阅读说明：本技术 一种纳米二氧化钛包覆改性废旧橡胶粉的制备方法 (Preparation method of nano titanium dioxide coated modified waste rubber powder ) 是由 舒兴旺 原国华 张瑞斌 吕船 刘涛 王俊 陶斌 姜京伟 朱江 蔡丽娜 林浩 李 于 2021-08-20 设计创作，主要内容包括：本发明公开了属于高分子材料改性技术领域的一种纳米二氧化钛包覆改性废旧橡胶粉的制备方法。该方法包括以下步骤：(1)废旧橡胶粉表面清水处理；(2)废旧橡胶粉表面酸性溶液处理；(3)废旧橡胶粉表面偶联剂处理；(4)废旧橡胶粉表面纳米二氧化钛包覆处理；(5)改性废旧橡胶粉团聚体破碎处理。其中纳米二氧化钛采用溶胶-凝胶法制备；将废旧橡胶粉掺入纳米二氧化钛溶胶-凝胶体系中,纳米二氧化钛在废旧橡胶粉表面沉积,形成有机废旧橡胶粉为核、无机纳米二氧化钛为壳的复合结构,该复合结构兼顾两种材料的优点,且通过材料复合,显著提升废旧橡胶粉的综合力学性能以及与胶结料(如环氧树脂、水泥浆体等)的界面相容性和界面粘接强度。(The invention discloses a preparation method of nano titanium dioxide coated modified waste rubber powder, belonging to the technical field of modification of high polymer materials. The method comprises the following steps: (1) treating the surface of the waste rubber powder with clear water; (2) treating the surface of the waste rubber powder with an acid solution; (3) treating the surface of the waste rubber powder with a coupling agent; (4) coating the surface of the waste rubber powder with nano titanium dioxide; (5) and (3) crushing modified waste rubber powder aggregates. Wherein the nano titanium dioxide is prepared by a sol-gel method; the waste rubber powder is doped into a nano titanium dioxide sol-gel system, and the nano titanium dioxide is deposited on the surface of the waste rubber powder to form a composite structure with organic waste rubber powder as a core and inorganic nano titanium dioxide as a shell.)

1. A preparation method of nano titanium dioxide coated modified waste rubber powder is characterized by comprising the following steps: (1) treating the surface of the waste rubber powder with clear water; (2) treating the surface of the waste rubber powder with an acid solution; (3) treating the surface of the waste rubber powder with a coupling agent; (4) coating the surface of the waste rubber powder with nano titanium dioxide; (5) and (3) crushing modified waste rubber powder aggregates.

2. The method as claimed in claim 1, wherein the waste rubber powder is 100-200 mesh ultra-fine rubber powder.

3. The preparation method according to claim 1, wherein the specific operation of the step (1) is as follows: soaking the waste rubber powder in clear water, treating for more than 20 minutes under continuous stirring, filtering and drying.

4. The preparation method according to claim 1, wherein the specific operation of the step (2) is as follows: soaking the waste rubber powder in an HCl solution with the mass concentration of 5-8% for 6-12 hours, washing with clear water, and airing.

5. The preparation method according to claim 1, wherein the specific operation of the step (3) is: uniformly mixing the waste rubber powder with an ethanol solution of a titanate coupling agent NDZ-201 with the mass concentration of 1-2% to ensure that the surface of the waste rubber powder is completely wetted, mixing for 10-30 minutes and then drying.

6. The preparation method of claim 5, wherein the ethanol solution of the titanate coupling agent NDZ-201 is added in an amount of 2-5 times of the mass of the waste rubber powder.

7. The preparation method according to claim 1, wherein the specific operation of the step (4) is as follows: adding the waste rubber powder treated by the coupling agent in the step (3) into a nano titanium dioxide sol-gel system, heating to 70-100 ℃, reacting for 1-4h, and finally preserving heat at 100 ℃ for 1-4h, wherein nano titanium dioxide is formed by depositing on the surface of the waste rubber powder.

8. The preparation method according to claim 7, wherein the nano titania sol-gel system is prepared by mixing the components in a volume ratio of 1.7: 4: 1: 4.25 of butyl titanate, absolute ethyl alcohol, 95 percent of ethanol solution and glacial acetic acid.

9. The preparation method according to claim 8, wherein the nano titania sol-gel system is prepared by the following steps: 1) uniformly mixing butyl titanate and absolute ethyl alcohol according to the proportion to obtain a solution A; 2) uniformly mixing glacial acetic acid and a 95% ethanol solution according to the proportion to obtain a solution B; 3) slowly dripping the solution A into the solution B while stirring the solution B at the temperature of 20-25 ℃; 4) sealing after the dropwise addition is finished, and continuously stirring for reacting for 6-8 h; 5) standing and aging for 4 days.

10. The preparation method according to claim 1, wherein the specific operation of the step (5) is: adopting a planetary ball mill for mechanical crushing, wherein the rotating speed is 2000-.

Technical Field

The invention belongs to the technical field of modification of high polymer materials, and particularly relates to a preparation method of nano titanium dioxide coated modified waste rubber powder.

Background

Along with the rapid development of the global automobile industry, the quantity of waste tires is increasing, the waste tires are difficult to decompose in the natural environment for hundreds of years, and the safety and beautification of the environment are seriously influenced. How to efficiently and reasonably utilize waste tires becomes an important subject to be solved urgently in all countries in the world.

The waste tires are crushed into rubber powder and mixed into concrete to prepare rubber concrete which is used for highway pavement engineering, and the method is a very promising disposal method. The existing cement concrete pavement has large brittleness and weak impact resistance, cracks are easy to generate under the action of internal stress (temperature stress and humidity stress), and the waste rubber is doped into the cement concrete to form a structural deformation center for absorbing strain energy, thereby obviously improving the brittleness and the impact resistance of the concrete and reducing various diseases caused by the internal stress.

However, the incorporation of rubber can cause the concrete to have greatly reduced compression and bending strength, mainly because: the rubber material is an organic material and has poor hydrophilicity; the cement paste is an inorganic material, has strong hydrophilicity, large difference of physical and chemical properties of the cement paste and the cement paste, poor compatibility and weak interface bonding force, obviously reduces the strength of the concrete, and hinders the large-scale application of the rubber concrete in pavement engineering.

At present, NaOH solution, NaCl solution, clear water and CCl are mainly adopted by a plurality of scientific researchers₄The surface of the rubber powder is modified by the solution, the polymer emulsion, the polyacrylamide, the polyvinyl acetal, the silane coupling agent and the like so as to improve the interface compatibility and the interface bonding strength of the rubber powder and the cement paste and improve the strength of the rubber concrete.

Disclosure of Invention

In view of the unsatisfactory modification method, the invention provides a method for modifying waste rubber powder by coating nano titanium dioxide, which can effectively improve the compatibility of the waste rubber powder and a cementing material and obviously improve the interfacial bonding strength between the waste rubber powder and the cementing material.

The preparation method of the nano titanium dioxide coated modified waste rubber powder comprises the following steps: (1) treating the surface of the waste rubber powder with clear water; (2) treating the surface of the waste rubber powder with an acid solution; (3) treating the surface of the waste rubber powder with a coupling agent; (4) coating the surface of the waste rubber powder with nano titanium dioxide; (5) and (3) crushing modified waste rubber powder aggregates.

The waste rubber powder is 100-mesh 200-mesh ultrafine rubber powder.

The specific operation of the step (1) is as follows: soaking the waste rubber powder in clear water, treating for more than 20 minutes under continuous stirring, filtering and drying.

The specific operation of the step (2) is as follows: soaking the waste rubber powder in an HCl solution with the mass concentration of 5-8% for 6-12 hours, washing with clear water, and airing.

The specific operation of the step (3) is as follows: uniformly mixing the waste rubber powder with an ethanol solution of a titanate coupling agent NDZ-201 with the mass concentration of 1-2% to ensure that the surface of the waste rubber powder is completely wetted, mixing for 10-30 minutes and then drying.

The mixing amount of the ethanol solution of the titanate coupling agent NDZ-201 is 2-5 times of the mass of the waste rubber powder.

The specific operation of the step (4) is as follows: adding the waste rubber powder treated by the coupling agent in the step (3) into a nano titanium dioxide sol-gel system, heating to 70-100 ℃, reacting for 1-4h, and finally preserving heat at 100 ℃ for 1-4h, wherein nano titanium dioxide is formed by depositing on the surface of the waste rubber powder.

The nano titanium dioxide sol-gel system is prepared from the following components in a volume ratio of 1.7: 4: 1: 4.25 of butyl titanate, absolute ethyl alcohol, 95 percent of ethanol solution and glacial acetic acid.

The preparation steps of the nano titanium dioxide sol-gel system are as follows: 1) uniformly mixing butyl titanate and absolute ethyl alcohol according to the proportion to obtain a solution A; 2) uniformly mixing glacial acetic acid and a 95% ethanol solution according to the proportion to obtain a solution B; 3) slowly dripping the solution A into the solution B while stirring the solution B at the temperature of 20-25 ℃; 4) sealing after the dropwise addition is finished, and continuously stirring for reacting for 6-8 h; 5) standing and aging for 4 days.

The specific operation of the step (5) is as follows: adopting a planetary ball mill for mechanical crushing, wherein the rotating speed is 2000-.

The invention has the following advantages:

(1) the modified waste rubber powder has higher mechanical property and better durability by a multi-stage treatment process. The surface of the waste rubber powder is treated by clear water to remove floating dust and pollutants on the surface; then, removing oil stains and loose structures on the surface by acid solution treatment; then, the surface polarity state is changed by treating with a titanate coupling agent, and the interface compatibility is improved; and finally, the waste rubber powder is coated by nano titanium dioxide to form a composite structure taking the waste rubber powder as a core and the nano titanium dioxide as a shell, so that the mechanical property and durability of the waste rubber powder are obviously improved.

(2) Surface polarization treatment, and interface compatibility and interface bonding strength of the modified waste rubber powder and the cementing material are obviously improved. According to the invention, the surface of the waste rubber powder is subjected to in-situ polymerization to form an inorganic nano titanium dioxide coating structure, the surface is changed from an organic group with no polarity or weak polarity into a hydroxyl group with strong polarity and an inorganic titanium structure, the surface is changed from non-polarity or weak polarity into strong polarity, and the interface compatibility and the interface bonding strength of the waste rubber powder and a cementing material (such as epoxy resin, cement mortar and the like) are obviously improved.

(3) An organic-inorganic core-shell composite structure is formed, and the comprehensive performance of the modified waste rubber powder is obviously improved. The invention prepares a composite structure which takes organic waste rubber powder as a core and inorganic nano titanium dioxide as a shell, the composite structure takes the advantages of two materials into consideration, and new excellent performance can be generated by compounding the materials, and the comprehensive performance of the waste rubber powder is obviously improved.

Detailed Description

In order to better understand the present invention, the following examples are further provided to illustrate the present invention, but the present invention is not limited to the following examples.

Example 1:

(1) soaking 100-mesh superfine waste rubber powder in clear water, treating for 30 minutes under continuous stirring, filtering and drying.

(2) And (2) adding the waste rubber powder cleaned in the step (1) into an HCl solution with the mass concentration of 5%, soaking for 8 hours, then washing for 2 times by using clear water, and airing.

(3) Preparing an ethanol solution with the mass concentration of 2% by using the titanate coupling agent NDZ-201, uniformly mixing the ethanol solution with the waste rubber powder treated in the step (2), wherein the mixing amount of the ethanol solution of the titanate coupling agent NDZ-201 is 2.5 times of the mass of the waste rubber powder, mixing for 10 minutes, and then drying.

(4) Adding the waste rubber powder treated by the coupling agent in the step (3) into a nano titanium dioxide sol-gel system, heating to 80 ℃ for reaction for 2h, and finally preserving the heat at 100 ℃ for 2h, so that nano titanium dioxide is formed on the surface of the waste rubber powder through deposition.

(5) And (4) mechanically crushing the modified waste rubber powder aggregate obtained in the step (4) by using a planetary ball mill at the rotating speed of 2000 r/min for 3 min.

Example 2:

(1) soaking 200-mesh superfine waste rubber powder in clear water, treating for 30 minutes under continuous stirring, filtering and drying.

(2) And (2) adding the waste rubber powder cleaned in the step (1) into an HCl solution with the mass concentration of 5%, soaking for 8 hours, washing for 3 times by using clear water, and airing.

(3) Preparing an ethanol solution with the mass concentration of 2% by using the titanate coupling agent NDZ-201, uniformly mixing the ethanol solution with the waste rubber powder treated in the step (2), wherein the mixing amount of the ethanol solution of the titanate coupling agent NDZ-201 is 3 times of the mass of the waste rubber powder, mixing for 15 minutes, and then drying.

(4) Adding the waste rubber powder treated by the coupling agent in the step (3) into a nano titanium dioxide sol-gel system, heating to 80 ℃ for reaction for 2h, and finally preserving the heat at 100 ℃ for 2h, so that nano titanium dioxide is formed on the surface of the waste rubber powder through deposition.

(5) And (4) mechanically crushing the modified waste rubber powder aggregate obtained in the step (4) by using a planetary ball mill at the rotating speed of 3000 r/min for 1 min.

Example 3:

(1) soaking 150-mesh superfine waste rubber powder in clear water, treating for 25 minutes under continuous stirring, filtering and drying.

(2) And (2) adding the waste rubber powder cleaned in the step (1) into an HCl solution with the mass concentration of 5%, soaking for 8 hours, washing for 3 times by using clear water, and airing.

(3) Preparing an ethanol solution with the mass concentration of 2% by using the titanate coupling agent NDZ-201, uniformly mixing the ethanol solution with the waste rubber powder treated in the step (2), wherein the mixing amount of the ethanol solution of the titanate coupling agent NDZ-201 is 4 times of the mass of the waste rubber powder, mixing for 20 minutes, and then drying.

(4) Adding the waste rubber powder treated by the coupling agent in the step (3) into a nano titanium dioxide sol-gel system, heating to 80 ℃ for reaction for 2h, and finally preserving the heat at 100 ℃ for 2h, so that nano titanium dioxide is formed on the surface of the waste rubber powder through deposition.

(5) And (4) mechanically crushing the modified waste rubber powder aggregate obtained in the step (4) by using a planetary ball mill at the rotating speed of 2500 rpm for 2 minutes.

In the above examples 1 to 3, the nano titania sol-gel system was prepared by mixing the following components in a volume ratio of 1.7: 4: 1: 4.25 of butyl titanate, absolute ethyl alcohol, 95 percent of ethanol solution and glacial acetic acid. The preparation method comprises the following specific steps: 1) uniformly mixing butyl titanate and absolute ethyl alcohol according to the proportion to obtain a solution A; 2) uniformly mixing glacial acetic acid and a 95% ethanol solution according to the proportion to obtain a solution B; 3) slowly dripping the solution A into the solution B during stirring of the solution B at the temperature of 25 ℃; 4) sealing after the dropwise addition is finished, and continuously stirring for reacting for 8 hours; 5) standing and aging for 4 days.