Wide-temperature-range elastic cement base rubber for buffer as well as preparation method and application of wide-temperature-range elastic cement base rubber

Abstract

The invention belongs to the technical field of high and low temperature resistant elastic daub, and particularly relates to a wide-temperature-range elastic daub base rubber for a buffer and a preparation method and application of the wide-temperature-range elastic daub base rubber. The wide-temperature-range elastic cement base rubber for the buffer is prepared from methyl cyclosiloxane, ethyl cyclosiloxane, phenyl cyclosiloxane, a phenylene ether monomer, a catalyst and an end-capping reagent through a copolymerization reaction, and has the excellent properties of low glass transition temperature, high viscosity, wide temperature range, insensitivity to temperature, cold resistance and heat resistance; the viscosity fluctuation along with the temperature is small, the property is stable, and the elastic cement can be used for preparing elastic cement materials which are high in performance, wide in temperature range and used in extreme environments.

Description

Technical Field

[0001] The present invention belongs to the technical field of high and low temperature resistant elastic cement, and specifically relates to a wide temperature range elastic cement base for a buffer, and a preparation method and application thereof. Background Art

[0002] The buffer is a mechanical device with a buffering and shock-absorbing function. It is widely used in aerospace, military defense, high-speed trains and other fields. Its working principle is to absorb the impact energy through the buffer medium and convert it into heat energy for dissipation when a collision occurs. The buffer medium of the buffer is varied, and the common ones are springs, inert gases, hydraulic oils, and elastic cement. The buffer made of elastic cement as the buffer medium has the advantages of simple structure, light weight, easy manufacturing, low cost, low impedance, high absorption rate, and long maintenance cycle.

[0003] Elastic putty is a polymer compound miscible between solid and liquid, which has the characteristics of viscoelasticity, compressibility and fluidity. It is generally based on unvulcanized silicone rubber as the base material, and is mixed with damping fillers, heat stabilizers, compression agents, flame retardants, etc.

[0004] At present, the research on elastic cement materials in China mainly focuses on damping fillers, formula design, etc., and there is less research on the elastic cement base itself. The base used in most relevant patents is dimethyl silicone rubber or low phenyl silicone rubber, for example: the patent application with patent publication number CN103073723A uses low phenyl silicone rubber, the patent application CN102863795A uses dimethyl silicone rubber, and the patent application CN105524467A uses low phenyl silicone rubber.

[0005] Both types of silicone rubber have their own shortcomings. The molecular chain of dimethyl silicone rubber is more flexible and the glass transition temperature is lower, but its viscosity decreases significantly with increasing temperature, and its damping effect is poor at high temperatures. Low-phenyl silicone rubber has a better damping effect because it contains rigid phenyl groups in its molecular chain, but its glass transition temperature is higher and it is easy to crystallize at around -50°C, causing the damping function to fail, and it cannot meet the use requirements in extremely low temperature environments. Summary of the invention

[0006] Based on the above technical background, in order to solve the problem that the existing elastic putty base has a high glass transition temperature and its viscosity is greatly affected by temperature, and cannot meet the requirements of wide temperature range use, the main purpose of the present invention is to provide a wide temperature range elastic putty base for buffers and its preparation method and application, so as to overcome the shortcomings of the prior art.

[0007] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention includes:

[0008] The first aspect of the present invention is to provide a wide temperature range elastic cement base for a buffer, wherein the wide temperature range elastic cement base for the buffer is prepared from the following raw materials in parts by weight: 50 to 80 parts of methyl cyclosiloxane, 10 to 40 parts of ethyl cyclosiloxane, 1 to 10 parts of phenyl cyclosiloxane, 1 to 12 parts of phenylene ether monomer, 0.5 to 3 parts of a catalyst, and 0.1 to 1 part of a capping agent.

[0009] Preferably, the wide temperature range elastic adhesive base for the buffer is made from the following raw materials in parts by weight: 60-80 parts of methylcyclosiloxane, 10-37 parts of ethylcyclosiloxane, 1-5 parts of phenylcyclosiloxane, 2-10 parts of phenylene oxide monomer, 0.5 parts of catalyst, and 0.1-0.5 parts of end-capping agent.

[0010] Preferably, the methylcyclosiloxane is selected from one or more of hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane and tetramethyltetravinylcyclosiloxane; and / or,

[0011] Preferably, the ethylcyclosiloxane is selected from one or more of trimethyltriethylcyclotrisiloxane, hexaethylcyclotrisiloxane and octaethylcyclotetrasiloxane.

[0012] Preferably, the phenylcyclosiloxane is selected from one or more of trimethyltriphenylcyclotrisiloxane, tetramethyltetraphenylcyclotetrasiloxane, pentamethylpentaphenylcyclopentasiloxane, hexaphenylcyclotrisiloxane and octaphenylcyclotetrasiloxane; and / or,

[0013] Preferably, the phenylene oxide monomer is selected from one or more of 4,4'-bis(dimethylmethoxysilyl)diphenyl ether, 4,4'-bis(dimethylethoxysilyl)diphenyl ether and 4,4'-bis(dimethylhydroxysilyl)diphenyl ether.

[0014] Preferably, the catalyst is selected from one or both of tetramethylammonium hydroxide siliconate and tetraethylammonium hydroxide siliconate; and / or,

[0015] Preferably, the end-capping agent is selected from one or more of tetramethyldisiloxane, octamethyltrisiloxane, tetramethyldiphenyldisiloxane, dimethyltetraphenyldisiloxane and hexaphenyldisiloxane.

[0016] The second aspect of the present invention is to provide a method for preparing the wide temperature range elastic cement base adhesive for the buffer according to the first aspect of the present invention, the preparation method comprising the following steps:

[0017] Step 1, methylcyclosiloxane, ethylcyclosiloxane, phenylcyclosiloxane, phenylene oxide monomer, catalyst and end-capping agent are mixed, heated, vacuumized, reacted under negative pressure, then heated continuously, copolymerized, maintained at constant temperature, vacuumized, reacted under negative pressure, then heated continuously;

[0018] Step 2: After the reaction is completed, the temperature is increased and the pressure is reduced to remove low-boiling substances. After cooling, a wide-temperature range elastic cement base adhesive for the buffer is obtained.

[0019] In step 1,

[0020] Preferably, methylcyclosiloxane, ethylcyclosiloxane, phenylcyclosiloxane, phenylene oxide monomer, catalyst and end-capping agent are mixed, heated to 50-80° C., vacuumed to -0.01-0.06 MPa, and reacted under negative pressure for 0.5-2 h.

[0021] Preferably, the temperature is continued to be raised to 105-120°C, the copolymerization reaction is carried out for 2-4 hours, the temperature is maintained unchanged, the pressure is reduced to -0.01-0.06 MPa by vacuum, and the reaction is carried out at this temperature and pressure for 0.5-2 hours, and then the temperature is continued to be raised to 130-160°C, and the reaction is carried out at this temperature for 0.5-2 hours.

[0022] In step 2,

[0023] Preferably, after the reaction is completed, the temperature is raised to 180-200° C., the low-boiling substances are removed under reduced pressure, and the reaction mixture is cooled to room temperature to obtain a wide-temperature range elastic cement base for the buffer.

[0024] The third aspect of the present invention is to provide an application of the wide temperature range elastic cement base adhesive for the buffer described in the first aspect of the present invention in the production of high-performance, wide temperature range elastic cement materials for use in extreme environments.

[0025] The beneficial effects of the present invention are:

[0026] (1) The wide-temperature elastic cement base for buffers of the present invention is prepared from methylcyclosiloxane, ethylcyclosiloxane, phenylcyclosiloxane, phenylether monomer, catalyst and end-capping agent. The base is a polysiloxane copolymer containing four types of links: methyl links, ethyl links, phenyl links and phenylether links. The ethyl links play a role in lowering the glass transition temperature of the base, the phenylether links in the main chain are large in volume and can slow down the effect of temperature rise on the viscosity of the base, the phenyl links play a role in inhibiting crystallization, and the methyl links can reduce costs. The present invention adjusts the ratio of the four links by adjusting the amount of raw materials added, and the obtained wide-temperature elastic cement base for buffers has the excellent properties of low glass transition temperature, high viscosity and wide temperature range, and the base is insensitive to temperature and has stable properties, and can be used to make high-performance, wide-temperature elastic cement materials for use in extreme environments.

[0027] (2) The wide-temperature elastic cement base for the buffer of the present invention is obtained by ring-opening copolymerization of methylcyclosiloxane, ethylcyclosiloxane, phenylcyclosiloxane and phenyl ether monomers to obtain a polysiloxane copolymer containing four chain segments (i.e., the base glue of the present invention). The preparation method of the present invention is simple, has low requirements on equipment, and is suitable for large-scale industrial production. The base glue prepared by the preparation method has excellent cold resistance, heat resistance, damping and other properties, and can be used as a base glue for making elastic cement materials used in extreme environments, so that the base glue of the present invention has good application prospects in the field of elastic cement technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The infrared spectrum of the No. 1 base rubber prepared in Example 1 is shown;

[0029] Figure 2 The DSC curve of the No. 3 base gum prepared in Example 3 is shown;

[0030] Figure 3 The DSC curve of base gum No. 4 prepared in Example 4 is shown. DETAILED DESCRIPTION

[0031] The present invention will be described in detail below, and the characteristics and advantages of the present invention will become clearer and more distinct with the description.

[0032] Among all rubbers, silicone rubber has the lowest glass transition temperature. The glass transition temperature of ethyl silicone rubber is below -145°C, the glass transition temperature of dimethyl silicone rubber is about -125°C, and the glass transition temperature of low phenyl silicone rubber is generally -110°C. The glass transition temperature of the base rubber synthesized by the present invention is about -130°C, which is lower than the glass transition temperature of dimethyl and low phenyl silicone rubbers commonly used as base rubbers for elastic cement.

[0033] High viscosity means that the base rubber has a higher viscosity. Generally speaking, the higher the base rubber viscosity, the better the damping performance.

[0034] The wide temperature range refers to the wide effective damping temperature range of the base rubber. Specifically, compared with the commonly used dimethyl and low-phenyl silicone rubbers, the base rubber of the present invention has a low glass transition temperature, and at room temperature and above, the viscosity decreases as the temperature increases.

[0035] The first aspect of the present invention is to provide a wide temperature range elastic cement base for a buffer, wherein the wide temperature range elastic cement base for the buffer is prepared from the following raw materials in parts by weight: 50 to 80 parts of methyl cyclosiloxane, 10 to 40 parts of ethyl cyclosiloxane, 1 to 10 parts of phenyl cyclosiloxane, 1 to 12 parts of phenylene ether monomer, 0.5 to 3 parts of a catalyst, and 0.1 to 1 part of a capping agent.

[0036] Preferably, the wide temperature range elastic adhesive base for the buffer is made from the following raw materials in parts by weight: 60-80 parts of methylcyclosiloxane, 10-37 parts of ethylcyclosiloxane, 1-5 parts of phenylcyclosiloxane, 2-10 parts of phenylene oxide monomer, 0.5 parts of catalyst, and 0.1-0.5 parts of end-capping agent.

[0037] The methylcyclosiloxane is selected from one or more of hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane and tetramethyltetravinylcyclosiloxane.

[0038] Preferably, the methylcyclosiloxane is hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane or tetramethyltetravinylcyclosiloxane.

[0039] The ethylcyclosiloxane is selected from one or more of trimethyltriethylcyclotrisiloxane, hexaethylcyclotrisiloxane and octaethylcyclotetrasiloxane.

[0040] Preferably, the ethylcyclosiloxane is selected from one or both of hexaethylcyclotrisiloxane and octaethylcyclotetrasiloxane.

[0041] The phenylcyclosiloxane is selected from one or more of trimethyltriphenylcyclotrisiloxane, tetramethyltetraphenylcyclotetrasiloxane, pentamethylpentaphenylcyclopentasiloxane, hexaphenylcyclotrisiloxane and octaphenylcyclotetrasiloxane.

[0042] Preferably, the phenylcyclosiloxane is selected from one of octaphenylcyclotetrasiloxane and tetramethyltetraphenylcyclotetrasiloxane.

[0043] The phenylene oxide monomer is selected from one or more of 4,4'-bis(dimethylmethoxysilyl)diphenyl ether, 4,4'-bis(dimethylethoxysilyl)diphenyl ether and 4,4'-bis(dimethylhydroxysilyl)diphenyl ether.

[0044] Preferably, the phenylene oxide monomer is 4,4'-bis(dimethylmethoxysilyl)diphenyl ether, 4,4'-bis(dimethylethoxysilyl)diphenyl ether or 4,4'-bis(dimethylhydroxysilyl)diphenyl ether.

[0045] The catalyst is selected from one or both of tetramethylammonium hydroxide silicon alkoxide and tetraethylammonium hydroxide silicon alkoxide.

[0046] Preferably, the catalyst is tetramethylammonium hydroxide siliconate or tetraethylammonium hydroxide siliconate.

[0047] The end-capping agent is selected from one or more of tetramethyldisiloxane, octamethyltrisiloxane, tetramethyldiphenyldisiloxane, dimethyltetraphenyldisiloxane and hexaphenyldisiloxane.

[0048] Preferably, the end-capping agent is tetramethyldiphenyldisiloxane, dimethyltetraphenyldisiloxane, hexaphenyldisiloxane or tetramethyldisiloxane.

[0049] The second aspect of the present invention is to provide a method for preparing the wide temperature range elastic cement base adhesive for the buffer according to the first aspect of the present invention, the preparation method comprising the following steps:

[0050] Step 1, methylcyclosiloxane, ethylcyclosiloxane, phenylcyclosiloxane, phenylene oxide monomer, catalyst and end-capping agent are mixed, heated, vacuumized, reacted under negative pressure, then heated continuously, copolymerized, maintained at constant temperature, vacuumized, reacted under negative pressure, then heated continuously;

[0051] Step 2: After the reaction is completed, the temperature is increased and the pressure is reduced to remove low-boiling substances. After cooling, a wide-temperature range elastic cement base adhesive for the buffer is obtained.

[0052] The above steps are described in detail below.

[0053] In step 1, methylcyclosiloxane, ethylcyclosiloxane, phenylcyclosiloxane, phenylene oxide monomer, catalyst and end-capping agent are mixed, the temperature is raised to 50-80° C., the pressure is reduced to -0.01-0.06 MPa by vacuum, and the reaction is carried out under negative pressure for 0.5-2 h.

[0054] Preferably, after mixing, the temperature is raised to 50° C., the pressure is reduced to -0.04 MPa by vacuum, and the reaction is carried out for 0.5 to 1 h.

[0055] Then continue to raise the temperature to 105-120°C, carry out copolymerization reaction for 2-4 hours, maintain the temperature unchanged, evacuate the pressure to -0.01-0.06MPa, react at this temperature and pressure for 0.5-2 hours, then continue to raise the temperature to 130-160°C, react at this temperature for 0.5-2 hours to decompose the catalyst.

[0056] Preferably, the temperature is then continued to be raised to 110°C, and the copolymerization reaction is carried out for 2 to 3 hours. The temperature is maintained unchanged, and the pressure is reduced to -0.04 to -0.05 MPa by vacuum pumping, and the reaction is carried out at this temperature and pressure for 1 hour. The temperature is then continued to be raised to 150°C, and the reaction is carried out at this temperature for 0.5 to 1 hour to decompose the catalyst.

[0057] In step 2, after the reaction is completed, the temperature is raised to 180-200° C., the low-boiling substances are removed under reduced pressure, and the mixture is cooled to room temperature to obtain a wide-temperature range elastic cement base for buffers.

[0058] Preferably, after the reaction is completed, the temperature is raised to 180° C., the low-boiling substances are removed under reduced pressure, and the reaction mixture is cooled to room temperature to obtain a wide-temperature range elastic cement base for the buffer.

[0059] The third aspect of the present invention is to provide an application of the wide temperature range elastic cement base adhesive for the buffer described in the first aspect of the present invention in the production of high-performance, wide temperature range elastic cement materials for use in extreme environments.

[0060] Example

[0061] The present invention is further described below by specific examples, which are limited to illustrating the present invention but not to limiting the scope of the present invention. The raw materials used in the examples of the present invention were all purchased.

[0062] Example 1

[0063] 80 parts of hexamethylcyclotrisiloxane, 10 parts of hexaethylcyclotrisiloxane, 2 parts of octaphenylcyclotetrasiloxane, 5 parts of 4,4'-bis(dimethylmethoxysilyl)diphenyl ether, 0.5 parts of tetramethylammonium hydroxide silicon alkoxide, and 0.1 parts of tetramethyldiphenyldisiloxane were put into a reaction kettle at one time; the temperature was raised to 55°C, the pressure was reduced to -0.04MPa by vacuum, and the reaction was carried out for 0.5 hours; then the temperature was continued to be raised to 110°C, and the ring-opening copolymerization reaction was carried out for 3 hours; the temperature was maintained unchanged, the pressure was reduced to -0.04MPa, and the reaction was carried out at this pressure for 1 hour; then the temperature was raised to 150°C, and the temperature was maintained for 0.5 hours to decompose the catalyst; finally, the temperature was raised to 180°C, and the low-boiling substances were removed by decompression. Cooling to room temperature, a No. 1 base rubber was obtained.

[0064] The infrared spectrum of No. 1 base glue obtained by testing is as follows Figure 1 As shown, Figure 1 Medium, 3051 and 3021cm -1 295cm is the stretching vibration absorption peak of CH bond on phenyl and phenylene; -1 、2902cm -1 The saturated CH single bond stretching vibration absorption peak is at 1582cm -1 、1493cm -1 and 1411cm -1 The absorption peak of the benzene ring skeleton deformation vibration is at 1300~1200cm -1 The absorption peaks are the side chain symmetric CH3 and CH2CH3 deformation vibrations; 1174cm -1 The absorption peak of SiC6H4OC6H4Si symmetric stretching vibration is 1073cm -1 and 1011cm -1 The Si-O-Si bond stretching vibration absorption peak is at 788cm -1 The Si-C bond plane swing absorption peak is at 736cm -1 and 697cm -1The absorption peak of the side chain phenyl CH out-of-plane vibration is the characteristic absorption peak of the side phenyl structure. The above infrared results show that the synthesized base rubber contains four chain segments: dimethyl, diethyl, phenylene oxide, and methylphenyl.

[0065] Example 2

[0066] 70 parts of octamethylcyclotetrasiloxane, 25 parts of hexaethylcyclotrisiloxane, 2 parts of tetramethyltetraphenylcyclotetrasiloxane, 5 parts of 4,4'-bis(dimethylethoxysilyl)diphenyl ether, 0.5 parts of tetraethylammonium hydroxide silicon alkoxide, and 0.1 parts of dimethyltetraphenyldisiloxane were put into a reaction kettle at one time; the temperature was raised to 55°C, the pressure was reduced to -0.04MPa under vacuum, and the reaction was carried out for 1 hour; then the temperature was continued to be raised to 110°C, and the ring-opening copolymerization reaction was carried out for 2 hours; the temperature was maintained unchanged, the pressure was reduced to -0.05MPa, and the reaction was carried out at this pressure for 1 hour; then the temperature was raised to 150°C, and the temperature was maintained for 1 hour to decompose the catalyst; finally, the temperature was raised to 180°C, and the low-boiling substances were removed under reduced pressure. Cooling to room temperature, a No. 2 base rubber was obtained.

[0067] Example 3

[0068] 65 parts of octamethylcyclotetrasiloxane, 30 parts of hexaethylcyclotrisiloxane, 1 part of octamethylcyclotetrasiloxane, 1 part of tetramethyltetraphenylcyclotetrasiloxane, 5 parts of 4,4'-bis(dimethylethoxysilyl)diphenyl ether, 0.5 parts of tetramethylammonium hydroxide silicon alkoxide, and 0.1 parts of hexaphenyldisiloxane were put into a reaction kettle at one time; the temperature was raised to 55°C, the pressure was reduced to -0.04MPa by vacuum, and the reaction was carried out for 1 hour; then the temperature was continued to be raised to 110°C, and the ring-opening copolymerization reaction was carried out for 3 hours; the temperature was maintained unchanged, the pressure was reduced to -0.05MPa, and the reaction was carried out at this pressure for 1 hour; then the temperature was raised to 150°C, and the temperature was maintained for 0.5 hours to decompose the catalyst; finally, the temperature was raised to 180°C, and the low-boiling substances were removed by decompression. Cooling to room temperature, a No. 3 base rubber was obtained.

[0069] The DSC curve of No. 3 base rubber obtained by testing is as follows Figure 2 As shown, Figure 2 It can be seen that the glass transition temperature of base glue No. 3 is -130.0℃.

[0070] Example 4

[0071] 60 parts of octamethylcyclotetrasiloxane, 25 parts of hexaethylcyclotrisiloxane, 5 parts of tetramethyltetraphenylcyclotetrasiloxane, 2 parts of 4,4'-bis(dimethylethoxysilyl)diphenyl ether, 0.5 parts of tetramethylammonium hydroxide silicon alkoxide, and 0.1 parts of hexaphenyldisiloxane were put into the reaction kettle at one time; the temperature was raised to 55°C, the pressure was reduced to -0.04MPa under vacuum, and the reaction was carried out for 1 hour; then the temperature was continued to be raised to 110°C, and the ring-opening copolymerization reaction was carried out for 3 hours; the temperature was maintained unchanged, the pressure was reduced to -0.05MPa, and the reaction was carried out at this pressure for 1 hour; then the temperature was raised to 150°C, and the temperature was maintained for 0.5 hours to decompose the catalyst; finally, the temperature was raised to 180°C, and the low-boiling substances were removed under reduced pressure. Cooled to room temperature, and No. 4 base rubber was obtained.

[0072] The DSC curve of No. 4 base rubber obtained by testing is as follows Figure 3 As shown, from Figure 3 It can be seen that the glass transition temperature of No. 4 base glue is -131.3℃.

[0073] Example 5

[0074] 60 parts of octamethylcyclotetrasiloxane, 35 parts of hexaethylcyclotrisiloxane, 2 parts of tetramethyltetravinylcyclotetrasiloxane, 2 parts of tetramethyltetraphenylcyclotetrasiloxane, 5 parts of 4,4'-bis(dimethylhydroxysilyl)diphenyl ether, 0.5 parts of tetramethylammonium hydroxide silicon alkoxide, and 0.1 parts of tetramethyldisiloxane were put into a reaction kettle at one time; the temperature was raised to 55°C, the pressure was reduced to -0.04MPa by vacuum, and the reaction was carried out for 1 hour; then the temperature was continued to be raised to 110°C, and the ring-opening copolymerization reaction was carried out for 3 hours; the temperature was maintained unchanged, the pressure was reduced to -0.05MPa, and the reaction was carried out at this pressure for 1 hour; then the temperature was raised to 150°C, and the temperature was maintained for 0.5 hours to decompose the catalyst; finally, the temperature was raised to 180°C, and the low-boiling substances were removed by decompression. Cooling to room temperature, a No. 5 base rubber was obtained.

[0075] Example 6

[0076] 60 parts of octamethylcyclotetrasiloxane, 25 parts of hexaethylcyclotrisiloxane, 2 parts of tetramethyltetraphenylcyclotetrasiloxane, 10 parts of 4,4'-bis(dimethylhydroxysilyl)diphenyl ether, 0.5 parts of tetramethylammonium hydroxide silicon alkoxide, and 0.1 parts of tetramethyldisiloxane were put into the reaction kettle at one time; the temperature was raised to 55°C, the pressure was reduced to -0.04MPa under vacuum, and the reaction was carried out for 1 hour; then the temperature was continued to be raised to 110°C, and the ring-opening copolymerization reaction was carried out for 3 hours; the temperature was maintained unchanged, the pressure was reduced to -0.05MPa, and the reaction was carried out at this pressure for 1 hour; then the temperature was raised to 150°C, and the temperature was maintained for 0.5 hours to decompose the catalyst; finally the temperature was raised to 180°C, and the low-boiling substances were removed under reduced pressure. Cooling to room temperature, a No. 6 base rubber was obtained.

[0077] Example 7

[0078] 60 parts of octamethylcyclotetrasiloxane, 35 parts of hexaethylcyclotrisiloxane, 2 parts of tetramethyltetraphenylcyclotetrasiloxane, 5 parts of 4,4'-bis(dimethylhydroxysilyl)diphenyl ether, 0.5 parts of tetramethylammonium hydroxide silicon alkoxide, and 0.5 parts of tetramethyldisiloxane were put into the reaction kettle at one time; the temperature was raised to 55°C, the pressure was reduced to -0.04MPa by vacuum, and the reaction was carried out for 1 hour; then the temperature was continued to be raised to 110°C, and the ring-opening copolymerization reaction was carried out for 3 hours; the temperature was maintained unchanged, the pressure was reduced to -0.05MPa, and the reaction was carried out at this pressure for 1 hour; then the temperature was raised to 150°C, and the temperature was maintained for 0.5 hours to decompose the catalyst; finally the temperature was raised to 180°C, and the low-boiling substances were removed by decompression. Cooling to room temperature, a No. 7 base rubber was obtained.

[0079] Experimental example

[0080] Experimental Example 1 Performance Test

[0081] The base glues prepared in Examples 1 to 7 were tested for crystallinity, glass transition temperature and viscosity. The glass transition temperature test standard is GB / T 29611-2013, and the test instrument is DSC 3 of METTLER TOLEDO. During the experiment, the sample weight is 10-15 mg. During the test, the sample is heated from -170°C to 50°C. The rate of temperature change is set to 5°C / min, and the glass transition temperature (Tg) is determined by the temperature at which the heat capacity changes to half. The crystallization condition can be known from the DSC curve. If a crystallization peak appears on the DSC curve, it indicates that the sample crystallizes at this temperature.

[0082] The viscosity test standard is GB10247-2008, and the test instrument is SNB-3 rotary viscometer produced by Shanghai Precision Instrument Co., Ltd. The test results are shown in Table 1.

[0083] Table 1

[0084]

[0085] It can be seen from Table 1 that the glass transition temperature of the base glue obtained in Examples 1 to 7 of the present invention is -131 to -126°C, and there is basically no crystallization phenomenon. The base glues obtained in Examples 1 to 7 have relatively high viscosity within the temperature range of -50 to 70°C, and within this temperature range, the viscosity of the base glues obtained in Examples 1 to 7 changes little with temperature.

[0086] The above results show that the glass transition temperature of the base glue of the present invention is as low as -131°C. The base glue has the excellent properties of low glass transition temperature, high viscosity and wide temperature range, and the viscosity of the base glue is less sensitive to temperature and has stable properties.

[0087] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

Claims

1. A wide temperature range elastic cement base for a buffer, characterized in that: The wide-temperature elastic adhesive base for the buffer is prepared from the following raw materials in parts by weight: 50-80 parts of methylcyclosiloxane, 10-40 parts of ethylcyclosiloxane, 1-10 parts of phenylcyclosiloxane, 1-12 parts of phenylene oxide monomer, 0.5-3 parts of catalyst, and 0.1-1 parts of end-capping agent.

2. The wide temperature range elastic cement base adhesive for buffer according to claim 1, characterized in that: The wide-temperature elastic adhesive base for the buffer is prepared from the following raw materials in parts by weight: 60-80 parts of methylcyclosiloxane, 10-37 parts of ethylcyclosiloxane, 1-5 parts of phenylcyclosiloxane, 2-10 parts of phenylene oxide monomer, 0.5 parts of catalyst, and 0.1-0.5 parts of end-capping agent.

3. The wide temperature range elastic cement base for buffer according to claim 1, characterized in that: The methylcyclosiloxane is selected from one or more of hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane and tetramethyltetravinylcyclosiloxane; and / or, The ethylcyclosiloxane is selected from one or more of trimethyltriethylcyclotrisiloxane, hexaethylcyclotrisiloxane and octaethylcyclotetrasiloxane.

4. The wide temperature range elastic cement base for buffer according to claim 1, characterized in that: The phenylcyclosiloxane is selected from one or more of trimethyltriphenylcyclotrisiloxane, tetramethyltetraphenylcyclotetrasiloxane, pentamethylpentaphenylcyclopentasiloxane, hexaphenylcyclotrisiloxane and octaphenylcyclotetrasiloxane; and / or, The phenylene oxide monomer is selected from one or more of 4,4'-bis(dimethylmethoxysilyl)diphenyl ether, 4,4'-bis(dimethylethoxysilyl)diphenyl ether and 4,4'-bis(dimethylhydroxysilyl)diphenyl ether.

5. The wide temperature range elastic cement base adhesive for buffer according to claim 1, characterized in that: The catalyst is selected from one or both of tetramethylammonium hydroxide silicon alkoxide and tetraethylammonium hydroxide silicon alkoxide; and / or, The end-capping agent is selected from one or more of tetramethyldisiloxane, octamethyltrisiloxane, tetramethyldiphenyldisiloxane, dimethyltetraphenyldisiloxane and hexaphenyldisiloxane.

6. A method for preparing the wide temperature range elastic cement base adhesive for buffers according to any one of claims 1 to 5, characterized in that: The preparation method comprises the following steps: Step 1, methylcyclosiloxane, ethylcyclosiloxane, phenylcyclosiloxane, phenylene oxide monomer, catalyst and end-capping agent are mixed, heated, vacuumized, reacted under negative pressure, then heated continuously, copolymerized, maintained at constant temperature, vacuumized, reacted under negative pressure, then heated continuously; Step 2: After the reaction is completed, the temperature is increased and the pressure is reduced to remove low-boiling substances. After cooling, a wide-temperature range elastic cement base adhesive for the buffer is obtained.

7. The preparation method according to claim 6, characterized in that: In step 1, Mix methylcyclosiloxane, ethylcyclosiloxane, phenylcyclosiloxane, phenylene oxide monomer, catalyst and end-capping agent, heat to 50-80°C, evacuate and reduce the pressure to -0.01-0.06MPa, and react under negative pressure for 0.5-2h.

8. The preparation method according to claim 6, characterized in that: In step 1, Continue to raise the temperature to 105-120°C, carry out copolymerization reaction for 2-4 hours, maintain the temperature unchanged, evacuate the pressure to -0.01-0.06MPa, react at this temperature and pressure for 0.5-2 hours, then continue to raise the temperature to 130-160°C, and react at this temperature for 0.5-2 hours.

9. The preparation method according to claim 6, characterized in that: In step 2, After the reaction is completed, the temperature is raised to 180-200°C, the low-boiling substances are removed under reduced pressure, and the mixture is cooled to room temperature to obtain a wide-temperature range elastic cement base adhesive for buffers.

10. Use of the wide-temperature range elastic cement base for a buffer as claimed in any one of claims 1 to 5 in the production of a high-performance, wide-temperature range elastic cement material for use in extreme environments.

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