Environmentally friendly water-retaining natural polymers and methods thereof

Abstract

The present invention provides a water-retaining polymer capable of retaining water for a long time and in large quantities and a method for preparing the same. The polymer is capable of slowly releasing the retained water according to the needs of crops and soil. Therefore, the water-retaining polymer minimizes the water demand during irrigation and other uses. In addition, the polymer is environmentally friendly, pollution-free and completely biodegradable. This polymer can be used to grow plants on barren land and marble mud. The use of this polymer also minimizes the need for fertilizers for crops. In addition, the water-retaining polymer is inexpensive and therefore affordable for farmers. Due to the reduced water and fertilizer requirements using this water-retaining polymer, the total production cost of farmers is reduced by 60%, thereby increasing agricultural income generation.

Description

Technical Field

[0001] The present invention relates to a polymer, in particular to an environmentally friendly water-retaining polymer and also to a method for preparing the environmentally friendly water-retaining polymer. Background Art

[0002] Every country’s economy depends to some extent on agriculture. The agricultural sector requires a lot of water for irrigation, and lack of water for plants and crops leads to a reduction in cultivated areas, so 30% to 40% of productive land is not cultivated.

[0003] Super absorbent polymers (also known as SAP), hydrogels, absorbent polymers, absorbent gels, super soakers, super slurpers, hydrogels are high molecular weight synthetic absorbent polymer materials. They have the potential to absorb up to 100,000% of their weight in a short period of time by osmosis and form particles in the soil to enhance soil properties. SAP is usually a hygroscopic material like white sugar, which swells in water to form a transparent gel composed of individual particles that can retain water even under pressure without the risk of fire or rupture / explosion.

[0004] Super absorbent polymers for agricultural use are mainly prepared by solution polymerization or suspension polymerization of acrylic acid and crosslinkers such as potassium. The polymers so formed are called polyacrylates, and their swelling capacity and gel modulus depend largely on the amount and type of crosslinker used. Polyacrylates are non-toxic, non-irritating and non-corrosive in nature and have been tested to be biodegradable with an annual degradation rate of 10% to 15%. They show a high potential for water absorption and can freely release 95% of the same substance under the suction pressure of plant roots.

[0005] All existing water-retaining super absorbent polymers are manufactured by using chemicals, so they have adverse effects on crops, soil, soil water content, soil fertility (soil fertilizer capacity), and farmers. Existing polymers pollute soil and air and are not fully biodegradable or take a long time to fully degrade. Examples of available super absorbent polymers are sodium polyacrylate, polyacrylamide copolymer, ethylene-maleic anhydride copolymer, polyvinyl alcohol copolymer, etc. All these SAPs are made by chemical methods and are not completely beneficial to crop and soil health.

[0006] Therefore, there has long been a need for an environmentally friendly, fully biodegradable super absorbent polymer and method thereof that has good water retention capacity and sustainability. Summary of the invention

[0007] An object of the present invention is to provide a water-retaining polymer capable of retaining water for a long period of time.

[0008] Another object of the present invention is to provide a water retaining polymer that minimizes water demand during irrigation.

[0009] Another object of the present invention is to provide an environmentally friendly, pollution-free and completely biodegradable water-retaining polymer.

[0010] It is yet another object of the present invention to provide a water retaining polymer that can reduce the fertilizer requirements of crops.

[0011] Yet another object of the present invention is to provide a water retaining polymer which can be used for growing plants on barren land and marble slurry.

[0012] Another object of the present invention is to provide a low-cost water-retaining polymer.

[0013] Another object of the present invention is to provide a method for preparing an environmentally friendly and easy-to-implement water-retaining polymer.

[0014] The present invention provides a water-retaining polymer that can retain water for a long time and in large quantities. The polymer can slowly release the retained water according to the needs of crops and soil. Therefore, the water-retaining polymer minimizes the water demand during irrigation and other uses. In addition, the polymer is environmentally friendly, pollution-free and completely biodegradable. The present invention also provides a method for preparing the water-retaining polymer that is easy to implement and environmentally friendly.

[0015] The invention provides an environmentally friendly water-retaining natural polymer, comprising: biological waste; a cross-linking agent; and a polysaccharide; the cross-linking agent is non-carcinogenic, non-toxic and easily biodegradable, and the polysaccharide is one of flaxseed gum, xanthan gum, gum arabic, guar gum, tragacanth gum, gum arabic, alginic acid and hyaluronic acid or a combination thereof.

[0016] The invention provides a method for producing an environmentally friendly water-retaining natural polymer, the method comprising the following steps: extracting pectin from biological waste; dissolving the pectin in a 3% to 8% NaOH solution and a 3% to 10% urea solution for 10 to 45 minutes, and stirring at 100 rpm to 500 rpm; adding polysaccharide at a ratio of 1:3 to 3:1 and stirring for 25 to 35 minutes; adding a cross-linking agent of 1% to 10% of the total weight of the pectin and the polysaccharide; culturing the mixture at 55°C to 90°C for 5 to 6 hours; cooling and drying the mixture at 60°C to 80°C for 15 to 24 hours; and grinding the mixture to obtain a polymer with a mesh size of 60 to 150; the cross-linking agent is non-carcinogenic, non-toxic and easily biodegradable, and the polysaccharide is one of linseed gum, xanthan gum, gum arabic, guar gum, tragacanth gum, gum arabic, alginic acid and hyaluronic acid or a combination thereof.

[0017] The water-retaining polymer of the present invention can be used to grow plants on barren land and marble mud. The use of this polymer also minimizes the fertilizer requirements of crops. In addition, the water-retaining polymer is low-priced and therefore affordable for farmers. Due to the reduced water and fertilizer requirements using this water-retaining polymer, the overall production cost of farmers is reduced by 60%, thereby increasing agricultural income generation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to better understand the embodiments of the methods described in the present application and to more clearly show how they may be implemented, reference will now be made by way of example to the accompanying drawings, in which like reference numerals refer to like elements / components throughout, and in which:

[0019] Figure 1 Different steps of a method for preparing an environmentally friendly water-retaining natural polymer according to an embodiment of the present invention are shown.

[0020] Figure 2 Shown is a bar graph showing a comparison of corn plant growth under different testing conditions in accordance with an embodiment of the present invention. DETAILED DESCRIPTION

[0021] Embodiments of the invention will now be described herein with reference to the accompanying examples and drawings. Those skilled in the art will appreciate that the foregoing general description and the following detailed description are merely exemplary and explanatory of the present invention and are not intended to limit the present invention.

[0022] The present invention provides a water-retaining polymer capable of retaining a large amount of water for a long time. The water-retaining polymer has good water-retaining performance, biocompatibility, biodegradability, and mechanical strength, and can retain a large amount of water for a long time.

[0023] Furthermore, the present invention provides a method for preparing a water-retaining polymer that is cost-effective, easy to implement, and environmentally friendly.

[0024] According to an embodiment of the present invention, the water-retaining polymer includes biological waste, a cross-linking agent and polysaccharide.

[0025] In addition, the biological waste includes but is not limited to one or a combination of fruit waste, vegetable waste, fig barks and oil cake residue. In addition, the fruit waste includes but is not limited to one or a combination of citrus fruit peels, lemon peels, banana peels and jackfruit peels. The polysaccharide used to prepare the water-retaining polymer and cross-linked with pectin is a natural polysaccharide, which includes but is not limited to linseed gum, cellulose, cellulose derivatives, xanthan gum, gum arabic, guar gum, tragacanth gum, acacia gum, alginic acid and hyaluronic acid or a combination thereof. The cross-linking agent used to cross-link pectin and polysaccharides is but is not limited to sulfosuccinic acid. Sulfosuccinic acid is an efficient cross-linking agent, non-carcinogenic, non-toxic and easily biodegradable, and environmentally friendly.

[0026] According to one embodiment of the present invention, the polymer is environmentally friendly, pollution-free and completely degradable because it is composed entirely of organic components that are easily degraded individually or in combination as polymers. These components do not cause harm, leave residues or pollute the soil or air when they degrade. The water-retaining polymer provides some nutrients when it degrades, providing micro- and macronutrients to the soil and plants, and acts as an organic fertilizer, reducing the need for other fertilizers for crop growth by 40% to 60%.

[0027] Water-retaining polymers can reduce water demand by 60-80% and are therefore very beneficial in conserving water. This saved water can be further used for various other purposes and for irrigating land that is not being cultivated due to water shortage.

[0028] The water-retaining polymer is effective even on barren land and marble mud, and can therefore be a solution for using plots that have become barren or plots on which marble mud has been dumped after making them barren.

[0029] In addition, the 40% to 80% reduction in water demand has reduced farmers’ production costs. This lower production cost in turn has increased revenue generation in the agricultural sector.

[0030] In addition, the water-retaining polymer can retain water for 15 to 21 days and has a water absorption capacity of 60% to 80%. The environmentally friendly polymer provides nutrients while degrading, which can increase plant growth by 100% to 300%, and the polymer can be reused for up to 6 months.

[0031] According to another embodiment of the present invention, method 100 starts from step 101, wherein pectin is extracted from fruit waste. In step 102, the pectin powder obtained in step 101 is dissolved in a 6% NaOH and 12% urea mass concentration solution and stirred for 10 to 15 minutes. In step 103, flaxseed gum powder is added to the mixture of step 102 at a ratio of 1:3 to 3:1, and stirring is continued for 30 minutes. In step 104, sulfosuccinic acid, a cross-linking agent, is added at 1% to 10% of the total weight of pectin and polysaccharide, and cultured at 55° C. to 90° C. for 6 hours. In step 105, the reaction mixture is cooled and dried at 60° C. to 80° C. for 24 hours. In step 106, the dried mixture obtained in step 105 is ground into powder particles to obtain a water-retaining polymer.

[0032] In addition, in the preparation method of the water-retaining polymer, the NaOH aqueous solution is 3% to 8%, and the urea aqueous solution is 3% to 10%. The pectin powder is dissolved in the NaOH and urea solutions for 10 to 45 minutes and continuously stirred at 100 rpm to 500 rpm. The mesh size of the powder particles of the water-retaining polymer is 60 to 150.

[0033] In addition, the biological waste in the method includes but is not limited to one or a combination of fruit waste, vegetable waste, fig bark and oil cake residue. In addition, the fruit waste includes but is not limited to one or a combination of citrus fruit peels, lemon peels, banana peels and jackfruit peels. The polysaccharide used to prepare the water-retaining polymer and cross-linked with pectin is a natural polysaccharide, including but not limited to one or a combination of linseed gum, cellulose, cellulose derivatives, xanthan gum, gum arabic, guar gum, tragacanth gum, gum arabic, alginic acid and hyaluronic acid. The cross-linking agent used to cross-link pectin and polysaccharides is but is not limited to sulfosuccinic acid. Sulfosuccinic acid is a highly efficient cross-linking agent, non-carcinogenic, non-toxic and easily biodegradable, and environmentally friendly.

[0034] The use of fruit waste to prepare water-retaining polymers basically solves two problems. One is to deal with fruit waste, and the other is to produce a natural, environmentally friendly, cost-saving, sustainable and efficient water-retaining polymer that is helpful for crop growth and farmers.

[0035] According to one embodiment of the present invention, pectin is extracted from peels collected at various production sites such as juice shops, food processing sites, etc. The collected waste is then cleaned and any irrelevant materials such as leaves and branches are removed. The peel is washed with tap water and then washed with double distilled water to remove any physical impurities on the surface. The waste is then dried at a temperature below 60°C for 24 to 48 hours until a specified weight is obtained. Next, the dried material is ground and sieved using a 60 to 80 mesh sieve. The powder thus obtained is mixed with water in a ratio of 1:50, and the pH value is maintained at 1 to 4 using lemon juice. The mixture is heated at 55°C for 3 hours and then cooled for further processing. Then, soluble pectin and insoluble pectin are separated from the mixture using cheesecloth. Then, soluble pectin is precipitated using ethanol in an equal proportion to the soluble pectin. The ethanol is added while the mixture is continuously stirred. The mixture containing ethanol is then left for 30 minutes to allow the pectin to float on the surface. The mixture is then centrifuged to remove water and ethanol. The pectin thus obtained is dried and stored in powder form for further use.

[0036] The pectin used for preparing the water-retaining polymer preferably contains galacturonic acid content of more than 75%, methoxy content of 9% to 15%, and esterification degree of less than 50%, more preferably 20% to 25%.

[0037] Example

[0038] In an embodiment of the present invention, the water-retaining polymers were tested for their water-retaining capacity. The experiment was conducted at 21°C, and the humidity was maintained at 60% using a humidifier. In the experiment, 5 g of starch-based, 5 g of pectin-based, 5 g of acrylic acid-based, and three orange peel-based variables were placed in six separate containers. 200 ml of distilled water was added to each container and allowed to stand for 10 minutes. The water-retaining capacity of the six polymers was calculated using the formula.

[0039]

[0040] Where gs: is the weight of the expanded sample, gi: is the initial weight or net weight of the sample.

[0041] The results showed that orange peel-based polymer had the strongest water retention capacity of 76.1%, acrylic SAP had a water absorption capacity of 74.7%, and pectin and starch had water absorption capacities below 70%.

[0042] In another embodiment of the present invention, seven planting containers are filled with 1 kg of topsoil, and different samples to be tested are added to each container. The added samples are 25 g starch SAP, 25 g pectin SAP, 25 g acrylic acid SAP, and these three samples are considered as positive controls for the experiment. 25 g orange peel powder, 25 g orange peel solution and 25 g orange peel mixture are used as experimental groups, and containers without any samples are used as controls. Each added sample is thoroughly mixed with the soil and saturated with 100 ml of water on day 0. In the next 21 days, no additional water is added to the container. Soil moisture is then measured using a soil moisture meter at a specific time every day for 21 days.

[0043] It was observed that the soil moisture level in the containers with orange peel powder, acrylic SAP, starch SAP and pectin SAP was significantly higher after 10 days compared to the control without samples. After 21 days, the soil moisture in the pots containing "orange peel powder", "orange peel mixture", starch SAP and acrylic SAP remained at a humidity level of 3.8 to 4.8. These humidity levels were favorable for plant growth.

[0044] In another experiment, the growth of plants was measured. It was observed that the number of flowers of the plants with the orange peel mixture and acrylic SAP was significantly higher than that of the plants in the containers without samples. In addition, the plants in the containers with the orange peel mixture were healthier and stronger than those in the containers with acrylic SAP. It was also observed that the plants in the containers without samples began to die after the 10th day, while in the other containers with the acrylic SAP and orange peel mixture, the plants continued to grow healthily until the 16th day and began to die only after the 20th day.

[0045] In another experiment, the polymer was tested with corn plants in the field. An area of ​​100 square feet was selected for the experiment and the seeds used were Pratap Pakka-5. The soil type was sandy loam and measurements and observations were taken for 100 days. The experimental observations are shown in the following table and are presented as Figure 1 The bar graph shown represents.

[0046]

[0047] The test was conducted with 8 corn plants and the plants were irrigated only twice. It was observed that the maximum growth of the plants was given grade A, followed by the others as follows:

[0048] Level A > Level B > Other SAP > Coverage > General

[0049] The observed water retention capacity was:

[0050] Other SAP > Level A > Level B > Coverage > General

[0051] Stem diameter:

[0052] Stem thickness: Grade A > Grade B > Other SAP > Coverage > General

[0053] In the case of Class A, the highest average number of leaves per plant is:

[0054] Level A > Level B > Other SAP > Coverage > General

[0055] In another experiment, the effect of different ratios of polysaccharide and cross-linking agent on water absorption was observed. Table 1 shows the results obtained.

[0056]

[0057] It will be apparent to those skilled in the art that various modifications and variations may be made to the products and methods of the present invention without departing from the spirit or scope of the present invention. Therefore, the present invention is intended to cover modifications and variations of the present invention as long as they fall within the scope of the appended claims and their equivalents. In addition, the above-described embodiments are only attached for the purpose of illustrating the claimed invention and should not be construed as limiting the scope of the claimed invention.

Claims

1. An environmentally friendly water-retaining natural polymer, wherein: include: pectin extracted from biowaste; Cross-linking agent; and Polysaccharides; The cross-linking agent is non-carcinogenic, non-toxic and easily biodegradable, the cross-linking agent includes sulfosuccinic acid, the cross-linking agent is 1 to 10% of the total weight of the pectin and the polysaccharide, and the mass ratio of the pectin to the polysaccharide is 1:3 to 3:1, The polysaccharide is one of flaxseed gum, xanthan gum, guar gum and tragacanth gum or a combination thereof.

2. The environmentally friendly water-retaining natural polymer according to claim 1, wherein: The biological waste includes one or a combination of fruit waste, vegetable waste, fig bark and oil cake residue; the fruit waste includes citrus fruit peel, banana peel and jackfruit peel.

3. The environmentally friendly water-retaining natural polymer according to claim 1, wherein: The polymer is fully biodegradable and environmentally friendly.

4. The environmentally friendly water-retaining natural polymer according to claim 1, wherein: The polymers, when degraded, provide micro- and macronutrients to the soil and reduce the need for fertilizers for plant growth by 40% to 60%.

5. The environmentally friendly water-retaining natural polymer according to claim 1, wherein: The polymer reduces the water requirement of plants by up to 60% to 80%.

6. The environmentally friendly water-retaining natural polymer according to claim 1, wherein: The polymer is able to retain water for 15 to 20 days.

7. The environmentally friendly water-retaining natural polymer according to claim 1, wherein: The cross-linking agent accounts for 3-6% of the total weight of the pectin and the polysaccharide.

8. A method for producing an environmentally friendly water-retaining natural polymer, wherein: The method comprises the following steps: Extraction of pectin from biowaste; Dissolving the pectin in a 3% to 8% NaOH solution and a 3% to 10% urea solution for 10 to 45 minutes, and stirring at 100 rpm to 500 rpm; Add polysaccharide at a mass ratio of pectin to polysaccharide of 1:3 to 3:1 and stir for 25-35 minutes; Adding 1% to 10% of the total weight of the pectin and the polysaccharide as a cross-linking agent; The mixture was incubated at 55°C to 90°C for 5 to 6 hours; Cooling and drying the mixture at 60°C to 80°C for 15 to 24 hours; and Grinding the mixture to obtain a polymer having a mesh size of 60 to 150; The cross-linking agent is non-carcinogenic, non-toxic and easily biodegradable, and the cross-linking agent includes sulfosuccinic acid, The polysaccharide is one of flaxseed gum, xanthan gum, guar gum and tragacanth gum or a combination thereof.

9. The method according to claim 8, wherein: The biological waste includes one or a combination of fruit waste, vegetable waste, fig bark and oil cake residue; the fruit waste includes citrus fruit peel, banana peel and jackfruit peel.

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