CN111978602B

CN111978602B - Preparation method of high-damping constant-Mooney-viscosity natural rubber and product prepared by same

Info

Publication number: CN111978602B
Application number: CN202010649597.8A
Authority: CN
Inventors: 周其彬
Original assignee: Individual
Current assignee: Zhou Qibin
Priority date: 2020-07-08
Filing date: 2020-07-08
Publication date: 2022-06-28
Anticipated expiration: 2040-07-08
Also published as: CN111978602A

Abstract

The invention discloses a preparation method of high-damping constant-Mooney viscosity natural rubber and a prepared product, belonging to the technical field of natural rubber processing, wherein the high-damping constant-Mooney viscosity natural rubber is prepared by adding maleic anhydride modified polystyrene and constant-viscosity agent hydrazino ethanol into crepe rubber; the Mooney rubber is stable, can be directly mixed with other materials without plastication to prepare a high-damping rubber product, can be widely applied to bridge shock absorption and vehicle shock absorption, and has high popularization value.

Description

Preparation method of high-damping constant-Mooney-viscosity natural rubber and product prepared by same

Technical Field

The invention relates to the technical field of natural rubber processing, in particular to high-damping constant-Mooney-viscosity natural rubber with high equivalent damping ratio, stable Mooney viscosity, good consistency of rubber materials and excellent mechanical properties and a preparation method thereof.

Background

Vibration often presents a serious hazard to people's life and production, and must be controlled by effective means. The damping rubber converts vibration energy into heat energy by utilizing the dynamic visco-elastic behavior of the rubber and emits the heat energy into the environment, thereby reducing the harm brought by vibration. The higher the equivalent damping ratio of the rubber, the stronger this conversion capability.

The raw rubber of the damping rubber is selected from a plurality of raw rubbers, and the raw rubbers are commonly used such as natural rubber, butyl rubber, nitrile rubber and the like, wherein the natural rubber is most widely used due to wide sources, low price, excellent mechanical properties and the like. But the main chain of the natural rubber is flexible, the internal consumption is small, and the equivalent damping ratio is low. In order to improve the damping performance of natural rubber, a large amount of filler or micromolecule damping agent is generally added in the subsequent mixing to improve the damping performance of the final product. Although the damping performance of the product is improved by the method, the mechanical property is damaged. In addition, the micromolecule damping agent is easy to separate out of the product along with the time, so that the damping performance of the product is reduced, and even the product fails.

There is a need to develop a high damping rubber having both damping and mechanical properties.

Disclosure of Invention

Based on the problems and technical requirements in the field, the inventor of the present invention has conducted intensive research and found that natural rubber with a high effective damping ratio can be obtained by mixing and reacting maleic anhydride modified polystyrene and crepe rubber in a certain proportion for a certain period of time, and the mechanical properties of the natural rubber are not reduced compared with those of ordinary full-emulsion natural rubber. Further experimental research of the inventor finds that the high-damping natural rubber prepared by the method is treated by constant-viscosity agent hydrazino ethanol, the obtained rubber has high equivalent damping ratio and excellent mechanical property, the Mooney viscosity is very stable, the Mooney viscosity change value within 12 months after leaving a factory is lower than 10, plastication is not needed, and the rubber can be directly used for mixing production. Based on these findings, the following technical solutions are claimed:

The invention provides a preparation method of high-damping constant-Mooney viscosity natural rubber, which is characterized by comprising the following steps of:

(1) adding maleic anhydride modified polystyrene into the crepe rubber which is crushed, purified and dried, and stirring and mixing the materials;

(2) spraying a constant viscosity agent on the mixture obtained in the step (1), and continuously stirring and mixing; the constant viscosity agent is hydrazine ethanol;

(3) and (6) cooling.

Preferably, the preparation method, wherein the dry stirring and mixing time in the step (1) is not less than 3 minutes;

the usage amount of the maleic anhydride modified polystyrene is 5 to 15 percent based on the usage amount of the crepe rubber.

Preferably, the preparation method is used for preparing the maleic anhydride modified polystyrene with the amount of 7-12%, 8-11% or 10% of the amount of the crepe rubber.

Preferably, the preparation method, wherein the time of the dry-stirring mixing in the step (2) is not less than 3 minutes; the using amount of the crepe adhesive is 2-6 per mill.

Preferably, the preparation method is used, wherein the amount of the constant viscosity agent is 4-5 per mill based on the amount of the crepe adhesive.

The second aspect of the invention provides the high-damping constant-Mooney-viscosity natural rubber prepared by the preparation method, which is characterized in that the Mooney viscosity ML (1+4) is between 50 and 70 ℃ at 100 ℃; the equivalent damping ratio is greater than 0.12.

Preferably, the high-damping constant-Mooney natural rubber is characterized in that the change value of the Mooney viscosity of the natural rubber within 12 months is lower than 10.

Preferably, the high-damping constant-Mooney natural rubber is characterized in that the change value of the Mooney viscosity of the natural rubber within 12 months is lower than 7.

Preferably, the high-damping constant-Mooney viscosity natural rubber is characterized in that the initial plasticity is greater than 30, and the plasticity retention rate is greater than 60.

Preferably, the high-damping constant-Mooney viscosity natural rubber is characterized in that the tensile strength is more than 20MPa, and the elongation at break is more than 650%.

According to the technology for preparing the high-damping constant-Mooney viscosity natural rubber based on the natural rubber, the larger side group is introduced into the main chain of the natural rubber through the mixing and grafting reaction of the active high polymer, so that the steric hindrance is increased, the damping capacity of the natural rubber is improved, the risk of separating out the damping agent mixed later is avoided, the main chain of the natural rubber is not damaged through the grafting reaction, and the excellent mechanical property is still maintained. In addition, the constant viscosity agent is added, so that the Mooney property of the natural rubber is constant, and the subsequent direct mixing can be performed, thereby avoiding the damage of the conventional plastication to the mechanical property and the damping property of the natural rubber. The method has very important significance for developing high-performance natural rubber damping shock absorption products.

According to the technology for preparing the high-damping constant Mooney viscosity natural rubber, the obtained high-damping constant Mooney viscosity natural rubber has the characteristics of high equivalent damping ratio, small Mooney viscosity change and high mechanical property (exemplary test data show that the Mooney viscosity ML (1+4)100 ℃ of the obtained product can be controlled between 50 and 70, the change value of the Mooney viscosity within 12 months is lower than 10, the initial plastic value is greater than 30, the plastic retention rate is greater than 60, the tensile strength is greater than 20Mpa, the elongation at break is greater than 650 percent, and the equivalent damping ratio is greater than 0.12), so that the high-damping constant Mooney viscosity natural rubber is very suitable for producing high-end damping products; the adopted maleic anhydride modified polystyrene is solid particles, has no pollution and is easy to add; the constant viscosity agent hydrazino ethanol adopted is safe and environment-friendly.

The technology for preparing the high-damping constant-Mooney viscosity natural rubber does not generate any dust and wastewater in the whole processing process, and is very friendly to personnel and environment; and conventional equipment and other procedures do not need to be changed, and the procedure of dry stirring maleic anhydride modified polystyrene and constant-viscosity agent hydrazino ethanol is only needed to be added in the conventional main-line processing production process of the natural rubber, so that the method is very easy to popularize and implement.

Detailed Description

The present invention will be further described with reference to specific examples, but the present invention is not limited to the following examples. Variations and advantages that may occur to those skilled in the art may be incorporated into the invention without departing from the spirit and scope of the inventive concept, and the scope of the appended claims is intended to be protected. The experimental methods in the following examples, which are not specified under specific conditions, are generally performed under conventional conditions. Materials used in the following examples, etc., are commercially available unless otherwise specified. The experimental methods in the examples are conventional methods unless otherwise specified; the percentages in the examples are by weight unless otherwise specified.

Materials used in the examples illustrate:

hydrazinoethanol, CAS number 109-84-2, is commercially available.

Maleic anhydride-modified polystyrene: CAS number 9011-13-6, commercially available.

Example 1

Crushing the wrinkled giant salamander, rinsing impurities, drying and weighing for later use.

Weighing constant viscosity agent hydrazino ethanol according to 5 per mill of the weight of the crepe adhesive, then adding the constant viscosity agent hydrazino ethanol and the crepe adhesive into a dry stirring machine together for mixing, and stirring for 4 minutes.

Then cooling, briquetting and other processes are carried out to prepare the natural rubber with constant Mooney viscosity.

Example 2

The procedure is as described in example 1, but before the addition of the homostat hydrazinoethanol, the maleic anhydride-modified polystyrene is weighed out in an amount of 10% by weight of the crepe rubber and stirred in a dry mixer for 4 minutes together with the crepe rubber, and then treated with the homostat hydrazinoethanol.

Example 3

Weighing maleic anhydride modified polystyrene according to 5 percent of the weight of crepe adhesive, stirring the maleic anhydride modified polystyrene and the crepe adhesive in a dry stirring machine for 3 minutes,

then constant viscosity agent hydrazine ethanol with the weight of 2 per mill of the crepe adhesive is sprayed into the dry stirring machine, and the stirring is continued for 3 minutes.

Then cooling, briquetting and other processes are carried out to prepare the high-damping constant-Mooney viscosity natural rubber.

Example 4

Weighing maleic anhydride modified polystyrene according to 15% of the weight of the crepe adhesive, and stirring the polystyrene and the crepe adhesive in a dry stirring machine for 6 minutes;

then constant viscosity agent hydrazine ethanol with the weight of 6 per mill of the crepe adhesive is sprayed into the dry stirring machine, and the stirring is continued for 6 minutes.

Example 5

Weighing maleic anhydride modified polystyrene according to 10 percent of the weight of crepe adhesive, and stirring the maleic anhydride modified polystyrene and the crepe adhesive in a dry stirring machine for 5 minutes

Then constant viscosity agent hydrazino ethanol with the weight of 4 per mill of the crepe adhesive is sprayed into a dry stirring machine, and stirring is continued for 4 minutes.

Comparative example: standard Natural rubber (WF)

Performance test, inspection basis:

GB/T8086-2008 determination of content of impurities in natural crude rubber

GB/T8088 determination of nitrogen content in 2008 natural crude rubber and natural latex

GB/T24131 determination of content of volatile components of 2009 raw rubber

GB/T4498.1-2013 determination of rubber Ash content

GB/T3510 & lt 2006 quick plasticity meter method for determining plasticity of unvulcanized rubber

Determination of the Natural Green rubber plasticity Retention Rate (PRI) in GB/T3517-

Determination of Mooney viscosity of GB/T1232.1-2000 unvulcanized rubber

GB/T528 & lt 2009 & gt determination of tensile stress strain performance of vulcanized rubber or thermoplastic rubber

GB/T9870 & lt 2006 determination of dynamic Properties of vulcanized rubber or thermoplastic rubber

The physical and mechanical properties of the products of examples 1-5 are shown in Table 1, wherein the products of examples 2-5 can meet the requirements of high damping constant Mooney viscosity natural rubber.

TABLE 1

The products of examples 1 to 5 and comparative example were tested for Mooney viscosity for one year each month (M represents month) after shipment. The Mooney viscosities of the products of examples 1-5 were stable and the Mooney viscosity change was small compared to that of standard natural rubber, as shown in Table 2.

TABLE 2

The above detailed description of the preferred embodiments of the present invention is provided for the purpose of illustrating the technical concepts and features of the present invention, and is intended to enable those skilled in the art to understand the present invention and implement the present invention, and not to limit the scope of the present invention. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.

Claims

1. A preparation method of high-damping constant-Mooney viscosity natural rubber is characterized by comprising the following steps:

(1) adding maleic anhydride modified polystyrene into the crepe rubber which is crushed, purified and dried, and mixing the materials under dry stirring, wherein the consumption of the maleic anhydride modified polystyrene is 5-15% based on the consumption of the crepe rubber;

(2) Spraying a constant viscosity agent on the mixture obtained in the step (1), wherein the amount of the constant viscosity agent is 2 per mill to 6 per mill based on the amount of crepe adhesive, and continuously stirring and mixing; the constant viscosity agent is hydrazino ethanol;

(3) and (6) cooling.

2. The production method according to claim 1, wherein the dry mixing in step (1) is carried out for a period of not less than 3 minutes.

3. The method according to claim 2, wherein the maleic anhydride modified polystyrene is used in an amount of 7-12% based on the amount of crepe rubber.

4. The method according to claim 3, wherein the maleic anhydride modified polystyrene is used in an amount of 8-11% based on the amount of crepe rubber.

5. The method according to claim 4, wherein the maleic anhydride modified polystyrene is used in an amount of 10% based on the amount of crepe rubber.

6. The production method according to claim 1, wherein the dry mixing in the step (2) is carried out for a time of not less than 3 minutes.

7. The preparation method according to claim 6, wherein the amount of the permanent adhesion agent is 4 to 5 per thousand based on the amount of crepe adhesive.

8. The high-damping constant-Mooney natural rubber prepared by the preparation method of any one of claims 1 to 7, wherein the Mooney ML (1+4) temperature is between 50 and 70 at 100 ℃; the equivalent damping ratio is greater than 0.12.

9. The high damping constant Mooney natural rubber of claim 8, having a Mooney change of less than 10 within 12 months.

10. The high damping constant Mooney natural rubber of claim 8, having a Mooney change of less than 7 within 12 months.

11. The high damping constant Mooney viscosity natural rubber according to claim 8, wherein the initial plasticity is greater than 30 and the plasticity retention is greater than 60.

12. The high damping constant Mooney viscosity natural rubber according to claim 8, having a tensile strength greater than 20MPa and an elongation at break greater than 650%.