CN104725530A - Preparation method of O-carboxylated chitin - Google Patents
Preparation method of O-carboxylated chitin Download PDFInfo
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- CN104725530A CN104725530A CN201410459828.3A CN201410459828A CN104725530A CN 104725530 A CN104725530 A CN 104725530A CN 201410459828 A CN201410459828 A CN 201410459828A CN 104725530 A CN104725530 A CN 104725530A
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Abstract
The invention relates to a preparation method of O-carboxylated chitin. The method comprises the following steps: adding ground chitin and a few phase transfer catalysts to 30-50wt% of a sodium hydroxide solution to undergo low-temperature alkalization, filtering to obtain alkalized chitin, adding a modifier containing carboxyl to an organic solvent in batches, stirring the materials to react at 25-60 DEG C for 2-6 hours, regulating the pH value of a product till neutral with a dilute acid after reaction, washing the product with 60-100% (V/V) ethanol or acetone 3-5 times, and drying to obtain O-carboxylated chitin. The preparation method has the advantages that the preparation method is simple in process and mild in reaction conditions, dispenses with plenty of organic solvents, is high in product yield, conduces to reducing environmental pollution and is suitable for industrial production; the reaction time is obviously reduced by adding a few catalysts.
Description
Technical field
The present invention relates to
oneplant the preparation method of O-carboxylation chitin, belong to the preparing technical field of chitin derivativ.
Background technology
Chitin is the second largest natural macromolecule amylose earth being only second to Mierocrystalline cellulose (Cellulose).The current research to this natural resource and utilization mainly concentrate on its deacetylated product---Chitosan-phospholipid complex, and relatively less to the research of chitin derivativ.Because chitin manufacturing process is simple, cheap, there are good physicochemical property simultaneously, improve its physical and chemical performance by chemical reaction, can be applicable to many fields.
Water-solubility chitin derivative is the chitin derivativ that a class has excellent application performance.Chitin, through carboxylation reaction, its molecule is introduced and is had water miscible carboxylic group, obtain carboxylated product, i.e. carboxylation chitin.Chitin can react with carboxylic haloalkane in the basic conditions, in-the OH of C-6, introduce carboxyl, can generate 6-O-carboxylation chitin.This product is the anionic polymer having carboxyl in structure, soluble in water, has excellent biocidal property, moisture retention and oxidation-resistance, can be widely used in the fields such as medicine, makeup and food.
At present, the suitability for industrialized production of water soluble chitin derivative is less, mainly because its manufacturing cost is high, need to be refined by methods such as a large amount of organic solvent deposit, dialysis, the contaminated wastewater environment that high alkali liquid produces, severe reaction conditions, and yield is on the low side, these factors all limit promoting the use of of it.
It is raw material that United States Patent (USP) (USP4619995) discloses Hayes with chitin, in high alkali liquid after alkalization, carries out carboxylation reaction and prepare water-soluble chitosan in isopropanol medium.But be react under high temperature in concentrated base in its preparation process, easily make chitosan molecule splitting of chain in reaction process, cause product viscosity to reduce, molecular structure is destroyed, and affects product performance.Chinese patent (CN201310237735.1) discloses a kind of preparation method of carboxymethyl chitin.The method carboxylation reaction time longer (72 ~ 120 hours), need to carry out freezing alkalization (-40 ~-18 DEG C) at low temperature, and need dialysis treatment.
Trujillo Ralph take chitin as raw material, basified with 65%NaOH, adds Mono Chloro Acetic Acid and carry out carboxylation substitution reaction in Virahol, then that crude product is water-soluble, and acetone or alcohol precipitates, and centrifugal post-drying prepares carboxymethyl chitin.The method needs to consume a large amount of organic solvent and precipitates product, and productive rate is lower, be only about 45%, per kilogram raw material need consume 15 kilograms of NaOH, environmental pollution serious (Trujillo Ralph Preparation of Carboxy methyl chitin. Carbohyd.Res., 1968(7): 483-485); In cm-chitosan prepared by seapeak etc., need double alkalisation process, consume a large amount of NaOH solution, a large amount of alkali lye cause discharge of wastewater seriously polluted (in seapeak, Pan Mingwang, Li Zuobang etc. the synthesis of carboxymethyl chitin and chitosan and performance study thereof. Hebei University of Technology's journal, 2000,03).
For the deficiency that prior art exists, the invention provides a kind of preparation method of O-carboxylation chitin, effectively can reduce concentration of lye and alkali consumption by adding phase-transfer catalyst, decreasing discharging of waste liquid, and without the need to organic solvent deposit, having saved cost.The method reaction conditions is gentle, cost is low, yield is high, be suitable for suitability for industrialized production.
Summary of the invention
The object of this invention is to provide a kind of preparation method of O-carboxylation chitin, this preparation method's reaction conditions is gentle, cost is low, productive rate is high, is suitable for suitability for industrialized production.
technical scheme provided by the invention is:
technical solution of the present invention, by the reasonable employment of phase-transfer catalyst, when ensuring the quality of products constant, shortens the reaction times.
A preparation method for O-carboxylation chitin, carboxyl substituted mainly occurs on crust prime ring carbon 6-OH, and substitution value is 0.6 ~ 1.0, and viscosity-average molecular weight is 5.0 × 10
4---1.0 × 10
5.It is characterized in that:
(1) chitin got after pulverizing joins in 30 ~ 50wt% sodium hydroxide solution and stirs, and adds a certain amount of phase-transfer catalyst, alkalizes 4 ~ 10 hours at-10 ~ 0 DEG C;
Described phase-transfer catalyst comprises: the one in sodium lauryl sulphate, Sodium dodecylbenzene sulfonate, polyoxyethylene glycol or triethyl benzyl ammonia chloride, its addition is the mass percent that 0.1 ~ 1%(accounts for chitin), the mass ratio of chitin and 30 ~ 50wt% sodium hydroxide solution is 1
:4 ~ 10;
(2) obtain the chitin that alkalizes after filtering, add appropriate organic solvent and fully stir, then get a certain amount of carboxylic properties-correcting agent portion-wise addition, stirring reaction 2 ~ 6 hours at 25 ~ 60 DEG C;
Described organic solvent is ethanol or Virahol, and the mass volume ratio of chitin and organic solvent is 1
:5 ~ 10, the mole ratio of chitin and properties-correcting agent is 1
:2 ~ 5;
Described properties-correcting agent is the one in Mono Chloro Acetic Acid, 2-chloropropionic acid or 3-chloropropionic acid;
(3) reaction terminates the rare acid for adjusting pH of after product to neutral, with 60%-100%(V/V) ethanol (or acetone) washs 3 ~ 5 times, namely obtains the O-carboxylation chitin that C-6 oxygen position replaces after drying;
Described diluted acid is selected from the aqueous solution in hydrochloric acid, acetic acid, sulfuric acid or citric acid.
The present invention has following advantage and beneficial effect relative to prior art:
(1) effectively can shorten alkalization time by adding a small amount of phase-transfer catalyst in preparation method of the present invention, only needing 4 ~ 10 hours (alkalization time of existing technology of preparing is substantially all more than 12 hours);
(2) mass yield of technical solution of the present invention product can reach 90 ~ 120%, and the product yield having studied report is at present only 40-80%, and does not need to use a large amount of organic solvent refining crude, decreases the consumption of solvent, reduces production cost;
(3) when guaranteeing that yield does not reduce, the concentration of lye used in preparation technology of the present invention is down to 30 ~ 50% by common more than 60%, and reaction conditions is gentle, reduces the corrosion to equipment;
(4) when guaranteeing that yield does not reduce, in preparation technology of the present invention, per kilogram product alkali consumption reduces obviously relative to the method in background technology, decreases three waste discharge and environmental pollution.
Accompanying drawing illustrates: Fig. 1 is the infrared spectrogram of O-carboxylation chitin; Fig. 2 is the infrared spectrogram of chitin.
embodiment 1:
The chitin got after 100g pulverizing joins (namely the mass ratio of chitin and sodium hydroxide solution is 1:4) in the sodium hydroxide solution of 400 gram 50%, adds 0.1g sodium lauryl sulphate, stirs, alkalize 4 hours at 0 DEG C; Join in 500mL Virahol after thaw at RT, stir lower point and slowly add Mono Chloro Acetic Acid 94g altogether for 3 times, every minor tick 10 minutes, reacts 6 hours at 25 DEG C; Reaction terminates rear filtration, collects solids, adds 300mL95% ethanol (V/V) and soaks, and by acetic acid adjust ph to 6, filter, with 60% ethanol (V/V) washing and filtering gained solid 5 times, 60 DEG C of oven dry, obtain O-carboxylation chitin 96g.
embodiment 2:
The chitin got after 100g pulverizing joins (namely the mass ratio of chitin and sodium hydroxide solution is 1:10) in 1000 gram of 30% sodium hydroxide solution, and adds 1.0g Sodium dodecylbenzene sulfonate, stirs, and alkalizes 10 hours at-10 DEG C; Join in 1000mL dehydrated alcohol after thaw at RT, stir lower point and slowly add 2-chloropropionic acid 275g altogether for 5 times, every minor tick 10 minutes, reacts 2 hours at 60 DEG C; Reaction terminates rear filtration, collects solids, adds 300mL 95% ethanol (V/V) and soaks, and with salt acid for adjusting pH value to 7, filter, with 80% ethanol (v/v) washing and filtering gained solid 3 times, 60 DEG C of oven dry, obtain O-carboxylation chitin 112g.
embodiment 3:
The chitin got after 100g pulverizing joins (mass ratio of chitin and sodium hydroxide solution is 1:6) in the NaOH solution of 600 gram 40%, and adds 0.6g polyoxyethylene glycol, fully stirs, and alkalizes 8 hours at-6 DEG C; Join in 800mL dehydrated alcohol after thaw at RT, stir lower point and slowly add Mono Chloro Acetic Acid 200g altogether for 5 times, every minor tick 10 minutes, reacts 4 hours at 50 DEG C; Reaction terminates rear filtration, collects solids, adds 300mL95% ethanol (V/V) and soaks, and by citric acid adjust ph to 7.5, filter, with 75% acetone (V/V) washing and filtering gained solid 4 times, 60 DEG C of oven dry, obtain O-carboxylation chitin 117g.
embodiment 4:
The chitin got after 100g pulverizing joins (mass ratio of chitin and sodium hydroxide solution is 1:8) in the NaOH solution of 800 gram 35%, adds 0.8g triethyl benzyl ammonia chloride, fully stirs, alkalize 6 hours at-5 DEG C; Join in 750mL Virahol after thaw at RT, stir lower point and slowly add 2-chloropropionic acid 135g altogether for 4 times, every minor tick 10 minutes, reacts 5 hours at 35 DEG C; Reaction terminates rear filtration, collects solids, adds 300mL95% ethanol (V/V) and soaks, and by sulfuric acid adjust ph to 8, filter, with 95% ethanol (V/V) washing and filtering gained solid 3 times, 60 DEG C of oven dry, obtain desired product O-carboxylation chitin 104g.
test example:
(1) acid base titration is adopted to measure the substitution value of embodiment 1 ~ 4 gained O-carboxylation chitin:
Get a certain amount of product, accurately claim its quality, be designated as W, be placed in 250mL Erlenmeyer flask, in stirring, add the HCl standardized solution of 0.1mol/L, be made into the solution that mass concentration is 1wt%.Titration is carried out with the NaOH standardized solution of 0.1mol/L.Initial stage often adds 0.25mL NaOH, records a pH value, when closing on terminal close to pH value, often adds a NaOH, records a pH value.Take pH as ordinate zou, the NaOH volume consumed with titration is for X-coordinate, and curve plotting, obtains point of inflexion on a curve by second derivative, and the calculation formula of substitution value (DS) is as follows:
DS = 203A/（1000-80A）
In formula: A=(V2-V1) C
naOH/ W
The quality g of W---sample; V
2-V
1---the NaOH volume L that titration sample consumes
C
naOH---the volumetric molar concentration mol/L of NaOH solution
(2) viscosity-average molecular weight of viscosity method working sample is adopted:
Get a certain amount of product being dried to constant weight, accurately weighed, be solvent with 0.1mol/L acetic acid/0.2mol/L NaCl, prepare certain density sample liquid, No. 3 sand core funnels filter, and precision measures filtrate 10mL, at 25 DEG C, with relative viscosity (η r) and the specific viscosity (η sp) of determination of ubbelohde viscometer sample, limiting viscosity ([η]) calculation formula is as follows:
[η] =
According to Mark-Houwink empirical equation: [η]=7.92 × 10-3 M η, the viscosity-average molecular weight of calculation sample;
(3) mensuration of iso-electric point
Get the aqueous solution that a certain amount of product configuration becomes 1.0wt%, adjust a series of different pH value with certain density NaOH and HCl solution and obtain sample solution, leave standstill, centrifugation, measure the absorbancy of supernatant liquor at 280nm place.Due to more close to iso-electric point, the solvability of sample is poorer, precipitates more, cause the density loss of product in its aqueous solution, and its concentration and transmittance is inversely proportional to.According to transmittance-pH value curve, determine the iso-electric point of sample.
The O-carboxylation chitin prepared the method for embodiment 1 ~ 4 carries out the detection of index of correlation, the results are shown in Table 1:
Table 1 different embodiment O-carboxylation chitin quality examination data
Claims (7)
1. a preparation method for O-carboxylation chitin, is characterized in that,
Chitin after the first step gets pulverizing joins in 30 ~ 50wt% sodium hydroxide solution, stirs, and adds a certain amount of phase-transfer catalyst, quaternization at-10 ~ 0 DEG C; Described phase-transfer catalyst comprises: the one in sodium lauryl sulphate, Sodium dodecylbenzene sulfonate, polyoxyethylene glycol or triethyl benzyl ammonia chloride;
Second step filters the first step reaction solution, obtains the chitin that alkalizes, adds appropriate organic solvent and fully stir, then get a certain amount of carboxylic properties-correcting agent portion-wise addition, stirring reaction at 25 ~ 60 DEG C; Described organic solvent is ethanol or Virahol, and described properties-correcting agent is the one in Mono Chloro Acetic Acid, 2-chloropropionic acid or 3-chloropropionic acid;
Three-step reaction terminates the rare acid for adjusting pH of after product to neutral, with 60%-100%(V/V) ethanol (or acetone) washs 3 ~ 5 times, namely obtains the O-carboxylation chitin that C-6 oxygen position replaces after drying; Described diluted acid is selected from the aqueous solution in hydrochloric acid, acetic acid, sulfuric acid or citric acid.
2. preparation method described in claim 1, is characterized in that, the amount of the first step phase-transfer catalyst is 0.1 ~ 1% of chitin quality.
3. preparation method described in claim 1, is characterized in that, the mass ratio of the first step chitin and 30 ~ 50wt% sodium hydroxide solution is 1
:4 ~ 10.
4. preparation method described in claim 1, is characterized in that, the mass ratio of the first step chitin and 30 ~ 50wt% sodium hydroxide solution is 1
:3 ~ 5.
5. preparation method described in claim 1, is characterized in that, the mass volume ratio of second step chitin and organic solvent is 1
:5 ~ 10.
6. preparation method described in claim 1, is characterized in that, the mol ratio of second step chitin and properties-correcting agent is 1
:2 ~ 5.
7. preparation method described in claim 1, is characterized in that, the first step quaternization time is 4 ~ 10 hours.
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Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106519076A (en) * | 2016-12-29 | 2017-03-22 | 广西还珠海洋生物科技有限公司 | Process for extracting chitosan from oyster shells |
| CN106519075A (en) * | 2016-12-29 | 2017-03-22 | 广西还珠海洋生物科技有限公司 | Process for extracting chitin from oyster shells |
| CN106589165A (en) * | 2016-12-29 | 2017-04-26 | 广西还珠海洋生物科技有限公司 | Method for extracting chitin from oyster shells |
| CN106632729A (en) * | 2016-12-29 | 2017-05-10 | 广西北部湾制药股份有限公司 | Process for extracting chitin from shrimps and crabs |
| CN106699926A (en) * | 2016-12-29 | 2017-05-24 | 广西北部湾制药股份有限公司 | Technology for extracting chitosan from shrimps and craps |
| CN106749761A (en) * | 2016-12-29 | 2017-05-31 | 广西北部湾制药股份有限公司 | The technique of chitin extraction from shrimp crab |
| CN106832053A (en) * | 2016-12-29 | 2017-06-13 | 广西北部湾制药股份有限公司 | A kind of technique that shitosan is extracted in the crab from shrimp |
| CN107602726A (en) * | 2017-10-26 | 2018-01-19 | 中国科学院过程工程研究所 | Low molecule amount C6 carboxy chitins and preparation method thereof |
| CN107722138A (en) * | 2017-07-31 | 2018-02-23 | 山东人文置业有限公司 | A kind of chitin prepares the new method of water-soluble carboxymethyl chitosan |
| CN114106217A (en) * | 2021-12-22 | 2022-03-01 | 微能生命科技集团有限公司 | Preparation method of high-substitution-degree 6-O-carboxymethyl chitin |
| CN114560963A (en) * | 2022-02-14 | 2022-05-31 | 四川吉百瑞生物医疗科技有限公司 | Preparation method and application of chitosan azelaic acid and derivatives thereof |
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Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN106832053A (en) * | 2016-12-29 | 2017-06-13 | 广西北部湾制药股份有限公司 | A kind of technique that shitosan is extracted in the crab from shrimp |
| CN106519075A (en) * | 2016-12-29 | 2017-03-22 | 广西还珠海洋生物科技有限公司 | Process for extracting chitin from oyster shells |
| CN106589165A (en) * | 2016-12-29 | 2017-04-26 | 广西还珠海洋生物科技有限公司 | Method for extracting chitin from oyster shells |
| CN106632729A (en) * | 2016-12-29 | 2017-05-10 | 广西北部湾制药股份有限公司 | Process for extracting chitin from shrimps and crabs |
| CN106699926A (en) * | 2016-12-29 | 2017-05-24 | 广西北部湾制药股份有限公司 | Technology for extracting chitosan from shrimps and craps |
| CN106749761A (en) * | 2016-12-29 | 2017-05-31 | 广西北部湾制药股份有限公司 | The technique of chitin extraction from shrimp crab |
| CN106519076A (en) * | 2016-12-29 | 2017-03-22 | 广西还珠海洋生物科技有限公司 | Process for extracting chitosan from oyster shells |
| CN107722138A (en) * | 2017-07-31 | 2018-02-23 | 山东人文置业有限公司 | A kind of chitin prepares the new method of water-soluble carboxymethyl chitosan |
| CN107602726A (en) * | 2017-10-26 | 2018-01-19 | 中国科学院过程工程研究所 | Low molecule amount C6 carboxy chitins and preparation method thereof |
| CN107602726B (en) * | 2017-10-26 | 2020-08-14 | 中国科学院过程工程研究所 | Low molecular weight C6-carboxyl chitin and preparation method thereof |
| CN114106217A (en) * | 2021-12-22 | 2022-03-01 | 微能生命科技集团有限公司 | Preparation method of high-substitution-degree 6-O-carboxymethyl chitin |
| CN114106217B (en) * | 2021-12-22 | 2022-09-30 | 微能生命科技集团有限公司 | Preparation method of high-substitution-degree 6-O-carboxymethyl chitin |
| CN114560963A (en) * | 2022-02-14 | 2022-05-31 | 四川吉百瑞生物医疗科技有限公司 | Preparation method and application of chitosan azelaic acid and derivatives thereof |
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Application publication date: 20150624 |