阅读说明：本技术 一种废轮胎裂解炭黑的改性方法、橡胶复合材料及其应用 (Modification method of waste tire pyrolysis carbon black, rubber composite material and application thereof ) 是由 孙翀 马永洁 李本新 刘吉文 段咏欣 袁媛 陈晓燕 于 2021-10-19 设计创作，主要内容包括：本发明提供了一种废轮胎裂解炭黑的改性方法、橡胶复合材料及其应用,包括如下步骤：(1)预处理：将废轮胎裂解炭黑进行粉碎,筛选一定粒径分布范围的粉体,得到裂解炭黑粉体；(2)采用低温等离子体对步骤(1)中的裂解炭黑粉体进行改性处理,得到改性裂解炭黑。本发明通过对废轮胎裂解炭黑(CBp)进行预处理,屏蔽掉小粒径CBp,以及大粒径CBp,然后选用特定粒径和特定粒径范围的CBp粉体,利用CBp表面橡胶分子链在等离子激发条件下的可极化性,并借助于等离子体的刻蚀作用,能够明显减小CBp的粒径、增大其比表面积,优化其表面化学基团结构及组成,从而有利于提高相邻CBp聚集体间的“粒子网络”强度,提高对橡胶基体的补强性。(The invention provides a modification method of waste tire pyrolysis carbon black, a rubber composite material and application thereof, wherein the method comprises the following steps: (1) pretreatment: crushing the waste tire pyrolysis carbon black, and screening powder with a certain particle size distribution range to obtain pyrolysis carbon black powder; (2) and (3) modifying the cracked carbon black powder in the step (1) by adopting low-temperature plasma to obtain the modified cracked carbon black. The method comprises the steps of pretreating the waste tire cracking carbon black (CBp), shielding off small particle size CBp and large particle size CBp, selecting CBp powder with specific particle size and specific particle size range, utilizing the polarizability of rubber molecular chains on the surface of CBp under the condition of plasma excitation, and utilizing the etching effect of plasma, the particle size of CBp can be obviously reduced, the specific surface area of the rubber molecular chains can be increased, and the surface chemical group structure and composition of the rubber molecular chains can be optimized, so that the strength of a 'particle network' between adjacent CBp aggregates can be improved, and the reinforcement of a rubber matrix can be improved.)

1. A method for modifying pyrolysis carbon black of waste tires is characterized by comprising the following steps:

(1) pretreatment: crushing the waste tire pyrolysis carbon black, and screening powder with a certain particle size distribution range to obtain pyrolysis carbon black powder;

(2) and (3) modifying the cracked carbon black powder in the step (1) by adopting low-temperature plasma to obtain the modified cracked carbon black.

2. The method for modifying pyrolytic carbon black of waste tires according to claim 1, wherein in the step (1), the particle size of the powder is screened, and the particle size distribution range of the screened pyrolytic carbon black powder is 0.4-20 μm; alternatively, from 0.4 to 19 μm; alternatively, from 0.405 to 18.7 μm;

optionally, the particle size D (90) of the screened pyrolysis carbon black powder is 13-18 μm, optionally 13-15 μm, optionally 14.1 μm;

optionally, the pulverizing method in step (1) is: the comminution is carried out with a gas mill, the blowing power of which is optionally selected to be 40 Hz.

3. The method for modifying waste tire pyrolysis carbon black of claim 1, wherein the modified pyrolysis carbon black in the step (2) is powder, optionally, the particle size distribution of the modified pyrolysis carbon black is 0.5-30 μm, optionally 0.523-27.4 μm;

optionally, the particle size D (90) of the modified pyrolysis carbon black is 15-20 μm, optionally 15-18 μm, optionally 17.0 μm.

4. The method for modifying waste tire cracking carbon black according to any one of claims 1 to 3, wherein in the step (2), the low-temperature plasma reaction atmosphere comprises one or more of argon, helium, ammonia and water vapor, optionally argon;

and/or in the step (2), the low-temperature plasma processing power is 50W-200W, and the reaction time is 1min-4 min;

and/or, in the step (2), the low-temperature plasma treatment refers to exciting plasma at room temperature;

and/or, in the step (2), the reactor of the low-temperature plasma adopts a roller type design.

5. The method for modifying waste tire cracking carbon black according to claim 4,

when the reaction atmosphere is argon, the treatment power is 50W-200W, and the reaction time is 1min-4 min; optionally, the treatment power is 50W, 100W, 150W or 200W, the reaction time is 1-4min, optionally, the treatment power is 200W, and the reaction time is 2 min;

when the reaction atmosphere is helium, the treatment power is 200W, and the reaction time is 1-4 min; optionally the reaction time is 1min, 2min, 3min or 4min, optionally the reaction time is 2 min;

when the reaction atmosphere is water vapor, the treatment power is 200W, and the reaction time is 1-4 min; optionally the reaction time is 2 min;

when the reaction atmosphere is ammonia gas, the treatment power is 200W, and the reaction time is 1-4 min; alternatively the reaction time is 2 min.

6. A modified waste tire cracking carbon black obtained by the method according to any one of claims 1 to 5.

7. A rubber reinforcing agent, comprising the modified waste tire cracking carbon black of claim 6.

8. The rubber composite material is characterized by comprising the following raw materials: rubber and the modified waste tire cracking carbon black of claim 6;

optionally, the rubber composite material comprises the following raw materials: 100 parts of rubber and 40-60 parts of the modified waste tire pyrolysis carbon black;

optionally, the rubber composite material comprises the following raw materials: 100 parts of rubber, 40-60 parts of modified waste tire cracking carbon black, 1-3 parts of anti-aging agent, 1.5-2 parts of accelerator, 1-1.5 parts of stearic acid, 3-4 parts of zinc oxide and 1-3 parts of sulfur;

optionally, the rubber composite material comprises the following raw materials: 100 parts of rubber, 45-55 parts of modified waste tire cracking carbon black, 1-3 parts of anti-aging agent, 1.5-2 parts of accelerator, 1-1.5 parts of stearic acid, 3-4 parts of zinc oxide and 1-3 parts of sulfur;

optionally, the rubber composite material comprises the following raw materials: 100 parts of rubber, 45-55 parts of modified waste tire pyrolysis carbon black, 2 parts of an anti-aging agent, 1.75 parts of an accelerator, 1.25 parts of stearic acid, 3.5 parts of zinc oxide and 2 parts of sulfur;

optionally, the rubber composite material comprises the following raw materials: 100 parts of rubber, 50 parts of modified waste tire pyrolysis carbon black, 2 parts of anti-aging agent, 1.75 parts of accelerator, 1.25 parts of stearic acid, 3.5 parts of zinc oxide and 2 parts of sulfur;

optionally, the antioxidant is selected from one or two of quinoline antioxidant and p-phenylenediamine antioxidant;

optionally, the accelerator is selected from sulfenamide accelerators.

9. A method for producing a rubber composite material, characterized in that the raw materials of the rubber composite material according to any one of claims 6 to 8 are mixed at a vulcanization temperature of 160 ℃ to obtain the rubber composite material.

10. Use of the modified waste tire cracking carbon black of claim 5 in the preparation of compounded rubber.

Technical Field

The invention relates to the technical field of materials, in particular to a method for modifying waste tire pyrolysis carbon black, a rubber composite material and application thereof.

Background

It is estimated that nearly 10 million tires are scrapped each year worldwide. More than 50% of the waste water is discarded without being treated, so that soil pollution is easily caused, even fire is caused, and great potential safety hazard is brought to the life health of people. At present, the treatment modes of waste tires mainly comprise burying, burning, tire retreading, thermal cracking, preparation of reclaimed rubber, rubber powder and the like. Compared with landfill and incineration, thermal cracking has higher energy utilization efficiency and lower environmental hazard degree; and high value-added products such as pyrolysis carbon black, pyrolysis oil, pyrolysis gas, steel wires and the like can be obtained after pyrolysis, so that the grading and independent pricing of each part becomes possible. Taken together, thermal cracking is undoubtedly one of the most promising current scrap tire solutions.

The cracked carbon black (CBp for short) is one of the important products of waste tire thermal cracking, CBp has high surface ash content and carbonaceous deposit content, poor surface activity, large particle size and low structure degree, and untreated CBp can only be used as a low-end rubber product, and the functionality and the economic benefit are not ideal. In order to improve the service performance of the pyrolysis carbon black, related researchers have made a great deal of research on the waste tire pyrolysis technology and the pyrolysis carbon black modification method. For example, researchers have demineralized (chemical leaching) CBp to recover CB trapped in CBp to produce a standardized CB product for commercial purposes; researchers also modify CBp by using the principle of 'alkali washing + macromolecule wrapping', so that the surface of CBp is cleaned and improved, and active sites are exposed, thereby restoring the original reinforcing performance. The existing CBp modification method is limited by the problems of high energy consumption, high pollution, poor modification effect and the like, and cannot be widely used. Therefore, an efficient modification method is urgently needed to optimize the structure and the function of the waste tire cracking carbon black so as to enable the waste tire cracking carbon black to be efficiently and circularly applied to rubber products.

Disclosure of Invention

Object of the Invention

In order to overcome the defects of the traditional cracked carbon black modification technology, the invention aims to provide a modified method of the cracked carbon black of the waste tire, a rubber composite material and application thereof; according to the modification method of the pyrolysis carbon black, chemical groups and structures on the surface of CBp can be optimized through the etching effect of the plasma, the interaction between the chemical groups and rubber molecular chains can be improved, and the reinforcement of a rubber matrix is improved.

Solution scheme

In order to realize the purpose of the invention, the technical scheme adopted by the invention is as follows:

in a first aspect, the present invention provides a method for modifying pyrolysis carbon black of waste tires, comprising the following steps:

(1) pretreatment: crushing the waste tire pyrolysis carbon black, and screening powder with a certain particle size distribution range to obtain pyrolysis carbon black powder;

(2) and (3) modifying the cracked carbon black powder in the step (1) by adopting low-temperature plasma to obtain the modified cracked carbon black.

The surface of CBp is subjected to quality improvement and modification treatment by low-temperature glow discharge plasma, so that CBp after treatment has higher-quality reinforcement performance. In order to improve the uniformity of powder treatment, the reactor of the low-temperature plasma is designed by adopting a drum-type principle. In order to remove impurities in the reactor as much as possible, a vacuum pump is firstly opened for vacuumizing before the experiment is started, and then argon feed gas is introduced to flush the reactor.

Further, in the step (1), the particle size of the powder is screened, and the particle size distribution range of the screened pyrolysis carbon black powder is 0.4-20 μm; alternatively, from 0.4 to 19 μm; alternatively, from 0.405 to 18.7 μm.

The inventor of the invention finds that the small particle size CBp and the large particle size CBp are shielded by selecting CBp a proper particle size range, so that the particle size range before modification is narrowed, and the obtained modified CBp has better performance.

Further, the particle size D (90) of the screened pyrolysis carbon black powder is 13-18 μm (the particle size distribution range can be 0.4-20 μm), optionally 13-15 μm (the particle size distribution range can be 0.4-19 μm), optionally 14.1 μm (the particle size distribution range can be 0.405-18.7 μm).

Preferably, the particle diameter D (90) of the cracked carbon black powder screened in the step (1) is 13-15 μm, and the particle diameter distribution range can be 0.4-19 μm.

Further, the crushing method in the step (1) comprises the following steps: the comminution is carried out with a gas mill, the blowing power of which is optionally selected to be 40 Hz.

Further, the modified pyrolytic carbon black in the step (2) is powder, optionally, the particle size distribution of the modified pyrolytic carbon black is 0.5-30 μm (which may correspond to the particle size distribution range of 0.4-20 μm before modification, i.e., the particle size distribution range of the powder in the step (1)), optionally, 0.523-27.4 μm (which may correspond to the particle size distribution range of 0.405-18.7 μm before modification, i.e., the particle size distribution range of the powder in the step (1)).

Further, the particle size D (90) of the modified pyrolytic carbon black is 15-20 μm (which may correspond to the particle size D (90) after screening in step (1) (i.e., before modification) being 13-18 μm), optionally 15-18 μm (which may correspond to the particle size D (90) after screening in step (1) (i.e., before modification) being 13-15 μm), optionally 17.0 μm (which may correspond to the particle size D (90) after screening in step (1) (i.e., before modification) being 14.1 μm).

Further, in the step (2), the low-temperature plasma reaction atmosphere includes one or more of argon, helium, ammonia and water vapor, and optionally argon.

Further, in the step (2), the low-temperature plasma processing power is 50W-200W, and the reaction time is 1min-4 min;

further, in the step (2), the low temperature plasma treatment means exciting plasma at room temperature. (generally, room temperature conditions fall within the category of low temperatures in plasma treatment.)

Further, when the reaction atmosphere is argon, the treatment power is 50W-200W, and the reaction time is 1min-4 min; optionally a treatment power of 50W, 100W, 150W or 200W and a reaction time of 1-4min, optionally a treatment power of 200W and a reaction time of 2 min.

When the reaction atmosphere is helium, the treatment power is 200W, and the reaction time is 1-4 min; optionally the reaction time is 1min, 2min, 3min or 4min, optionally the reaction time is 2 min.

When the reaction atmosphere is water vapor, the treatment power is 200W, and the reaction time is 1-4 min; optionally the reaction time is 2 min;

when the reaction atmosphere is ammonia gas, the treatment power is 200W, and the reaction time is 1-4 min; alternatively the reaction time is 2 min.

On the other hand, the modified waste tire cracking carbon black is prepared by the method.

In still another aspect, a rubber reinforcing agent is provided, which comprises the modified waste tire cracking carbon black.

In another aspect, a rubber composite is provided, which comprises the following raw materials: rubber and the modified waste tire cracking carbon black.

Further, the rubber composite material comprises the following raw materials: 100 parts of rubber and 40-60 parts of the modified waste tire pyrolysis carbon black; preparing low-temperature plasma modified CBp filled natural rubber composite material. Receiving

Further, the rubber composite material comprises the following raw materials: 100 parts of rubber, 40-60 parts of modified waste tire cracking carbon black, 1-3 parts of anti-aging agent, 1.5-2 parts of accelerator, 1-1.5 parts of stearic acid, 3-4 parts of zinc oxide and 1-3 parts of sulfur;

further, the rubber composite material comprises the following raw materials: 100 parts of rubber, 45-55 parts of modified waste tire cracking carbon black, 1-3 parts of anti-aging agent, 1.5-2 parts of accelerator, 1-1.5 parts of stearic acid, 3-4 parts of zinc oxide and 1-3 parts of sulfur;

further, the rubber composite material comprises the following raw materials: 100 parts of rubber, 45-55 parts of modified waste tire pyrolysis carbon black, 2 parts of an anti-aging agent, 1.75 parts of an accelerator, 1.25 parts of stearic acid, 3.5 parts of zinc oxide and 2 parts of sulfur;

further, the rubber composite material comprises the following raw materials: 100 parts of rubber, 50 parts of modified waste tire pyrolysis carbon black, 2 parts of anti-aging agent, 1.75 parts of accelerator, 1.25 parts of stearic acid, 3.5 parts of zinc oxide and 2 parts of sulfur.

Further, the antioxidant is a conventional commercial product for delaying or inhibiting rubber aging, and can be one or two of quinoline antioxidant (RD) and p-phenylenediamine antioxidant (4020).

Further, the accelerator is a formulation for reinforcing rubber articles, is a conventional commercially available product, and may include a sulfenamide (NOBS) accelerator and the like.

On one hand, the preparation method of the rubber composite material is also provided, and the rubber composite material is obtained by mixing the raw materials of the rubber composite material and vulcanizing at 160 ℃.

In a further aspect, the modified waste tire cracking carbon black is applied to the preparation of composite rubber.

Advantageous effects

(1) According to the invention, the scrap tire cracking carbon black (CBp) is pretreated, then CBp powder with specific particle size and specific particle size range is selected, the polarizability of CBp surface rubber molecular chains under the plasma condition is utilized, and by means of the etching effect of plasma, the particle size of CBp can be obviously reduced, the specific surface area of the rubber molecular chains is increased, and the surface chemical group structure and composition of the rubber molecular chains are optimized, so that the strength of a 'particle network' between adjacent CBp aggregates is improved, the interaction between the rubber molecular chains and the rubber molecular chains is improved, and the reinforcement of a rubber matrix is improved.

(2) In the pretreatment process, small particle size CBp and large particle size CBp can be shielded through particle size screening, so that the particle size range before modification is narrowed, but the particle size distribution of the waste tire pyrolysis carbon black modified by plasma is widened and is biased to a high particle size area, and the modified CBp serving as a reinforcing agent can effectively improve the mechanical property of the compounded rubber.

(3) Compared with unmodified CBp filled natural rubber, the tensile stress and the wear resistance of the modified CBp filled natural rubber are greatly improved.

(4) Compared with the prior chemical modification technology, the modification method is simple and quick, does not depend on a rubber matrix, does not need a solvent and does not produce waste chemicals.

(5) Compared with a physical blending method, the method has more obvious modification effect. Therefore, the invention has potential application value in the field of development of CBp-containing rubber products with high stress at definite elongation and high wear resistance.

Drawings

One or more embodiments are illustrated by the corresponding figures in the drawings, which are not meant to be limiting. The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

FIG. 1 is a schematic view of the dispersion of the waste tire cracking carbon black (CBp) of the present invention in acetone solution by CBp after modification of examples 4, 6, 9, 10 by low temperature plasma in different atmospheres;

FIG. 2 graph of the thermogravimetric curves of CBp of the scrap tire cracking carbon black (CBp) of the present invention after modification by low temperature plasma in different atmospheres by examples 4, 6, 9, and 10.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are a part of the embodiments of the present invention, but not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Furthermore, in the following detailed description, numerous specific details are set forth in order to provide a better understanding of the present invention. It will be understood by those skilled in the art that the present invention may be practiced without some of these specific details. In some embodiments, materials, elements, methods, means, and the like that are well known to those skilled in the art are not described in detail in order to not unnecessarily obscure the present invention.

Throughout the specification and claims, unless explicitly stated otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element or component but not the exclusion of any other element or component.

Example 1

The preparation process of the low-temperature plasma modification CBp is as follows;

the surface of the waste tire cracking carbon black (CBp) is subjected to quality improvement and modification treatment by adopting low-temperature glow discharge plasma, and the reaction conditions of the plasma are as follows: and (3) taking argon gas as a reaction atmosphere, setting the power at 50W and the reaction time at 2min to obtain the plasma modified waste tire CBp.

In order to improve the uniformity of powder treatment, the reactor adopts a drum-type design; in order to remove gas impurities in the reactor as much as possible, a vacuum pump is firstly opened for vacuum pumping treatment before the experiment is started, and then reaction gas is introduced to flush the reactor.

Example 2

The difference from example 1 is that the modification power of the plasma reaction condition was changed to 100W.

Example 3

The difference from example 1 is that the modification power of the plasma reaction condition was changed to 150W.

Example 4

The difference from example 1 is that the modification power of the plasma reaction condition was changed to 200W. The performance of the low-temperature plasma modified CBp obtained in the embodiment is better than that of the low-temperature plasma modified CBp obtained in the embodiments 1-3, and the name is CBp-Ar.

Example 5

A preparation method of low-temperature plasma modification CBp comprises the steps of treating CBp by glow discharge low-temperature plasma to obtain low-temperature plasma modification CBp;

the processing conditions of the low temperature plasma pair CBp were: under the helium atmosphere, the treatment power is 200W, and the treatment time is 1 min.

Example 6

The difference from example 5 is that the treatment time of the low temperature plasma treatment condition of CBp was 2 min. The low-temperature plasma modification CBp obtained in the embodiment is better than the low-temperature plasma modification CBp obtained in the embodiments 5, 7 and 8 and is named as CBp-He.

Example 7

The difference from example 5 is that the treatment time of the low temperature plasma treatment condition of CBp was 3 min.

Example 8

The difference from example 5 is that the treatment time of the low temperature plasma treatment condition of CBp was 4 min.

Example 9

A preparation method of low-temperature plasma modification CBp comprises the steps of treating CBp by glow discharge low-temperature plasma to obtain low-temperature plasma modification CBp;

the processing conditions of the low temperature plasma pair CBp were: under the water vapor atmosphere, the treatment power is 200W, and the treatment time is 2 min.

The low temperature plasma modification CBp obtained in this example was named CBp-H₂O。

Example 10

Compared with example 9, the atmosphere of CBp treated by the low-temperature plasma was ammonia gas, as the same applies.

The low temperature plasma modification CBp obtained in this example was named CBp-NH₃。

Example 11

(1) Pretreating the cracked carbon black of the waste tire: crushing the waste tire cracking carbon black by a gas crusher at the power of 40Hz, and screening to obtain cracking carbon black powder, wherein the particle diameter D (90) of the screened cracking carbon black powder is 14.1 mu m, and the particle diameter distribution is 0.405-18.7 mu m (the screened cracking carbon black powder is named as air powder CBp).

(2) The gas powder CBp was then plasma treated using the plasma reaction conditions of example 4.

The low-temperature plasma modification CBp obtained in this example was named as gas powder + modification CBp.

Example 12

(1) Pretreating the cracked carbon black of the waste tire: crushing the waste tire cracking carbon black by a gas crusher at the power of 40Hz, and screening to obtain cracking carbon black powder, wherein the particle size D (90) of the screened cracking carbon black powder is 15 mu m, and the particle size distribution is 0.4-18.9 mu m.

(2) The CBp pretreated in step (1) was then plasma treated using the plasma reaction conditions of example 4 to provide modified CBP-2. The performance of the modified CBP-2 obtained in this example is similar to that of the gas powder + modified CBp obtained in example 11.

Example 13

(1) Pretreating the cracked carbon black of the waste tire: crushing the waste tire cracking carbon black by a gas crusher at the power of 40Hz, and screening to obtain cracking carbon black powder, wherein the particle diameter D (90) of the screened cracking carbon black powder is 13 mu m, and the particle diameter distribution is 0.42-19 mu m.

(2) The CBp pretreated in step (1) was then plasma treated using the plasma reaction conditions of example 4 to provide modified CBP-3. The modified CBP-3 obtained in this example has properties similar to those of the gas powder + modified CBp of example 11.

Application examples

Preparation of rubber composite with modification CBp: a series of physical and mechanical property tests were carried out on a natural rubber composite material prepared by adding CBp50phr of the low-temperature plasma modification prepared in examples 1 to 11, 2phr of an antioxidant, 1.75phr of an accelerator, 1.25phr of stearic acid, 3.5phr of zinc oxide and 2phr of sulfur to 100 parts by weight of a natural rubber, and carrying out vulcanization at 160 ℃ as shown in Table 2.

Wherein, the anti-aging agent adopts RD, and the accelerating agent adopts NOBS.

The results of the tests on the modified CBp of examples 4, 6, 9 and 10 are shown in FIG. 1, FIG. 2, Table 1 and Table 2.

As can be seen from fig. 1, CBp after low temperature plasma modification is in a suspended state in acetone solution, indicating that the polarity of the surface of the low temperature plasma modified CBp particles is increased.

As can be seen from FIG. 2, the weight loss of CBp after low-temperature plasma modification is increased between 30 ℃ and 200 ℃, because CBp surface polar groups after modification are increased, which proves that the low-temperature plasma modification technology has an activating effect on the CBp surface.

TABLE 1 elemental composition of CBp modified scrap tire carbon black (CBp) by low temperature plasma in different atmospheres

As can be seen from table 1, the O element content of the modified CBp bulk surface was significantly increased after the low-temperature plasma modification.

TABLE 2 physical and mechanical Properties of CBp-filled rubber composites modified with different atmospheres of low temperature plasmas from scrap tire pyrolysis carbon black (CBp)

Unmodified CBp refers to untreated CBp powder.

As can be seen from table 2, when argon gas was used as the plasma atmosphere, the effect of CBp obtained by modification was the most excellent, and the preferable processing conditions for plasma were: argon atmosphere, power 200w, time 2 min.

To further illustrate the effect of screening suitable particle size ranges on modified scrap tire cracking carbon black, particle size D (90) and particle size distribution ranges were measured for untreated CBp, modified CBp (obtained in example 4), air powder CBp (obtained in example 11 by pulverizing screened air powder CBp) and air powder + modified CBp (obtained in example 11), respectively, as shown in Table 3.

TABLE 3 particle size distribution of argon plasma modified scrap tire cracked carbon black before and after pretreatment by gas pulverizer

Unmodified CBp refers to untreated CBp powder.

As can be seen from Table 3, D (90) of the modified CBp obtained after plasma modification is obviously reduced compared with that of the untreated CBp, which indicates that the plasma modification has a relatively obvious etching effect, the particle size distribution width after modification is obviously narrowed, and the dual functions of grafting and etching are shown. D (90) of the gas powder CBp obtained after gas powder screening is lower than that of untreated CBp, and the particle size distribution of the gas powder CBp is narrower than that of untreated CBp; however, D (90) of CBp (gas powder + modification CBp) modified with gas powder CBp was significantly improved, and the particle size distribution was significantly broadened and was biased toward a high particle size region, as compared with CBp modified with plasma alone. For this phenomenon, the inventors of the present invention guess that: CBp samples with more uniform particle size distribution selected in the gas powder process are modified by plasma, and the particle size distribution of the CBp samples is obviously widened and is biased to a high particle size area due to the grafting effect of surface molecular chains and the interaction of 'particle networks'.

For further study, untreated CBp, modified CBp obtained in example 4, and air powder + modified CBp obtained in example 11 were filled in natural rubber according to the methods of application examples, respectively, to obtain rubber composites, and the mechanical properties of the rubber composites were examined, and the results are shown in table 4.

TABLE 4 physical and mechanical Properties of Ar plasma modified waste tire cracking carbon black filled rubber composite before and after pretreatment by gas pulverizer

Unmodified CBp refers to untreated CBp powder.

As can be seen from table 4, compared with untreated CBp, the elongation stress of the natural rubber vulcanizate filled with Ar modified CBp (obtained in example 4) is significantly increased, the increase of elongation stress of 100%, 200% and 300% reaches 18% to 20%, and the wear loss is reduced by 15%. The improvement range of the performances of CBp (obtained in example 11) filled with natural rubber vulcanized rubber through gas powder and plasma modification respectively reaches 39-44%, and the reduction range of the abrasion amount reaches 21.4%. That is, CBp with a narrower particle size distribution (0.460-18.7 μm) obtained by screening in example 11 exhibited better mechanical properties than those of the samples (0.357-27.4 μm) without particle size distribution selection.

And further testing 100% strain tensile fatigue life, the 100% strain tensile fatigue life of untreated CBp filled natural rubber vulcanizate is 14.4 ten thousand times, the 100% strain tensile fatigue life of modified CBp (obtained in example 4) filled natural rubber vulcanizate is 21.9 ten thousand times, the lifting amplitude reaches 52.1%, the 100% strain tensile fatigue life of CBp (obtained in example 11) filled natural rubber vulcanizate which is modified after air powder screening is 30.2 ten thousand times, and the lifting amplitude reaches 109.7%.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.