CN114349874A - Preparation method of hydrophobically modified sodium carboxymethyl starch - Google Patents
Preparation method of hydrophobically modified sodium carboxymethyl starch Download PDFInfo
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- CN114349874A CN114349874A CN202111589062.7A CN202111589062A CN114349874A CN 114349874 A CN114349874 A CN 114349874A CN 202111589062 A CN202111589062 A CN 202111589062A CN 114349874 A CN114349874 A CN 114349874A
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- carboxymethyl starch
- sodium carboxymethyl
- hydrophobically modified
- ethanol
- glycidyl ether
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Abstract
The invention provides a preparation method of hydrophobically modified sodium carboxymethyl starch, belonging to the technical field of modified starch. The method comprises the steps of taking commercially available sodium carboxymethyl starch as a raw material, introducing a hydrophobic long carbon chain into a mixed solvent by taking N, N-dimethylbenzylamine as a catalyst, and preparing the hydrophobic modified sodium carboxymethyl starch under the conditions of certain reaction temperature and reaction time, wherein the substitution degree can reach 0.04-0.36, the viscosity is increased from 440mpa.s to 2353mpa.s (gamma is 60S)‑1). The thickener has excellent performance and can be used in the fields of printing and dyeing, medicines, foods and daily chemicals. The method has simple process and one-step synthesis, saves a plurality of processes, and has higher degree of substitution and obviously improved viscosity. The invention takes water-ethanol as a mixed solvent, is green and environment-friendly, has the yield of 86 percent, overcomes the defects of the original carboxymethyl starch sodium, and obviously improves the viscosity.
Description
Technical Field
The invention provides a preparation method of hydrophobically modified sodium carboxymethyl starch, belonging to the technical field of modified starch.
Technical Field
In recent years, starch has been widely researched and developed by scholars at home and abroad mainly due to the fact that the starch is wide in source, low in price, easy to degrade and contains more active group hydroxyl groups. In order to fully utilize and exert the advantages of the starch, the inherent properties of the starch can be changed by modification, the excellent properties of the starch are fully utilized, the defects of the starch are overcome, and the application range of the starch is widened to meet the production requirements.
Sodium carboxymethyl starch (CMS) as an anionic modified starch has the advantages of stable viscosity, high transparency, good freeze-thaw stability, biocompatibility and the like when being dissolved in cold water and paste, is applied to a plurality of fields, and widens the application of starch. The performance of CMS is closely related to the Degree of Substitution (DS), and sodium carboxymethyl starch with high degree of substitution (DS >0.6) has stronger bonding and water retention, and is widely required in the industries of buildings, foods, paper making, daily chemicals, medicines and the like.
However, in order to further expand the application field and application performance, the viscosity, water retention property, etc. of carboxymethyl starch are still to be further improved. Hydrophobization of carboxymethyl starch is one of the effective methods to further improve viscosity properties.
A small amount of hydrophobic groups are introduced to a hydrophilic main chain, so that a hydrophobic association type thickener is synthesized, a hydrophilic part and a lipophilic group are arranged in a molecule, certain surface activity is presented, a hydrophobic association network structure can be formed by introducing the hydrophobic groups, the hydrodynamic volume is increased, the viscosity is increased, and the thickening phenomenon is generated, so that the starch has amphipathy, good adsorbability and a water-based paint thickener by hydrophobic modification, and can also be used as a medicine release.
The main methods for hydrophobically modifying the sodium carboxymethyl starch include esterification, etherification and the like, and specifically comprise the following steps:
one-step method:
wangyuan Hao uses carboxymethyl starch (CMS) as raw material, caproyl chloride as esterification reagent, dimethyl sulfoxide (DMSO) as solvent, pyridine as organic base to synthesize caproyl esterified carboxymethyl starch (HCMS) (Wangyuan Hao, having root, Zhang Shufen. preparation and viscosity property [ J ]. fine chemical industry, 2012,29(6): 5.). Zhang Yan Nu takes sodium carboxymethyl starch as raw material, stearic acid as esterifying agent, lipase as catalyst, add drier, combine dry method to prepare compound modified starch (Zhang Yan Nu, Zhang Yang. a carboxymethyl starch stearate and its preparation method: CN102199639A [ P ].2011) with enzyme method, the lipase is a catalyst, the price is expensive, the economic benefits are low. Octenyl succinic anhydride is used as an esterifying agent to obtain the modified sodium carboxymethyl starch with the degree of substitution of 0.03 to 0.53 in DMSO/p-toluenesulfonic acid.
There are problems: 1. the currently used method uses DMSO as a reaction solvent, and a large amount of solvent is consumed for post-treatment; 2. lipase is used as a catalyst, and the price is high.
(II) a two-step method:
thomas Heize uses benzyl chloride as a hydrophobic group, firstly carries out hydrophobic modification on Starch, and then carries out carboxymethylation modification, wherein the Starch is used as a raw material, and the benzyl group is firstly introduced and then carboxymethylation is carried out, or alkyl glycidyl ether is used as a hydrophobic agent, and then carboxymethylation modification is carried out (Heize T, Rensing S, Koschella A. Starch Derivatives of High Degree of functionalization.13.novel Amphiphilic Starch Products [ J ]. Starch Stroke, 2007,59 (5)).
Lehmann A hydrophobicizes and modifies starch with alkyl glycidyl ether as a hydrophobicizing agent, and then carboxymethylates the modified starch to prepare amphiphilic hydrophobicized carboxymethyl starch (Mihyun L, Kraun B, et al. Exploitation of Cationic Nanoparticles for Bioprinting of Large-Scale Constructs with High Printing Fidelity [ J ]. Acs Applied Materials & Interfaces, 2018).
There are problems: the occurrence of the carboxymethylation and hydrophobization modification two-step reaction of starch requires the regulation of proper pH, otherwise, the reaction is not favorably carried out, and the preparation is complicated and is only suitable for laboratory preparation.
Disclosure of Invention
Aiming at the problems of low viscosity, poor temperature and salt resistance and the like of carboxymethyl starch sodium sold in the current market, the invention provides a preparation method for improving the viscosity of carboxymethyl starch sodium by hydrophobically modified carboxymethyl starch sodium. The invention adopts commercially available sodium carboxymethyl starch as a raw material, utilizes a tertiary amine catalyst, and adopts a one-step method to perform etherification reaction in a water-ethanol mixed solvent to introduce long-carbon-chain hydrophobic groups. And a method using water-ethanol as a mixed solvent in sodium carboxymethyl starch has not yet been found.
The technical scheme of the invention is as follows:
a preparation method of hydrophobically modified sodium carboxymethyl starch comprises the following steps:
dissolving alkyl glycidyl ether in ethanol, adding a tertiary amine catalyst, stirring for dissolving, adding a water-ethanol mixed solvent, finally adding sodium carboxymethyl starch into the system, reacting for 4-8 hours at the temperature of 50-90 ℃, separating out in industrial ethanol after the reaction is finished, drying and crushing.
The mass ratio of the tertiary amine catalyst to the sodium carboxymethyl starch is 0.01:1-0.05: 1.
The mass ratio of the ethanol to the sodium carboxymethyl starch is 5: 1-25: 1.
The mass ratio of the alkyl glycidyl ether to the sodium carboxymethyl starch is 0.3:1 to 1: 1.
The mass ratio of the amount of the water-ethanol mixed solvent to the sodium carboxymethyl starch is 10:1 to 3: 1.
Further, the alkyl glycidyl ether is C8-C10One or more of glycidyl ether, aryl glycidyl ether, octyl glycidyl ether and butyl glycidyl ether.
The tertiary amine catalyst is one or more of N, N-dimethylbenzylamine, triethylamine, hexamethylenetetramine, triethylenediamine and tetraethylmethylenediamine.
Further, in the water-ethanol mixed solvent, the mass ratio of water to ethanol is 1:4 to 1: 1.
The invention has the beneficial effects that:
(1) almost all carboxymethyl starch sold in the market has low viscosity and low substitution degree, and the carboxymethyl starch substitutes DMSO (dimethyl sulfoxide) by using water and ethanol as reaction solvents through a large amount of experiments, so that the production cost is reduced, the price is low, the handling is easy, the reaction efficiency is high, the substitution is uniform, and the viscosity is obviously improved.
(2) At present, modified starch is mainly prepared by alkalization, etherification and carboxymethylation at last or carboxymethylation and etherification at first, and the process is complicated. The method takes the commercially available carboxymethyl starch as a raw material, and has the advantages of simple preparation process and easy industrial scale production by etherification reaction, and can be used as a thickening agent and an emulsifying agent.
(3) At present, a small amount of tertiary amine catalyst is not found, the high reaction activity of an epoxy group and the etherification reaction of a long carbon chain serving as a hydrophobic group are utilized, and the hydrophobic group can be introduced to realize hydrophobic association without using sodium hydroxide or controlling PH so as to achieve the purpose of improving the viscosity of the sodium carboxymethyl starch.
Drawings
FIG. 1 is a hydrogen nuclear magnetic spectrum of hydrophobically modified sodium carboxymethyl starch prepared in example 1.
FIG. 2 is a hydrogen nuclear magnetic spectrum of the hydrophobically modified sodium carboxymethyl starch prepared in example 6.
FIG. 3 is a standard infrared spectrum of raw sodium carboxymethyl starch and hydrophobically modified sodium carboxymethyl starch prepared in example 1.
Detailed Description
The following further describes a specific embodiment of the present invention with reference to the drawings and technical solutions.
Example 1
Weighing 15g C8-C10 alkyl glycidyl ether, dissolving in 30g of absolute ethyl alcohol, adding 0.6g N, N-dimethylbenzylamine, stirring for dissolving, adding 120g of water, weighing 15g of sodium carboxymethyl starch, adding into a system, reacting for 4 hours at 70 ℃, separating out in industrial ethyl alcohol after the reaction is finished, drying, washing and crushing to obtain the hydrophobically modified sodium carboxymethyl starch with the substitution degree of 0.19 and the viscosity of 2353mpa.s (gamma is 60S)-1)。
The hydrogen nuclear magnetic spectrum of the hydrophobically modified sodium carboxymethyl starch prepared in this example is shown in FIG. 1, and 5.2-5.8ppm is the chemical shift of the proton at the C1 position of the glucose unit; 1.52ppm, 1.30ppm, 0.86ppm are chemical shifts of protons on two methylene groups adjacent to the terminal in the butoxy group, and the methyl group, and thus introduction of the butoxy group by etherification reaction can be confirmed.
FIG. 3 is a standard infrared spectrum of raw sodium carboxymethyl starch and hydrophobically modified sodium carboxymethyl starch prepared in example 1. The absorption peak at 1600cm-1 can be seen as-COO-The peak intensity of stretching vibration of (2) becomes large, and it can be confirmed that the etherification reaction occurred.
Example 2
Weighing 15g C8-C10 alkyl glycidylDissolving oil ether in 30g of absolute ethanol, adding 0.6g N, N-dimethylbenzylamine, stirring for dissolving, adding 120g of water, weighing 15g of sodium carboxymethyl starch, adding the sodium carboxymethyl starch into the system, reacting for 4 hours at 90 ℃, separating out in industrial ethanol after the reaction is finished, drying, washing and crushing to obtain the hydrophobically modified sodium carboxymethyl starch with the substitution degree of 0.17 and the viscosity of 1983mpa.s (gamma is 60S)-1)。
Example 3
Weighing 15g C8-C10 alkyl glycidyl ether, dissolving in 30g of absolute ethyl alcohol, adding 0.6g N, N-dimethylbenzylamine, stirring for dissolving, adding 120g of water, weighing 15g of sodium carboxymethyl starch, adding into a system, reacting for 4 hours at 50 ℃, separating out in industrial ethyl alcohol after the reaction is finished, drying, washing and crushing to obtain the hydrophobically modified sodium carboxymethyl starch with the substitution degree of 0.09 and the viscosity of 650mpa.s (gamma is 60S)-1)。
Example 4
Weighing 10g C8-C10 alkyl glycidyl ether, dissolving in 30g of absolute ethyl alcohol, adding 0.6g N, N-dimethylbenzylamine, stirring for dissolving, adding 120g of water, weighing 15g of sodium carboxymethyl starch, adding into the system, reacting for 4 hours at 70 ℃, separating out in industrial ethyl alcohol after the reaction is finished, drying, washing and crushing to obtain the hydrophobically modified sodium carboxymethyl starch with the substitution degree of 0.15 and the viscosity of 1950mpa.s (gamma is 60S)-1)。
Example 5
Weighing 5g C8-C10 alkyl glycidyl ether, dissolving in 30g of absolute ethyl alcohol, adding 0.6g N, N-dimethylbenzylamine, stirring for dissolving, adding 120g of water, weighing 15g of sodium carboxymethyl starch, adding into a system, reacting for 4 hours at 70 ℃, separating out in industrial ethyl alcohol after the reaction is finished, drying, washing and crushing to obtain the hydrophobically modified sodium carboxymethyl starch with substitution degree of 0.13 and viscosity of 980mpa.s (gamma is 60S)-1)。
Example 6
Weighing 15g of benzyl glycidyl ether, dissolving in 30g of absolute ethyl alcohol, adding 0.6g N, N-dimethylbenzylamine, stirring for dissolving, adding 120g of water, weighing 15g of sodium carboxymethyl starch, and adding into the systemReacting at 70 deg.C for 4 hr, precipitating in industrial ethanol, drying, washing, and pulverizing to obtain hydrophobically modified carboxymethyl starch sodium with substitution degree of 0.13 and viscosity of 980mpa.s (γ ═ 60S)-1)。
The hydrogen nuclear magnetic spectrum of the hydrophobically modified sodium carboxymethyl starch prepared in this example is shown in FIG. 2. 5.2-5.8ppm are the chemical shifts of the protons at the C1 position of the glucose units; 7.33ppm is the chemical shift of the benzyl proton, from which the introduction of a benzyl group by etherification reaction can be demonstrated.
Example 7
Weighing 15g of octyl glycidyl ether, dissolving the octyl glycidyl ether in 30g of absolute ethyl alcohol, adding 0.6g N, N-dimethylbenzylamine, stirring for dissolving, adding 120g of water, weighing 15g of sodium carboxymethyl starch, adding the sodium carboxymethyl starch into a system, reacting for 4 hours at the temperature of 70 ℃, separating out the sodium carboxymethyl starch in industrial ethyl alcohol after the reaction is finished, drying, washing and crushing to obtain the hydrophobically modified sodium carboxymethyl starch with the substitution degree of 0.26 and the viscosity of 650mpa.s (gamma is 60S)-1)。
Example 8
Weighing 15g of butyl glycidyl ether, dissolving the butyl glycidyl ether in 30g of absolute ethyl alcohol, adding 0.6g N, N-dimethylbenzylamine, stirring for dissolving, adding 120g of water, weighing 15g of sodium carboxymethyl starch, adding the sodium carboxymethyl starch into a system, reacting for 4 hours at the temperature of 70 ℃, separating out the sodium carboxymethyl starch in industrial ethyl alcohol after the reaction is finished, drying, washing and crushing to obtain the hydrophobically modified sodium carboxymethyl starch with the substitution degree of 0.36 and the viscosity of 550mpa.s (gamma is 60S)-1。
Example 9
Weighing 15g C8-C10 alkyl glycidyl ether, dissolving in 30g of absolute ethyl alcohol, adding 0.75g N, N-dimethylbenzylamine, stirring for dissolving, adding 120g of water, weighing 15g of sodium carboxymethyl starch, adding into a system, reacting for 4 hours at 70 ℃, separating out in industrial ethyl alcohol after the reaction is finished, drying, washing and crushing to obtain the hydrophobically modified sodium carboxymethyl starch with the substitution degree of 0.22 and the viscosity of 2353mpa.s (gamma is 60S)-1)。
Example 10
Weighing 15g C8-C10 alkyl glycidyl ether, dissolving in 3Adding 0.15g N, N-dimethylbenzylamine into 0g of absolute ethanol, stirring for dissolving, adding 120g of water, weighing 15g of sodium carboxymethyl starch, adding the sodium carboxymethyl starch into the system, reacting at 70 ℃ for 4 hours, separating out in industrial ethanol after the reaction is finished, drying, washing and crushing to obtain the hydrophobically modified sodium carboxymethyl starch with the substitution degree of 0.08 and the viscosity of 620mpa.s (gamma-60S)-1)。
Claims (5)
1. A preparation method of hydrophobically modified sodium carboxymethyl starch is characterized by comprising the following steps:
dissolving alkyl glycidyl ether in ethanol, adding a tertiary amine catalyst, stirring for dissolving, adding a water-ethanol mixed solvent, finally adding sodium carboxymethyl starch into the system, reacting for 4-8 hours at the temperature of 50-90 ℃, separating out in industrial ethanol after the reaction is finished, drying and crushing;
wherein:
the mass ratio of the tertiary amine catalyst to the sodium carboxymethyl starch is 0.01:1-0.05: 1;
the mass ratio of the ethanol to the sodium carboxymethyl starch is 5: 1-25: 1;
the mass ratio of the alkyl glycidyl ether to the sodium carboxymethyl starch is 0.3: 1-1: 1;
the mass ratio of the amount of the water-ethanol mixed solvent to the sodium carboxymethyl starch is 10:1 to 3: 1.
2. The method for preparing hydrophobically modified sodium carboxymethyl starch according to claim 1, wherein the alkyl glycidyl ether is C8-C10One or more of glycidyl ether, aryl glycidyl ether, octyl glycidyl ether and butyl glycidyl ether.
3. The method for preparing hydrophobically modified sodium carboxymethyl starch according to claim 1 or 2, wherein the tertiary amine catalyst is one or a mixture of more than two of N, N-dimethylbenzylamine, triethylamine, hexamethylenetetramine, triethylenediamine and tetraethylmethylenediamine.
4. The preparation method of hydrophobically modified sodium carboxymethyl starch according to claim 1 or 2, wherein the mass ratio of water to ethanol in the water-ethanol mixed solvent is 1:4 to 1: 1.
5. The preparation method of hydrophobically modified sodium carboxymethyl starch according to claim 3, wherein the mass ratio of water to ethanol in the water-ethanol mixed solvent is 1: 4-1: 1.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115926006A (en) * | 2022-12-26 | 2023-04-07 | 大连理工大学 | pH sensitive emulsifier and preparation method thereof |
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| GB714701A (en) * | 1951-02-23 | 1954-09-01 | Corn Prod Refining Co | Improvements in or relating to a process for the production of starch derivatives and the resulting product |
| EP0566911A1 (en) * | 1992-04-20 | 1993-10-27 | Aqualon Company | Improved leveling aqueous coating compositions |
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| JP2003252669A (en) * | 2002-03-04 | 2003-09-10 | Mitsui Chemicals Inc | Hydraulic composition |
| US6627751B1 (en) * | 1997-06-13 | 2003-09-30 | Akko Nobel N.V. | Hydrophobically modified anionic cellulose ethers |
| US20040009140A1 (en) * | 2000-10-12 | 2004-01-15 | Takafumi Nishijima | Skin pore minimizers and skin elasticity improvers |
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| US20130158194A1 (en) * | 2011-12-14 | 2013-06-20 | Rohm And Haas Company | Rheology modifier |
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2021
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Patent Citations (9)
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|---|---|---|---|---|
| GB714701A (en) * | 1951-02-23 | 1954-09-01 | Corn Prod Refining Co | Improvements in or relating to a process for the production of starch derivatives and the resulting product |
| EP0566911A1 (en) * | 1992-04-20 | 1993-10-27 | Aqualon Company | Improved leveling aqueous coating compositions |
| JPH09110901A (en) * | 1995-08-10 | 1997-04-28 | Kao Corp | New polysaccharide derivative |
| US6627751B1 (en) * | 1997-06-13 | 2003-09-30 | Akko Nobel N.V. | Hydrophobically modified anionic cellulose ethers |
| US20050277768A1 (en) * | 1999-01-15 | 2005-12-15 | Cooperatieve Verkoop-En Productievereniging Van Aardappelmeel En Derivaten Avebe B.A. | Hydrophobic starch derivatives |
| US20040009140A1 (en) * | 2000-10-12 | 2004-01-15 | Takafumi Nishijima | Skin pore minimizers and skin elasticity improvers |
| JP2003096101A (en) * | 2001-09-20 | 2003-04-03 | Toppan Printing Co Ltd | Cellulose/starch derivative, process for preparation thereof, and biodegradable laminate |
| JP2003252669A (en) * | 2002-03-04 | 2003-09-10 | Mitsui Chemicals Inc | Hydraulic composition |
| US20130158194A1 (en) * | 2011-12-14 | 2013-06-20 | Rohm And Haas Company | Rheology modifier |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115926006A (en) * | 2022-12-26 | 2023-04-07 | 大连理工大学 | pH sensitive emulsifier and preparation method thereof |
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