CN1386771A

CN1386771A - Resin with superhigh hydroscopicity and its synthesizing process

Info

Publication number: CN1386771A
Application number: CN 02113108
Authority: CN
Inventors: 李布青; 陈文明; 杨剑波; 殷雄
Original assignee: Institute Of Atomic Energy Agricultural Application Anhui Academy Of Agricultural Sciences
Current assignee: Institute Of Atomic Energy Agricultural Application Anhui Academy Of Agricultural Sciences
Priority date: 2002-05-31
Filing date: 2002-05-31
Publication date: 2002-12-25
Anticipated expiration: 2022-05-31
Also published as: CN1206252C

Abstract

An ultrahigh-hydroscopicity resin is prepared from diesterified polyethanediol as cross-linking agent, the second monomer and acrylic acid through copolymerization initiated by chemical initiator or high-energy radiation in the water solution, or reverse phase suspension polymerization at 50-80 deg.C for 2-5 hr. Its advantage is high hydroscopicity (200-6000 times).

Description

Resin with superhigh hydroscopicity and synthetic method thereof

(1), technical field

The present invention relates to a kind of functional resin and preparation method thereof, exactly is a kind of resin with superhigh hydroscopicity and synthetic method thereof.

(2), background technology

(superabsorbent SAP) is a kind of functional resin to High hydrophilous resin, also is functional materials.SAP is different with traditional water-absorbing materials such as paper, cotton, sponges, can absorb the water of deadweight hundreds of times and even thousands of times, and the water that sucks also is difficult for being extruded when pressurized.SAP had both had unique high-hydroscopicity energy and strong water retention capacity, has simultaneously the advantage of macromolecular material again, therefore paid attention to from the reserve of coming out, development rapidly, obtained using widely at numerous areas such as farming, woods, gardening, medicine, physiological hygiene, oil, chemical industry, environmental protection, building materials, food product pack at present, particularly obtained significant effect in the application aspect soil improvement, soil conservation, the water-saving agriculture.Present developing direction is further to improve its performance on the one hand, is on the other hand to expand new purposes.

SAP be have many hydrophilic radicals, cross-linking density is low, water insoluble but the high molecular polymer with spacial framework of water-swellable.Can be divided into natural macromolecule modification product and synthesising macromolecule copolymer two big classes by raw material sources.The former has starch is that SAP, fiber are SAP and other natural compoundss and derivative SAP thereof.USDA north institute began one's study from starch-grafted vinyl cyanide in 1961, found that its suction, water retention property have all surpassed water-absorbing material in the past.After starch is SAP, synthetic is that SAP rose rapidly since the seventies, at first in Japan, states such as U.S., moral, method, English than starch are following closely, synthetic is that the SAP polymerization technique is simple, the water-intake rate height, water retention capacity is strong, has now become the main direction of SAP research, exploitation, in the SAP of suitability for industrialized production, synthetic is that polyacrylate is occupied an leading position.

Synthetic is that the SAP kind is a lot, mainly contains acrylic acid or the like, vinyl cyanide, acrylic amide, polyvinyl alcohol, polyoxyethylene class etc.The synthetic principle is free radical polymerization, initiator commonly used has persulfuric acid salt, peroxide, the different dibutyronitrile of azo etc., also have radiation to cause in addition, as gamma-radiation, ultraviolet ray, microwave etc., chemically crosslinked during polymerization (adding linking agent) or radiation crosslinking, product has homopolymer, multipolymer, graft copolymerization etc.Polymerization process mainly contains substance law, solution method, inverse suspension method and emulsion method etc.

Mass polymerization refers to there is not solvent, has only reactant to carry out polymerization under the initiator effect, as the disclosed water-absorbing-retaining agent and process for producing same of CN116136A, is that vinylformic acid, ammoniacal liquor, sodium hydroxide, persulfuric acid zinc reacted 30～50 minutes under 35～50 ℃ of conditions.

Solution polymerization is that reactant monomer and initiator carry out polymerization in solvent.The big more options water of solvent all is to be solvent with water as disclosed synthetic methods such as CN1031234A, CN1041601A, CN1088941A, CN1146997A, CN1165152A; The selection organic solvent is also arranged, and as the disclosed a kind of preparation method of CN1175594A, is that maleic anhydride and double bond containing monomer are in the polymerization in toluene of initiator existence condition.

The inverse suspension polymerization method is a dispersion medium with solvent (oil phase), water-soluble monomer is dispersed into the water drop of suspension under suspension agent and violent stirring, initiator is dissolved in and carries out polymerization in the water drop, disclosed preparation method as CN1146997A, be the slurries that water soluble ethylene monomer the first step inverse suspension polymerization obtains polymer gel particles, under the tensio-active agent existence condition, carry out the second step letex polymerization with the second class vinyl monomer again.

Advantages such as the inverse suspension polymerization method has that preparation technology is simple, resin physical aspect and water absorbing properties are better, Recent study document and patent are more, as EP327981, EP349240, EP409136, EP521355, EP63268, JP06145253, JP062279511, JP06345819 etc.In this method, adopt N, N ｀-methylene-bisacrylamide or Viscoat 295 etc. to make linking agent mostly, because its carbochain is all shorter, the water-intake rate of resin is generally all not too high, though can improve water-intake rate by changing dosage of crosslinking agent and reaction conditions, the gel-strength and the water retention property of suction back resin are relatively poor again." chemistry with bonding " the 1998, the 1st phase discloses a kind of with the inverse suspension polymerization method of polyoxyethylene glycol double methacrylate as linking agent, and the chain length of linking agent is inquired into many conditions such as relation of resin water-intake rate, rate of water absorption, thinks PEG ₆₀₀(molecular weight polyethylene glycol is represented its chain length with this) is best, and the resin water-intake rate reaches 1200 times, inhales 125 times of salt solution and gel-strength and water retention property are preferably arranged.Think PEG simultaneously ₁₀₀₀Above person should not adopt.

CN85102156A is disclosed to be radiation polymerization, is mixed in proportion the back at NaOH and N, N ｀-methene base bisacrylamide existence condition C by certain density wilkinite and acrylamide solution ₀-gammairradiation, dosage are selected in 5.3rad/s, total dose 4.8 * 10 ⁴Rad.Offset plate after the polymerization through pulverize, 120 ℃ of dryings, to pulverize be No. 30 particles again, water-intake rate is 820 times.

(3), summary of the invention

The water absorbing properties of the water-absorbing resin three-dimensional space network structure lightly crosslinked with it is closely related.Its three-dimensional space network of high water absorbing capacity resin should have ordered structure, that is to say, the periphery of network structure is consistent as far as possible, and grid build size is identical as far as possible.This depends on that selected linear molecule wants sufficiently long and constitute the cross-linking process of network and the selection of linking agent.

At present in super absorbent resin synthetic adopt chemically crosslinkeds, because will get well than physical crosslinking or self-crosslinking effect more.Yet selected linking agent mostly is classical linking agent, and the emphasis of research all concentrates in the control of specific system middle crosslink density.

The present invention is based on the whole consideration of lightly crosslinked three-dimensional space network, set about, linking agent has been carried out deep research, select PEG at last from the suitable hard and soft property of molecular chain, the regularity of network structure and the synergetic property of ionic and non-ionic hydrophilic group ₁₅₀₀～PEG ₂₀₀₀₀The polyoxyethylene glycol double methacrylate or polyoxyethylene glycol methacrylate fat (PEGDA) as linking agent.PEGDA is a linking agent, is again second monomer of copolymerization simultaneously, obtains AA/PEGDA ionic/non-ionic type polyacrylic acid resin with superhigh hydroscopicity with first monomer vinylformic acid (AA) copolymerization.

PEGDA is the long flexible chain that has bifunctional, can form comparatively regular three-dimensional space network structure in reactive flexibility is crosslinked, and it is crosslinked that its grid build formation rate obviously is better than the small molecules rigidity, and sizing grid is also more even.PEGDA is a linking agent, in the formation of three-dimensional space network, plays a major role, and be again second monomer of copolymerization simultaneously, in resin, introduce a certain amount of PEG segment, can regulate the hard and soft property and the regularity of three-dimensional space network structure.Non-ionic segments of Yin Ruing and ionic groups-carboxyl produces synergy to improve water absorbing properties simultaneously.This product is inhaled deionized water and is reached 6000 times, and inhale salt solution (0.9% NaCl) and surpass 200 times, be High hydrophilous resin far above the synthetic of present reported in literature, can be referred to as resin with superhigh hydroscopicity, still have gel-strength and water retention property preferably after the suction.

PEGDA and part neutral AA are water miscible, can adopt chemical initiator or high-energy radiation initiated polymerization so it synthesizes in the aqueous solution, also can adopt inverse suspension polymerization.

(4), embodiment

Getting molecular weight and be 1500,2000,6000,20000 polyoxyethylene glycol (PEG) double esterification product P EGDA is made into 3～5% the aqueous solution of (weight percents, down with) is standby and (calls raw material A in the following text ₁₅₀₀, A ₂₀₀₀...).

Get vinylformic acid under frozen water cooling with the alkali lye neutralization, degree of neutralization 50～90% is made into 40% the aqueous solution standby (calling raw material B in the following text) then.

During polymerization, the consumption of raw material A is 0.15～2.5% of raw material B, to satisfy the lightly crosslinked requirement of absorbent resin.

Total monomer is 15～30% during polymerization.

One, radio polymerization

1, gets A ₁₅₀₀1.92g mix with B 75g, it is 30% that water is regulated monomer concentration, places radiant bottles, and logical nitrogen drives oxygen and is placed on cobalt source indoor predetermined dose rate place's radiation certain hour, reaction finishes when radiation dose reaches 0.8～2.2kGy, pulverizes, is drying to obtain product after the taking-up.

2, get A ₂₀₀₀2.08g, B 62.5g, it is 25% that water is regulated monomer concentration, surplus with embodiment 1.

3, get A ₆₀₀₀4.78g, B 50g, it is 20% that water is regulated monomer concentration, surplus with embodiment 1.

4, get A ₂₀₀₀₀11.76g, B 37.5g, it is 15% that water is regulated monomer concentration, surplus with embodiment 1.

5, get raw material B 12.5～37.5g, the raw material A that adds 0.15～2.5% (in raw material B), it is 15～30% that water is regulated monomer concentration, drop into then in the hexanaphthene of 150～200ml, stir adding 0.1～0.3g dispersion agent such as Span-60 etc. down, logical nitrogen drives oxygen, under agitation places the indoor predetermined dose rate place's radiation of cobalt source, reaction finishes when absorption dose reaches 0.8～2.2kGy, and precipitation, drying obtain product after taking out.

The product water-intake rate of radiation preparation: deionized water 4500～6000g/g, salt solution (0.9% NaCl) 160～230g/g.

Two, inverse suspension polymerization

6, in the four-hole boiling flask that agitator, thermometer, reflux condensing tube and nitrogen tube are housed, add 150～200ml hexanaphthene and 0.2～0.4g dispersion agent such as Span-60 etc., stir, raw material A and 0.05～0.25% initiator such as KPS etc. of under agitation adding raw material B 12.5～37.5g and 0.15～2.5% (in raw material B) then, it is 15～30% that water is regulated monomer concentration, stirring down, logical nitrogen drives oxygen, heat up, reacted 2～5 hours under 50～80 ℃ of conditions, cooling back discharging, precipitation, filtration, drying obtain product.Water-intake rate: deionized water 3400～4500g/g, salt solution (0.9% NaCl) 160～200g/g.

Three, chemistry of aqueous solution polymerization

7, the raw material A of getting raw material B 12.5～37.5g and 0.15～2.5% (in raw material B) drops in the flask, the initiator of adding 0.05～0.25% such as KPS etc. under stirring, it is 15～30% that water is regulated monomer concentration, logical nitrogen drives oxygen, heat up 50～80 ℃, reacted 2～5 hours, and took out gluey product, dry, pulverizing obtains product.Water-intake rate: deionized water 3900～4500g/g, salt solution (0.9% NaCl) 150～200g/g.

Claims

1, a kind of resin with superhigh hydroscopicity, be polyoxyethylene glycol double methacrylate or polyoxyethylene glycol double methyl methacrylate with the macromolecular compound that part neutral vinylformic acid (AA) copolymerization obtains, it is characterized in that: to use molecular weight be 1500～20000 polyoxyethylene glycol with the double esterification product (PEGDA) of acrylic or methacrylic acid second monomer as linking agent and copolymerization.

2, a kind of radiation polymerization of resin with superhigh hydroscopicity; comprise part neutral AA and a certain amount of PEGDA under nitrogen protection through the radiation of cobalt source, pulverizing and dry each unit process; it is characterized in that: degree of neutralization to be 50～90% AA with 0.15～2.5% PEGDA hybrid modulation become monomer concentration is 15～30% reaction solution, radiation dose is 0.8～2.2kGy.

3, a kind of inverse suspension polymerization method of resin with superhigh hydroscopicity; comprise part neutral AA and a certain amount of PEGDA and dispersion agent, initiator reaction, precipitation, filtration and dry each unit process under nitrogen protection; it is characterized in that: degree of neutralization to be 50～90% AA with 0.15～2.5% PEGDA hybrid modulation become monomer concentration is 15～30% reaction solution, reacted 2～5 hours under 50～80 ℃ of conditions.

4, a kind of water solution polymerization process of resin with superhigh hydroscopicity; comprise reaction and drying under initiator and nitrogen protection condition of part neutral AA and a certain amount of PEGDA, pulverize each unit process, it is characterized in that: to be 50～90% AA with 0.15～2.5% PEGDA hybrid modulation become degree of neutralization that monomer concentration is that 15～30% reaction solution reacted 2～5 hours under 50～80 ℃ of conditions.