Modified Soybean Protein Group Isolation Superstrong Water Absorber And Preparation Method
Technical field
The present invention relates to a kind of biodegradable Modified Soybean Protein Group Isolation Superstrong Water Absorber And Preparation Method that has, function of dominant high polymer material chemical field also belongs to the natural polymer field.
Background technology
Super strength water absorbent (claim super absorbent resin again, be called for short SAP) is a kind of new type functional macromolecular material that develops in recent years, and the hundred times that can absorb own wt is to thousands of times water, and water holding capacity is strong, can use repeatedly.The super-strong moisture absorbing agent is succeeded in developing in 1974 by United States Department of Agriculture the earliest, now is widely used in fields such as industry, agricultural, daily life, health care at first industrialization and begin to be widely used in hygienic material of Japan in 1978 subsequently.Patent has in the past proposed to utilize different material to prepare the method for super strength water absorbent, hydrolysate as starch-acrylonitrile grafting polymer, vinylacetate-the acrylic copolymer of saponification, and the Sodium Polyacrylate super strength water absorbent that obtains of inverse suspension polymerization etc., said method has also comprised the pick up (absorbing water, salt solution, urine etc.) of resin and the problems such as improvement of rate of liquid aspiration.But as super strength water absorbent in industry, agricultural horticulture and the extensive use of daily-use chemical industry industry, have nothing in common with each other according to the desired performance of its purposes, for example: Chinese patent CN1359974A is disclosed to be entitled as described in " process for preparing high-hydroscopicity composite resin for agricultural purpose ", the absorbent material of using on the agricultural there is different requirements, for example: require the gel after the SAP product particle absorbs water that certain intensity will be arranged, can in soil, keep certain shape like this, can well absorb water, water conservation, to reach the purpose that slow release is put.Simultaneously, because hydrogel intensity is higher, gel is difficult for disintegrating, and the water good reversibility is released in suction, thereby its useful life in soil is prolonged.Chinese patent CN1229808A is disclosed to be entitled as described in " water absorbing agent and manufacture method thereof and application ", as the used SAP of the hygienic material of usefulness such as sanltary towel, requirement has excellent urine patience, and has any urine formed and all stablize and in time the very little absorption property of passing change.
It is reported that super strength water absorbent production and selling amount surpasses 1,500,000 tons in the world, it is monomer crosslinked being polymerized that present SAP mainly adopts acrylic acid, and wherein 80% is used to make personal-care supplies such as disposable infant diaper, sanltary towel.Is the high polymer of main chain as all with the C-C key, and the cross linked polyacrylate of HMW (salt) SAP is difficult to be decomposed by microorganism in the soil and bacterium, is non-Biodegradable polymer.China is the potential consumption big country of personal-care supplies such as disposable paper diaper, sanitary napkin, along with the expansion day by day of SAP production scale and personal-care supplies application market, traditional cross linked polyacrylate (salt) SAP certainly will bring huge problem of environmental pollution after a large amount of discarding.
Summary of the invention
The object of the present invention is to provide a kind of soybean protein isolate that utilizes through chemical modification, has biodegradability with graft copolymerization of vinyl monomer preparation again, be suitable as super strength water absorbent of personal-care supplies absorbent materials such as producing sanitary napkin, paper nappy and preparation method thereof, energy conservation cost, and preparation technology is simple.
The present invention be by free-radical oxidation reduction cause, aqueous solution grafting copolymerization process is achieved in the following manner: earlier soybean isolate protein powder is hydrolyzed in sodium hydroxide solution molecule amount 10000~20000 water-solubility protein and with Peracetic acid carry out hydrophilically modified after, again with the aqueous solution of vinyl monomer, in the presence of multiple crosslinking agent, free-radical oxidation reduction initator, carry out crosslinked, grafting, copolyreaction makes the water imbibition gel, gel through pelletizing, drying, pulverizing, sieve the super strength water absorbent product.
This super strength water absorbent is a kind of crosslinked modified soybean protein isolate-vinyl monomer graft copolymer, and each component and percentage by weight are:
Modified soybean protein isolate 8.5~42.0
Vinyl monomer 57.5~90.5
Multiple crosslinking agent 0.22~0.55
Ammonium persulfate 0.14~0.29
Sodium hydrogensulfite 0.07~0.22
Used water-soluble vinyl monomer is one or more mixing in PAA, hydroxy-ethyl acrylate, acrylamide and the ALS among the present invention.
Concrete preparation method is:
1) adding percentage by weight in having the container of stirring is 8%~15% the modified soybean protein isolate aqueous solution 85~255 grams, vinyl monomer 40~85 grams, and multiple crosslinking agent 0.2~0.5 gram is stirred well to dissolving fully;
2) add 1.0% sodium hydrogensulfite, 6.2~19.5 grams again, 1.0% ammonium persulfate 12.3~26.0 grams, the back that stirs moves in the stainless steel reaction dish, keeps the reaction 30 minutes down of 35~45 ℃ of initial temperatures, after be warming up to 60~80 ℃ and continue reaction 1~2 hour;
3) polymer gel pelletizing, 105 ℃ are dried, are pulverized, sieve super strength water absorbent.
Above-mentioned multiple crosslinking agent is by N, and N '-methylene-bisacrylamide and glutaraldehyde are formed, and the consumption of multiple crosslinking agent is 0.22%~0.55% of a polymer raw gross mass, N, the mass ratio 0.8~2.5: 1.0 of N '-methylene-bisacrylamide and glutaraldehyde.The effect of crosslinking agent is can keep certain intensity after making water absorbing agent suction, N, and N '-methylene-bisacrylamide is main to form network structure with the vinyl monomer copolymerization, and the amino and the hydroxyl that dissociate in the main and modified protein of glutaraldehyde are crosslinked.Consumption crosses that soluble fraction increases in the low then water absorbing agent, causes water absorption rate to descend, and directly has influence on suction back gel strength, and suction back water-loss reducer is gel and become the thin viscous of no intensity not; Too high then intensity is better, but crosslinking points is many during polymerization, and the cyberspace that forms by crosslinking points diminishes, the also corresponding minimizing of the amount of liquid that can hold, and water absorbing capacity obviously diminishes.
Above-mentioned initator is the ammonium persulfate-sodium bisulfite redox initiator.Initiator amount directly has influence on the chain link molecular weight and the self-crosslinking degree of resin.Initiator amount is too small, and reaction speed is relatively slow, and polymerization time is long; The excessive then polymerisation of initiator amount takes place rapidly, removes danger to occur, also causes the degree of cross linking to increase and the molecular weight reduction, so gained water-loss reducer water absorption rate descends; Simultaneously, initiator amount also directly influences percent grafting, initiator amount increases percent grafting and also increases thereupon, but descends on the contrary above the increase percent grafting along with initiator amount behind certain consumption, and this may be along with initiator amount increases, grafting active site increases, percent grafting improves gradually, but excessive when initator, it is many more to produce the monomer free radical, homopolymerization speed is on the contrary greater than graft copolymerization speed, and is unfavorable to graft copolymerization.
The preparation method of used modified soybean protein isolate is among the present invention:
(1) soybean isolate protein powder is added deionized water to concentration 8%~15%, every kilogram of dry weight of protein adds 5% beta-mercaptoethanol, 0.2~0.5 gram, stir, add NaOH solution and transfer pH to 13.0~14.0, after with pulverizer the protein gel body being rubbed, send in the reactor, stir, be heated to 100 ℃, make glycinin under alkali condition, dissociation reaction take place, be degraded to molecular weight and be 10000~20000 component, and making the cystine linkage cracking, the structure of glycinin is launched, and forms the protein aqueous solution of linear macromolecule;
(2) protein solution is cooled to 70~80 ℃, adds the Peracetic acid of dry weight of protein 0.2%~0.5%, stirring reaction 15~30 minutes.Peracetic acid can make the sulfhydryl oxidase on the protein side chain become the sulfonic group of strongly hydrophilic, makes the protein solution bleaching simultaneously, increases its whiteness after polymerization.
The albumen base superpower water absorbent of the present invention's preparation is inhaled deionized water absorption rate Q
(water)=145~538g.g
-1Inhale 0.9% saline solution multiplying power Q
(salt)=42~66.7g.g
-1
The present invention compared with prior art has characteristics:
1) adopting modified soybean protein isolate and water-soluble vinyl monomer is primary raw material graft copolymerization, suction, the water retention property of the water absorbing agent of preparation are good, salt tolerant, urine patience can be better than simple acrylic homopolymer, and cost of material reduces, and has favorable economic benefit.
2) adopt solution polymerization process, the room temperature initiated polymerization, technology is simple, processing ease.
3) in polymer network, introduce the native protein chain link, can make water absorbing agent energy biodegradation after use is discarded, have environmental benefit preferably.
The specific embodiment
Below directly adopt the mode of embodiment to describe the present invention:
Embodiment 1:
1. the preparation of modified soybean protein isolate
(1) soybean isolate protein powder is added deionized water to concentration 12.0%, every kilogram of protein (dry weight) adds 5% beta-mercaptoethanol, 0.3 gram, stir, add NaOH solution and transfer pH=14, after with pulverizer the protein gel body being rubbed, send in the reactor, stir, be heated to 100 ℃, make glycinin under alkali condition, dissociation reaction take place, be degraded to molecular weight and be the protein aqueous solution of 10000~20000 linear macromolecule.
(2) protein solution is cooled to 75 ℃, the Peracetic acid that adds dry weight of protein 0.4%, stirring reaction 20 minutes can make sulfhydryl oxidase on the protein side chain become the sulfonic group of strongly hydrophilic, make protein solution bleaching simultaneously, solid content is 12% modified protein solution.
2. the preparation of modified soy-bean protein base superpower water absorbent: the adding percentage by weight is 12% the modified soybean protein isolate aqueous solution 150 grams in having the container of stirring, deionized water 100 grams, vinyl monomer PAA 65 grams, N, N '-methylene-bisacrylamide 0.15 restrains and 25.0% glutaraldehyde 0.56 restrains, and is stirred well to dissolving fully; Add 1.0% sodium hydrogensulfite, 10.0 grams again, 1.0% ammonium persulfate 15.0 grams, move in the stainless steel reaction dish after stirring, keep initial temperature to react 30 minutes down for 35~45 ℃, after be warming up to 70 ℃ and continue reaction 2 hours, with polymer gel pelletizing, 105 ℃ dry, pulverize, sieve the super strength water absorbent product, it inhales deionized water absorption rate Q (water)=324g.g
-1Inhale saline solution multiplying power Q (salt)=51.2g.g of 0.9%
-1
Embodiment 2
1. the preparation of modified soybean protein isolate
(1) soybean isolate protein powder is added deionized water to concentration 8%, every kilogram of protein (dry weight) adds 5% beta-mercaptoethanol, 0.4 gram, stir, add NaOH solution and transfer pH=13, after with pulverizer the protein gel body being rubbed, send in the reactor, stir, be heated to 100 ℃, make glycinin under alkali condition, dissociation reaction take place, be degraded to molecular weight and be the protein aqueous solution of 10000~20000 linear macromolecule.
(2) protein solution is cooled to 80 ℃, adds the Peracetic acid of dry weight of protein 0.5%, stirring reaction 15 minutes makes sulfhydryl oxidase on the protein side chain become the sulfonic group of strongly hydrophilic, solid content is 8% modified protein solution.
2. the preparation of modified soy-bean protein base superpower water absorbent: the adding percentage by weight is 8% the modified soybean protein isolate aqueous solution 215 grams in having the container of stirring, deionized water 100 grams, PAA 85 grams, N, N '-methylene-bisacrylamide 0.20 gram, 25% glutaraldehyde, 0.45 gram is stirred well to dissolving fully; Add 1.0% sodium hydrogensulfite, 16.0 grams again, 1.0% ammonium persulfate 22.0 grams, move in the stainless steel reaction dish after stirring, keep initial temperature to react 30 minutes down for 35~45 ℃, after be warming up to 80 ℃ and continue reaction 1.5 hours, with polymer gel pelletizing, 105 ℃ dry, pulverize, sieve the super strength water absorbent product, it inhales deionized water absorption rate Q (water)=469g.g-1; Inhale saline solution multiplying power Q (salt)=48.2g.g-1 of 0.9%.
Embodiment 3
1. the preparation of modified soybean protein isolate
(1) soybean isolate protein powder is added deionized water to concentration 15%, every kilogram of protein (dry weight) adds 5% beta-mercaptoethanol, 0.5 gram, stir, add NaOH solution and transfer pH=14, after with pulverizer the protein gel body being rubbed, send in the reactor, stir, be heated to 100 ℃, make glycinin under alkali condition, dissociation reaction take place, be degraded to molecular weight and be the protein aqueous solution of 10000~20000 linear macromolecule.
(2) protein solution is cooled to 70 ℃, adds the Peracetic acid of dry weight of protein 0.3%, stirring reaction 15 minutes makes sulfhydryl oxidase on the protein side chain become the sulfonic group of strongly hydrophilic, solid content is 15% modified protein solution.
2. the preparation of modified soy-bean protein base superpower water absorbent: the adding percentage by weight is 15% the modified soybean protein isolate aqueous solution 180 grams in having the container of stirring, deionized water 125 grams, PAA 58 grams, N, N '-methylene-bisacrylamide 0.25 gram, 25% glutaraldehyde, 0.40 gram is stirred well to dissolving fully; Add 1.0% sodium hydrogensulfite, 12.0 grams again, 1.0% ammonium persulfate 18.0 grams, move in the stainless steel reaction dish after stirring, keep initial temperature to react 30 minutes down for 35~45 ℃, after be warming up to 80 ℃ and continue reaction 2 hours, with polymer gel pelletizing, 105 ℃ dry, pulverize, sieve the super strength water absorbent product, it inhales deionized water absorption rate Q (water)=297g.g-1; Inhale saline solution multiplying power Q (salt)=55.3g.g-1 of 0.9%.
Embodiment 4
Other are identical with embodiment 1, and different is that vinyl monomer is PAA 35.0 grams and acrylamide 30.0 gram mixtures, the super strength water absorbent product that reaction obtains, and it inhales deionized water absorption rate Q (water)=306g.g-1; Inhale saline solution multiplying power Q (salt)=59.3g.g-1 of 0.9%.
Embodiment 5
Other are identical with embodiment 1, and different is that vinyl monomer is PAA 25.0 grams and ALS 40.0 gram mixtures, the super strength water absorbent product that reaction obtains, and it inhales deionized water absorption rate Q (water)=523g.g-1; Inhale saline solution multiplying power Q (salt)=49.7g.g-1 of 0.9%.
Embodiment 6
Other are identical with embodiment 1, and different is that vinyl monomer is PAA 45.0 grams and hydroxy-ethyl acrylate 20.0 gram mixtures, the super strength water absorbent product that reaction obtains, and it inhales deionized water absorption rate Q (water)=412g.g-1; Inhale saline solution multiplying power Q (salt)=48.7g.g-1 of 0.9%.
Embodiment 7
Other are identical with embodiment 3, different is 15% the modified soybean protein isolate aqueous solution 255 grams, deionized water 100 grams, PAA 45 grams, N, N '-methylene-bisacrylamide 0.35 gram, 25% glutaraldehyde, 0.6 gram, 1.0% sodium hydrogensulfite 16.0 grams, 1.0% ammonium persulfate 26.0 grams, reactive polymeric thing gel through pelletizing, 105 ℃ dry, pulverize, sieve the super strength water absorbent product, it inhales deionized water absorption rate Q (water)=151.g.g-1; Inhale saline solution multiplying power Q (salt)=48.2g.g-1 of 0.9%.