阅读说明：本技术 一种高耐盐的高吸水树脂及其制备工艺 (High-salt-tolerance super absorbent resin and preparation process thereof ) 是由 李方 于 2020-08-11 设计创作，主要内容包括：本发明属于树脂技术领域,具体涉及一种高耐盐的高吸水树脂及其制备工艺,高耐盐的高吸水树脂包括以下质量组分的原料：海藻酸钠5～10份、丙烯酸80～100份、丙烯酰胺50～60份、壳聚糖20～30份、硅藻土10～20份、腐殖酸10～20份、引发剂0.05～2.5份、交联剂0.3～5份、抗氧化剂0.05～3份。本发明的制备工艺将壳聚糖直接溶于丙烯酸溶液中进行反应,对丙烯酸起到中和作用,因此不需要在反应前对丙烯酸进行中和处理,减少了工艺步骤,降低了生产成本。利用海藻酸钠提高了树脂的可降解性,起到了保护环境的作用。硅藻土的多孔结构给其他原料起到了承载作用,并且提高了树脂的吸水率,硅藻土和海藻酸钠反应,提高了硅藻土的絮凝性能。(The invention belongs to the technical field of resin, and particularly relates to a high-salt-tolerance super absorbent resin and a preparation process thereof, wherein the high-salt-tolerance super absorbent resin comprises the following raw materials in parts by mass: 5-10 parts of sodium alginate, 80-100 parts of acrylic acid, 50-60 parts of acrylamide, 20-30 parts of chitosan, 10-20 parts of diatomite, 10-20 parts of humic acid, 0.05-2.5 parts of an initiator, 0.3-5 parts of a cross-linking agent and 0.05-3 parts of an antioxidant. The preparation process of the invention directly dissolves the chitosan in the acrylic acid solution for reaction, and plays a role in neutralizing the acrylic acid, so that the acrylic acid does not need to be neutralized before the reaction, the process steps are reduced, and the production cost is reduced. The sodium alginate is utilized to improve the degradability of the resin, and the function of protecting the environment is played. The porous structure of the diatomite plays a bearing role for other raw materials, the water absorption rate of the resin is improved, and the flocculation performance of the diatomite is improved through the reaction of the diatomite and the sodium alginate.)

1. The high-salt-tolerance super absorbent resin is characterized by comprising the following raw materials: sodium alginate, acrylic acid, acrylamide, chitosan, diatomite, humic acid, an initiator, a cross-linking agent and an antioxidant.

2. The high salt-resistant super absorbent resin as claimed in claim 1, which comprises the following raw materials by mass: 5-10 parts of sodium alginate, 80-100 parts of acrylic acid, 50-60 parts of acrylamide, 20-30 parts of chitosan, 10-20 parts of diatomite, 10-20 parts of humic acid, 0.05-2.5 parts of an initiator, 0.3-5 parts of a cross-linking agent and 0.05-3 parts of an antioxidant.

3. The high-salt-resistance high-water-absorption resin as claimed in claim 1, wherein the cross-linking agent is one or more of N, N-methylene bisacrylamide, polyethylene glycol diacrylate, glycerol, pentaerythritol, trimethylol methane triacrylate and sodium citrate.

4. The high salt resistant super absorbent resin according to claim 1, wherein said initiator is benzoyl peroxide or azobisisobutyronitrile peroxide or dilauroyl peroxide or di-tert-butyl peroxide.

5. The high salt-tolerant high water absorbent resin according to claim 1, wherein the antioxidant is any one of 2, 6-di-tert-butyl-4-methylphenol, 4-hydroxydodecanoic acid anilide, antioxidant 1076, and antioxidant 264.

6. A preparation process of a high salt-resistant super absorbent resin is characterized by comprising the following steps:

step 1, directly dissolving chitosan in acrylic acid to neutralize the acrylic acid, wherein the neutralization degree is 60-80%, and the reaction temperature is 25-30 ℃;

step 2, adding acrylamide and humic acid solution, stirring for 20min, and uniformly mixing to obtain a mixed solution A; slowly adding the sodium alginate solution and the diatomite, stirring for 15min at room temperature, and uniformly mixing to obtain a turbid solution B;

step 4, introducing nitrogen and formaldehyde into the turbid liquid B, removing oxygen, adding an initiator under a stirring state for polymerization reaction at the reaction temperature of 60-90 ℃, adding a cross-linking agent, uniformly mixing, and after the reaction is finished, granulating, drying, crushing and screening to obtain high-salt-resistance high-water-absorption resin particles;

and 5, soaking the high-salt-tolerance super absorbent resin particles in an antioxidant solution for 20-30 min, taking out and drying.

7. The process for preparing the high salt-resistant high water-absorbent resin according to claim 6, wherein the concentration of the sodium alginate solution is 15 g/L-40 g/L.

8. The process for preparing the high salt-resistant high water-absorbent resin according to claim 6, wherein the drying temperature in the step 4 and the step 5 is 60 ℃ to 70 ℃.

9. The process for preparing the high-salt-tolerance super absorbent resin according to claim 6, wherein the particle size of the high-salt-tolerance super absorbent resin sieved in the step 4 is 20-100 meshes.

10. The process for preparing the high-salt-tolerance high-water-absorption resin according to claim 6, wherein the cross-linking agent is one or more of N, N-methylene bisacrylamide, polyethylene glycol diacrylate, glycerol, pentaerythritol, trimethylol methane triacrylate and sodium citrate; the initiator is benzoyl peroxide or azobisisobutyronitrile peroxide or dilauroyl peroxide or di-tert-butyl peroxide; the antioxidant is any one of 2, 6-di-tert-butyl-4-methylphenol, 4-hydroxydodecanoic acid anilide, antioxidant 1076 and antioxidant 264.

Technical Field

The invention belongs to the technical field of resin, and particularly relates to high-salt-tolerance super absorbent resin and a preparation process thereof.

Background

The super absorbent resin is a cross-linked network polymer containing a large number of strong polar groups, and is firstly prepared by adopting starch grafted polyacrylonitrile by Fanta and the like and then saponifying. From the last 60 s to date, super absorbent resins have been developed globally and can be divided into two main categories according to raw materials, wherein the first category is natural polymers such as starch and cellulose; the second type is a synthetic polymer, such as polyacrylic acid, polyoxyethylene, polyvinyl alcohol, wherein at present more than 80% of the super absorbent resin is polymerized from acrylic acid monomers.

The super absorbent resin is used as a novel functional polymer material, and has wide application in the aspects of medicine and health, agriculture, forestry, gardening, desert control and the like due to the unique water absorption and water retention performance. The reason for the water absorption of the super absorbent resin is that a large number of hydrophilic functional groups exist on the molecular chain of the super absorbent resin. These hydrophilic groups are most likely carboxyl groups, and furthermore, hydroxyl groups, amide groups, amino groups, sulfonic acid groups, phosphoric acid groups, sulfinic acid groups, and the like can be used. From the beginning of the 80 s, superabsorbent resins were used in sanitary materials as carriers for absorption of artificial body fluids. Thereafter, the demand for superabsorbent resins has risen dramatically, with 80% to 85% of the production being applied to sanitary articles as the most predominant absorbent material for human body fluids, particularly urine. The application environment of the super absorbent resin mostly contains K⁺、Ca²⁺、Na⁺When inorganic salt ions are used, the water absorption capacity of the resin is easily reduced by metal ions, and is generally reduced from hundreds of times to dozens of times.

At present, the super absorbent resin generally has the problems of higher synthesis industrial cost and poorer salt resistance, and the traditional super absorbent resin cannot be naturally degraded, thereby causing the problem of environmental pollution.

Disclosure of Invention

The invention aims to: the high salt-resistant super absorbent resin and the preparation process thereof have good biodegradability, high water absorption and simple preparation process.

The technical scheme of the invention is as follows: the high salt-resistant super absorbent resin comprises the following raw materials: sodium alginate, acrylic acid, acrylamide, chitosan, diatomite, humic acid, an initiator, a cross-linking agent and an antioxidant.

Preferably, the raw materials comprise the following components in mass percentage: 5-10 parts of sodium alginate, 80-100 parts of acrylic acid, 50-60 parts of acrylamide, 20-30 parts of chitosan, 10-20 parts of diatomite, 10-20 parts of humic acid, 0.05-2.5 parts of an initiator, 0.3-5 parts of a cross-linking agent and 0.05-3 parts of an antioxidant.

Preferably, the cross-linking agent is one or a mixture of N, N-methylene bisacrylamide, polyethylene glycol diacrylate, glycerol, pentaerythritol, trimethylolmethane triacrylate and sodium citrate.

Preferably, the initiator is benzoyl peroxide or azobisisobutyronitrile peroxide or dilauroyl peroxide or di-tert-butyl peroxide.

Preferably, the antioxidant is any one of 2, 6-di-tert-butyl-4-methylphenol, 4-hydroxydodecanoic acid anilide, antioxidant 1076 and antioxidant 264.

The invention also provides a preparation process of the high salt-resistant super absorbent resin, which comprises the following steps:

step 1, directly dissolving chitosan in acrylic acid to neutralize the acrylic acid, wherein the neutralization degree is 60-80%, and the reaction temperature is 25-30 ℃;

step 2, adding acrylamide and humic acid solution, stirring for 20min, and uniformly mixing to obtain a mixed solution A; slowly adding the sodium alginate solution and the diatomite, stirring for 15min at room temperature, and uniformly mixing to obtain a turbid solution B;

step 4, introducing nitrogen and formaldehyde into the turbid liquid B, removing oxygen, adding an initiator under a stirring state for polymerization reaction at the reaction temperature of 60-90 ℃, adding a cross-linking agent, uniformly mixing, and after the reaction is finished, granulating, drying, crushing and screening to obtain high-salt-resistance high-water-absorption resin particles;

and 5, soaking the high-salt-tolerance super absorbent resin particles in an antioxidant solution for 20-30 min, taking out and drying.

Preferably, the concentration of the sodium alginate solution is 15 g/L-40 g/L.

Preferably, the drying temperature in the step 4 and the step 5 is 60-70 ℃.

Preferably, the particle size of the high salt-resistant super absorbent resin particles sieved in the step 4 is 20-100 meshes.

Preferably, the cross-linking agent is one or a mixture of N, N-methylene bisacrylamide, polyethylene glycol diacrylate, glycerol, pentaerythritol, trimethylolmethane triacrylate and sodium citrate; the initiator is benzoyl peroxide or azobisisobutyronitrile peroxide or dilauroyl peroxide or di-tert-butyl peroxide; the antioxidant is any one of 2, 6-di-tert-butyl-4-methylphenol, 4-hydroxydodecanoic acid anilide, antioxidant 1076 and antioxidant 264.

The invention has the beneficial effects that:

1. the chitosan is directly dissolved in the acrylic acid solution for reaction, the acrylic acid solution replaces the common solvent acetic acid solution of the common chitosan, except that the solvent acetic acid can be subtracted, the chitosan has amino groups and plays a role in neutralizing the acrylic acid, so that the acrylic acid does not need to be neutralized before the reaction, the process steps are reduced, and the production cost is reduced.

2. Acrylamide is added into acrylic acid, is a non-ionic substance and cannot be ionized in a solution, and the salt resistance of the resin is improved by utilizing the acrylamide.

3. The sodium alginate has wide source and low cost, has good degradability and biocompatibility, improves the degradability of the resin, and plays a role in protecting the environment.

4. The porous structure of the diatomite plays a bearing role for other raw materials, the water absorption rate of the resin is improved, and the flocculation performance of the diatomite is improved through the reaction of the diatomite and the sodium alginate.

5. The chitosan not only plays a role in neutralizing acrylic acid, can enhance the bridging and net capturing effects of the sodium alginate in the reaction process with the sodium alginate, improves the flocculation effect, further promotes aggregation and growth of flocs on the basis of the adsorption bridging of the chitosan by the sodium alginate, is more favorable for forming a molecular chain net structure, promotes the net capturing effect, has a certain chelating effect on metal, also has a certain adsorption effect on copper ions by the sodium alginate, and can achieve a good turbidity removal effect.

6. The cross-linking agent mainly plays a cross-linking role in a polymerization system, so that the system can form a three-dimensional network structure, when the cross-linking agent is used in an excessive amount, pores among the network structure of the system are reduced due to the excessive cross-linking degree of the resin, molecules and ions are not easy to permeate into the resin, and meanwhile, the swelling degree of the resin is limited, so that the water absorption capacity of the resin is reduced; when the dosage of the cross-linking agent is too small, the solubility of the copolymer resin is larger due to too low cross-linking degree, and the copolymer resin is not beneficial to absorbing and maintaining water, the cross-linking agent is selected in a proper amount, the mass component value is between 0.3 and 5 parts, the proportion of the cross-linking agent and other raw materials is moderate, and the water absorption rate of the resin is further improved.

7. The degree of monomer neutralization directly influences the types of hydrophilic groups on resin molecular chains and the number of charges, and further influences the water absorption capacity of the polymer. When the neutralization degree is lower, the system is acidic, which is beneficial to initiating reaction, so that the monomer conversion rate is higher, the ion concentration in the resin is reduced, the electrostatic repulsion and osmotic pressure of a network structure are reduced, the water absorption of the copolymer resin is reduced, the metal ion concentration in the copolymer resin is increased due to the excessively high neutralization degree, the water solubility of the resin is enhanced, and the stability of the resin and the improvement of the water absorption rate are also not beneficial. The neutralization degree of the chitosan and the acrylic acid is 60-80%, and the neutralization degree is proper, so that the resin stability is facilitated, and the water absorption rate is improved. When the neutralization degree of the acrylic acid is continuously increased, the water absorption performance of the resin is gradually reduced, mainly because the reaction time is too long due to the excessively high neutralization degree, the acrylic acid cannot form a high molecular polymer, meanwhile, a large amount of cations have a shielding effect on anions on molecular chains, the expansion among the molecular chains is hindered, and the water absorption performance of the product is reduced, so the optimal neutralization degree in the invention is 70%.

8. Humic acid is added into the formula, the source of the humic acid is wide, the humic acid has good biological activity and chemical activity, and the humic acidThe acid contains a large amount of-OH, -NH₂And hydrophilic groups such as-O' -CO-and the like are favorable for improving the hydrophilic performance of the resin, increasing the space network structure of the resin and improving the water absorption performance of the resin.

9. After the sodium alginate and the humic acid are mixed, free hydroxyl can appear in the solution, the binding capacity to heavy metal ions is increased, the sodium alginate and the humic acid both contain carboxyl and hydroxyl, formaldehyde is added in the preparation process, the sodium alginate and the humic acid are crosslinked, and the adsorption surface area is increased, so that the water absorption effect generated by mixing the sodium alginate and the humic acid is better than the treatment effect generated by singly using the sodium alginate.

Detailed Description

The technical solution of the present invention will be described in detail with reference to specific examples.