WO2020108057A1

WO2020108057A1 - Method for preparing modified lignin/chitosan rubber reinforcing filler

Info

Publication number: WO2020108057A1
Application number: PCT/CN2019/107744
Authority: WO
Inventors: 陶伟珍
Original assignee: 陶伟珍
Priority date: 2018-11-29
Filing date: 2019-09-25
Publication date: 2020-06-04
Also published as: CN109749145A; CN109749145B

Abstract

Provided is a method for preparing a modified lignin/chitosan rubber reinforcing filler, comprising the following steps: S1. purification of lignin; S2. oxidation and sulfonation of lignin; S3. complexing of lignin/chitosan; S4. synthesis of bisstearoyl ethyl glycidyl ammonium chloride; and S5. preparation of modified lignin/chitosan. The modified lignin/chitosan rubber reinforcing filler of the invention has the following advantages: by the modification of chitosan and lignin, the reactive activity is further improved, the mechanical properties of a rubber are significantly improved, and at the same time, the two have a very good synergistic effect.

Description

Method for preparing modified lignin/chitosan rubber reinforced filler

Technical field

The invention relates to the field of rubber fillers, in particular to a method for preparing modified lignin/chitosan rubber reinforced fillers.

Background technique

Lignin is present in the xylem of most land plants, and forms the skeleton of the plant with cellulose and hemicellulose. It is a complex polymer compound. It is generally believed that the basic structural unit of lignin is phenylpropane, and there are three basic structures: guaiacyl propane, syringyl propane, and p-hydroxyphenyl propane. There are many functional groups on the structural unit of lignin, such as aromatic group, phenolic hydroxyl group, alcoholic hydroxyl group, carboxyl group, etc. The presence of these functional groups makes lignin have strong reactivity. Lignin can be used as an additive in rubber. The phenolic and carboxyl groups in its molecule can not only improve the anti-aging effect of the material, but also improve the physical and mechanical properties of the material.

Chitosan (CS) is a renewable resource obtained by chitin through different degrees of deacetylation. The CS molecule has active hydroxyl and amino groups, and has strong chemical reaction ability. It is prone to hydrolysis, alkylation, acylation, hydroxylation, grafting, quaternary ammonium saltation and other reactions, and can generate various derivatives with different properties. The substance has a realistic basis for combining with other substances and giving the copolymer its own characteristics.

Natural rubber (NR) is generally a concentrated natural latex or granular rubber collected from Brazilian trefoil rubber and processed through a series of processes, with excellent comprehensive performance. Although both CS and NR are very popular natural polymers with unique properties and potential use value in materials research, the mixing of the two to give the new composite with its own characteristics can be achieved by simple mixing. The present invention will modify CS as a reinforcing material.

Summary of the invention

Technical problem to be solved: The purpose of the present invention is to provide a method for preparing modified lignin/chitosan rubber reinforced filler, and the prepared filler has good reinforcement effect.

Technical solution: A method for preparing modified lignin/chitosan rubber reinforced filler, including the following steps:

S1. Purification of lignin: dissolve lignin in dioxane-water solution, centrifuge to obtain centrifugal liquid, add ether to the centrifuge liquid dropwise, obtain a precipitate, wash and dry the precipitate to obtain purified lignin;

S2. Oxidation and sulfonation of lignin: add lignin to deionized water containing sodium hydroxide, heat until lignin is completely dissolved, adjust the pH of the solution to 5, then add hydrogen peroxide and ferrous sulfate to react, After reaching the reaction time, add alkali to adjust the pH of the solution to 9, add formaldehyde and diethanolamine, and then react at 70-80 ℃, then increase the temperature to 90 ℃, add sodium sulfite, after the reaction is complete, add acid to precipitate lignin, wash and dry Oxidized sulfonated lignin;

S3. Lignin/chitosan compound: dissolve the lignin prepared in step S2 in dioxane-water solution, dissolve chitosan in acetic acid aqueous solution, mix the two solutions, add glutaraldehyde Union, finally suction filtered at room temperature, washed, and dried in an infrared box to obtain lignin / chitosan composite powder;

S4. Synthesis of distearoylethylepoxypropylammonium chloride: Heat the reflux of distearoyldiethylenetriamine and benzene, and add epichlorohydrin dropwise, stir until the reaction is complete, then evaporate benzene and Excess epichlorohydrin gives bis-stearamide ethyl epoxypropyl ammonium chloride;

S5. Preparation of modified lignin/chitosan: add the lignin/chitosan composite powder prepared in step S3 to deionized water, heat and stir until completely dissolved, adjust the pH to 10, and then add double stearin dropwise Amide ethyl epoxypropyl ammonium chloride, the reaction is complete under stirring, and then filtered by suction to dry to obtain modified lignin/chitosan.

Further, the volume ratio of dioxane-water in step S1 is 9:1.

Further, in the step S3, the solution prepared by dissolving the lignin prepared in step S2 in dioxane-water is configured with a concentration of 3%, and the chitosan is dissolved in a 2-3% aqueous acetic acid solution with a concentration of 2 -5% solution, mix the two solutions at a volume ratio of 1:0.5-1.5, add 0.3-0.8% glutaraldehyde for cross-linking, and finally filter with suction at room temperature, wash, and dry in an infrared box to obtain Lignin/chitosan composite powder.

Further, in step S4, the concentration of distearoyl diethylene triamine and epichlorohydrin dissolved in benzene is 0.8-1 mol/L.

Further, in step S5, the lignin/chitosan composite powder prepared in step S3 is added to deionized water to prepare a solution with a concentration of 0.5 mol/L, heated to 40-50°C and stirred until completely dissolved, adjusted When the pH is 10, then add bisstearic acid ethyl epoxypropyl ammonium chloride dropwise, react with stirring for 1-3 hours, and then filter and dry to obtain modified lignin/chitosan.

Beneficial effect: The modified lignin/chitosan rubber reinforced filler of the present invention has the following advantages: through the modification of chitosan and lignin, the reactivity is further improved, and the mechanical properties of the rubber are significantly improved. Good synergy.

detailed description

Example 1

A method for preparing modified lignin/chitosan rubber reinforced filler includes the following steps:

S1. Purification of lignin: Dissolve 5 times parts by weight of lignin in 100 times parts by weight of dioxane-water solution, the volume ratio of dioxane-water is 9:1, centrifuge to obtain centrifuge liquid, centrifuge Ether was added dropwise to the solution to obtain a precipitate, which was washed and dried to obtain purified lignin;

S2. Oxidation and sulfonation of lignin: add lignin to deionized water containing sodium hydroxide, heat until lignin is completely dissolved, adjust the pH of the solution to 5, then add hydrogen peroxide and ferrous sulfate to react, After reaching the reaction time, add alkali to adjust the pH of the solution to 9, add formaldehyde and diethanolamine, react at 70 ℃, then increase the temperature to 90 ℃, add sodium sulfite, after the reaction is complete, add acid to precipitate lignin, wash and dry to obtain oxidation Sulfonated lignin;

S3. Compound of lignin/chitosan: dissolve the lignin prepared in step S2 in dioxane-water solution with a concentration of 3%, and dissolve chitosan in 2% aqueous acetic acid with a concentration of 5% solution, mix the two solutions at a volume ratio of 1:0.5, add 0.3% glutaraldehyde for cross-linking, and finally suction filter at room temperature, wash, and dry in an infrared oven to obtain lignin/chitosan Sugar compound powder;

S4. Synthesis of distearoylethylepoxypropyl ammonium chloride: the distearoyl diethylene triamine and benzene are heated to reflux to react, and epichlorohydrin, bis stearoyl diethylene triamine and The concentration of epichlorohydrin dissolved in benzene is 0.8mol/L. After stirring until the reaction is complete, benzene and excess epichlorohydrin are evaporated to obtain bis-stearamide ethyl epoxypropyl ammonium chloride;

S5. Preparation of modified lignin/chitosan: the lignin/chitosan composite powder prepared in step S3 is added to deionized water to prepare a solution with a concentration of 0.5mol/L, heated to 40°C and stirred until complete Dissolve, adjust the pH to 10, then add bisstearic acid ethyl epoxypropyl ammonium chloride dropwise, react for 1h with stirring, and then filter and dry to obtain modified lignin/chitosan.

Example 2

S1. Purification of lignin: dissolve 10 times by weight of lignin in 100 times by weight of dioxane-water solution, the volume ratio of dioxane-water is 9:1, centrifuge to obtain centrifugal liquid, centrifuge Ether was added dropwise to the solution to obtain a precipitate, which was washed and dried to obtain purified lignin;

S2. Oxidation and sulfonation of lignin: add lignin to deionized water containing sodium hydroxide, heat until lignin is completely dissolved, adjust the pH of the solution to 5, then add hydrogen peroxide and ferrous sulfate to react, After reaching the reaction time, add alkali to adjust the pH of the solution to 9, add formaldehyde and diethanolamine, react at 80 ℃, then increase the temperature to 90 ℃, add sodium sulfite, after the reaction is complete, add acid to precipitate lignin, wash and dry to obtain oxidation Sulfonated lignin;

S3. Compound of lignin/chitosan: dissolve the lignin prepared in step S2 in dioxane-water solution with a concentration of 3%, and dissolve chitosan in 3% aqueous acetic acid with a concentration of 2% solution, mix the two solutions at a volume ratio of 1:1.5, add 0.8% glutaraldehyde for cross-linking, and finally suction filter at room temperature, wash, and dry in an infrared oven to obtain lignin/chitosan Sugar compound powder;

S4. Synthesis of distearoylethylepoxypropyl ammonium chloride: the distearoyl diethylene triamine and benzene are heated to reflux to react, and epichlorohydrin, bis stearoyl diethylene triamine and The concentration of epichlorohydrin dissolved in benzene is 1mol/L. After stirring until the reaction is complete, benzene and excess epichlorohydrin are evaporated to obtain bis-stearamide ethyl epoxypropyl ammonium chloride;

S5. Preparation of modified lignin/chitosan: add the composite powder of lignin/chitosan prepared in step S3 to deionized water to prepare a solution with a concentration of 0.5mol/L, heat to 50°C and stir until complete Dissolve, adjust the pH to 10, then dropwise add bisstearic acid ethyl epoxypropyl ammonium chloride, react for 3 hours with stirring, and then filter and dry to obtain modified lignin/chitosan.

Example 3

S1. Purification of lignin: Dissolve 6 times parts by weight of lignin in 100 times parts by weight of dioxane-water solution, the volume ratio of dioxane-water is 9:1, centrifuge to obtain centrifugal liquid, centrifuge Ether was added dropwise to the solution to obtain a precipitate, which was washed and dried to obtain purified lignin;

S2. Oxidation and sulfonation of lignin: add lignin to deionized water containing sodium hydroxide, heat until lignin is completely dissolved, adjust the pH of the solution to 5, then add hydrogen peroxide and ferrous sulfate to react, After the reaction time is reached, add alkali to adjust the pH of the solution to 9, add formaldehyde and diethanolamine, react at 75℃, then increase the temperature to 90℃, add sodium sulfite, after the reaction is complete, add acid to precipitate lignin, wash and dry to obtain oxidation Sulfonated lignin;

S3. Compound of lignin/chitosan: dissolve the lignin prepared in step S2 in dioxane-water solution with a concentration of 3%, and dissolve chitosan in 2.2% aqueous acetic acid with a concentration of 3-4% solution, mix the two solutions at a volume ratio of 1:1.2, add 0.4% glutaraldehyde for crosslinking, and finally suction filter at room temperature, wash, and dry in an infrared oven to obtain lignin/ Chitosan compound powder;

S4. Synthesis of distearoylethylepoxypropyl ammonium chloride: the distearoyl diethylene triamine and benzene are heated to reflux to react, and epichlorohydrin, bis stearoyl diethylene triamine and The concentration of epichlorohydrin dissolved in benzene is 0.9mol/L. After stirring until the reaction is complete, benzene and excess epichlorohydrin are evaporated to obtain bisstearamide ethyl epoxypropyl ammonium chloride;

S5. Preparation of modified lignin/chitosan: add the composite powder of lignin/chitosan prepared in step S3 to deionized water to prepare a solution with a concentration of 0.5mol/L, heat to 45°C and stir until complete Dissolve, adjust the pH to 10, then add bisstearic acid ethyl epoxypropyl ammonium chloride dropwise, react with stirring for 2h, and then filter and dry to obtain modified lignin/chitosan.

Example 4

S1. Purification of lignin: Dissolve 9 times parts by weight of lignin in 100 times parts by weight of dioxane-water solution, the volume ratio of dioxane-water is 9:1, centrifuge to obtain centrifuge liquid, centrifuge Ether was added dropwise to the solution to obtain a precipitate, which was washed and dried to obtain purified lignin;

S3. Compound of lignin/chitosan: dissolve the lignin prepared in step S2 in dioxane-water solution with a concentration of 3%, and dissolve chitosan in 2.8% acetic acid aqueous solution with a concentration of 3-4% solution, mix the two solutions at a volume ratio of 1:0.8, add 0.6% glutaraldehyde for cross-linking, and finally suction filter at room temperature, wash, and dry in an infrared oven to obtain lignin/ Chitosan compound powder;

Example 5

S1. Purification of lignin: Dissolve 8 times parts by weight of lignin in 100 times parts by weight of dioxane-water solution, the volume ratio of dioxane-water is 9:1, centrifuge to obtain centrifugal fluid, centrifuge Ether was added dropwise to the solution to obtain a precipitate, which was washed and dried to obtain purified lignin;

S2. Oxidation and sulfonation of lignin: add lignin to deionized water containing sodium hydroxide, heat until lignin is completely dissolved, adjust the pH of the solution to 5, then add hydrogen peroxide and ferrous sulfate to react, After the reaction time is reached, add alkali to adjust the pH of the solution to 9, add formaldehyde and diethanolamine, react at 78°C, then increase the temperature to 90°C, add sodium sulfite, after the reaction is complete, add acid to precipitate lignin, wash and dry to obtain oxidation Sulfonated lignin;

S3. Compound of lignin/chitosan: dissolve the lignin prepared in step S2 in dioxane-water solution with a concentration of 3%, and dissolve chitosan in 2.5% aqueous acetic acid with a concentration of 3.5% solution, mix the two solutions at a volume ratio of 1:1, add 0.5% glutaraldehyde for crosslinking, and finally filter with suction at room temperature, wash, and dry in an infrared oven to obtain lignin/chitosan Sugar compound powder;

S5. Preparation of modified lignin/chitosan: add the composite powder of lignin/chitosan prepared in step S3 to deionized water to prepare a solution with a concentration of 0.5mol/L, heat to 48°C and stir until complete Dissolve, adjust the pH to 10, then add bisstearic acid ethyl epoxypropyl ammonium chloride dropwise, react with stirring for 2h, and then filter and dry to obtain modified lignin/chitosan.

Comparative Example 1

No lignin was added, and the rest was the same as in Example 1.

Comparative Example 2

Chitosan was not added, and the rest was the same as in Example 1.

The formula of the rubber sample is as follows: 110 parts of natural rubber, 20 parts of modified lignin/chitosan rubber reinforced filler, 30 parts of carbon black, 5 parts of stearic acid, 3 parts of ZnO, 5 parts of antioxidant, 2 parts of sulfur, vulcanization 2 copies of accelerator.

Physical properties: Shore A hardness is measured according to GB/T 531, tensile properties and tear strength are according to GB/T 528 and GB/T 529, respectively, and the tensile rate is 500 mm·min ^-1 .

Claims

A method for preparing modified lignin/chitosan rubber reinforced filler, characterized in that it includes the following steps:

S1. Purification of lignin: dissolve lignin in dioxane-water solution, centrifuge to obtain centrifugal liquid, add ether to the centrifuge liquid dropwise, obtain a precipitate, wash and dry the precipitate to obtain purified lignin;

S2. Oxidation and sulfonation of lignin: add lignin to deionized water containing sodium hydroxide, heat until lignin is completely dissolved, adjust the pH of the solution to 5, then add hydrogen peroxide and ferrous sulfate to react, After reaching the reaction time, add alkali to adjust the pH of the solution to 9, add formaldehyde and diethanolamine, and then react at 70-80 ℃, then increase the temperature to 90 ℃, add sodium sulfite, after the reaction is complete, add acid to precipitate lignin, wash and dry Oxidized sulfonated lignin;

S3. Lignin/chitosan compound: dissolve the lignin prepared in step S2 in dioxane-water solution, dissolve chitosan in acetic acid aqueous solution, mix the two solutions, add glutaraldehyde Union, finally suction filtered at room temperature, washed, and dried in an infrared box to obtain lignin / chitosan composite powder;

S4. Synthesis of distearoylethylepoxypropylammonium chloride: Heat the reflux of distearoyldiethylenetriamine and benzene, and add epichlorohydrin dropwise, stir until the reaction is complete, then evaporate benzene and Excess epichlorohydrin gives bis-stearamide ethyl epoxypropyl ammonium chloride;

S5. Preparation of modified lignin/chitosan: add the lignin/chitosan composite powder prepared in step S3 to deionized water, heat and stir until completely dissolved, adjust the pH to 10, and then add double stearin dropwise Amide ethyl epoxypropyl ammonium chloride, the reaction is complete under stirring, and then filtered by suction to dry to obtain modified lignin/chitosan.
The method for preparing a modified lignin/chitosan rubber reinforced filler according to claim 1, wherein the volume ratio of dioxane-water in step S1 is 9:1.
The method for preparing a modified lignin/chitosan rubber reinforced filler according to claim 1, wherein in step S3, the lignin prepared in step S2 is dissolved in a solution of dioxane-water A solution with a concentration of 3%, chitosan is dissolved in a 2-3% aqueous acetic acid solution to prepare a solution with a concentration of 2-5%, the two solutions are mixed in a volume ratio of 1:0.5-1.5, and 0.3-0.8% of pentane is added The dialdehyde is cross-linked, and finally suction filtered at room temperature, washed, and dried in an infrared box to obtain a lignin/chitosan composite powder.
The method for preparing the modified lignin/chitosan rubber reinforced filler according to claim 1, wherein the concentration of distearoyl diethylene triamine and epichlorohydrin dissolved in benzene in step S4 It is 0.8-1mol/L.
The method for preparing a modified lignin/chitosan rubber reinforced filler according to claim 1, wherein in step S5, the lignin/chitosan composite powder prepared in step S3 is added to deionized water Prepare a solution with a concentration of 0.5mol/L, heat to 40-50°C and stir until completely dissolved, adjust the pH to 10, then add bisstearic acid ethyl epoxypropyl ammonium chloride dropwise, and react for 1-3h under stirring , And then suction-dried to obtain modified lignin/chitosan.