NC / Bu-NENA / IPDI adhesive system and preparation method thereof

Abstract

The invention discloses an NC / Bu-NENA / IPDI adhesive system and a preparation method thereof. The NC / Bu-NENA / IPDI adhesive system comprises the following raw materials: 55%-65% of a nitrocotton single-base spherical drug, 30%-35% of butyl-nitroxyethyl nitramine, 1%-2% of a composite stabilizer CS-85, 1%-10% of isophorone diisocyanate and 0.02%-0.1% of triphenyl bismuth. The specific impulse of the cross-linked double-base propellant reaches 1993.55 N.s.kg <-1 > (7MPa), and the cross-linked double-base propellant is suitable for preparation of dumbbell-shaped mechanical samples of the cross-linked double-base propellant and research on a formula process of a cross-linked modified double-base propellant adhesive system.

Description

Technical Field

[0001] The invention relates to an NC / Bu-NENA / IPDI adhesive system and a preparation method thereof, which are mainly used for preparing dumbbell-shaped mechanical specimens of cross-linked double-base propellants and studying the formulation process of cross-linked modified double-base propellant adhesive systems. Background Art

[0002] The mechanical properties of cross-linked modified double-base (XLDB) propellants determine whether their energy performance, combustion performance, and storage performance can be truly reflected, and are the basic premise for ensuring the integrity of the charge structure and the reliability of the engine. The XLDB propellant binder system (cross-linked double-base propellant) is composed of nitrocellulose (NC), energetic plasticizer, curing agent, curing catalyst, combustion catalyst and other components. It is the matrix and skeleton of XLDB propellant, and its performance directly determines the mechanical properties of XLDB propellant.

[0003] However, the mass percentage composition of the binder system is very different from that of the propellant formula. For example, "Study on Mechanical Properties of NC / NG / AP / Al Composite Modified Double-Base Propellants" Energetic Materials, 2007, 15(4): 345-348. reported two micro-crosslinked composite modified double-base propellants (propellant basic formula: NC 12%~30%, NG 30%~35%, AP6.5%~32.5%, RDX 0%~32.5%, Al 6.5%~19.5%, DINA 2.5%~4.5%, stabilizer 1.5%~3.5%, combustion catalyst 2.5%~4%, functional additive 1%~3%). The first micro-crosslinked XLDB propellant formula is NC15%, NG 30%-35%, TDI / TPB 0.5% / 0.05%; the second micro-crosslinked XLDB propellant formula is NC 12%, NG 30%-35%, TDI / TPB 0.5% / 0.05%. The plasticizing ratio of the above formula system is greater than 2. Direct application in the preparation of the adhesive system leads to the sedimentation of the NC spherical drug, the phase separation of the energetic plasticizer, and the poor curing effect; while reducing the plasticizing ratio and introducing a crosslinked network structure both lead to an increase in the glass transition temperature (Tg) of the system, and the hardness of the billet block is high, and it is impossible to cut samples and prepare standard dumbbell-shaped mechanical specimens. For example, "Study on the Performance of Bu-NENA / NC Low-Sensitivity Double-Base Propellant" Energetic Materials, 2017, 25(10): 794-798. A Bu-NENA / NC double-base propellant was reported, whose formula was Bu-NENA 30.40%, NC 59.10%, dimethyl diphenylurea 1.30%, and vaseline 0.2%. Its mechanical specimen was a dumbbell-shaped specimen with a gauge length of 20mm, a thickness of 1.5mm, and a width of 4mm in the middle parallel part. However, its mechanical specimen was not a military standard specimen, which was not conducive to data reference and reference.

[0004] In summary, the existing cross-linked modified double-base propellant binder system (cross-linked double-base propellant) has difficulties in preparing mechanical specimens and cannot meet the urgent needs of XLDB propellant formulation and process debugging. Summary of the invention

[0005] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a NC / Bu-NENA / IPDI adhesive system and a preparation method thereof, which greatly improves the efficiency of preparing mechanical specimens of cross-linked double-base propellants while maintaining process performance.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions to achieve the above problems:

[0007] The invention discloses an NC / Bu-NENA / IPDI adhesive system, which comprises the following raw materials: nitrocellulose monobasic spherical medicine, butyl-nitroxyethylnitramine, composite stabilizer CS-85, isophorone diisocyanate and triphenyl bismuth.

[0008] The present invention also includes the following technical features:

[0009] Specifically, the raw materials include, by mass percentage, 55% to 65% of nitrocellulose monobasic spherical medicine, 30% to 35% of butyl-nitroxyethylnitramine, 1% to 2% of composite stabilizer CS-85, 1% to 10% of isophorone diisocyanate and 0.02% to 0.1% of triphenyl bismuth.

[0010] Specifically, the raw materials include, by mass percentage, 62.22% of nitrocellulose monobasic spherical medicine, 34.23% of butyl-nitroxyethylnitramine, 1.5% of composite stabilizer CS-85, 2% of isophorone diisocyanate and 0.05% of triphenyl bismuth.

[0011] Specifically, the composite stabilizer CS-85 includes dimethyl diphenyl urea and N-methyl p-nitroaniline in a mass ratio of 8:5.

[0012] The preparation method of the NC / Bu-NENA / IPDI adhesive system comprises the following steps:

[0013] Step 1, liquid preparation: prepare the liquid according to the mass ratio of butyl-nitroethyl nitramine / composite stabilizer CS-85 = 20 / 1, mix butyl-nitroethyl nitramine and composite stabilizer CS-85 evenly, heat at 50°C until the solid is completely dissolved, evacuate to -0.09MPa, maintain for 2h, and set aside;

[0014] Step 2, drying of pure butyl-nitrooxyethyl nitramine: heat Bu-NENA to 50°C, evacuate to -0.09 MPa, maintain for 2 hours, and set aside;

[0015] Step 3, the NC / Bu-NENA / IPDI adhesive system is manufactured by a slurry casting process: first, the liquid prepared in step 1 is added to a polytetrafluoroethylene beaker, and then the dried butyl-nitroxylethylnitramine in step 2 is added, and a wooden spoon is slowly stirred until a homogeneous phase is obtained; then, the nitrocellulose monobasic spherical medicine is added to the polytetrafluoroethylene beaker, and stirred at room temperature for 10 minutes; then, isophorone diisocyanate and triphenyl bismuth are added, and stirring is continued at room temperature for 10 minutes; and a uniformly mixed NC / Bu-NEN A / IPDI adhesive system is obtained.

[0016] A method for preparing a mechanical specimen of an NC / Bu-NENA / IPDI adhesive system comprises the following steps:

[0017] Preparation of silicone mechanical mold: Wipe the silicone mechanical mold clean with absorbent cotton, apply the release agent to the surface of the silicone mechanical mold and set aside;

[0018] The uniformly mixed NC / Bu-NENA / IPDI adhesive system prepared by the preparation method of the NC / Bu-NENA / IPDI adhesive system was cast into a silicone mechanical mold and vacuumed for 30 minutes; the mold was removed after curing in an oven at 70°C for 72 hours to obtain a NC / Bu-NENA / IPDI adhesive mechanical specimen.

[0019] Compared with the prior art, the present invention has the following technical effects:

[0020] The present invention preferably uses a plasticizing ratio of Bu-NENA / NC=0.55 as the binder system, designs and manufactures a silicone mechanical mold according to GJB 770B-2005 method 413.1, and prepares a standard dumbbell-shaped mechanical specimen of NC / Bu-NENA / IPDI cross-linked double-base propellant. The theoretical specific impulse of the propellant reaches 1993.55 N·s·kg -1 (7MPa), while the comparison technology does not involve relevant technical measures. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a type A mechanical specimen specified in GJB 770B-2005 method 413.1.

[0022] Figure 2 This is a real photo of the 16-slot silicone mechanical mold.

[0023] Figure 3 This is a real photo of the NC / Bu-NENA / IPDI adhesive system film. DETAILED DESCRIPTION

[0024] The present invention provides an NC / Bu-NENA / IPDI adhesive system and a preparation method thereof. The invention concept is as follows: a small sample of the NC / Bu-NENA / IPDI adhesive system is prepared to determine that the optimal plasticizing ratio is 0.55; based on the Fox formula (Formula 1), the plasticizing ratio Bu-NENA / NC=0.55 is approximately calculated, and the glass transition temperature (T g ) is about 73.0℃. (NC glass transition temperature is 173℃, Bu-NENA melting point is -27.25℃)

[0025]

[0026] Where: T g is the glass transition temperature of the polymer plasticizing system, T g1 and T g2 are the glass transition temperatures of the polymer and plasticizer respectively (melting point of the plasticizer); w1 and w2 are the mass fractions of the polymer and plasticizer respectively.

[0027] NC / Bu-NENA / IPDI binder system sample prepared by slurry casting process g The sample cutting machine and standard dumbbell-shaped mechanical sample punching equipment cannot produce samples due to the high hardness and high viscosity. Therefore, a silicone mechanical mold was designed and manufactured based on GJB 770B-2005 method 413.1, and a release agent was applied to facilitate demoulding. While maintaining the process performance, the efficiency of preparing mechanical samples of cross-linked double-base propellants was greatly improved.

[0028] The NC / Bu-NENA / IPDI adhesive system provided by the present invention has a mass percentage composition of: 55% to 65% NC single base ball, 30% to 35% Bu-NENA, 1% to 2% composite stabilizer CS-85, 1% to 10% IPDI, and 0.02% to 0.1% TPB. The composite stabilizer CS-85 (dimethyl diphenylurea / N-methyl p-nitroaniline = 8 / 5) is dissolved in butyl-nitrooxyethyl nitramine and added into the propellant formula.

[0029] The preparation method of the NC / Bu-NENA / IPDI adhesive system comprises the following steps:

[0030] Step 1, liquid preparation: prepare the liquid according to the mass ratio of butyl-nitroethyl nitramine / composite stabilizer CS-85 = 20 / 1, mix butyl-nitroethyl nitramine and composite stabilizer CS-85 evenly, heat at 50°C until the solid is completely dissolved, evacuate to -0.09MPa, maintain for 2h, and set aside;

[0031] Step 2, drying of pure butyl-nitrooxyethyl nitramine: heat Bu-NENA to 50°C, evacuate to -0.09 MPa, maintain for 2 hours, and set aside;

[0032] Step 3, the NC / Bu-NENA / IPDI adhesive system is manufactured by a slurry casting process: first, the liquid prepared in step 1 is added to a polytetrafluoroethylene beaker, and then the dried butyl-nitroxylethylnitramine in step 2 is added, and a wooden spoon is slowly stirred until a homogeneous phase is obtained; then, the nitrocellulose monobasic spherical medicine is added to the polytetrafluoroethylene beaker, and stirred at room temperature for 10 minutes; then, isophorone diisocyanate and triphenyl bismuth are added, and stirring is continued at room temperature for 10 minutes; and a uniformly mixed NC / Bu-NEN A / IPDI adhesive system is obtained.

[0033] The method for preparing a mechanical specimen of a NC / Bu-NENA / IPDI adhesive system comprises the following steps:

[0034] Preparation of silicone mechanical mold: Wipe the silicone mechanical mold clean with absorbent cotton, apply the release agent to the surface of the silicone mechanical mold and set aside;

[0035] The uniformly mixed NC / Bu-NENA / IPDI adhesive system prepared by the preparation method of the NC / Bu-NENA / IPDI adhesive system was cast into a silicone mechanical mold and vacuumed for 30 minutes; the mold was removed after curing in an oven at 70°C for 72 hours to obtain a NC / Bu-NENA / IPDI adhesive mechanical specimen.

[0036] Specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0037] The nitrocellulose (NC) single-base spherical medicine, butyl-nitrooxyethyl nitramine (Bu-NENA), and composite stabilizer CS-85 (dimethyl diphenyl urea / N-methyl p-nitroaniline=8 / 5) used in the present invention are all produced by Xi'an Modern Chemistry Research Institute; isophorone diisocyanate (IPDI), triphenyl bismuth (TPB), release agent, etc. are all commercially purchased chemicals.

[0038] According to GJB 770B-2005 method 413.1, the silicone mechanical mold is designed and manufactured. The specimen is type A. Its shape and size diagram are shown in the figure below. Figure 1 and 2 shown.

[0039] Embodiment 1:

[0040] This embodiment provides a NC / Bu-NENA / IPDI adhesive system and a preparation method thereof, which is implemented according to the following mass percentage composition: 62.22% NC single base ball, 34.23% Bu-NENA, 1.50% composite stabilizer CS-85, 2.00% IPDI, and 0.05% TPB.

[0041] The preparation method is as follows:

[0042] Liquid preparation: (1) Prepare liquid according to the mass ratio of Bu-NENA / composite stabilizer = 20 / 1, mix 400g Bu-NENA and 20g composite stabilizer CS-85 evenly, heat at 50°C until the solid is completely dissolved, evacuate to -0.09MPa, maintain for 2h, and set aside. (2) Dry pure Bu-NENA, heat 200g Bu-NENA to 50°C, evacuate to -0.09MPa, maintain for 2h, and set aside.

[0043] Preparation of silicone mechanical mold: Use absorbent cotton to wipe the silicone mechanical mold clean, apply the release agent to the surface of the silicone mechanical mold and set aside.

[0044] The NC / Bu-NENA / IPDI adhesive system was manufactured by slurry casting process: 94.50g liquid was added to a polytetrafluoroethylene beaker, and then 12.67g dry Bu-NENA was added, and a wooden spoon was slowly stirred until homogeneous; 186.67g NC single base balls were added to the polytetrafluoroethylene beaker and stirred at room temperature for 10 minutes; 6.01g IPDI and 0.15g TPB were added, and stirring was continued at room temperature for 10 minutes. The uniformly mixed NC / Bu-NENA / IPDI adhesive system was cast into a silicone mechanical mold and vacuumed for 30 minutes; the NC / Bu-NENA / IPDI adhesive mechanical specimen was obtained by curing in an oven at 70°C for 72 hours and then demolding.

[0045] Embodiment 2:

[0046] This embodiment provides a NC / Bu-NENA / IPDI adhesive system and a preparation method thereof, which is implemented according to the following mass percentage composition: 60.98% NC single base ball, 33.54% Bu-NENA, 1.50% composite stabilizer CS-85, 3.93% IPDI, 0.05% TPB. The manufacturing method of this embodiment is the same as that of embodiment 1.

[0047] Embodiment 3:

[0048] This embodiment provides a NC / Bu-NENA / IPDI adhesive system and a preparation method thereof, which is implemented according to the following mass percentage composition: 59.79% NC single base ball, 32.89% Bu-NENA, 1.50% composite stabilizer CS-85, 5.77% IPDI, 0.05% TPB. The manufacturing method of this embodiment is the same as that of embodiment 1.

[0049] The actual photos of the NC / Bu-NENA / IPDI adhesive system films in each embodiment are as follows: Figure 3 shown.

[0050] Performance test: The theoretical specific impulse of the embodiment was calculated using REAL software. The results are shown in Table 1.

[0051] Table 1 Theoretical specific impulse of the embodiment

[0052] Sample No. <![CDATA[Theoretical specific impulse / N·s·kg -1 (7 MPa)]]> Example 1 1993.55 Example 2 1977.57 Example 3 1964.48

Claims

1. A NC / Bu-NENA / IPDI adhesive system, characterized in that: The invention comprises the following raw materials: nitrocellulose monobasic spherical medicine, butyl-nitrooxyethylnitramine, composite stabilizer CS-85, isophorone diisocyanate and triphenylbismuth.

2. The NC / Bu-NENA / IPDI adhesive system according to claim 1, characterized in that Calculated by mass percentage, the raw materials include: 55% to 65% of nitrocellulose mono-based spherical medicine, 30% to 35% of butyl-nitroxyethylnitramine, 1% to 2% of composite stabilizer CS-85, 1% to 10% of isophorone diisocyanate and 0.02% to 0.1% of triphenyl bismuth.

3. The NC / Bu-NENA / IPDI adhesive system according to claim 1, characterized in that Calculated by mass percentage, the raw materials include: 62.22% of nitrocellulose single-base spherical medicine, 34.23% of butyl-nitroxyethylnitramine, 1.5% of composite stabilizer CS-85, 2% of isophorone diisocyanate and 0.05% of triphenyl bismuth.

4. The NC / Bu-NENA / IPDI adhesive system according to claim 1, characterized in that The composite stabilizer CS-85 comprises dimethyl diphenyl urea and N-methyl p-nitroaniline in a mass ratio of 8:

5.

5. The method for preparing the NC / Bu-NENA / IPDI adhesive system according to any one of claims 2 to 4, characterized in that: The following steps are involved: Step 1, liquid preparation: prepare the liquid according to the mass ratio of butyl-nitroethyl nitramine / composite stabilizer CS-85 = 20 / 1, mix butyl-nitroethyl nitramine and composite stabilizer CS-85 evenly, heat at 50°C until the solid is completely dissolved, evacuate to -0.09MPa, maintain for 2h, and set aside; Step 2, drying of pure butyl-nitrooxyethyl nitramine: heat Bu-NENA to 50°C, evacuate to -0.09 MPa, maintain for 2 hours, and set aside; Step 3, the NC / Bu-NENA / IPDI adhesive system is manufactured by a slurry casting process: first, the liquid prepared in step 1 is added to a polytetrafluoroethylene beaker, and then the dried butyl-nitroxylethylnitramine in step 2 is added, and a wooden spoon is slowly stirred until a homogeneous phase is obtained; then, the nitrocellulose monobasic spherical medicine is added to the polytetrafluoroethylene beaker, and stirred at room temperature for 10 minutes; then, isophorone diisocyanate and triphenyl bismuth are added, and stirring is continued at room temperature for 10 minutes; and a uniformly mixed NC / Bu-NEN A / IPDI adhesive system is obtained.

6. A method for preparing a mechanical specimen of a NC / Bu-NENA / IPDI adhesive system, characterized in that: The following steps are involved: Preparation of silicone mechanical mold: Wipe the silicone mechanical mold clean with absorbent cotton, apply the release agent to the surface of the silicone mechanical mold and set aside; Casting the uniformly mixed NC / Bu-NENA / IPDI adhesive system prepared by the preparation method of the NC / Bu-NENA / IPDI adhesive system according to claim 5 into a silicone mechanical mold, and evacuating the mold for 30 minutes; The NC / Bu-NENA / IPDI adhesive mechanical specimen was obtained after curing in an oven at 70°C for 72 hours and demolding.

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