A kind of method of preparing high viscosity oxidized sodium alginateTechnical field
The invention belongs to seaweed chemical technical field, relate in particular to a kind of method of preparing high viscosity oxidized sodium alginate.
Background technology
The sodium alginate extracting from brown alga is a kind of statistic copolymer by beta-D-mannuronic acid and α-L-guluronic acid, nontoxic and there is good biocompatibility, can form gel with divalent ions (except magnesium ion) such as calcium ions, therefore be widely used in the fields such as biotechnology and organizational project.Use the oxygenants such as sodium periodate, potassium permanganate can make the structure of the suitable diol structure oxidation generation dialdehyde on sodium alginate unit prosposition, make its good linking agent that becomes a kind of low toxicity, good biocompatibility, widened the Application Areas of sodium alginate.The gelation of high viscosity oxidized sodium alginate and the quantity of crosslinked group are all higher than low viscous oxidized sodium alginate.Therefore when preparing oxidized sodium alginate, should improve its viscosity as far as possible.
The raw material of preparing oxidized sodium alginate in prior art is sodium alginate finished product, because sodium alginate is lyophilic colloid, the operations such as the dehydration in preparing sodium alginate process, dry and pulverizing can be destroyed its viscosity greatly, cause sodium alginate molecular rupture, shorten, the quantity of crosslinked other groups of molecular chain of the oxidized sodium alginate of preparation declines, impact is cross-linked the molecular weight of rear material, and then affects the performance of material.The article of delivering as chemical reagent periodical the 31st volume the 2nd phase Wang Jianyun etc.: point out in the preparation of < < new type natural linking agent oxidized sodium alginate and performance study > > thereof, using sodium alginate molecular weight of the oxidized sodium alginate of preparation after being oxidized, washing, being dried to be dropped to by 280,000 of former sodium alginate is 10,000 left and right, and the viscosity of the oxidized sodium alginate of preparation is lower.
Summary of the invention
The lower problem of oxidized sodium alginate viscosity for preparing in prior art, the invention provides a kind of method of preparing high viscosity oxidized sodium alginate, has solved the low problem of oxidized sodium alginate viscosity of preparing in prior art.
For achieving the above object, the present invention is achieved by the following technical solutions:
A method of preparing high viscosity oxidized sodium alginate, it comprises the following steps:
(1) take the Lalgine that water content is 60%-70% is raw material, by raw material pulverizing;
(2) aqueous solution that adds the organic solvent that the volume fraction with quality such as above-mentioned Lalgine raw materials is 70%-80% after, washs under agitation condition;
(3) after washing, add sodium hydroxide solution reaction to neutral, obtain sodium alginate;
(4) in above-mentioned sodium alginate, directly add sodium periodate solution, under agitation condition, 15 ℃-30 ℃ of lucifuge insulations are reacted to sodium periodate and cannot be detected;
(5) add after completion of the reaction organic solvent, dehydration, pulverizing;
(6) to add volume fraction be that aqueous solutions of organic solvent countercurrent washing to the sodium iodate of 80%-90% cannot detect to the material after pulverizing;
(7) by the dry oxidized sodium alginate that makes after the material dewatering after above-mentioned washing, pulverizing.
Further improvement to technique scheme: described organic solvent is methyl alcohol, ethanol or acetone.
Further improvement to technique scheme: stir lower washing 15-30 minute in described step (2).
Further improvement to technique scheme: the mass ratio that in sodium hydroxide solution, sodium hydroxide accounts for total solution in described step (3) is 20%-32%.
Further improvement to technique scheme: the mole dosage of described step (4) meso-periodic acid sodium is the 10%-75% of the molar weight of sodium alginate unit.
Further improvement to technique scheme: be dried as cryodrying in described step (7), drying temperature is no more than 40 ℃, and vacuum tightness is-0.1MPa.
Compared with prior art, advantage of the present invention and positively effect are: brown alga processing is take in the present invention, and to extract alginates intermediate-Lalgine be raw material, this raw material is due to not process dehydration, the operations such as dry and pulverizing, its viscosity is far above the viscosity of sodium alginate, after adding alcohol washing in Lalgine, add sodium hydroxide reaction to neutral, add again the sodium periodate solution preparing, under agitation condition, lucifuge insulation reaction, in reaction, control temperature of reaction, after adding after completion of the reaction alcohol, dewater, pulverize, crushing rear material adds alcohol countercurrent washing, remove the small molecular weight impurities such as inorganic salt wherein, after material dewatering after washing, pulverize, be dried to obtain oxidized sodium alginate, therefore, under same reaction conditions, the oxidized sodium alginate viscosity that the oxidized sodium alginate viscosity of utilizing this invention to prepare is prepared compared with prior art exceeds more than 50%, and preparation method of the present invention can produce at original alginate production line, easily realize industrialization.
Embodiment
Below in conjunction with embodiment, the present invention is further detailed explanation.
Embodiment 1
The method of preparing high viscosity oxidized sodium alginate of the present invention comprises the following steps:
1, getting water ratio is in 70%(Lalgine raw material, only to contain moisture and two kinds of components of Lalgine) Lalgine 100kg as raw material, after pulverizing, add in liquid phase neutralization tank;
2, to adding volume fraction in liquid phase neutralization tank, be 80% methanol aqueous solution 100kg, stir washing half an hour;
3, after washing, add massfraction be the reaction of 32% sodium hydroxide solution to neutral, obtain sodium alginate;
4, at lucifuge place, accurately take 19.5kg sodium periodate (for the molar weight of sodium alginate unit 40%) be dissolved in the distilled water of 245kg; The mole dosage of described sodium periodate is the 10%-75%(M of sodium alginate unit molar weightsodium periodate/ Msodium alginate unit molar weight=10-75%), and its solution needs lucifuge preparation, now with the current.The consumption of controlling sodium periodate can be prepared the sodium alginate of different oxidisabilities.
Start stirring, the above-mentioned sodium periodate solution preparing is joined in sodium alginate, 15 ℃ of lucifuge insulations are reacted to sodium periodate and cannot be detected;
5, add 188kg methyl alcohol, stir after 5 minutes and use gallus-type centrifuge dewatering;
6, the sodium alginate after dehydration is pulverized, used methanol aqueous solution countercurrent washing to the sodium iodate that volume fraction is 80% to detect;
7, lower 40 ℃ of the material dewatering after above-mentioned washing, pulverizing, vacuum tightness-0.1MPa dried to obtain to oxidized sodium alginate.
After testing, the oxidisability of the oxidized sodium alginate making is 38.6%, viscosity 667mpa.s, and yield is 79.7%.The viscosity of the oxidized sodium alginate that use sodium alginate finished product is prepared by this technique is 362mpa.s, the oxidized sodium alginate that viscosity is prepared far below the present invention.
Embodiment 2
1, getting water content is in 40%(Lalgine raw material, only to contain moisture and two kinds of components of Lalgine) Lalgine 100kg as raw material, after pulverizing, add in liquid phase neutralization tank;
2, in liquid phase neutralization tank, adding volume fraction is 75% aqueous ethanolic solution 100kg, stirs washing half an hour;
3, after washing, add massfraction be the reaction of 32% sodium hydroxide solution to neutral, obtain sodium alginate;
4, at lucifuge place, accurately take 29.2kg sodium periodate (for sodium alginate unit molar weight 60%) be dissolved in 365kg distilled water;
Under agitation condition, the above-mentioned sodium periodate solution preparing is joined in sodium alginate, 20 ℃ of lucifuge insulations are reacted to sodium periodate and cannot be detected;
5, add 285kg ethanol, stir after 5 minutes and use gallus-type centrifuge dewatering;
6, the sodium alginate after dehydration is pulverized, used aqueous ethanolic solution countercurrent washing to the sodium iodate that volume fraction is 80% to detect;
7, the material dewatering after above-mentioned washing, pulverizing, 40 ℃ of constant pressure and dries are obtained to oxidized sodium alginate.
After testing, the oxidisability of the oxidized sodium alginate making is 57.6%, viscosity 589mpa.s, and yield is 81.5%.The viscosity of the oxidized sodium alginate that use sodium alginate finished product is prepared by this technique is 262mpa.s, the oxidized sodium alginate that viscosity is prepared far below the present invention.
Above embodiment is only in order to technical scheme of the present invention to be described, but not is limited; Although the present invention is had been described in detail with reference to previous embodiment, for the person of ordinary skill of the art, the technical scheme that still can record previous embodiment is modified, or part technical characterictic is wherein equal to replacement; And these modifications or replacement do not make the essence of appropriate technical solution depart from the spirit and scope of the present invention's technical scheme required for protection.