A method for determining the spreading and penetration of a transition layer on the surface of a double-base propellant grain by a dynamic contact angle method

Abstract

The present application belongs to the technical field of material surface liquid spreading penetration measurement, and particularly relates to a method for determining the spreading and penetration of a transition layer on the surface of a double-base propellant grain by a dynamic contact angle method. The relative deviation value of the dynamic contact angle measuring instrument is obtained by comparison of the data image and calculation, and the volume correction coefficient of the dynamic contact angle measuring instrument is calculated. The liquid volume of the transition layer is calculated according to the volume correction coefficient of the dynamic contact angle measuring instrument. The spreading speed is calculated by comparing the contact angle of the transition layer liquid on the surface of the double-base propellant and the non-penetration medium with the change of time. The penetration rate of the transition layer on the double-base propellant is obtained according to the change of the volume of the transition layer liquid penetrating into the double-base propellant with the change of time. The method can improve the accuracy of measurement, and can more accurately provide relevant data in the analysis process, thereby providing theoretical guidance for many practical application processes.

Description

Technical Field

[0001] This invention belongs to the field of material surface liquid spreading and penetration measurement technology, specifically relating to a method for determining the spreading and penetration of a transition layer on the surface of a double-base propellant grain using a dynamic contact angle method. Background Technology

[0002] The spreading and penetration of liquid droplets on solid material surfaces is a common phenomenon in daily life and production. From the simplest raindrops hitting the eaves, to pesticide droplets sprayed from sprayers onto plant leaves in agriculture, to ink droplets impacting the substrate in industrial printing, and even in complex industrial processes such as aerospace, metallurgy, and semiconductor component manufacturing, liquid spreading and penetration are ubiquitous and closely linked to people's lives and production. Therefore, studying the spreading and penetration behavior of liquids on solid material surfaces and its measurement methods is of significant value.

[0003] The transition layer, located between the double-base propellant and the coating layer, can effectively improve the adhesion reliability of the coating layer. The diffusion and penetration behavior and rate of the transition layer on the surface of the double-base propellant have a significant impact on its dispersion. Further research in this area will help to understand and improve related processes and conditions, thereby enhancing the adhesion strength between the double-base propellant and the coating layer.

[0004] Current research on droplet changes on solid surfaces largely focuses on droplet spreading behavior, analyzing changes in contact angle after droplet contact with the solid surface to understand the liquid's behavior and surface properties. However, for transition layers on double-base propellant surfaces, after brushing or spraying, the transition layer undergoes not only spreading on the surface but also penetrating into the propellant due to internal driving forces such as capillary action within the propellant, the liquid's own gravity, and the concentration difference between the transition layer and the propellant surface. Studies on the diffusion and penetration rates of different transition layers on double-base propellant grains are currently scarce. Therefore, researching the diffusion and penetration of transition layers on double-base propellant grains using relevant methods is of significant importance. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for determining the spreading and penetration of the transition layer on the surface of a double-base propellant grain using the dynamic contact angle method.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: A method for determining the spreading and penetration of a transition layer on the surface of a double-base propellant grain using the dynamic contact angle method includes the following steps: Step 1: Use a dynamic contact angle meter to measure the dynamic contact angle changes of the transition layer liquid on the surface of the non-permeable medium, and track the surface contact angle and volume changes of the transition layer liquid on the non-permeable medium; through dynamic contact angle image analysis, obtain the volume change law of the non-permeable transition layer liquid, and further compare it with the volume data of the dynamic contact angle meter; through multiple dynamic contact angle tests, obtain the relative deviation value of the dynamic contact angle meter and calculate the volume correction coefficient of the dynamic contact angle meter. Step 2: Keeping the test conditions unchanged, use a dynamic contact angle measuring instrument to measure the change of contact angle of the transition layer liquid on the surface of the double-base propellant, track the change of contact angle over time, and after multiple dynamic contact angle tests, calculate the change of transition layer liquid volume over time using the volume correction coefficient of the dynamic contact angle measuring instrument obtained in Step 1. Step 3: Compare the contact angle of the transition layer liquid on the surface of the double-base propellant and the surface of the non-permeable medium with time to calculate the spreading rate. Then, based on the change in the volume of the transition layer liquid penetrating into the double-base propellant with time, obtain the permeation rate of the transition layer on the double-base propellant.

[0007] Furthermore, the non-permeable medium in step 1 is selected from either glass or stainless steel.

[0008] Furthermore, the formula for calculating the volume of the transition layer liquid permeating into the double-base propellant in step 3 is as follows: = - -

[0009] in, The transition layer volume is for penetration into the interior of the double-base propellant. This represents the initial droplet transition layer volume on the surface of the double-base propellant. This represents the liquid volume on the surface of the double-base propellant after a certain period of time. This represents the volume of the evaporated solution. and Calculation based on the corrected volume It can be calculated by the volume difference of an impermeable surface liquid under certain conditions and within a certain time.

[0010] Transition layer liquid volume The calculation method is as follows: The formula for calculating the volume of the liquid shown in the image is as follows: ,in, Pi is a mathematical constant and can be 3.14. r is the radius of the sphere after the contact angle is filled in. h is the liquid height, which is the distance from the tip of the droplet to the plane of the measured medium.

[0011] tThe volume of the transition layer liquid at time is ,in, for t The volume of the unpermeable portion of the transition layer at any given moment. for t The volume of the spherical cap is calculated from the contact angle images at different times. The volume of the spherical cap was calculated from the contact angle image at time 0. This refers to the actual volume (usually mL) of the transition layer liquid sphere before or immediately after the drop. Note: and The calculation must be performed without changing the video frame rate or the image magnification.

[0012] Furthermore, the penetration rate of the transition layer on the surface of the double-base propellant in step 3 can be calculated by the following formula:

[0013] Where v is the permeation rate of the transition layer on the surface of the double-base propellant at time t.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: The spreading of the transition layer liquid on the surface of the double-base propellant and its penetration into the double-base propellant can be obtained by simple dynamic contact angle measurement. The spreading and penetration rates can be calculated, providing theoretical guidance for many practical applications.

[0015] By comparing the dynamic contact angle of a non-permeable surface with the calculated data images, the relative deviation value of the dynamic contact angle measuring instrument is obtained, and the volume correction coefficient of the dynamic contact angle measuring instrument is calculated to improve the accuracy of the measurement and provide more accurate relevant data in the analysis process. Attached Figure Description

[0016] Figure 1 Contact angle data processing image. Detailed Implementation

[0017] To facilitate understanding of the present invention, a more comprehensive description will be given below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0018] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0019] Example 1

[0020] Measuring the spreading and penetration rate of toluene diisocyanate (transition layer) on the surface of a double-base propellant. (1) The dynamic contact angle of toluene diisocyanate on the glass surface was measured using a dynamic contact angle meter to track the changes in the contact angle and volume of the liquid on the glass surface. The results of six average dynamic contact angle measurements showed that the contact angle of toluene diisocyanate on the glass surface changed little over time, changing from 46.5° to 45.3° within 1 minute. The volume change pattern of toluene diisocyanate was obtained through dynamic contact angle image analysis. The volume within 1 minute was calculated as follows: =0.88µL Therefore, the transition layer volume changed from 0.89µL to 0.88µL; further comparison with the volume data of the dynamic contact angle measuring instrument showed that its recorded volume changed from 0.90µL to 0.88µL, obtaining the relative deviation value of the dynamic contact angle measuring instrument and calculating the volume correction coefficient of 0.994. The results of the six dynamic contact angle measurements were analyzed, and the average correction coefficient of 0.983 was obtained.

[0021] (2) Under the same test conditions such as temperature and humidity, the contact angle of toluene diisocyanate on the surface of double-base propellant was measured by a dynamic contact angle measuring instrument. The contact angle was tracked over time. The results of 6 average dynamic contact angle measurements showed that the contact angle of toluene diisocyanate on the surface of double-base propellant changed significantly over time, from 58.7° to 35.6° within 1 minute. The liquid volume was calculated over time using the instrument volume correction coefficient obtained in the first step. Within 1 minute, the volume changed from 0.98µL to 0.95µL.

[0022] (3) By comparing the changes in the contact angle and volume of toluene diisocyanate on the glass and double-base propellant surfaces over time, the spreading rate of toluene diisocyanate on the double-base propellant surface and its penetration rate on the double-base propellant were calculated. = - - =0.98-0.95-0.01=0.02µL Permeation rate =0.02 / 1=0.02µL / min Spreading speed can be expressed by the change in contact angle. = =23.1° / min The results showed that toluene diisocyanate mainly spreads on the surface of the double-base propellant and does not penetrate much.

[0023] Example 2

[0024] Measuring the spreading and penetration rate of Lekner JQ-1 (transition layer) on the surface of double-base propellant. (1) The dynamic contact angle of Lekner JQ-1 on the glass surface was measured using a dynamic contact angle meter to track the changes in the contact angle and volume of the liquid on the glass surface. The results of five average dynamic contact angle measurements showed that the contact angle of Lekner JQ-1 on the glass surface changed little over time, changing from 28.0° to 26.9° within 1 minute. Through dynamic contact angle image analysis, the volume change law of Lekner JQ-1 was obtained. The volume within 1 minute was calculated as follows: =0.28µL Therefore, the volume of the transition layer changed from 0.36µL to 0.28µL; further comparison with the volume data of the dynamic contact angle measuring instrument showed that its recorded volume changed from 0.36µL to 0.29µL, obtaining the relative deviation value of the dynamic contact angle measuring instrument and calculating the volume correction coefficient of 0.983. The results of the five dynamic contact angle measurements were analyzed, and the average correction coefficient of 0.986 was obtained.

[0025] (2) Under the same test conditions such as temperature and humidity, the contact angle of Lekner JQ-1 on the surface of double-base propellant was measured using a dynamic contact angle measuring instrument. The change of contact angle over time was tracked. The results of five average dynamic contact angle measurements showed that the contact angle of Lekner JQ-1 on the surface of double-base propellant changed significantly over time, from 21.0° to 3.1° within 1 minute. The change of liquid volume over time was calculated using the instrument volume correction coefficient obtained in the first step. Within 1 minute, the volume changed from 0.36µL to 0.02µL.

[0026] (3) By comparing the changes in contact angle and volume of Lekner JQ-1 on the glass and double-base propellant surfaces over time, the spreading rate of Lekner JQ-1 on the double-base propellant surface and its penetration rate on the double-base propellant were calculated. = - - =0.36-0.02-0.08=0.26µL Permeation rate =0.26 / 1=0.26µL / min Spreading speed can be expressed by the change in contact angle. = =17.9° / min The results show that Lekner JQ-1 can not only spread rapidly on the surface of double-base propellant, but also penetrate rapidly into the interior of the double-base propellant. Based on this, a suitable solvent for bonding and penetration of the transition layer into the double-base propellant can be selected.

[0027] The above description is only for better explaining the embodiments of the present invention and is not intended to limit them. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention shall fall within the scope of the present invention.

Claims

1. A method for determining the spreading and penetration of a transition layer on the surface of a double-base propellant grain using the dynamic contact angle method, characterized in that, Includes the following steps: Step 1: Use a dynamic contact angle meter to measure the dynamic contact angle changes of the transition layer liquid on the surface of the non-permeable medium, and track the surface contact angle and volume changes of the transition layer liquid on the non-permeable medium; through dynamic contact angle image analysis, obtain the volume change law of the non-permeable transition layer liquid, and further compare it with the volume data of the dynamic contact angle meter; through multiple dynamic contact angle tests, obtain the relative deviation value of the dynamic contact angle meter and calculate the volume correction coefficient of the dynamic contact angle meter. Step 2: Keeping the test conditions unchanged, use a dynamic contact angle measuring instrument to measure the change of contact angle of the transition layer liquid on the surface of the double-base propellant, track the change of contact angle over time, and after multiple dynamic contact angle tests, calculate the change of transition layer liquid volume over time using the volume correction coefficient of the dynamic contact angle measuring instrument obtained in Step 1. Step 3: Compare the contact angle of the transition layer liquid on the surface of the double-base propellant and the surface of the non-permeable medium with time to calculate the spreading rate. Then, based on the change in the volume of the transition layer liquid penetrating into the double-base propellant with time, obtain the permeation rate of the transition layer on the surface of the double-base propellant.

2. The method for determining the spreading and penetration of the transition layer on the surface of a double-base propellant grain using the dynamic contact angle method according to claim 1, characterized in that, In step 1, the non-permeable medium is selected from either glass or stainless steel.

3. The method for determining the spreading and penetration of the transition layer on the surface of a double-base propellant grain using the dynamic contact angle method according to claim 1, characterized in that, The formula for calculating the volume of the transition layer liquid permeating into the double-base propellant in step 3 is as follows: ； in, The transition layer volume is for penetration into the interior of the double-base propellant. This represents the initial droplet transition layer volume on the surface of the double-base propellant. This represents the liquid volume on the surface of the double-base propellant after a certain period of time. This represents the volume of the evaporated solution.

4. The method for determining the spreading and penetration of the transition layer on the surface of a double-base propellant grain using the dynamic contact angle method according to claim 1, characterized in that, The formula for calculating the permeation rate of the transition layer on the surface of the double-base propellant in step 3 is as follows: ； in, for The permeation rate of the transition layer on the surface of the double-base propellant at any given time.

Images