Method for controlling thermal degradation of chitosan-transition metal salt system

Abstract

The invention belongs to the technical field of chitosan degradation and relates to a method for controlling thermal degradation of a chitosan-transition metal salt system. The method includes steps:preparing transition metal ion aqueous solution; preparing acetic acid solution; weighing chitosan, and adding acetic acid solution; adding the transition metal ion aqueous solution into the chitosansolution; pouring mixed liquid into a petri dish to obtain a sample film after constant weight is achieved at a constant temperature; subjecting the sample film to infrared spectroscopic analysis, X-ray diffraction analysis and thermal analysis. The method provides theoretical guiding significance for realizing mild, efficient and controllable chitosan degradation, lays a scientific theoretical foundation for development and application of a metal ion and chitosan mixture in catalysis, biology, medicine, environment protection and the like and for expanding of an application range of coordination chemistry, and provides practical guiding significance for industrial production and practical application.

Description

technical field

[0001] The invention belongs to the technical field of chitosan degradation, and in particular relates to a method for controlling thermal degradation of a chitosan-transition metal salt system. Background technique

[0002] Chitin [(1,4)-2-acetylamino-2-deoxy-β-D-glucan, Chitin], also known as chitin, chitin, etc., is a linear polymer of acetylglucosamine, it It has a wide range of sources and is the second largest natural polymer after cellulose. It mainly exists in the shells of crustaceans, the inner skeletons of molluscs, insect wings, and the cell walls of fungi and algae. Chitosan [(1,4)-2-amino-2-deoxy-β-D-glucan, Chitosan, referred to as CTS], also known as chitosan, chitosamine, deacetylated chitin, chitosan Sugar is the product obtained by heating chitin in alkaline solution and removing N-acetyl group. It is the organic nitrogen source with the largest nitrogen content besides protein, and it is also the only alkaline polysaccharide in nature. ...

Examples

Embodiment 1

[0030] A method for controlling thermal degradation of chitosan-transition metal salt system, said research method comprising the following steps:

[0031] Step 1. Dissolving the transition metal salt in purified water to prepare an aqueous transition metal ion solution with a transition metal ion concentration of 0.0005 to 0.002 g / mL;

[0032] Step 2. Pipette 5 mL of glacial acetic acid into a 500 mL volumetric flask, dilute with purified water, settle to dissolve, shake well, and set aside;

[0033] Step 3. Weigh 1 g of chitosan, place it in a 250 mL beaker, add 50 mL of the acetic acid solution prepared in step 2, stir with a glass rod, then magnetically stir for 0.5 h, and stand for 24 h for later use;

[0034] Step 4. Add 20 mL of transition metal ion aqueous solution prepared in step 1 to the chitosan acetic acid solution prepared in step 3, then add 30 mL of purified water, magnetically stir for 1 h, leave standstill for 24 h, and degas;

[0035] Step 5. Pour the chito...

Embodiment 2

[0038] Step 1. Cadmium acetate (C 4 h 5 CdO 4 2H 2 O) Dissolved in purified water, prepared into transition metal ion aqueous solutions with transition metal ion concentrations of 0, 0.0005 g / mL, 0.001 g / mL, 0.0015 g / mL, and 0.002 g / mL respectively, and placed them in 1, 2, 3, 4, 5 volumetric flasks;

[0039] Step 2. Pipette 5 mL of glacial acetic acid into a 500 mL volumetric flask, dilute with purified water, settle to dissolve, shake well, and set aside;

[0040] Step 3. Weigh 5 parts of chitosan, each part of chitosan content is 1 g, then place them in 250 mL beakers respectively, add 50 mL of the acetic acid solution prepared in step 2, stir with a glass rod, and then magnetically stir for 0.5 h, after standing for 24 h for later use;

[0041] Step 4. In the chitosan acetic acid solution prepared in step 3, add respectively the transition metal ion aqueous solution prepared by 20 mL of step 1, then add 30 mL of purified water, stir magnetically for 1 h, leave standst...

Embodiment 3

[0046] Step 1. Cobalt chloride (CoCl 2 ·6H 2 O) Dissolved in purified water, prepared into transition metal ion aqueous solutions with transition metal ion concentrations of 0, 0.0005 g / mL, 0.001 g / mL, 0.0015 g / mL, and 0.002 g / mL respectively, and placed them in 1, 2, 3, 4, 5 volumetric flasks;

[0047] Step 2. Pipette 5 mL of glacial acetic acid into a 500 mL volumetric flask, dilute with purified water, settle to dissolve, shake well, and set aside;

[0048] Step 3. Weigh 5 parts of chitosan, each part of chitosan content is 1 g, then place them in 250 mL beakers respectively, add 50 mL of the acetic acid solution prepared in step 2, stir with a glass rod, and then magnetically stir for 0.5 h, after standing for 24 h for later use;

[0049] Step 4. In the chitosan acetic acid solution prepared in step 3, add respectively the transition metal ion aqueous solution prepared by 20 mL of step 1, then add 30 mL of purified water, stir magnetically for 1 h, leave standstill for ...

technical field

[0001] The invention belongs to the technical field of chitosan degradation, and in particular relates to a method for controlling thermal degradation of a chitosan-transition metal salt system. Background technique

[0002] Chitin [(1,4)-2-acetylamino-2-deoxy-β-D-glucan, Chitin], also known as chitin, chitin, etc., is a linear polymer of acetylglucosamine, it It has a wide range of sources and is the second largest natural polymer after cellulose. It mainly exists in the shells of crustaceans, the inner skeletons of molluscs, insect wings, and the cell walls of fungi and algae. Chitosan [(1,4)-2-amino-2-deoxy-β-D-glucan, Chitosan, referred to as CTS], also known as chitosan, chitosamine, deacetylated chitin, chitosan Sugar is the product obtained by heating chitin in alkaline solution and removing N-acetyl group. It is the organic nitrogen source with the largest nitrogen content besides protein, and it is also the only alkaline polysaccharide in nature. ...

Examples

Embodiment 1

[0030] A method for controlling thermal degradation of chitosan-transition metal salt system, said research method comprising the following steps:

[0031] Step 1. Dissolving the transition metal salt in purified water to prepare an aqueous transition metal ion solution with a transition metal ion concentration of 0.0005 to 0.002 g / mL;

[0032] Step 2. Pipette 5 mL of glacial acetic acid into a 500 mL volumetric flask, dilute with purified water, settle to dissolve, shake well, and set aside;

[0033] Step 3. Weigh 1 g of chitosan, place it in a 250 mL beaker, add 50 mL of the acetic acid solution prepared in step 2, stir with a glass rod, then magnetically stir for 0.5 h, and stand for 24 h for later use;

[0034] Step 4. Add 20 mL of transition metal ion aqueous solution prepared in step 1 to the chitosan acetic acid solution prepared in step 3, then add 30 mL of purified water, magnetically stir for 1 h, leave standstill for 24 h, and degas;

[0035] Step 5. Pour the chito...

Embodiment 2

[0038] Step 1. Cadmium acetate (C 4 h 5 CdO 4 2H 2 O) Dissolved in purified water, prepared into transition metal ion aqueous solutions with transition metal ion concentrations of 0, 0.0005 g / mL, 0.001 g / mL, 0.0015 g / mL, and 0.002 g / mL respectively, and placed them in 1, 2, 3, 4, 5 volumetric flasks;

[0039] Step 2. Pipette 5 mL of glacial acetic acid into a 500 mL volumetric flask, dilute with purified water, settle to dissolve, shake well, and set aside;

[0040] Step 3. Weigh 5 parts of chitosan, each part of chitosan content is 1 g, then place them in 250 mL beakers respectively, add 50 mL of the acetic acid solution prepared in step 2, stir with a glass rod, and then magnetically stir for 0.5 h, after standing for 24 h for later use;

[0041] Step 4. In the chitosan acetic acid solution prepared in step 3, add respectively the transition metal ion aqueous solution prepared by 20 mL of step 1, then add 30 mL of purified water, stir magnetically for 1 h, leave standst...

Embodiment 3

[0046] Step 1. Cobalt chloride (CoCl 2 ·6H 2 O) Dissolved in purified water, prepared into transition metal ion aqueous solutions with transition metal ion concentrations of 0, 0.0005 g / mL, 0.001 g / mL, 0.0015 g / mL, and 0.002 g / mL respectively, and placed them in 1, 2, 3, 4, 5 volumetric flasks;

[0047] Step 2. Pipette 5 mL of glacial acetic acid into a 500 mL volumetric flask, dilute with purified water, settle to dissolve, shake well, and set aside;

[0048] Step 3. Weigh 5 parts of chitosan, each part of chitosan content is 1 g, then place them in 250 mL beakers respectively, add 50 mL of the acetic acid solution prepared in step 2, stir with a glass rod, and then magnetically stir for 0.5 h, after standing for 24 h for later use;

[0049] Step 4. In the chitosan acetic acid solution prepared in step 3, add respectively the transition metal ion aqueous solution prepared by 20 mL of step 1, then add 30 mL of purified water, stir magnetically for 1 h, leave standstill for ...