Method for measuring spreading and permeating conditions of transition layer on surface of double-base propellant grain by dynamic contact angle method

Abstract

The invention belongs to the technical field of material surface liquid spreading and permeating measurement, and particularly relates to a method for measuring spreading and permeating conditions of a transition layer on the surface of a double-base propellant grain through a dynamic contact angle method. According to the method, 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 through calculation and comparison of the dynamic contact angle measuring instrument and a data image; calculating the change of the liquid volume of the transition layer along with time according to the volume correction coefficient of the dynamic contact angle tester; and comparing the change of the contact angle of the transition layer liquid on the surface of the double-base propellant and the surface of the non-permeable medium along with time, calculating to obtain the spreading speed, and obtaining the permeation rate of the transition layer on the double-base propellant according to the change condition of the volume of the part, permeating into the double-base propellant, of the transition layer liquid along with time. According to the method, the measurement accuracy can be improved, related data in the analysis process can be more accurately provided, and theoretical guidance is provided for many practical application processes.

Description

Technical Field

[0001] The invention belongs to the technical field of liquid spreading and penetration measurement on material surfaces, and particularly relates to a method for measuring the spreading and penetration of a transition layer on the surface of a double-base propellant grain using a dynamic contact angle method. Background Art

[0002] The spreading and penetration of liquid droplets on solid surfaces are common in everyday life and production, from simple raindrops impacting rooftops, to agricultural sprayers spraying pesticide droplets onto plant leaves, to industrial inkjet printing droplets impacting substrates, to complex industrial processes such as aerospace, metallurgy, and semiconductor component production. Liquid spreading and penetration are ubiquitous and closely linked to our daily lives and production. Therefore, studying the spreading and penetration behavior of liquids on solid surfaces and their measurement methods is of great value.

[0003] The transition layer, located between the double-base propellant and the cladding, can effectively improve the adhesion reliability of the cladding. The diffusion and penetration behavior of the transition layer on the double-base propellant surface and its speed have a significant impact on the dispersion of the transition layer on the double-base propellant surface. Research on this topic will help understand and improve related processes and conditions, thereby promoting the improvement of the bonding strength between the double-base propellant and the cladding.

[0004] Existing research on the process of liquid droplets on solid surfaces has mostly focused on the spreading behavior of liquid droplets on solid surfaces, using the change in contact angle after a liquid droplet lands on a solid surface to analyze the changing behavior of the liquid on the material surface and the surface properties of the material. However, for the transition layer on the surface of a double-base propellant, after the transition layer is brushed or sprayed on the double-base propellant surface, due to internal driving forces such as capillary action within the double-base propellant, the gravity of the transition layer liquid itself, and the concentration difference between the double-base propellant surface and the internal transition layer, the transition layer not only spreads on the double-base propellant surface but also penetrates into the double-base propellant. Currently, little research has been conducted on the diffusion and penetration rates of different transition layers on the surface of double-base propellant grains. Therefore, it is of great significance to conduct research on the diffusion and penetration of transition layers on the surface of double-base propellant grains using relevant methods. Summary of the Invention

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

[0006] To achieve the above object, the technical solution of the present invention is as follows: A method for measuring the spreading and penetration of a transition layer on the surface of a double-base propellant grain using a dynamic contact angle method comprises the following steps: Step 1: Using 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, tracking the surface contact angle and volume changes of the transition layer liquid on the non-permeable medium; through dynamic contact angle image analysis, the volume change pattern of the non-penetrated transition layer liquid is obtained, and further compared with the volume data of the dynamic contact angle meter. Through multiple dynamic contact angle tests, the relative deviation value of the dynamic contact angle meter is obtained and the volume correction coefficient of the dynamic contact angle meter is calculated; Step 2: Keeping the test conditions unchanged, use a dynamic contact angle meter to measure the change in the contact angle of the transition layer liquid on the double-base propellant surface, and track the change in the contact angle over time. After multiple dynamic contact angle tests, calculate the change in the volume of the transition layer liquid over time using the volume correction coefficient of the dynamic contact angle meter obtained in step 1; Step 3: Compare the contact angles of the transition layer liquid on the double-base propellant surface and the non-permeable medium surface over time, calculate the spreading speed, and then calculate the penetration rate of the transition layer on the double-base propellant based on the volume change of the transition layer liquid penetrating into the double-base propellant over time.

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

[0008] Furthermore, the volume of the portion of the transition layer liquid that penetrates into the double-base propellant in step 3 is calculated as follows: = - -

[0009] in, is the volume of the transition layer that penetrates into the double-base propellant. is the volume of the initial dripping transition layer on the double-base propellant surface, is the volume of liquid on the surface of the double-base propellant after a certain period of time, is the volume of the evaporated solution. and By calculating the corrected volume, It can be calculated by the volume difference of the liquid on the impermeable surface under certain conditions and within a certain period of time.

[0010] Transition layer liquid volume The calculation method is as follows: The formula for calculating the volume of the liquid portion shown in the picture is ,in, is the ratio of the circle to the circle, which can be taken as 3.14; r is the radius of the sphere after the contact angle is supplemented by the sphere; and h is the liquid height, that is, the distance between the vertex of the droplet and the plane of the measured medium.

[0011] tThe volume of the transition layer liquid at time ,in, for t The volume of the transition layer that is not penetrated at the moment, for t The volume of the spherical cap is calculated from the contact angle picture at each moment. The volume of the spherical cap is calculated from the contact angle image at time 0. The actual volume of the transition layer liquid ball before dripping or the transition layer liquid at time 0 (usually in mL). Note: and The calculation must be performed without changing the video frame rate and image magnification.

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

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

[0014] Compared with the prior art, the present invention has the following beneficial effects: Through simple dynamic contact angle measurement, the spreading of the transition layer liquid on the surface of the double-base propellant and the penetration inside the double-base propellant can be obtained, and its spreading and penetration speed can be calculated, providing theoretical guidance for many practical application processes.

[0015] By comparing the calculation of the non-permeable surface dynamic contact angle meter with the data image, the relative deviation value of the dynamic contact angle meter is obtained and the volume correction coefficient of the dynamic contact angle meter is calculated to improve the accuracy of the measurement and provide relevant data in the analysis process more accurately. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Image of contact angle data processing. DETAILED DESCRIPTION

[0017] To facilitate understanding of the present invention, the present invention will be described more fully below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0018] Unless otherwise defined, all technical terms used hereinafter have the same meanings as those generally understood by those skilled in the art. The technical terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention. Example 1

[0019] Measuring the spreading and penetration rate of toluene diisocyanate (transition layer) on the surface of double-base propellant (1) The dynamic contact angle measurement instrument was used to measure the dynamic contact angle change of toluene diisocyanate on the glass surface, and the contact angle and volume change of the liquid on the glass surface were tracked. The results of 6 average dynamic contact angle measurement tests showed that the contact angle of toluene diisocyanate on the glass surface changed little with time. Within 1 minute, it changed from 46.5° to 45.3°. Through dynamic contact angle image analysis, the volume change law of toluene diisocyanate was obtained. Within 1 minute, its volume was calculated as follows: =0.88µL Therefore, the volume of the transition layer changed from 0.89µL to 0.88µL. Further comparison with the volume data of the dynamic contact angle meter showed that the recorded volume changed from 0.90µL to 0.88µL, and the relative deviation value of the dynamic contact angle meter was obtained, and the volume correction coefficient of the dynamic contact angle meter was calculated to be 0.994. The results of 6 dynamic contact angle measurements were analyzed separately, and the average correction coefficient was 0.983.

[0020] (2) Under the same test conditions of temperature, humidity, etc., a dynamic contact angle meter was used to measure the change in the contact angle of toluene diisocyanate on the surface of the double-base propellant, and the change in the contact angle over time was tracked. The results of 6 average dynamic contact angle measurement tests showed that the contact angle of toluene diisocyanate on the surface of the double-base propellant changed greatly over time, changing from 58.7° to 35.6° within 1 minute. The change in liquid volume over time was calculated using the instrument volume correction coefficient obtained in the first step. Within 1 minute, its volume changed from 0.98µL to 0.95µL.

[0021] (3) By comparing the contact angle and volume of toluene diisocyanate on the glass and double-base propellant surfaces over time, the spreading speed of toluene diisocyanate on the double-base propellant surface and the penetration rate of toluene diisocyanate on the double-base propellant were calculated. = - - =0.98-0.95-0.01=0.02µL Permeation rate =0.02 / 1=0.02µL / min The spreading speed can be expressed by the change in contact angle = =23.1° / min The results show that toluene diisocyanate mainly spreads on the surface of double-base propellant and basically does not penetrate. Example 2

[0022] Measuring the penetration rate of Lekna JQ-1 (transition layer) on the surface of double-base propellant (1) The dynamic contact angle measurement instrument was used to measure the dynamic contact angle change of Liechtenstein JQ-1 on the glass surface, and the contact angle and volume change of the liquid on the glass surface were tracked. The results of 5 average dynamic contact angle measurement tests showed that the contact angle of Liechtenstein JQ-1 on the glass surface changed little with time. Within 1 minute, it changed from 28.0° to 26.9°. Through dynamic contact angle image analysis, the volume change law of Liechtenstein JQ-1 was obtained. Within 1 minute, its volume 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 meter showed that the recorded volume changed from 0.36µL to 0.29µL. The relative deviation value of the dynamic contact angle meter was obtained, and the volume correction coefficient of the dynamic contact angle meter was calculated as 0.983. The results of five dynamic contact angle measurements were analyzed, and the average correction coefficient was 0.986.

[0023] (2) Under the same test conditions of temperature, humidity, etc., a dynamic contact angle meter was used to measure the contact angle change of Lekna JQ-1 on the surface of double-base propellant, and the change of contact angle over time was tracked. The average dynamic contact angle measurement results of 5 times showed that the contact angle of Lekna JQ-1 on the surface of double-base propellant changed greatly over time, changing 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, its volume changed from 0.36µL to 0.02µL.

[0024] (3) By comparing the contact angle and volume changes of Lekna JQ-1 on the glass and double-base propellant surfaces over time, the spreading speed of Lekna JQ-1 on the double-base propellant surface and the penetration rate of Lekna JQ-1 on the double-base propellant were calculated. = - - =0.36-0.02-0.08=0.26µL Permeation rate =0.26 / 1=0.26µL / min The spreading speed can be expressed by the change in contact angle = =17.9° / min The results show that Lekna JQ-1 can not only spread quickly on the surface of the double-base propellant, but also quickly penetrate into the interior of the double-base propellant. Based on this, a suitable solvent for the bonding and penetration of the transition layer into the double-base propellant can be selected.

[0025] The above description is only for better explanation of the embodiments of the present invention and is not intended to limit the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention are intended to be 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 a dynamic contact angle method, characterized in that: The following steps are involved: Step 1: Using 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, tracking the surface contact angle and volume changes of the transition layer liquid on the non-permeable medium; through dynamic contact angle image analysis, the volume change pattern of the non-penetrated transition layer liquid is obtained, and further compared with the volume data of the dynamic contact angle meter. Through multiple dynamic contact angle tests, the relative deviation value of the dynamic contact angle meter is obtained and the volume correction coefficient of the dynamic contact angle meter is calculated; Step 2: Keeping the test conditions unchanged, use a dynamic contact angle meter to measure the change in the contact angle of the transition layer liquid on the double-base propellant surface, and track the change in the contact angle over time. After multiple dynamic contact angle tests, calculate the change in the volume of the transition layer liquid over time using the volume correction coefficient of the dynamic contact angle meter obtained in step 1; Step 3: Compare the contact angles of the transition layer liquid on the double-base propellant surface and the non-permeable medium surface over time, calculate the spreading speed, and then calculate the penetration rate of the transition layer on the double-base propellant surface based on the volume change of the transition layer liquid penetrating into the double-base propellant over time.

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

3. The method for measuring the spreading and penetration of a transition layer on the surface of a double-base propellant grain by a dynamic contact angle method according to claim 1, characterized in that: The calculation formula for the volume of the portion of the transition layer liquid that penetrates into the double-base propellant in step 3 is as follows: ； in, is the volume of the transition layer that penetrates into the double-base propellant. is the volume of the initial dripping transition layer on the double-base propellant surface, is the volume of liquid on the surface of the double-base propellant after a certain period of time, is the volume of the evaporated solution.

4. The method for measuring the spreading and penetration of a transition layer on the surface of a double-base propellant grain by a dynamic contact angle method according to claim 1, characterized in that: The calculation formula for the penetration rate of the transition layer on the double-base propellant surface in step 3 is as follows: ； in, for The penetration rate of the transition layer on the surface of the double-base propellant at each moment.

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