阅读说明：本技术 一种高吸水复合材料及其制备方法 (High-water-absorption composite material and preparation method thereof ) 是由 马国富 桑武堂 王向兵 李小侠 彭辉 雷自强 于 2021-09-13 设计创作，主要内容包括：本发明公开一种高吸水复合材料,该高吸水复合材料主要由以下原料聚合反应得到：丙烯酸100重量份,聚天冬氨酸10～50重量份,2-丙烯酰胺基-2-甲基-1-丙烷磺酸10～50重量份,废旧纤维0～10重量份,引发剂1.5～2重量份,交联剂0.05～0.25重量份。与现有技术相比,本发明的高吸水复合材料制备过程简单、成本低廉、具有优异的吸水、保水和反复溶胀性能,既能充分回收再利用了生活废弃纤维资源,又扩大了聚天冬氨酸的利用范围,在减少污染、节约资源以及能源等方面具有很大的环境效益和经济效益。(The invention discloses a high water absorption composite material which is mainly obtained by polymerization reaction of the following raw materials: 100 parts of acrylic acid, 10-50 parts of polyaspartic acid, 10-50 parts of 2-acrylamido-2-methyl-1-propanesulfonic acid, 0-10 parts of waste fiber, 1.5-2 parts of initiator and 0.05-0.25 part of cross-linking agent. Compared with the prior art, the high water absorption composite material has the advantages of simple preparation process, low cost, excellent water absorption, water retention and repeated swelling performance, can fully recycle domestic waste fiber resources, expands the utilization range of polyaspartic acid, and has great environmental benefit and economic benefit in the aspects of reducing pollution, saving resources, saving energy and the like.)

1. The high water absorption composite material is characterized by being mainly obtained by polymerization reaction of the following raw materials:

100 parts by weight of acrylic acid, based on the total weight of the composition,

10 to 50 parts by weight of polyaspartic acid,

10-50 parts by weight of 2-acrylamido-2-methyl-1-propanesulfonic acid,

0 to 10 parts by weight of waste fibers,

1.5 to 2 parts by weight of an initiator,

0.05 to 0.25 part by weight of a crosslinking agent.

2. The superabsorbent composite of claim 1 wherein: the waste fibers are waste paper fibers.

3. The superabsorbent composite of claim 1 wherein: the cross-linking agent is N, N' -methylene bisacrylamide.

4. The superabsorbent composite of claim 1 wherein: the initiator is potassium persulfate.

5. The superabsorbent composite of claim 1 wherein: the weight parts of the raw materials are as follows:

100 parts of acrylic acid, 15-25 parts of polyaspartic acid, 10-15 parts of 2-acrylamido-2-methyl-1-propanesulfonic acid, 2-10 parts of waste fiber, 1.5-2 parts of an initiator and 0.05-0.25 part of a cross-linking agent.

6. A method for preparing a superabsorbent composite as claimed in any of claims 1 to 5 comprising the steps of:

firstly, polyaspartic acid, waste fiber and 2-acrylamide-2-methyl-1-propanesulfonic acid are mixed and heated to form uniform mixed liquid, then an initiator is added into the mixed liquid, then acrylic acid and a cross-linking agent which are neutralized in advance to a certain neutralization degree are added into the mixed liquid, and after the addition is finished, heat preservation reaction is carried out, so that the high water absorption composite material is obtained.

7. The method of claim 6, wherein: and stirring for 0.1-2 hours after the initiator is added.

8. The method of claim 6, wherein: the reaction temperature is 60-80 ℃.

9. The method of claim 6, wherein: the acrylic acid is pre-neutralized to a neutralization degree of 50 to 80%, preferably, the acrylic acid is pre-neutralized to a neutralization degree of 60 to 70%.

10. The method of claim 6, wherein: the reaction was carried out under nitrogen.

Technical Field

The invention relates to a high water absorption composite material and a preparation method thereof.

Background

In recent years, a high water-absorbing composite material has been favored by researchers as a highly effective water treatment material. The drought-resistant product is a chemical water-saving and high-tech drought-resistant product which is developed quickly at present, has the characteristics of quickly absorbing and slowly releasing water, reduces the surface area of a culture substrate and the evaporation capacity of the substrate water, can store gravity water which cannot be continuously utilized by plants when being applied to agriculture, effectively increases the substrate water holding capacity, and improves the water utilization rate.

Due to the ongoing development of modern urbanization processes, municipal environmental waste is being produced at an exponential rate, while paper products are one of the largest solid waste. Compared with natural fiber, the waste paper fiber is a recyclable resource with huge quantity, realizes the full utilization of the waste paper fiber, can save plant fiber raw materials, simultaneously reduces the discharge of solid waste, and reduces the production cost. According to statistics, the whole industry of pulping, papermaking and paper products finishes 25498 ten thousand tons of paper pulp, paper, paperboard and paper products in 2020, and the increase is 1.22% on a same scale; the total amount of recovered waste paper in 2020 is 5439 ten thousand tons, which is increased by 4.75% in the last year, and the annual increase rate of the total amount of recovered waste paper in 2011-Busy 2020 is 2.63%, but the utilization rate of the waste paper is reduced year by year. The research mainly limited to the waste paper fiber focuses on the fixed thinking of the use performance and the physicochemical property of the recycled paper, and the research on the subsequent recycling and use performance of the waste paper fiber from the form and the structural characteristics is relatively less. Therefore, the improvement of the resource utilization rate of the waste paper fiber, especially the high-valued utilization rate, is one of the future research hotspots.

Polyaspartic Acid (PASP) is a polyamino acid with a carboxylic acid side chain and a protein-like structure formed by combining a plurality of alpha-amino acids by peptide bonds (CO-NH). Under the action of microbes in the environment, the active sites are broken and decomposed into small fragments, and finally, CO is generated by decomposition₂And H₂O, is a biodegradable water-soluble polypeptide.

Disclosure of Invention

Based on the defects of the prior art, the invention aims to provide a high-water-absorption composite material with low cost and excellent performance.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

the high water absorption composite material is characterized by being mainly obtained by polymerization reaction of the following raw materials in parts by weight:

100 parts by weight of acrylic acid, based on the total weight of the composition,

10 to 50 parts by weight of polyaspartic acid,

10-50 parts by weight of 2-acrylamido-2-methyl-1-propanesulfonic acid,

0 to 10 parts by weight of waste fibers,

1.5 to 2 parts by weight of an initiator,

0.05 to 0.25 part by weight of a crosslinking agent.

Preferably, the waste fibers are waste paper fibers.

Preferably, the cross-linking agent is N, N' -methylenebisacrylamide.

Preferably, the initiator is potassium persulfate.

Preferably, the weight parts of the raw materials are as follows:

100 parts by weight of acrylic acid, based on the total weight of the composition,

15 to 25 parts by weight of polyaspartic acid,

10-15 parts by weight of 2-acrylamido-2-methyl-1-propanesulfonic acid,

2-10 parts by weight of waste fibers,

1.5 to 2 parts by weight of an initiator,

0.05 to 0.25 part by weight of a crosslinking agent.

More preferably, the weight parts of the raw materials are as follows:

100 parts by weight of acrylic acid, based on the total weight of the composition,

20 to 25 parts by weight of polyaspartic acid,

12-13 parts by weight of 2-acrylamido-2-methyl-1-propanesulfonic acid,

2-10 parts by weight of waste fibers,

1.5 to 2 parts by weight of an initiator,

0.2 to 0.25 part by weight of a crosslinking agent.

The preparation method of the high water absorption composite material comprises the following steps:

firstly, polyaspartic acid, waste fiber and 2-acrylamide-2-methyl-1-propane sulfonic acid are mixed and heated to form uniform mixed liquid;

adding an initiator into the mixed solution;

and then adding acrylic acid and a cross-linking agent which are neutralized in advance to a certain neutralization degree into the mixed solution, and after the addition is finished, carrying out heat preservation reaction to obtain the high water-absorbing composite material.

Preferably, after the initiator is added, stirring is carried out for 0.1-2 hours to generate a certain amount of free radicals.

Preferably, the reaction temperature is 60-80 ℃.

Preferably, the acrylic acid is pre-neutralized to a neutralization degree of 50 to 80%.

Preferably, the acrylic acid is pre-neutralized to a neutralization degree of 60 to 70%.

Preferably, the reaction is carried out under nitrogen protection.

Advantageous effects

Compared with the prior art, the high water absorption composite material has the advantages of simple preparation process, low cost, excellent water absorption, water retention and repeated swelling performance, can fully recycle domestic waste fiber resources, expands the utilization range of polyaspartic acid, and has great environmental benefit and economic benefit in the aspects of reducing pollution, saving resources, saving energy and the like. Provides a new idea for the preparation and research of the high water absorption composite material, and is an important process for realizing the strategy of sustainable development and being environment-friendly.

Drawings

FIG. 1 is a FT-IR infrared spectrum of a superabsorbent composite of the invention.

FIG. 2 is a scanning electron microscope image of the super absorbent composite of the present invention.

FIG. 3 is a diagram showing the water retention performance of the super absorbent composite material prepared by the present invention in distilled water.

FIG. 4 is a graph showing the repeated swelling behavior of the superabsorbent composite prepared in accordance with the present invention in distilled water.

FIG. 5 is a graph comparing the water absorption capacity of superabsorbent composites made according to the present invention with that of commercially available absorbent materials.

FIG. 6 is a graph of the water (salt) absorption performance of superabsorbent composites incorporating different PASP contents.

Detailed Description

The invention is further described in detail below with reference to the drawings and examples.

The waste fiber of the invention is waste paper fiber.

Example 1

The specific preparation process of the high water absorption composite material is as follows:

2.1 g of sodium hydroxide (dissolved in 6 ml of distilled water) was added dropwise to 5.4 g of Acrylic Acid (AA) until the neutralization degree of acrylic acid became 70% for use.

1.08 g of Polyaspartic Acid (PASP), 0.108 g of waste paper and 0.675 g of 2-acrylamido-2-methyl-1-propanesulfonic Acid (AMPS) were added to a four-necked flask equipped with a mechanical stirring device, a constant pressure dropping funnel and a nitrogen gas conduit in a 70 ℃ water bath, and heated and stirred for 1 hour to form a uniform mixed solution.

Then, 0.10 g of potassium persulfate (KPS) solution as an initiator was added thereto, and the mixture was continuously stirred for 15 min to generate radicals.

Subsequently, acrylic acid having a neutralization degree of 70% and a crosslinking agent 0.013 g N, N-Methylenebisacrylamide (MBA) were added dropwise thereto. After the dropwise addition, the isothermal reaction was continued for 1 h until complete polymerization. The whole experimental process is protected by nitrogen. After the reaction was completed, the reaction mixture was dried at 60 ℃ to a constant weight, and the dried sample was pulverized and sieved, and the particle size of all samples used for the test was 20 to 50 mesh.

For comparison, the superabsorbent composite blank was prepared in accordance with the above except that no wastepaper fiber was added.

FIG. 1 is a FT-IR infrared spectrum of a superabsorbent composite prepared in accordance with the present invention. (a) The curve is waste paper fiber; (b) the curve is PASP; (c) the curve is a superabsorbent composite. 2922 cm above the a-curve^-1Is C-H stretching vibration peak at 1161cm^-1And 1114cm^-1Absorption peaks for cyclic C-C and C-O-C glycosidic ether linkages, respectively, the three groups of peaks indicating the presence of cellulose; 3416 cm on the b curve^-1Is poly-aspartic acid N-H stretching vibrationPeak 1595 cm^-1Is the peak of C-N-H bending vibration, 1402 cm^-1Is the symmetric stretching vibration peak of carboxylate radical; the peaks of the above groups remained or even were significantly reduced or disappeared after the polymerization (i.e., on the c-curve), indicating the success of the graft polymerization reaction.

FIG. 2 is a scanning electron microscope image of the super absorbent composite prepared by the present invention. Wherein, the graph (a) is a blank sample without adding PASP and waste paper fiber, and the graph (b) is a high water absorption composite material. As can be observed from the SEM image, the blank has a relatively smooth surface and a cross section with a plurality of micropore structures; the surface of the super absorbent composite material prepared by adding the PASP and the waste paper fiber is irregular, and is relatively rough and has more porous structures, which shows that the introduction of the PASP and the waste paper fiber influences the structure of the super absorbent composite material, thereby effectively reducing the physical crosslinking degree among polymer chains and increasing the water (salt) absorption rate of the super absorbent composite material.

FIG. 3 is a diagram showing the water retention performance of the super absorbent composite material prepared by the present invention in distilled water. As can be seen, the superabsorbent composite blank has a water holding capacity of less than 60% after 6 days at room temperature, while the superabsorbent composite still has a water holding capacity of more than 60% after 6 days at room temperature. The result shows that the high water absorption composite material reinforced by the waste paper fiber has good water retention performance.

FIG. 4 is a graph showing the repeated swelling behavior of the superabsorbent composite prepared in accordance with the present invention in distilled water. As can be seen, the water content of the superabsorbent composite blank after 5 repeated swellages was about 10%, whereas the water content of the superabsorbent composite after 5 repeated swellages exceeded 30%. The result shows that the high water absorption composite material is a high water absorption composite material which can be fully recycled.

FIG. 5 is a comparison graph of water absorption capacity of the super absorbent composite prepared by the present invention and commercially available water absorbent materials (Guseyi American Water purification materials Co., Ltd.) and a blank super absorbent composite. It can be seen from the figure that the superabsorbent composite has a water absorption capacity of about 50.61% greater than that of the commercially available absorbent material and about 36.56% greater than that of the blank. The result shows that if the waste paper fiber and the polyaspartic acid are used for preparing the high water absorption composite material, the production cost can be reduced, the reasonable utilization of resources is realized, the environment is protected, and the high water absorption composite material has good economic and social benefits.

Examples 2 to 6

Unlike example 1, when the amount of PASP used was adjusted to 0.54 g, 1.08 g, 1.62 g, 2.16 g, and 2.70 g, superabsorbent composites having PASP contents of 10wt%, 20wt%, 30wt%, 40wt%, and 50wt% with respect to AA were obtained, respectively.

FIG. 6 is a graph of the water (salt) absorption performance of superabsorbent composites incorporating different PASP contents. As can be seen from the figure, when the PASP content is less than 20%, the water absorption capacity of the superabsorbent polymer tends to increase because the probability of collision of the macromolecular radical with the monomer increases with the increase of the PASP content, the degree of graft copolymerization increases, and the water absorption capacity increases. When the PASP content was 20%, the water absorption capacity was the maximum (710.2 g/g and 73.2 g/g in distilled water and 0.9% NaCl solution, respectively). When the content of the PASP is more than 20 percent, the water absorption capacity of the high water absorption material begins to be reduced because the AA/AMPS does not react with excessive PASP any more due to the fact that the reaction rate is increased and the branching and self-crosslinking reaction is accelerated due to the further increase of the dosage of the PASP, so that the swelling capacity of the material is poor, and the water absorption capacity is reduced.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.