Preparation method of environment-friendly activated rubber powder

Abstract

The invention provides an environment-friendly activated rubber powder preparation method which is characterized by comprising the following preparation steps: step 1, adding a hydrogen bond donor and a hydrogen bond acceptor into a flask according to a certain molar ratio, and stirring for 30 minutes at the reaction pressure of normal pressure and the temperature of 100 DEG C to obtain a colorless transparent deep-eutectic solvent DES; 2, the waste tire tread rubber powder serves as a matrix, the mass ratio of the colorless transparent deep eutectic solvent DES to the rubber powder is 2: 1, the reaction pressure is normal pressure, the temperature is 80 DEG C, the reaction time is 2 h, discharging can be conducted after the reaction reaches the set time, the technical indexes such as the content of polycyclic aromatic hydrocarbon in the activated rubber powder all meet the standard requirements of vulcanized rubber powder, and the rubber powder can be recycled. The toxicity is far lower than the numerical range required by the standard, and can be used for producing civil products.

Description

Technical Field

[0001] The invention relates to a method for preparing an environmentally friendly activated rubber powder, in particular to a method for preparing an activated rubber powder using waste tire tread rubber powder as a raw material and a low eutectic solvent DES as an activator. Background Art

[0002] Waste rubber is a solid waste existing in the environment. It is difficult to degrade naturally, and the black pollution it forms has become one of the prominent environmental problems in the world. How to achieve efficient resource utilization of waste rubber has become an important topic in the field of organic solid waste resource utilization. There are four main ways to deal with waste rubber: producing recycled rubber (about 70%), tire retreading (about 8%) and cracking and refining (2%). Among them, the most important way to use waste tires is to produce recycled rubber, but there are problems such as secondary pollution, low production efficiency, poor product performance, and high energy consumption in the recycling process.

[0003] At present, further resource utilization of waste tire rubber powder is the most energy-saving, environmentally friendly and efficient way. Rubber powder can be blended with raw rubber to prepare high-quality composite rubber, but the structure of waste tire rubber powder is dense cross-linked network, surface inertness, weak chemical reaction activity, and poor compatibility with polymer matrix. If it is directly filled in the material, it is difficult to form a good bonding interface, and the product performance is poor and usually decreases with the increase of rubber powder dosage. The activators currently used are often accompanied by problems such as strong odor, heavy pollution or containing carcinogens. How to prepare environmentally friendly, non-toxic and harmless activated rubber powder with excellent performance is an urgent problem to be solved. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a method for preparing an environmentally friendly activated rubber powder, comprising using waste tire tread rubber powder as a matrix, using a low eutectic solvent DES prepared by a hydrogen bond donor and a hydrogen bond acceptor in a certain proportion as an activator, and using DES to activate the rubber powder to obtain the environmentally friendly activated rubber powder.

[0005] To achieve the above object, the technical solution of the present invention is as follows: An environmentally friendly activated rubber powder preparation method comprises the following preparation steps: step 1: adding a hydrogen bond donor and a hydrogen bond acceptor into a flask according to a certain molar ratio, reacting at normal pressure and 100° C., and stirring for 30 minutes to obtain a colorless and transparent low eutectic solvent DES; Step 2: Use waste tire tread rubber powder as the matrix, the mass ratio of colorless transparent low eutectic solvent DES to rubber powder is 2:1, the reaction pressure is normal pressure, the temperature is 80℃, the reaction time is 2 h, and the material can be discharged after the reaction reaches the specified time.

[0006] Preferably, the hydrogen bond donor and the hydrogen bond acceptor are choline chloride and urea respectively and are added into the flask at a molar ratio of 1:2.

[0007] Preferably, the hydrogen bond donor and the hydrogen bond acceptor are choline chloride and ethylene glycol respectively and are added into the flask at a molar ratio of 1:2.

[0008] Preferably, the preparation conditions of DES are as follows: the hydrogen bond donor and the hydrogen bond acceptor are choline chloride and malonic acid respectively, which are added into the flask in a molar ratio of 1:2.

[0009] Through the above technical scheme, the activated rubber powder prepared by the method for preparing activated rubber powder with DES provided by the present invention has technical indicators such as polycyclic aromatic hydrocarbon content, heating loss of activated rubber powder with toxic and harmful substances, ash content, acetone extract content, rubber hydrocarbon content, etc. in the activated rubber powder, from raw materials to final products, which all meet the standard requirements of vulcanized rubber powder, and the toxicity is far below the numerical range required by the standard, and can be used to produce civilian products. The preparation method uses low-priced raw materials, can be prepared under normal pressure and low temperature conditions, has low energy consumption, and DES can be recycled and reused, with low cost.

[0010] In order to more clearly and in detail introduce the method for preparing activated rubber powder provided by the present invention and the effect of recycling the activated rubber powder in rubber, a description will be given below in conjunction with specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 The present invention is a flow chart of an environmentally friendly activated rubber powder preparation method. DETAILED DESCRIPTION

[0012] In order to make the technical means, creative features and purpose effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods. Example

[0013] This example compares the performance of a styrene-butadiene rubber (SBR) base formulation containing activated rubber powder and unactivated rubber powder.

[0014] Choline chloride and urea were added to the flask in a molar ratio of 1:2. The reaction pressure was normal pressure, the temperature was 100°C, and the mixture was stirred for 30 min to obtain colorless and transparent DES. The mass ratio of DES to rubber powder was 2:1. The reaction pressure was normal pressure, the temperatures were 80°C, 100°C, and 120°C, respectively, and the reaction time was 2 h, corresponding to activated rubber powder-1, activated rubber powder-2, and activated rubber powder-3, respectively.

[0015] Preparation of samples and comparative samples: According to the formula in Table 1, first put SBR on the roller of the mixing mill, and then add rubber powder, ZnO, CZ, SA, 4010NA, and S in turn. After triangle packing 5 times and thin passing 5 times, the obtained mixed rubber is vulcanized at 160°C according to the positive vulcanization time to obtain comparative rubber sample 1.

[0016] Table 1 Example 1 Formula Table

[0017] Note: The unit is part, and the mesh size of rubber powder is 80 mesh.

[0018] The activated rubber powder was tested according to the standard "GB / T 19208-2020 Vulcanized Rubber Powder", and the test results are shown in Table 2.

[0019] Table 2 GB / T 19208-2020 Requirements and test results for vulcanized rubber powder

[0020] It can be seen from Table 2 that all test results of the activated rubber powder samples meet the requirements of GB / T 19208-2020 vulcanized rubber powder standard and are non-toxic and harmless to the environment and human body.

[0021] The performance tests of the vulcanized rubber samples listed in Table 3 are shown in Table 3.

[0022] Table 3 Vulcanized rubber performance test results

[0023] From the above results, it can be found that the sample containing the activated rubber powder prepared at 80°C (sample 1) has higher tensile strength and longer fatigue life than the sample containing the same amount of unactivated rubber powder (comparison sample 1). As the preparation temperature increases, although the tensile strength remains basically unchanged, the fatigue life is greatly shortened. Compared with the sample containing 10 parts of unactivated rubber powder (comparison sample 2), although the tensile strength is similar, the fatigue life is greatly shortened. In summary, the activated rubber powder prepared under normal pressure and low temperature conditions has a better effect. This is because DES was originally used for purification and desulfurization, and has a good desulfurization effect. Using DES as an active agent to activate the rubber powder has the effect of selectively desulfurizing the surface of the rubber powder, that is, directional breaking of sulfur-sulfur bonds, while protecting carbon-carbon bonds from damage. When used in rubber products, the activated rubber powder is closely bonded to the rubber matrix interface, the fatigue life is extended, and it is also beneficial to maintain mechanical properties.

[0024] Example 2 This example lists three preparation methods of DES modified activated rubber powder and compares their performance.

[0025] Choline chloride was added to the flask with urea, ethylene glycol and malonic acid in a molar ratio of 1:2, the reaction pressure was normal pressure, the temperature was 100°C, and the mixture was stirred for 30 minutes to obtain colorless and transparent DES. The mass ratio of DES to rubber powder was 2:1, the reaction pressure was normal pressure, the temperature was 80°C, and the reaction time was 2 hours, corresponding to samples DES-1, DES-2, and DES-3, respectively. Vulcanized rubber 1, vulcanized rubber 2, and vulcanized rubber 3 were prepared according to the method of Example 1, and the performance tests are shown in Table 4. The vulcanized rubbers prepared from the three types of DES activated rubber powders have similar properties and all have good activation effects.

[0026] Table 4 Vulcanized rubber performance test results

Claims

1. A method for preparing an environmentally friendly activated rubber powder, characterized in that: The method comprises the following preparation steps: Step 1: The hydrogen bond donor and the hydrogen bond acceptor are added to the flask in a certain molar ratio, the reaction pressure is normal pressure, the temperature is 100°C, and the colorless and transparent low eutectic solvent DES is obtained by stirring for 30 minutes; Step 2: Use waste tire tread rubber powder as the matrix, the mass ratio of colorless transparent low eutectic solvent DES to rubber powder is 2:1, the reaction pressure is normal pressure, the temperature is 80℃, the reaction time is 2 h, and the material can be discharged after the reaction reaches the specified time.

2. The method for preparing an environmentally friendly activated rubber powder according to claim 1, characterized in that: The hydrogen bond donor and hydrogen bond acceptor are choline chloride and urea, respectively, which are added into the flask at a molar ratio of 1:

2.

3. The method for preparing an environmentally friendly activated rubber powder according to claim 1, characterized in that: The hydrogen bond donor and hydrogen bond acceptor are choline chloride and ethylene glycol, respectively, which are added into the flask in a molar ratio of 1:

2.

4. The method for preparing an environmentally friendly activated rubber powder according to claim 1, characterized in that: The hydrogen bond donor and hydrogen bond acceptor are choline chloride and malonic acid, respectively, which are added into the flask at a molar ratio of 1:2.

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