Preparation of thiophenol material with good heavy metal adsorption, rubber reinforcement and vulcanization performance

Abstract

The invention discloses preparation of a thiophenol material with good heavy metal adsorption, rubber reinforcement and vulcanization performance. The method comprises the following steps: drying phenol, blending the dried phenol with sulfur and a base catalyst, carrying out closed heating reaction, and drying to obtain the thiophenol material. The thiophenol material is used in rubber and wastewater treatment, and the thiophenol material is found to have good vulcanization reinforcing effect and adsorption effect, and has wide application prospect.

Description

Technical Field

[0001] The invention relates to the preparation and application of a vulcanizing agent, a reinforcing agent and an adsorbent, in particular to a preparation method and application of a thiophenol material as a vulcanizing agent and an adsorbent, and belongs to the field of functional polymer materials. Background Art

[0002] In the field of rubber, although traditional vulcanizing agents can achieve the vulcanization and cross-linking of rubber and improve the physical and mechanical properties of rubber, there are many disadvantages. The traditional vulcanization system has a slow vulcanization speed, and harmful substances such as nitrosamines are easily produced during the vulcanization process, posing a threat to the environment and human health. Although organic peroxides have a fast vulcanization speed, they are easy to cause the breakage of rubber molecular chains, resulting in unstable performance of rubber products, and there are safety hazards in their storage and use processes. Therefore, it is urgent to develop a new type of vulcanizing agent that is efficient, environmentally friendly and has excellent performance. In the field of adsorbents, the currently widely used adsorbents have good adsorption effects on certain pollutants, but there are problems such as high cost and difficulty in regeneration, and they can often only be discarded, causing waste of resources and secondary pollution. Therefore, it is of great practical significance to find a new type of adsorbent with a wide source, low cost and good adsorption performance.

[0003] Phenols are an important class of organic compounds. The lone pair of electrons contained in the phenolic hydroxyl groups in phenolic compounds can react with heavy metal ions to form stable complexes. The complexes formed by phenol and heavy metal ions have a certain stability, so that the heavy metal ions can be separated from the solution. This complexation reaction is highly selective. Different phenolic compounds have different complexing abilities for different heavy metal ions. The appropriate phenolic adsorbent can be selected according to the type of heavy metal ions to remove heavy metal ions. At the same time, the hydroxyl (-OH) in phenolic compounds has strong activity and can react with the active points (such as double bonds) in rubber molecules to form a cross-linked network structure between rubber molecules. These cross-linking points can prevent the slippage and relative displacement of rubber molecular chains, thereby improving the physical properties of rubber.

[0004] Sulfur is a naturally occurring element that has been used by humans for hundreds of years. The sulfur atoms in organic sulfur compounds have lone pairs of electrons, which can react with heavy metal ions to form stable chelates with them and are extremely insoluble in water, thereby effectively removing heavy metal ions from the solution. Sulfur has suitable chemical activity and can react with double bonds in rubber molecular chains. Rubber molecules contain a large number of carbon-carbon double bonds, and sulfur atoms can open the double bonds and form covalent bonds with rubber molecular chains, thereby building a cross-linked network structure between rubber molecules. This reactivity allows sulfur to effectively transform rubber from a linear structure to a three-dimensional network structure, thereby changing the physical and chemical properties of rubber.

[0005] By utilizing the high-temperature ring-opening property of sulfur and reacting with phenol under alkaline conditions, the obtained thiophenol material contains a large number of sulfur atoms and phenolic hydroxyl groups, which increases its reaction active sites. Increasing its reaction activity can greatly increase the adsorption amount and degree of vulcanization, and has broad application prospects in the fields of heavy metals, dye adsorption and rubber industry. Summary of the invention

[0006] The purpose of the present invention is to provide a method for preparing a thiophenol material. The preparation method has simple process, convenient operation and low price. The prepared thiophenol material can significantly improve the mechanical strength of rubber and the adsorption amount of heavy metals and dyes in wastewater, can improve production efficiency and economic benefits, and shows extremely broad application space and potential. In the future development process, it is expected to shine in many fields and become a key force to promote the progress of related industries. It has market value and development opportunities that cannot be underestimated.

[0007] In order to achieve the purpose of the present invention, the following technical solutions are provided:

[0008] A method for preparing a thiophenol material, characterized by the following steps:

[0009] After the phenol is dried, it is evenly mixed with sulfur and an alkaline catalyst and added to a three-necked flask. Deionized water is added and the mixture is sealed and heated to react for a certain period of time to allow the sulfur to fully modify the phenol to generate thiophenol material. The reactants are dissolved with alkaline water and separated after sulfur removal. Acid water is added to the supernatant to obtain a precipitate, which is then washed with clean water and dried.

[0010] The phenols used in the synthetic thiophenol material further include cardanol, lignin, monophenol, diphenol, and triphenol.

[0011] The monophenol used in the further described synthetic thiophenol material is phenol.

[0012] The diphenols used in the further described synthetic thiophenol material include catechol, resorcinol and hydroquinone.

[0013] The triphenols used in the further described synthetic thiophenol material include pyrogallol, phloroglucinol and pyrogallol.

[0014] The mass ratio of phenol to sulfur in the synthetic thiophenol material is further 1:0.2-20.

[0015] The molar ratio of the base catalyst to phenol in the further described synthetic thiophenol material is 0.2 to 10:1.

[0016] The reaction conditions are as follows: the temperature is 80-200°C and the time is 1-48h.

[0017] The pH of the alkaline aqueous solution is further 8-12, and hydrochloric acid solution is added to adjust the pH to 2-6 in order to remove unreacted sulfur, phenol and alkaline catalyst.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The preparation method of the thiophenol material of the present invention has low raw material cost and wide sources for preparing the thiophenol material. The thiophenol material can be applied to the vulcanization crosslinking agent and rubber reinforcing agent of rubber products, and can also be used as an adsorbent for wastewater treatment, and has a wide range of applications. Moreover, the preparation method is process controllable and the conditions are mild. The prepared thiophenol material can significantly improve the mechanical properties of rubber, and as an adsorbent material, it also has a high adsorption capacity and a fast adsorption rate, and is suitable for large-scale promotion. DETAILED DESCRIPTION

[0020] The present invention will be further described below by specific embodiments. The following examples are intended to illustrate the present invention rather than to further limit the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art may make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

[0021] Embodiment 1:

[0022] Take 1g of cardanol and place it in a three-necked flask, add 2g of sulfur, 0.5g of Na 2 CO 3 , then add deionized water with a pH value of 12 as the reaction medium. Heat to 180°C in an oil bath and keep stirring for 12 hours. During the reaction, sulfur reacts chemically with the active groups in cardanol, introducing sulfur elements to achieve vulcanization modification.

[0023] The obtained sulfurized cardanol is kneaded with natural rubber. The wear rate of the natural rubber after sulfurization with modified cardanol can be reduced by about 30% compared with the unsulfurized state.

[0024] Embodiment 2:

[0025] Take 2.5g of lignin and place it in a three-necked flask, add 5g of sulfur, 1g of sodium carboxylate, and then add deionized water with a pH value of 12 as the reaction medium. Use an oil bath to heat to 160°C and keep stirring for 12 hours. During the reaction, sulfur reacts chemically with the active groups in the lignin molecules, introducing sulfur elements to achieve sulfurization modification. After the reaction is completed, cool and filter to separate, add hydrochloric acid to the obtained liquid to adjust to pH = 4 to obtain a precipitate, and freeze-dry after centrifugal separation to obtain a sulfurized modified lignin material.

[0026] The obtained vulcanized lignin is mixed with butadiene rubber. The softening temperature of butadiene rubber after vulcanization with modified lignin increases from 70-80°C to 120-140°C, and the thermal stability is significantly improved, which can meet the use requirements in higher temperature environments.

[0027] Embodiment 3:

[0028] Weigh 2.2g of catechol, 1g of elemental sulfur and 1.1g of sodium bicarbonate, mix them thoroughly, grind and mix them, place them in a hydrothermal reactor, and then put them in an oven. Adjust the oven temperature to 180°C and react for 24 hours to react the elemental sulfur with the alkali lignin to generate sulfided catechol. Then dissolve it in an alkaline aqueous solution with a pH of 11, filter and separate it to obtain a dark black liquid. Add hydrochloric acid solution to the obtained liquid, adjust the pH to 5, and centrifuge and freeze-dry to obtain a sulfide-modified catechol-based adsorbent material.

[0029] In the adsorption experiment of malachite green, the adsorption amount of the generated sulfurized modified catechol-based adsorbent material increased rapidly with time in the first 60 minutes, then slowed down, and remained basically unchanged after 6 hours. At this time, the adsorption amount can reach about 1130 mg / g.

[0030] Embodiment 4:

[0031] Weigh 1g of alkali lignin, 1g of elemental sulfur and 0.5g of sodium hydroxide, mix thoroughly, grind and mix, place in a hydrothermal reactor, then put into an oven, adjust the oven temperature to 180°C, react for 24 hours to react the elemental sulfur with the alkali lignin to form sulfided lignin. Then dissolve in an alkaline aqueous solution with a pH of 11, filter and separate to obtain a dark black liquid. Add hydrochloric acid solution to the obtained liquid, adjust the pH to 5, and centrifuge and freeze-dry to obtain a sulfided modified lignin-based adsorption material.

[0032] In the adsorption experiment of malachite green, the adsorption amount of the generated sulfurized modified lignin-based adsorption material increased rapidly with time in the first 60 minutes, then slowed down, and remained basically unchanged after 6 hours. At this time, the adsorption amount can reach about 940 mg / g.

[0033] Embodiment 5:

[0034] Weigh 1g of pyrogallol, 4.2g of elemental sulfur and 0.5g of sodium hydroxide, mix thoroughly, grind and mix, place in a hydrothermal reactor, then put into an oven, adjust the oven temperature to 180°C, react for 24 hours to react sulfur with pyrogallol to generate sulfidized pyrogallol. Then dissolve in an alkaline aqueous solution with a pH of 11, filter and separate to obtain a dark black liquid. Add hydrochloric acid solution to the obtained liquid, adjust the pH to 5, and centrifuge and freeze-dry to obtain a sulfurized modified pyrogallol-based adsorbent material.

[0035] In the adsorption experiment of malachite green, the generated sulfurized modified pyrogallol-based adsorption material showed that the adsorption amount increased rapidly with time in the first 60 minutes, then slowed down, and remained basically unchanged after 6 hours. At this time, the adsorption amount can reach about 400 mg / g.

Claims

1. A sulfided lignin, characterized in that : Its chemical structural formula is as follows: Among them, lignin is the lignin structure.

2. A method for preparing a thiophenol material, characterized by the following steps: In this method, phenol is dried, mixed with sulfur and an alkali catalyst, and then heated in a sealed manner for reaction. After alkali dissolution, filtration separation, acid precipitation, centrifugation, water washing, freeze drying and other operations, a thiophenol material is obtained.

3. The method for preparing a thiophenol material as claimed in claim 2, characterized in that The phenols used include cardanol, lignin, monophenol, diphenol and triphenol.

4. The method for preparing a thiophenol material according to claim 3, characterized in that The monophenol used is phenol.

5. The method for preparing a thiophenol material according to claim 3, characterized in that The diphenols used include catechol, resorcinol and hydroquinone triphenol.

6. The method for preparing a thiophenol material according to claim 3, characterized in that The triphenols used include pyrogallol, phloroglucinol and pyrogallol.

7. The method for preparing a thiophenol material according to claim 2, characterized in that The base catalyst used includes Na2CO3, NaHCO3, sodium carboxylate and mixtures thereof.

8. The method for preparing a thiophenol material according to claim 2, characterized in that The mass ratio of phenol to sulfur in the synthetic thiophenol material is 1:0.2-20.

9. The method for preparing a thiophenol material according to claim 2, characterized in that The mass ratio of the base catalyst to the phenol in synthesizing the thiophenol material is 0.2 to 10:

1.

10. The method for preparing a thiophenol material according to claim 2, characterized in that The molar ratio of the base catalyst to sulfur in synthesizing the thiophenol material is 0.1 to 3:

1.

11. The method for preparing a thiophenol material according to claim 2, characterized in that The reaction conditions for synthesizing the thiophenol material are a temperature of 80-200° C. and a reaction time of 1-48 h.

12. The method for preparing a thiophenol material according to claim 2, characterized in that The pH of the alkaline aqueous solution is 8-12, and hydrochloric acid solution is added to adjust the pH to 2-6.

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