石化(北京)化工研究院有限公司

Dates

Publication Date: 20260508
Application Date: 20241106

Claims (18)

1. A polymer solution phase diagram rapid test method for fusing test data and a theoretical model comprises the following steps: (1) Preparing a plurality of polymer solutions with different volume fractions, wherein the volume fraction of at least two polymer solutions is higher than the critical volume fraction of the polymer and the volume fraction of at least two polymer solutions is lower than the critical volume fraction of the polymer; (2) Obtaining a phase transition temperature T for each polymer solution; (3) Drawing a plurality of numerical points by taking the phase transition temperature T and the volume fraction phi of the polymer solution as the abscissa, and fitting by using a formula 1 and a formula 2 to obtain a phase diagram of the polymer solution; Fitting the numerical points of which the volume fraction of the polymer solution is lower than the critical volume fraction by adopting a formula 1, and fitting the numerical points of which the volume fraction of the polymer solution is higher than the critical volume fraction by adopting a formula 2; Equation 1 Equation 2 In the formulas 1 and 2, alpha 1 、α 2 , beta and delta are fixed parameters which are irrelevant to the properties of a polymer system and the chain length of the polymer, N represents the polymerization degree of the polymer chain, T C and phi c respectively represent the critical temperature and critical volume fraction of the polymer solution, T represents the phase transition temperature of the polymer solution, phi represents the volume fraction of the polymer solution, and phi 0 、Φ 1 and phi 2 are unknown parameters without chain length dependence.
2. The rapid polymer solution phase diagram test method of claim 1, wherein α 1 ＝-0.22,α 2 ＝0.014,β＝0.326,Δ＝0.501;Φ 0 、Φ 1 and Φ 2 are obtained by fitting.
3. The method for rapidly testing a polymer solution phase diagram by fusing test data and a theoretical model according to claim 1, wherein the number of the plurality of polymer solutions is not less than 5, preferably 5-6.
4. The method for rapidly testing a polymer solution phase diagram by fusing test data and a theoretical model according to claim 1, wherein the phase transition temperature is measured by a static small-angle laser light scattering instrument, and the static small-angle laser light scattering instrument comprises a laser light source, a laser beam expander, a first lens, a temperature-controllable sample cell and a small-angle copolymerization Jiao Erji tube detection system which are sequentially arranged; The small angle co-Jiao Erji tube detection system includes a second lens with a first collimating system and a scattered light signal detector with a second collimating system.
5. The rapid polymer solution phase diagram test method for fusing test data with theoretical models of claim 4, wherein the laser light source is a helium neon laser red light source with a wavelength of 632.8nm and/or a green light source with a wavelength of 532nm, which is used for providing an incident signal for the system.
6. The rapid polymer solution phase diagram test method for fusing test data with a theoretical model of claim 4, wherein the temperature controllable sample cell comprises a sample container, a constant temperature heater and a temperature control assembly; the sample container is used for containing a solution sample to be tested, and is preferably an optical quartz sealing bottle or a quartz capillary; The constant temperature heater is used as a solid medium for controlling the temperature of the sample and provides a laser detection path; the temperature control component is used for accurately controlling the temperature of the constant-temperature heater.
7. The method for rapid polymer solution phase diagram analysis of fusion test data with a theoretical model of claim 6, wherein, The constant temperature heater is vertically arranged with the light path, a through light hole is arranged in parallel with the light path, a sample groove for placing the sample container is arranged in the non-through hole in the vertical direction, and the sample groove is sized to enable the sample container to be closely attached to the inner wall of the sample groove; The inside of the constant temperature heater is provided with a plurality of communicated flow channels, the inlet and the outlet of the flow channels are respectively positioned at two sides of the constant temperature heater, heating medium from the temperature control assembly enters the flow channels from the lower inlet, and the heating medium circulates back to the temperature control assembly from the upper outlet at the other side.
8. The method for rapidly testing a polymer solution phase diagram by fusing test data with a theoretical model according to claim 7, wherein the constant temperature heater is a multi-channel constant temperature heater; The multichannel constant temperature heater is fixed on a precise parallel moving table driven by a computer and a stepping motor, and the position of the multichannel constant temperature heater is controlled by the stepping motor, so that laser can be focused to the center of a solution sample to be tested through a first lens; preferably, the multichannel constant temperature heater is provided with 3-30 channels for accommodating sample containers, and preferably 5-8 channels.
9. The method for rapid testing of polymer solution phase diagram fusing test data and theoretical model according to claim 6, wherein the constant temperature heater is made of high heat conduction material, preferably stainless steel, copper or aluminum, more preferably brass; The temperature-controllable sample cell is also provided with a thermocouple, a heat-resistant pipeline and a heat-insulating sleeve, and the outside of the constant temperature heater is coated with fireproof heat-insulating foam cotton; when the thermocouple is used, the temperature sensing port of the thermocouple is immersed in a control group sealed container only containing the pure solvent of the test system and is used for monitoring the internal temperature of the sample cell in real time.
10. The rapid testing method for the polymer solution phase diagram fusing the test data and the theoretical model according to claim 6, wherein the temperature control component comprises a heating and refrigerating oil bath-constant temperature circulator and a heating medium, the heating range of the heating and refrigerating oil bath-constant temperature circulator is-50-300 ℃, and the temperature control precision is +/-0.01 ℃.
11. The method for rapidly testing a polymer solution phase diagram by fusing test data and a theoretical model according to claim 4, wherein the second lens is arranged at a position where an included angle of 3-10 degrees is formed between the other side of the temperature-controllable sample cell and the incident light direction and the horizontal distance between the center of the lens and the center of the sample cell is fixed to be a double focal length, and the scattered light signal detector is arranged at the position of the double focal length behind the second lens.
12. The method for rapidly testing a polymer solution phase diagram by fusing test data and a theoretical model according to claim 4, wherein the small angle copolymerization Jiao Erji pipe detection system further comprises a signal and data processing module, and the phase diagram of the polymer solution system is obtained through software calculation processing by recording the composition and the temperature corresponding to the signal mutation of the phase change point.
13. The rapid polymer solution phase diagram test method for fusing test data with theoretical models of claim 4, wherein the center of each component height on the laser path is at the same level.
14. The rapid polymer solution phase diagram test method for fusing test data with theoretical models of claim 1, wherein the sampling step of step (1) further comprises maintaining the prepared polymer solution in a homogeneous state.
15. The rapid polymer solution phase diagram test method for fusing test data and theoretical models according to claim 14, wherein a quartz bottle is used as a sample container, the polymer solution sample preparation method comprises the following steps: step (1), calculating the mass of a polymer sample and an organic solvent required by a target volume fraction sample of a system to be detected according to the volume of a quartz bottle; Step (2), accurately weighing the polymer sample and the organic solvent according to the calculation result, and filling the polymer sample and the organic solvent into a quartz bottle for sealing; And (3) heating by adopting an oil bath, and waiting for the sample to be dissolved into a uniform system.
16. The rapid polymer solution phase diagram test method for fusing test data and theoretical models according to claim 14, wherein a quartz capillary is used as a sample container, the polymer solution sample preparation method comprising the steps of: step (1), accurately weighing a polymer sample and an organic solvent, mixing, heating and dissolving to prepare a high-concentration polymer solution mother solution; Step (2), connecting each sample inlet and each sample outlet of the microfluidic chip by using a pump pipe with proper inner diameter, and respectively connecting the other end of the pump pipe to the micro-injector and the quartz capillary orifice; step (3), setting flow rates of different injection ports of the microinjector according to experimental requirements; Step (4), respectively injecting polymer solution mother liquor, organic solvent and carrier solvent into each micro-channel sample inlet, and controlling flow rate and sample injection time to enable each polymer droplet finally flowing into the quartz capillary tube to form a target concentration gradient; and (5) sealing the quartz capillary containing a plurality of polymer liquid drops to be tested, and placing the quartz capillary in a proper temperature environment to keep each liquid drop in a stable and homogeneous state.
17. The method for rapid polymer solution phase diagram testing by fusing test data with theoretical models according to any one of claims 4 to 13, wherein the method for obtaining the phase transition temperature comprises the steps of: (1) Placing one or more sample containers containing a polymer solution in a sample cell of a temperature controllable sample cell; (2) The starting device is used for focusing laser to the central position of the sample container through the laser beam expander and the first lens, the incident laser is focused again through the second lens through the first collimating system after being scattered by the sample, and finally enters the scattered light signal detector through the second collimating system for data acquisition and processing; (3) And controlling the temperature in the test process, and collecting scattered light signals of each sample at each temperature to obtain the phase transition temperature parameters of each sample.
18. The rapid polymer solution phase diagram test method of claim 17, wherein the method of obtaining the phase transition temperature comprises the steps of: Step (1), preheating a temperature-controllable sample cell in advance so that a polymer solution can still keep a stable homogeneous state after a sample container is placed in the sample cell; step (2), placing the sample container into a sample tank, and adjusting the height of a sample tank to enable laser to be focused on the central height position of the polymer solution in the sample tank; Step (3), standing for a period of time, and starting to perform program heating/cooling at a constant speed after the temperature of the sample solution is consistent with the temperature in the tank measured by the thermocouple; Detecting a scattered light signal and recording the actually measured temperature of a sample cell, wherein when the temperature of a polymer solution system reaches a certain temperature range, the scattered light signal is changed from weak to strong, and when the scattered light signal reaches the maximum value, the experiment is ended; And (5) plotting a temperature-dependent scattered light signal intensity change curve, and taking the measured temperature corresponding to the moment when the scattered light signal intensity is suddenly changed as the phase transition temperature of the polymer solution sample under the composition.

Description

Polymer solution phase diagram rapid test method integrating test data and theoretical model Technical Field The invention belongs to the technical field of polymer physical characterization and basic research, and particularly relates to a polymer solution phase diagram rapid test method for fusing test data and a theoretical model. Background The phase transition of the polymer solution is closely related to industrial production, for example, in the processes of solution polymerization technology and solution processing technology, the practical application of regulating the structure or performance of the polymer by regulating the properties, temperature and the like of the solvent is very common, and the drawing of the phase diagram of the polymer solution has very important significance for guiding and solving the practical application problem. Currently, methods for drawing a high polymer solution phase diagram by using a testing instrument include a laser light scattering method, an optical microscope method, a thermal analysis method and the like. However, it is quite difficult to accurately draw the phase diagram curve of the polymer solution by only experimental methods. First, the polymer solution phase diagram has significant chain length dependence, and the polymer sample used for the phase diagram mapping must have a narrow chain length distributionSecondly, in order to draw a complete phase diagram curve, a series of polymer solution samples with different volume fractions are usually prepared, the temperature dependence of each solution is measured sequentially, the phase diagram mapping process takes a very long time, and the demand for polymer samples with narrow molecular weight distribution is large. Up to now, high quality phase diagrams of polymer solutions have been relatively rare in the literature. Disclosure of Invention Aiming at the technical problems of large demand of narrow molecular weight distribution samples, long time consumption of phase diagram mapping and the like in the existing high molecular solution phase diagram testing technology, the invention aims to provide a universal high molecular solution phase diagram theoretical model, and the high-efficiency drawing of the high molecular solution phase diagram can be realized based on a small amount of accurate data measurement and assisted by a data fitting algorithm of the theoretical model. The invention provides a polymer solution phase diagram rapid test method for fusing test data and a theoretical model, which comprises the following steps: (1) Preparing a plurality of polymer solutions with different volume fractions, wherein the volume fraction of at least two polymer solutions is higher than the critical volume fraction of the polymer and the volume fraction of at least two polymer solutions is lower than the critical volume fraction of the polymer; (2) Obtaining a phase transition temperature T for each polymer solution; (3) Drawing a plurality of numerical points by taking the phase transition temperature T and the volume fraction phi of the polymer solution as the abscissa, and fitting by using a formula 1 and a formula 2 to obtain a phase diagram of the polymer solution; Fitting the numerical points of which the volume fraction of the polymer solution is lower than the critical volume fraction by adopting a formula 1, and fitting the numerical points of which the volume fraction of the polymer solution is higher than the critical volume fraction by adopting a formula 2; Equation 1 Equation 2 In the formulas 1 and 2, alpha 1、α2, beta and delta are fixed parameters which are irrelevant to the properties of a polymer system and the chain length of the polymer, N represents the polymerization degree of the polymer chain, T C and phi c respectively represent the critical temperature and critical volume fraction of the polymer solution, T represents the phase transition temperature of the polymer solution, phi represents the volume fraction of the polymer solution, and phi 0、Φ1 and phi 2 are unknown parameters without chain length dependence. The invention has the beneficial effects that based on the polymer solution phase diagram universality mathematical model provided by the invention, the polymer solution phase diagram rapid test method for fusing test data and a theoretical model is provided, the mapping period of the polymer solution phase diagram can be greatly shortened, and the rapid drawing of the high-quality polymer solution phase diagram is realized. Additional features and advantages of the invention will be set forth in the detailed description which follows. Drawings Exemplary embodiments of the present invention will be described in more detail with reference to the accompanying drawings. Fig. 1 is a schematic diagram of a static small angle laser light scattering instrument for measuring phase transition temperature according to an embodiment of the present invention. In the figure, 1, a laser