CN115850824A - A wide temperature range high damping rubber composite material and its preparation method - Google Patents

Abstract

The invention discloses a wide temperature range high damping rubber composite material and a preparation method thereof, belonging to the technical field of rubber materials and its preparation. The invention further improves the effective damping temperature range and damping factor of the rubber material under the condition that the rubber material has excellent mechanical strength. The rubber composite material of the present invention comprises butadiene rubber, butyl rubber, plasticizer, reinforcing filler, active agent, sulfur, anti-aging agent and accelerator, wherein the vinyl and propylene side group content of the butadiene rubber is between 60% and Between 80%, the glass transition temperature is -20℃～20℃. The rubber composite material provided by the invention is formed by introducing the butyl pentylene rubber through the coordination polymerization of an iron-based catalyst, and under the condition of excellent mechanical strength, the effective damping temperature range and damping performance of the rubber composite material are significantly improved.

Description

A wide temperature range high damping rubber composite material and preparation method thereof

Technical Field

The invention relates to a wide-temperature-range high-damping rubber composite material and a preparation method thereof, belonging to the technical field of rubber materials and preparation thereof.

Background Art

Damping material is a functional material that can absorb the system's vibration mechanical energy and sound energy and convert it into other forms of energy such as heat energy for consumption. It is mainly used in the fields of sound absorption and noise reduction of national defense equipment, vibration suppression and noise reduction in the machinery industry, vibration reduction and seismic isolation in bridge construction, etc.

Rubber materials have unique viscoelasticity and high loss capacity, and are important base materials for damping material products. As excellent rubber damping materials, the following conditions must be met: ① The loss factor peak must be high, and the peak corresponding temperature must match the working temperature. The Tg of most rubbers is lower than room temperature, while the transition temperature of most plastics is much higher than room temperature; ② The material temperature range, that is, the loss factor tanδ greater than 0.3, should be as wide as possible; ③ Good fatigue resistance and aging resistance. Rubber vibration damping pads (such as railways and bridges) are generally difficult to replace, so high fatigue resistance and aging resistance are required; ④ Good mechanical properties, able to withstand certain external force damage.

Butyl rubber is widely used in shock-absorbing and noise-reducing products because most of the side chains in its long-chain macromolecular structure are methyl groups, which has large elastic hysteresis and good damping effect. However, its glass transition temperature is around -60°C, and the optimal damping loss temperature range is between -50°C and 10°C. In order to improve its damping temperature range and damping factor, on the one hand, the temperature range of the damping material can be widened in a small range through compounding, but the damping loss factor of existing rubber-based damping materials is generally not high enough, and it is difficult to produce high-damping materials. On the other hand, the damping temperature range and room-temperature damping performance can be improved by blending with plastics or hindered phenol AO-80 and other materials, but the mechanical properties of the composite material are relatively low. Therefore, it is very necessary to provide a high-damping rubber composite material with a wide temperature range and a preparation method thereof.

Summary of the invention

The present invention provides a high-damping rubber composite material with a wide temperature range and a preparation method thereof in order to further improve the effective damping temperature range and damping factor of the rubber material while ensuring that the rubber material has excellent mechanical strength.

The technical solution of the present invention:

One of the purposes of the present invention is to provide a wide temperature range high damping rubber composite material, the composite material is composed of the following raw materials in parts by weight:

30-70 parts of butyl rubber;

30-70 parts of butyl rubber;

Plasticizer 0-30 parts;

30-80 parts of reinforcing filler;

2 to 9 parts of active agent;

0.5-3 parts of sulfur;

0.5-3 parts of accelerator;

1 to 5 parts of antioxidant;

Among them, the molecular weight of butadiene-pentadiene rubber is 20-40w, the molecular weight distribution is 3-5, the side group content is 60%-80%, the side groups are vinyl and propylene, and the Tg is -20℃～20℃; the butyl rubber is brominated butyl rubber or chlorinated butyl rubber.

It is further defined that the butadiene-vinyl rubber is prepared by coordination polymerization of isoprene monomers and butadiene monomers using an iron-based catalyst, and during the preparation process, the molar ratio of butadiene monomers to isoprene is 1:(2-5).

It is further defined that the butadiene-vinyl rubber is composed of 3,4-isoprene, 1,4-isoprene, 1,2-butadiene and 1,4-butadiene structural units.

It is further defined that the molar content of 1,2-butadiene is 70% to 90%, and the total molar content of cis-1,4-butadiene and trans-1,4-butadiene is 10% to 30%; the molar content of 3,4-isoprene is 60% to 80%, and the total molar content of cis-1,4-isoprene and trans-1,4-isoprene is 20% to 40%.

It is further defined that the plasticizer is a mixture of one or more of cycloparaffin oil, aromatic oil and paraffin oil.

It is further defined that the reinforcing filler is a mixture of one or more of carbon black, white carbon black, kaolin, talc, mica, montmorillonite, and carbon nanotubes.

It is further defined that the active agents are stearic acid and zinc oxide.

It is further defined that the antioxidant is antioxidant 4020 and/or antioxidant RD.

It is further defined that the accelerator is a mixture of one or more of a sulfonamide vulcanization accelerator, a thiazole vulcanization accelerator, a thiuram vulcanization accelerator, and a guanidine accelerator.

A second object of the present invention is to provide a method for preparing a wide temperature range high damping rubber composite material, the method comprising the following steps:

Step 1, in an internal mixer, the rotor speed is 40-50r/min, butyl rubber and butadiene-pentadiene rubber are mixed, the mixing temperature is 90°C-140°C, the mixing time is 60s-90s, then reinforcing filler is added, the mixing is continued for 90s-120s, plasticizer and stearic acid are added, the mixing temperature is 110°C-115°C, the mixing is continued for 210s-270s, and then the rubber is discharged to obtain a mixed rubber;

Step 2: Add a first-stage mixed rubber, sulfur, accelerator and zinc oxide into an internal mixer for mixing at a mixing temperature of 90° C. to 110° C. for a mixing time of 120 s to 180 s. After mixing, a wide temperature range high damping rubber composite material is obtained.

It is further defined that the debinding temperature in step 1 is not higher than 140°C.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The present invention introduces high-performance butyl-pentene rubber into the rubber composite material, and significantly improves the damping performance of the rubber composite material under the condition of good mechanical strength. This is mainly because the side group content of butyl-pentene rubber is between 60% and 80%, which makes the hysteresis loss of butyl-pentene rubber in dynamic strain larger, and improves the damping performance of butyl-pentene rubber. At the same time, the side group structure with small volume and large number can reduce the degree of entanglement within and between molecular chains and increase the distance between molecular chains, so that the reinforcing filler has a higher contact area and interaction force with the molecular chain, and further improves the damping factor of butyl-pentene rubber. At the same time, the molecular weight of the iron-based catalytic butyl-pentene rubber is selected to be between 20w and 40w. This molecular weight can make the butyl-pentene rubber have a Mooney viscosity that is conducive to the dispersion of reinforcing fillers, which can effectively reduce the filler network effect of the vulcanized rubber, reduce the inclusion rubber content, and increase the volume of effective rubber molecules that can move freely.

(2) The present invention significantly improves the damping temperature range of the rubber composite material by introducing high-performance butadiene-vinyl rubber into the rubber composite material under the condition of good mechanical strength. This is mainly because the molar ratio of butadiene monomers to isoprene monomers in the synthetic butadiene-vinyl rubber is 1:2 to 1:5, and the molar content of 1,2-butadiene in the butadiene-vinyl rubber structural unit is 70% to 90%, and the molar content of 1,4-butadiene is 10% to 30%. By introducing the butadiene structure with good flexibility, the number of side groups per unit volume of butadiene-vinyl rubber is increased, and the damping temperature range of butadiene-vinyl rubber is widened. At the same time, the molecular weight distribution of butadiene-vinyl rubber is 3 to 5, which increases the number of chain segment ends that can move in the molecular chain, further widening the damping temperature range of butadiene-vinyl rubber.

(3) The side groups in the high-performance butyl-pentadiene rubber introduced into the rubber composite material of the present invention are vinyl and propylene, and the molar content of 3,4-isoprene in the butyl-pentadiene rubber structural unit is 60% to 80%, and the molar content of 1,4-isoprene is 20% to 40%. Among them, the ability of propylene to restrict the movement of the chain segment is higher than that of vinyl, which is more conducive to the improvement of the damping performance and glass transition temperature of the butyl-pentadiene rubber, so that the glass transition temperature of the butyl-pentadiene rubber is between -20°C and 20°C. At the same time, the content of 1,4-isoprene in the present invention is designed mainly to make the range of 30 to 70 parts of butyl-pentadiene rubber and 30 to 70 parts of butyl rubber partially compatible rubber, and the blended rubber has two glass transition temperatures, and as the content of butyl-pentadiene rubber and butyl rubber approaches, the difference between the two glass transition temperatures gradually decreases. Therefore, by blending butyl-pentadiene rubber and butyl rubber, the effective damping temperature range and damping performance of the rubber composite material of the present invention are significantly improved.

DETAILED DESCRIPTION

In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, methods and instruments used are conventional materials, reagents, methods and instruments in the art unless otherwise specified, and can be obtained through commercial channels by those skilled in the art.

The formulations and compositions of the rubber composite materials in all the embodiments of the present invention are listed in Table 1, and the main properties of the rubber composite materials are listed in Table 2.

Embodiment 1:

The raw material ratio of the wide temperature range high damping rubber composite material of this embodiment is shown in the data corresponding to Example 1 in Table 1;

The molecular weight of the butadiene-vinyl rubber is 33.6w, the molecular weight distribution is 3.5, and the glass transition temperature is -3°C; the butadiene-vinyl rubber is prepared by coordination polymerization using an iron-based catalyst, and the molar ratio of monomers butadiene to isoprene is 1:2 during the preparation process; the iron-based butadiene-vinyl rubber consists of 3,4-isoprene, 1,4-isoprene, 1,2-butadiene and 1,4-butadiene structural units; the molar content of 1,2-butadiene is 82%, and the total molar content of cis-1,4-butadiene and trans-1,4-butadiene is 18%; the molar content of 3,4-isoprene is 78%, and the total molar content of cis-1,4-isoprene and trans-1,4-isoprene is 22%.

The method for preparing the wide temperature range high damping rubber composite material of Example 1 is carried out according to the following steps:

Step 1, in an internal mixer, the rotor speed is 40r/min, butyl rubber and butadiene-pentadiene rubber are mixed, the mixing temperature is 95°C, the mixing time is 90s, and then reinforcing filler is added, and the mixing is continued for 120s, and plasticizer and stearic acid are added, and the mixing temperature is 115°C. After mixing for 240s, the rubber is discharged, and the discharge temperature is 138°C to obtain a mixed rubber;

Step 2: Add a first-stage mixed rubber, sulfur, accelerator and zinc oxide into an internal mixer for mixing at a mixing temperature of 90° C. for 150 seconds. After mixing, a wide temperature range high damping rubber composite material is obtained.

Embodiment 2:

The raw material ratio of the wide temperature range high damping rubber composite material of this embodiment is shown in the data corresponding to Example 2 in Table 1;

The molecular weight of the butadiene-vinyl rubber is 37.8w, the molecular weight distribution is 3.3, and the glass transition temperature is 2°C; the butadiene-vinyl rubber is prepared by coordination polymerization using an iron-based catalyst, and the molar ratio of monomers butadiene to isoprene is 1:3 during the preparation process; the iron-based butadiene-vinyl rubber consists of 3,4-isoprene, 1,4-isoprene, 1,2-butadiene and 1,4-butadiene structural units; the molar content of 1,2-butadiene is 78%, and the total molar content of cis-1,4-butadiene and trans-1,4-butadiene is 22%; the molar content of 3,4-isoprene is 73%, and the total molar content of cis-1,4-isoprene and trans-1,4-isoprene is 17%.

The method for preparing the wide temperature range high damping rubber composite material of Example 2 is carried out according to the following steps:

Step 1, in an internal mixer, the rotor speed is 45r/min, butyl rubber and butadiene-pentadiene rubber are mixed, the mixing temperature is 90°C, the mixing time is 60s, and then reinforcing filler is added, and the mixing is continued for 100s, and plasticizer and stearic acid are added, the mixing temperature is 110°C, and the mixing is continued for 210s, and then the glue is discharged, and the glue discharge temperature is 130°C to obtain a mixed rubber;

Step 2: Add a first-stage mixed rubber, sulfur, accelerator and zinc oxide into an internal mixer for mixing at a mixing temperature of 100° C. for 120 seconds. After mixing, a wide temperature range high damping rubber composite material is obtained.

Embodiment 3:

The raw material ratio of the wide temperature range high damping rubber composite material of this embodiment is shown in the data corresponding to Example 3 in Table 1;

The molecular weight of the butadiene-vinyl rubber is 32.3w, the molecular weight distribution is 4, and the glass transition temperature is 6°C; the butadiene-vinyl rubber is prepared by coordination polymerization using an iron-based catalyst, and the molar ratio of monomers butadiene to isoprene is 1:3.5 during the preparation process; the iron-based butadiene-vinyl rubber consists of 3,4-isoprene, 1,4-isoprene, 1,2-butadiene and 1,4-butadiene structural units; the molar content of 1,2-butadiene is 74%, and the total molar content of cis-1,4-butadiene and trans-1,4-butadiene is 26%; the molar content of 3,4-isoprene is 75%, and the total molar content of cis-1,4-isoprene and trans-1,4-isoprene is 25%.

The method for preparing the wide temperature range high damping rubber composite material of Example 3 is carried out according to the following steps:

Step 1, in an internal mixer, the rotor speed is 50r/min, butyl rubber and butadiene-pentadiene rubber are mixed, the mixing temperature is 95°C, the mixing time is 90s, and then reinforcing filler is added, and the mixing is continued for 110s, and plasticizer and stearic acid are added, and the mixing temperature is 110°C. After mixing for 270s, the rubber is discharged, and the discharge temperature is 135°C to obtain a mixed rubber;

Step 2: Add a first-stage mixed rubber, sulfur, accelerator and zinc oxide into an internal mixer for mixing at a mixing temperature of 110° C. for 120 seconds to obtain a wide temperature range high damping rubber composite material.

Embodiment 4:

The raw material ratio of the wide temperature range high damping rubber composite material of this embodiment is shown in the data corresponding to Example 4 in Table 1;

The molecular weight of the butadiene-vinyl rubber is 36.3w, the molecular weight distribution is 3, and the glass transition temperature is 10°C; the butadiene-vinyl rubber is prepared by coordination polymerization using an iron-based catalyst, and the molar ratio of monomers butadiene to isoprene is 1:4 during the preparation process; the iron-based butadiene-vinyl rubber consists of 3,4-isoprene, 1,4-isoprene, 1,2-butadiene and 1,4-butadiene structural units; the molar content of 1,2-butadiene is 83%, and the total molar content of cis-1,4-butadiene and trans-1,4-butadiene is 17%; the molar content of 3,4-isoprene is 78%, and the total molar content of cis-1,4-isoprene and trans-1,4-isoprene is 22%.

The method for preparing the wide temperature range high damping rubber composite material of Example 4 is carried out according to the following steps:

Step 1, in an internal mixer, the rotor speed is 45r/min, butyl rubber and butadiene-pentadiene rubber are mixed, the mixing temperature is 90°C, the mixing time is 80s, and then reinforcing filler is added, and the mixing is continued for 100s, and plasticizer and stearic acid are added, and the mixing temperature is 115°C. After mixing for 270s, the rubber is discharged, and the discharge temperature is 135°C to obtain a mixed rubber;

Step 2: Add a first-stage mixed rubber, sulfur, accelerator and zinc oxide into an internal mixer for mixing at a mixing temperature of 110° C. for 120 seconds to obtain a wide temperature range high damping rubber composite material.

Comparative Example 1:

The formula of the rubber composite material of this comparative example is shown in the data corresponding to comparative example 1 in Table 1; the types of raw materials are the same as those of Example 3.

The method for preparing the wide temperature range high damping rubber composite material of Comparative Example 1 is carried out according to the following steps:

Step 1, in an internal mixer, the rotor speed is 50r/min, butyl rubber and butadiene-pentadiene rubber are mixed, the mixing temperature is 95°C, the mixing time is 90s, and then reinforcing filler is added, and the mixing is continued for 110s, and plasticizer and stearic acid are added, and the mixing temperature is 110°C. After mixing for 270s, the rubber is discharged, and the discharge temperature is 135°C to obtain a mixed rubber;

Step 2: Add a first-stage mixed rubber, sulfur, accelerator and zinc oxide into an internal mixer for mixing at a mixing temperature of 110° C. for 120 seconds to obtain a wide temperature range high damping rubber composite material.

Comparative Example 2:

The formula of the rubber composite material of this comparative example is shown in the data corresponding to comparative example 2 in Table 1; the types of raw materials are the same as those of Example 3.

The method for preparing the wide temperature range high damping rubber composite material of Comparative Example 2 is carried out according to the following steps:

Step 1, in an internal mixer, the rotor speed is 50r/min, butyl rubber and butadiene-pentadiene rubber are mixed, the mixing temperature is 95°C, the mixing time is 90s, and then reinforcing filler is added, and the mixing is continued for 110s, and plasticizer and stearic acid are added, and the mixing temperature is 110°C. After mixing for 270s, the rubber is discharged, and the discharge temperature is 135°C to obtain a mixed rubber;

Step 2: Add a first-stage mixed rubber, sulfur, accelerator and zinc oxide into an internal mixer for mixing at a mixing temperature of 110° C. for 120 seconds to obtain a wide temperature range high damping rubber composite material.

Comparative Example 3:

The formula of the rubber composite material of this comparative example is shown in the data corresponding to comparative example 3 in Table 1; the types of raw materials are the same as those of Example 4.

The method for preparing the wide temperature range high damping rubber composite material of Comparative Example 3 is carried out according to the following steps:

Step 1, in an internal mixer, the rotor speed is 45r/min, butyl rubber and butadiene-pentadiene rubber are mixed, the mixing temperature is 90°C, the mixing time is 80s, and then reinforcing filler is added, and the mixing is continued for 100s, and plasticizer and stearic acid are added, the mixing temperature is 115°C, and the mixing is continued for 270s, and then the glue is discharged, and the glue discharge temperature is 135°C to obtain a mixed rubber;

Step 2: Add a first-stage mixed rubber, sulfur, accelerator and zinc oxide into an internal mixer for mixing at a mixing temperature of 110° C. for 120 seconds to obtain a wide temperature range high damping rubber composite material.

Comparative Example 4:

The formula of the rubber composite material of this comparative example is shown in the data corresponding to comparative example 4 in Table 1;

The molecular weight of the butadiene-vinyl rubber is 48.5w, the molecular weight distribution is 3, and the glass transition temperature is 15°C; the butadiene-vinyl rubber is prepared by coordination polymerization using an iron-based catalyst, and the molar ratio of monomers butadiene to isoprene during the preparation process is 1:7; the iron-based butadiene-vinyl rubber consists of 3,4-isoprene, 1,4-isoprene, 1,2-butadiene and 1,4-butadiene structural units; the molar content of 1,2-butadiene is 80%, and the total molar content of cis-1,4-butadiene and trans-1,4-butadiene is 20%; the molar content of 3,4-isoprene is 78%, and the total molar content of cis-1,4-isoprene and trans-1,4-isoprene is 22%.

The method for preparing the wide temperature range high damping rubber composite material of Comparative Example 4 is carried out according to the following steps:

Step 1, in an internal mixer, the rotor speed is 45r/min, butyl rubber and butadiene-pentadiene rubber are mixed, the mixing temperature is 90°C, the mixing time is 80s, and then reinforcing filler is added, and the mixing is continued for 100s, and plasticizer and stearic acid are added, and the mixing temperature is 115°C. After mixing for 270s, the rubber is discharged, and the discharge temperature is 135°C to obtain a mixed rubber;

Step 2: Add a first-stage mixed rubber, sulfur, accelerator and zinc oxide into an internal mixer for mixing at a mixing temperature of 110° C. for 120 seconds to obtain a wide temperature range high damping rubber composite material.

Table 1 Composition of rubber composite materials

Table 2 Main properties of rubber composite materials

The damping temperature range in the table is DMA test, the test conditions are 10HZ, heating rate 5℃/min, dynamic strain 0.25%

As shown in Table 2, through the analysis of Examples 1-4 and Comparative Examples 1-2, it can be seen that the iron-based catalytic butyl-pentene rubber designed by the present invention has partial compatibility with butyl rubber, and on the basis of improving the mechanical properties and thermal oxidative aging properties of butyl rubber, the effective damping temperature range and damping performance of the rubber composite material are significantly improved. Through the analysis of Examples 1-4 and Comparative Example 3, it can be seen that under the conditions of 80 parts of butyl rubber and 20 parts of butyl-pentene rubber, the compatibility of butyl rubber and butyl-pentene rubber is improved. Through DMA test, the rubber composite material has a glass transition temperature, and the improvement of the effective damping temperature range and damping performance is limited. Through the analysis of Example 3 and Comparative Example 4, it can be seen that the content of butadiene in butyl-pentene rubber is reduced, so that the effective damping temperature range of the rubber composite material is narrowed, and at the same time, due to the high molecular weight of butyl-pentene rubber in Comparative Example 4, the damping performance (tanδ _max ) of the composite material is reduced.

Although the present invention has been disclosed as above in the form of preferred embodiments, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the definition of the claims.

Claims (10)

1. A high-damping rubber composite material with a wide temperature range, characterized in that it is composed of the following raw materials in parts by weight: 30-70 parts of butyl rubber; 30-70 parts of butyl rubber; Plasticizer 0-30 parts; 30-80 parts of reinforcing filler; 2 to 9 parts of active agent; 0.5-3 parts of sulfur; 0.5-3 parts of accelerator; 1 to 5 parts of antioxidant; Among them, the molecular weight of butadiene-pentadiene rubber is 20-40w, the molecular weight distribution is 3-5, the side group content is 60%-80%, the side groups are vinyl and propylene, and the Tg is -20℃～20℃; the butyl rubber is brominated butyl rubber or chlorinated butyl rubber. 2. The wide temperature range high damping rubber composite material according to claim 1 is characterized in that the butadiene-vinyl rubber is prepared by coordination polymerization of isoprene monomers and butadiene monomers using an iron-based catalyst, and the molar ratio of butadiene monomers to isoprene during the preparation process is 1:(2-5). 3. The wide temperature range high damping rubber composite material according to claim 1, characterized in that the butadiene-vinyl rubber is composed of 3,4-isoprene, 1,4-isoprene, 1,2-butadiene and 1,4-butadiene structural units. 4. The wide temperature range high damping rubber composite material according to claim 3 is characterized in that the molar content of 1,2-butadiene is 70% to 90%, and the total molar content of cis-1,4-butadiene and trans-1,4-butadiene is 10% to 30%; the molar content of 3,4-isoprene is 60% to 80%, and the total molar content of cis-1,4-isoprene and trans-1,4-isoprene is 20% to 40%. 5. The wide temperature range high damping rubber composite material according to claim 1, characterized in that the plasticizer is a mixture of one or more of cyclohexane oil, aromatic oil and paraffin oil. 6. The wide temperature range high damping rubber composite material according to claim 1, characterized in that the activator is stearic acid and zinc oxide. 7. The wide temperature range high damping rubber composite material according to claim 1, characterized in that the reinforcing filler is a mixture of one or more of carbon black, white carbon black, kaolin, talc, mica, montmorillonite, and carbon nanotubes. 8. The wide temperature range high damping rubber composite material according to claim 1, characterized in that the antioxidant is antioxidant 4020 and/or antioxidant RD. 9. The wide temperature range high damping rubber composite material according to claim 1, characterized in that the accelerator is a mixture of one or more of sulfonamide vulcanization accelerators, thiazole vulcanization accelerators, thiuram vulcanization accelerators, and guanidine accelerators. 10. A method for preparing the wide temperature range high damping rubber composite material according to claim 1, characterized in that it is prepared by a staged mixing method.