CN103788264B - A kind of grafting amido hydroximic acid polymkeric substance and preparation method thereof - Google Patents

Abstract

The invention discloses a grafted amidohydroxamic acid polymer and a preparation method thereof. The polymer is prepared by substitution reaction of polyacrylic acid or chloromethylated polystyrene and N-acetylaminohydroxamic acid, wherein , N-acetylaminoalkyl hydroxamic acid is obtained by N-amidation reaction of lactam and acetyl chloride, and then carries out ring-opening reaction with hydroxylamine under weakly alkaline conditions; the preparation method of the present invention has simple process, mild reaction conditions, The yield is high, and the grafting rate of hydroxamic acid in the prepared amidohydroxamic acid polymer is as high as 97%, and it has a good effect on iron, copper, cobalt, nickel, lanthanum, cerium, yttrium, praseodymium, neodymium, etc. in the solution. Good coordination performance, can be used as flocculant, or metal ion precipitant, or ion exchange resin.

Description

A kind of graft amido hydroxamic acid polymer and preparation method thereof

technical field

The invention relates to a grafted amido hydroxamic acid polymer and a preparation method thereof, belonging to the field of polymer preparation.

Background technique

Hydroxamic acid compounds are widely used in the fields of flotation of metal oxide ores, solvent extraction, chemical analysis, medicine and sewage treatment because of their unique coordination structure and excellent coordination performance with metal ions. Hydroxamic acid resin is also used in the separation and enrichment of iron, copper, rare earth and other metal ions.

At present, the synthesis of hydroxamic acid polymers is mostly prepared by polymer modification with polystyrene, polyacrylate, polyacrylonitrile, polyacrylamide, starch and their copolymers as the skeleton. Patent CN1872885A discloses a method for preparing a polymer amount of water-soluble polymer containing hydroxamic acid groups. In this method, the polymer amount of water-soluble acrylic acid polymer powder is dispersed in a polar organic solvent, respectively mixed with alkyl A heterogeneous esterification reaction and a hydroxamic acid reaction are carried out with a chemical reagent and a hydroxylamine solution to generate a water-soluble polymer containing a hydroxamic acid group in a polymer amount. Wang Bi and others studied the reaction of polyacrylamide with hydroxylamine under alkaline conditions to prepare a polymer collector containing hydroxamic acid side groups, which has a strong chelating ability with lead ions (Wang Bi, Xu Guili, Hu Xingqi. Chemistry Research and Application. 2008,20(5):561-564). Kumar et al. studied the adsorption and enrichment of rare earth elements such as La, Ce, and Pr in seawater by polyacrylamide hydroxamic acid resin. The enrichment factor can reach more than 100, and it is not interfered by Na(I) and Mg(II). (Kumar SA, Pandey SP, Shenoy NS, et al. Desalination, 2011, 281:49-54). Lee et al. used ethyl acrylate as a monomer, divinylbenzene as a crosslinking agent, and trimethylpentane as a porogen, prepared polyethylacrylate crosslinked divinylbenzene spheres by suspension polymerization, and then the resin Hydroxamic acid resin was prepared by reacting with hydroxylamine hydrochloride under basic conditions (T.S.Lee, D.W.Jeon, J.K.Kim, etal. Fibers and Polymers. 2001, 2(1):13～17.). Since the hydroximation reaction efficiency of polymers is limited by the polymer backbone, the reaction efficiency is low. Patent CN103304713A discloses a preparation method of poly N-hexyl hydroxamic acid acrylamide polymer, using polyacrylic acid polymer and 6-aminohexyl hydroxamic acid as raw materials, and reacting at a temperature of 100-160°C for 1-4 hours Synthesized poly N-hexyl hydroxamic acid acrylamide polymer. This method utilizes the carboxyl group of polyacrylic acid polymer and the amino group of 6-aminohexylhydroxamic acid to carry out substitution reaction to realize the grafting of polymer, which obviously improves the reaction efficiency, but the reaction temperature of this method is still high, and the high temperature of hydroxamic acid It is prone to rearrangement reaction and decomposition.

Contents of the invention

The purpose of the present invention is to provide a kind of amidohydroxamic acid polymer of high graft rate, and this polymer has good to iron, copper, cobalt, nickel, lanthanum, cerium, yttrium, praseodymium, neodymium etc. in solution Coordination performance, can be used as flocculant, or metal ion precipitant, or ion exchange resin.

Another object of the present invention is to provide a method for preparing the amidohydroxamic acid polymer with simple process, mild reaction conditions and high yield.

A grafted amidohydroxamic acid polymer of the present invention, the grafted amidohydroxamic acid polymer is composed of polyacrylic acid or chloromethylated polystyrene and N-acetylaminohydroxamic acid with the structure of formula I It is prepared through a substitution reaction and has a structural unit of formula II:

in,

n is 3~5, R is or group;

The grafting rate of N-acetylaminohydroxamic acid on polyacrylic acid or chloromethylated polystyrene is not less than 97%.

The polyacrylic acid includes linear polyacrylic acid with a molecular weight of 200-6× ¹⁰⁶ or a cross-linked polyacrylic resin with a cross-linking degree of 2%-12%, and the cross-linking degree of chloromethylated polystyrene is 2 %~12%.

The N-acetylaminoalkyl hydroxamic acid is prepared by the following method: adding C ₄ -C ₆ lactam and acetyl chloride into the reaction kettle at a molar ratio of 1:1.0-1.5, stirring at 0-50°C , carry out N-amidation reaction, and at the same time, slowly add a weakly basic compound of 1.0 to 3.0 times the molar amount of the lactam into the reaction kettle to neutralize the acid generated by the N-amidation reaction; N-amidation After the reaction is completed, add 1 to 1.2 times the molar amount of hydroxylamine of the lactam and a weakly basic compound of 1 to 3 times the molar amount of the lactam to the reaction kettle to carry out a ring-opening reaction. After the ring-opening reaction is completed, , Add acid to the reactor to adjust the pH value to acidic, that is, too.

The preferred reaction temperature of the N-acylation reaction is 15-40°C; most preferably 25-35°C.

The N-acylation reaction time is 1-4 hours.

The ring-opening reaction time is 1-4 hours.

The weakly basic compound is sodium bicarbonate, potassium bicarbonate, calcium bicarbonate, sodium carbonate, potassium carbonate, calcium carbonate, lithium carbonate, calcium oxide, sodium tert-butyl alkoxide or potassium tert-butyl alkoxide.

The process of slowly adding the weakly basic compound is to divide the weakly basic compound into several parts equally, and add the obtained several parts of alkali into the reaction solution in batches.

The solvent used in the N-acylation reaction is dichloromethane, chloroform or tetrahydrofuran, and the amount of the solvent used is 2 to 5 times the mass of the lactam.

The ring-opening reaction also adds water and/or methanol as a solvent.

The pH adjustment is acidic, preferably 4-6.

The hydroxylamine is added in the form of hydroxylamine salt, and the hydroxylamine salt is hydroxylamine hydrochloride, hydroxylamine sulfate or hydroxylamine carbonate.

The present invention also provides a preparation method of the grafted amidohydroxamic acid polymer, the preparation method is to combine the N-acetylaminohydroxamic acid with polyacrylic acid or chloromethylated polystyrene In the presence of a weakly basic compound and a condensing agent, carry out a substitution reaction at 20-80°C to obtain it; wherein, the carboxyl group in polyacrylic acid or the chloromethyl group in chloromethylated polystyrene: N-acetylamino hydroxyl The molar ratio of acetamido in the xamic acid: weakly basic compound: condensing agent is 1:1～2:1.5～4:0.5～1.

The condensing agent is N,N-carbonyldiimidazole (CDI), benzotriazole-N,N,N,N-tetramethyluronium hexafluorophosphate (HBTU), O-(7-nitrobenzene Triazole)-N,N,N,N-tetramethyluronium hexafluorophosphate (HATU), N,N-dicyclohexylcarbodiimide (HOBt), N,N-diisopropyl Carbodiimide (DIC) or benzotriazol-1-yl-oxytripyrrolidinylphosphonium hexafluorophosphate (PyBOP).

The weakly basic compound is sodium bicarbonate, potassium bicarbonate, calcium bicarbonate, sodium carbonate, potassium carbonate, calcium carbonate, lithium carbonate, calcium oxide, sodium tert-butyl alkoxide or potassium tert-butyl alkoxide.

The reaction temperature of the substitution reaction is preferably 40-60°C; most preferably 50°C.

The time for the substitution reaction is 1 to 4 hours.

The solvent used in the substitution reaction is acetone or toluene.

In the present invention, the linear grafted amido hydroxamic acid polymer prepared as a raw material can be used as a flocculant or a metal ion precipitant with a linear polyacrylic acid polymer; Hydroxamic acid resin prepared from vinyl resin can be used as ion exchange resin.

Beneficial effects of the present invention: the present invention first obtains N-acetylaminohydroxamic acid through a simple method, and then grafts N-acetylaminohydroxamic acid on polyacrylic acid or chloromethylated polystyrene resin to obtain high grafting grafted amido hydroxamic acid polymer. In the present invention, by strictly controlling the reaction temperature, combined with the use of a weak base compound, the decomposition and rearrangement reaction of N-acetylaminohydroxamic acid in the process of graft substitution reaction can be reduced to the greatest extent, so that the polymer can obtain higher yield While maintaining a super high hydroximation rate, the grafted amido hydroxamic acid polymer prepared by the present invention has good resistance to iron, copper, cobalt, nickel, lanthanum, cerium, yttrium, praseodymium, neodymium, etc. in the solution Coordination performance, can be used as a flocculant, or a metal ion precipitation agent, or an ion exchange resin; the preparation process of the polymer is simple, the reaction conditions are mild, and the product yield is high.

Description of drawings

[Figure 1] Infrared spectrum of linear poly 4-(N-acetylacrylamide)-butyl hydroxamic acid polymer.

[Figure 2] Infrared spectrum of linear poly 6-(N-acetylacrylamide)-hexyl hydroxamic acid polymer.

[Figure 3] The infrared spectrum of poly 4-(N-acetylacrylamide)-butyl hydroxamic acid resin.

[Figure 4] Infrared spectrum of poly 4-[(N-acetyl)-4-polyvinylbenzylamino]-butyl hydroxamic acid resin.

[Fig. 5] The infrared spectrum of poly 6-(N-acetylacrylamide)-hexyl hydroxamic acid resin.

[Fig. 6] The infrared spectrum of poly 6-[(N-acetyl)-4-polyvinylbenzylamino]-hexyl hydroxamic acid resin.

detailed description

The following examples are further descriptions of the content of the present invention, rather than limiting the protection scope of the present invention.

All parts and percentages in the examples refer to mass unless otherwise specified.

Example 1

Preparation of Linear Polymer of 4-(N-Acetylacrylamide)-Butyl Hydroxamic Acid

(1) Control the temperature of the reactor at 30°C, add 17.02 parts of 2-pyrrolidone with a purity of 99% and 16.48 parts of acetyl chloride with a purity of 99% into the reactor, add 45.28 parts of dichloromethane as a solvent, and mix 12.72 parts of Parts of sodium carbonate were added to the reactor in batches, and after 3 hours of reaction; then 13.90 parts of hydroxylamine hydrochloride and 42.40 parts of sodium carbonate were added to the above reactor, and 47.40 parts of methanol were added as a solvent for further reaction for 3 hours; then 1mol /L sulfuric acid adjusted to a pH value of 6 to precipitate an organic phase that is 4-acetamidobutyl hydroxamic acid.

(2) Add 32 parts of 4-acetamidobutyl hydroxamic acid prepared in step 1, 7.20 parts of linear polyacrylic acid with an average molecular weight of 3000 and 16 parts of CDI into the reactor, add 92 parts of toluene as a solvent, and stir Add 32.4 parts of sodium carbonate, heat to 50°C, react for 4 hours, filter to obtain a linear poly 4-(N-acetylacrylamide)-butyl hydroxamic acid solid, the product yield is 97.8%, calculated according to the elemental analysis results The hydroximation rate of the obtained polyacrylic acid was 97.6%. The infrared spectrum of the product is shown in Figure 1, where 3201cm ^-1 is NH and OH stretching vibration; 2912cm ^-1 and 2845cm ^-1 are saturated CH stretching vibration; 1637cm ^-1 is C=O stretching vibration, and 1569cm ^-1 is amide stretching vibration .

Example 2

Preparation of Linear Polymer of 6-(N-Acetylacrylamide)-Hexyl Hydroxamic Acid

(1) According to the method of step (1) of Example 1, the 17.02 parts of 2-pyrrolidone with a purity of 99% were changed to 22.64 parts of caprolactam with a purity of 99%, and the temperature of the reactor was controlled at 25°C. Other conditions remained unchanged. 6-Acetamidohexyl hydroxamic acid is obtained.

(2) Add 37.6 parts of ⁶ -acetylaminohexyl hydroxamic acid prepared in step 1, 7.20 parts of polyacrylic acid with an average molecular weight of 2×106 and 16 parts of CDI into the reactor, add 58 parts of acetone as a solvent, and stir Add 31.8 parts of sodium carbonate, heat to 40°C, react for 4 hours, filter to obtain poly-6-(N-acetylacrylamide)-hexylhydroxamic acid solid, the product yield is 96.1%, calculated according to the elemental analysis results The hydrooximation rate of polyacrylic acid is 98.9%. The infrared spectrum of the product is shown in Figure 2, where 3156cm ^-1 is NH and OH stretching vibration; 2934cm ^-1 and 2856cm ^-1 are saturated CH stretching vibration; 1644cm ^-1 is C=O stretching vibration, and 1582cm ^-1 is amide stretching vibration .

Example 3

Preparation of poly 4-(N-acetylacrylamide)-butyl hydroxamic acid resin

The preparation process of 4-acetamidobutyl hydroxamic acid is the same as step (1) of Example 1, except that the reaction temperature is adjusted to 25°C. Add 32 parts of 4-acetylaminobutyl hydroxamic acid, 8.62 parts of macroporous polyacrylic resin D113 and 16 parts of CDI into the reactor, add 58 parts of acetone as solvent, add 32.4 parts of sodium carbonate under stirring, and heat to 60°C , reacted for 4 hours, filtered to obtain poly 4-(N-acetylacrylamide)-butyl hydroxamic acid resin, the product yield was 96.4%, and the hydroximation rate of polyacrylic acid resin was calculated according to elemental analysis results to be 97.9% %. The infrared spectrum of the product is shown in Figure 3, in which 3429cm ^-1 is NH and OH stretching vibration; 2960cm ^-1 and 2927cm ^-1 are saturated CH stretching vibration; 1734cm ^-1 is C=O stretching vibration, 1635cm ^-1 is the stretching vibration of amide vibration.

Example 4

Preparation of poly 4-[(N-acetyl)-4-polyvinylbenzylamino]-butyl hydroxamic acid resin

The preparation process of 4-acetamidobutyl hydroxamic acid is the same as step (1) of Example 1, except that the reaction temperature is adjusted to 25°C. Add 32 parts of 4-acetamidobutyl hydroxamic acid, 18.11 parts of chloromethylated styrene resin (19.6% chlorine content) and 10 parts of CDI into the reactor, add 92 parts of toluene as solvent, add 25.2 parts under stirring Parts of sodium bicarbonate, heated to 50 ° C, reacted for 4 hours, filtered to obtain poly 4-[(N-acetyl)-4-polyvinylbenzylamino]-butyl hydroxamic acid resin, the product yield was 98.1% , according to the elemental analysis results, the hydroximation rate of chloromethylated styrene resin was 98.7%. The infrared spectrum of the product is shown in Figure 4, where 3441cm ^-1 is NH and OH stretching vibration; 3023cm ^-1 and 2924cm ^-1 are saturated CH stretching vibration; 1627cm ^-1 is amino stretching vibration.

Example 5

Preparation of poly 6-(N-acetylacrylamide)-hexyl hydroxamic acid resin

The preparation process of 6-acetamidohexyl hydroxamic acid is the same as step (1) of Example 2, except that the reaction temperature is adjusted to 35°C. Add 37.6 parts of 6-acetylaminohexyl hydroxamic acid, 8.62 parts of macroporous polyacrylic resin D113 and 16 parts of CDI into the reactor, add 58 parts of acetone as solvent, add 42.4 parts of sodium carbonate under stirring, and heat to 50°C. React for 4 hours and filter to obtain poly-6-(N-acetylacrylamide)-hexyl hydroxamic acid resin with a product yield of 97.7%. According to the elemental analysis results, the hydroximation rate of polyacrylic acid resin is calculated to be 97.2%. The infrared spectrum of the product is shown in Figure 5, in which 3426cm ^-1 is NH and OH stretching vibration; 2988cm ^-1 and 2927cm ^-1 are saturated CH stretching vibration; 1727cm ^-1 is C=O stretching vibration, 1645cm ^-1 is the stretching vibration of amide vibration.

Example 6

Preparation of poly 6-[(N-acetyl)-4-polyvinylbenzylamino]-hexyl hydroxamic acid resin

The preparation process of 6-acetamidohexylhydroxamic acid is the same as the step (1) of Example 2, except that the reaction temperature is adjusted to 25°C. Add 37.6 parts of 6-acetylaminohexyl hydroxamic acid, 18.11 parts of chloromethylated styrene resin (19.6% chlorine content) and 12 parts of DIC into the reactor, add 92 parts of toluene as solvent, and add 42.4 parts of Sodium carbonate, heated to 40 ° C, reacted for 4 hours, filtered to obtain poly 6-[(N-acetyl)-4-polyvinylbenzylamino]-hexyl hydroxamic acid resin, the product yield was 97.9%, according to element According to the analysis results, the hydroximation rate of polyacrylic acid resin was 97.6%. The infrared spectrum of the product is shown in Figure 6, in which 3448cm ^-1 is NH and OH stretching vibration; 3025cm ^-1 and 2925cm ^-1 are saturated CH stretching vibration; 1627cm ^-1 is amino stretching vibration.

Example 7

Precipitation properties of linear poly(4-(N-acetylacrylamide)-butyl hydroxamic acid)

Take 100 parts of Co(II), Cu(II), and Fe(III) metal ion solutions with a concentration of 10mmol/L, adjust the pH value to 5.5 with sulfuric acid, and add 1 part of linear poly-4-(N-acetylpropylene Amide)-butyl hydroxamic acid as a precipitating agent, stirred at 25°C for 30 minutes, filtered and separated the filtrate and precipitate, measured the concentration of metal ions in the filtrate, and calculated Co(II), Cu(II), Fe( The removal rates of III) were 89.22%, 95.30% and 90.85%, respectively, indicating that the linear poly 4-(N-acetylacrylamide)-butyl hydroxamic acid is effective for Co(II), Cu(II), Fe(III) Has good ability to remove sediment.

Example 8

Flocculation and Settling Properties of Linear Poly(6-(N-acetylacrylamide)-hexylhydroxamic acid)

After saponifying poly 6-(N-acetylacrylamide)-hexyl hydroxamic acid with sodium hydroxide, add it to the alumina red mud slurry with a solid content of 25%, poly 6-(N-acetylacrylamide) The dosage of -hexyl hydroxamic acid is 5mg/L, and the sedimentation process is basically completed in 15 minutes. Has good settling properties.

Example 9

Adsorption Properties of Polyamidohydroxamic Acid Resin to Metal Ions

Prepare Fe(III), Cu(II), Ni(II), La(III), and Y(III) metal ion solutions with a concentration of 1g/L respectively, and add examples 3 to 6 respectively in an amount of 4g/L. The prepared poly 4-(N-acetylacrylamide)-butyl hydroxamic acid resin, poly 6-(N-acetylacrylamide)-hexyl hydroxamic acid resin, poly 4-[(N-acetyl) -4-polyvinylbenzylamino]-butyl hydroxamic acid resin and poly 6-[(N-acetyl)-4-polyvinylbenzylamino]-hexyl hydroxamic acid resin, the control adsorption temperature is 25 °C, The adsorption time was 3 hours, and the adsorption capacity of the resin was measured as shown in Table 1.

Table 1 The adsorption capacity of polyamide hydroxamic acid resin to metal ions (unit: mmol/g)

Claims (8)

1. A preparation method of a grafted amido hydroximic acid polymer is characterized in that N-acetamido hydroximic acid with a structure shown in a formula 1 and polyacrylic acid or chloromethylated polystyrene are subjected to substitution reaction at 20-80 ℃ in the presence of a weak alkaline compound and a condensing agent to obtain the grafted amido hydroximic acid polymer with a structural unit shown in a formula II; wherein the molar ratio of carboxyl in polyacrylic acid or chloromethyl in chloromethylated polystyrene to acetylamino in N-acetylamino hydroximic acid to weakly basic compound to condensing agent is 1: 1-2: 1.5-4: 0.5-1;

wherein,

n is 3 to 5, R isA group;

the grafting rate of the N-acetamido-hydroximic acid on polyacrylic acid or chloromethylated polystyrene is not less than 97%.

2. The method of claim 1, wherein the polyacrylic acid comprises a molecular weight of 200 to 6 × 10⁶The linear polyacrylic acid or the cross-linked polyacrylic resin with the cross-linking degree of 2-12 percent, and the cross-linking degree of the chloromethylated polystyrene is 2-12 percent.

3. The method of claim 1, wherein the N-acetamidoalkyl hydroxamic acid is prepared by the following method: c is to be₄～C₆The method comprises the following steps of adding lactam and acetyl chloride into a reaction kettle according to a molar ratio of 1: 1.0-1.5, stirring at 0-50 ℃, carrying out an N-amidation reaction, slowly adding a weakly alkaline compound with a molar amount of 1.0-3.0 times that of the lactam into the reaction kettle, and neutralizing acid generated in the N-amidation reaction; and after the N-amidation reaction is finished, adding hydroxylamine with the molar weight 1-1.2 times of that of the lactam and a weakly alkaline compound with the molar weight 1-3 times of that of the lactam into the reaction kettle, carrying out ring-opening reaction, and after the ring-opening reaction is finished, adding acid into the reaction kettle to adjust the pH value to be acidic, thus obtaining the lactam.

4. The method according to claim 3, wherein the N-acylation reaction time is 1 to 4 hours.

5. The preparation method according to claim 3, wherein the ring-opening reaction time is 1 to 4 hours.

6. The process according to claim 1, wherein the condensing agent is N, N-carbonyldiimidazole, benzotriazole-N, N, N, N-tetramethyluronium hexafluorophosphate, O- (7-azobenzotriazol) -N, N, N, N-tetramethyluronium hexafluorophosphate, N, N-dicyclohexylcarbodiimide, N, N-diisopropylcarbodiimide or benzotriazol-1-yl-oxytripyrrolidinophosphonium hexafluorophosphate.

7. The method according to claim 1, wherein the weakly basic compound is sodium bicarbonate, potassium bicarbonate, calcium bicarbonate, sodium carbonate, potassium carbonate, calcium carbonate or lithium carbonate.

8. The method according to claim 1, wherein the substitution reaction time is 1 to 4 hours.