Method for grafting anhydride onto cellulosic material in ionic liquid to prepare carboxyl cellulose

Abstract

The invention discloses a method for grafting anhydride onto a cellulosic material in ionic liquid to prepare carboxyl cellulose. The method includes the following steps that an ionic-liquid cellulosic solution and an ionic-liquid anhydride solution are respectively prepared; the anhydride solution and the cellulosic solution are mixed to be subjected to a constant-temperature reaction, and the carboxyl cellulose is prepared. According to the method, the ionic liquid serves as an activating agent and a solvent; as a cellulose anhydride-grafted method is adopted, the reaction condition is moderate and easy to control, and the reaction is environmentally friendly and free of pollution; the ionic liquid solvent can be recycled through rotary evaporation and drying, and the recycling rate is as high as 98%. According to the reaction system, the grafting reaction only needs to be carried out for 1-2 h, the content of carboxyl in the carboxyl cellulose can be 14%-20%, and the content of the carboxyl in the carboxyl cellulose is greatly increased in a short time.

Description

technical field

[0001] The invention belongs to the technical field of biochemical industry, and relates to a method for preparing carboxy cellulose by grafting acid anhydride on cellulose material in ionic liquid. Background technique

[0002] Cellulose is the most abundant natural organic matter in the world, accounting for more than 50% of the carbon content in the plant kingdom, and about 1.5×10 can be synthesized through photosynthesis every year 12 t. The base ring of the cellulose macromolecule is a macromolecular polysaccharide composed of D-glucose with β-1,4 glycosidic bonds, which contains a large number of hydroxyl groups and is easy to form intramolecular and intermolecular hydrogen bonds. Due to its dense crystalline structure, cellulose is difficult to be dissolved by conventional solvents and cannot be melt-processed. Therefore, the key to making full use of cellulose is to find a solvent with good solubility for it.

[0003] Succinic anhydride, also known...

Examples

Embodiment 1

[0027] (1) Take an appropriate amount of microcrystalline cellulose in a beaker, and dry at 80°C for 4-6 hours;

[0028] (2) Weigh 2.25g of ionic liquid [EMIM][DEP] and 0.15g of dried microcrystalline cellulose, successively add them to 20ml iodine measuring bottle A, and carry out oil bath in a collector type constant temperature heating magnetic stirrer. Heat and magnetically stir, react at a constant temperature of 90°C for 1.5 hours to prepare a cellulose solution, at this time the microcrystalline cellulose is completely activated and dissolved in [EMIM][DEP];

[0029] (3) Weigh 1.5g of [EMIM][DEP] and 0.15g of succinic anhydride, add them to 20ml iodine bottle B successively, heat in an oil bath and magnetically stir in a collector type constant temperature heating magnetic stirrer, 40°C React at constant temperature for 1 hour to obtain a succinic anhydride solution;

[0030] (4) Add the above-mentioned cellulose solution and succinic anhydride solution successively in...

Embodiment 2

[0033] (1) Take an appropriate amount of microcrystalline cellulose in a beaker, and dry at 80°C for 4-6 hours;

[0034] (2) Weigh 2.25g of ionic liquid [EMIM][DEP] and 0.15g of dried microcrystalline cellulose, successively add them to 20ml iodine measuring bottle A, and carry out oil bath in a collector type constant temperature heating magnetic stirrer. Heat and magnetically stir, react at a constant temperature of 90°C for 2 hours to prepare a cellulose solution, at this time the microcrystalline cellulose is completely activated and dissolved in [EMIM][DEP];

[0035] (3) Weigh 1.5g of ionic liquid [EMIM][DEP] and 0.15g of succinic anhydride respectively, successively add to 20ml iodine measuring bottle B, carry out oil bath heating and magnetic stirring in the collector type constant temperature heating magnetic stirrer, React at a constant temperature of 40°C for 0.5h to obtain a succinic anhydride solution;

[0036] (4) Add the above-mentioned cellulose solution and su...

Embodiment 3

[0039] (1) Take an appropriate amount of microcrystalline cellulose in a beaker, and dry at 80°C for 4-6 hours;

[0040] (2) Weigh 2.25g of ionic liquid [EMIM][DEP] and 0.15g of dried microcrystalline cellulose, successively add them to 20ml iodine measuring bottle A, and carry out oil bath in a collector type constant temperature heating magnetic stirrer. Heating and stirring with magnetic force, and reacting at a constant temperature of 90°C for 2 hours to obtain a cellulose solution;

[0041] (3) Weigh 1.5g of ionic liquid [EMIM][DEP] and 0.15g of maleic anhydride, successively add to 20ml iodine measuring bottle B, heat in an oil bath and magnetically stir in a collector type constant temperature heating magnetic stirrer , constant temperature reaction at 40°C for 0.5h to obtain a maleic anhydride solution;

[0042] (4) Add the above-mentioned cellulose solution and maleic anhydride solution to a 20ml iodine flask C successively, heat in an oil bath and magnetically stir ...

technical field

[0001] The invention belongs to the technical field of biochemical industry, and relates to a method for preparing carboxy cellulose by grafting acid anhydride on cellulose material in ionic liquid. Background technique

[0002] Cellulose is the most abundant natural organic matter in the world, accounting for more than 50% of the carbon content in the plant kingdom, and about 1.5×10 can be synthesized through photosynthesis every year 12 t. The base ring of the cellulose macromolecule is a macromolecular polysaccharide composed of D-glucose with β-1,4 glycosidic bonds, which contains a large number of hydroxyl groups and is easy to form intramolecular and intermolecular hydrogen bonds. Due to its dense crystalline structure, cellulose is difficult to be dissolved by conventional solvents and cannot be melt-processed. Therefore, the key to making full use of cellulose is to find a solvent with good solubility for it.

[0003] Succinic anhydride, also known...

Examples

Embodiment 1

[0027] (1) Take an appropriate amount of microcrystalline cellulose in a beaker, and dry at 80°C for 4-6 hours;

[0028] (2) Weigh 2.25g of ionic liquid [EMIM][DEP] and 0.15g of dried microcrystalline cellulose, successively add them to 20ml iodine measuring bottle A, and carry out oil bath in a collector type constant temperature heating magnetic stirrer. Heat and magnetically stir, react at a constant temperature of 90°C for 1.5 hours to prepare a cellulose solution, at this time the microcrystalline cellulose is completely activated and dissolved in [EMIM][DEP];

[0029] (3) Weigh 1.5g of [EMIM][DEP] and 0.15g of succinic anhydride, add them to 20ml iodine bottle B successively, heat in an oil bath and magnetically stir in a collector type constant temperature heating magnetic stirrer, 40°C React at constant temperature for 1 hour to obtain a succinic anhydride solution;

[0030] (4) Add the above-mentioned cellulose solution and succinic anhydride solution successively in...

Embodiment 2

[0033] (1) Take an appropriate amount of microcrystalline cellulose in a beaker, and dry at 80°C for 4-6 hours;

[0034] (2) Weigh 2.25g of ionic liquid [EMIM][DEP] and 0.15g of dried microcrystalline cellulose, successively add them to 20ml iodine measuring bottle A, and carry out oil bath in a collector type constant temperature heating magnetic stirrer. Heat and magnetically stir, react at a constant temperature of 90°C for 2 hours to prepare a cellulose solution, at this time the microcrystalline cellulose is completely activated and dissolved in [EMIM][DEP];

[0035] (3) Weigh 1.5g of ionic liquid [EMIM][DEP] and 0.15g of succinic anhydride respectively, successively add to 20ml iodine measuring bottle B, carry out oil bath heating and magnetic stirring in the collector type constant temperature heating magnetic stirrer, React at a constant temperature of 40°C for 0.5h to obtain a succinic anhydride solution;

[0036] (4) Add the above-mentioned cellulose solution and su...

Embodiment 3

[0039] (1) Take an appropriate amount of microcrystalline cellulose in a beaker, and dry at 80°C for 4-6 hours;

[0040] (2) Weigh 2.25g of ionic liquid [EMIM][DEP] and 0.15g of dried microcrystalline cellulose, successively add them to 20ml iodine measuring bottle A, and carry out oil bath in a collector type constant temperature heating magnetic stirrer. Heating and stirring with magnetic force, and reacting at a constant temperature of 90°C for 2 hours to obtain a cellulose solution;

[0041] (3) Weigh 1.5g of ionic liquid [EMIM][DEP] and 0.15g of maleic anhydride, successively add to 20ml iodine measuring bottle B, heat in an oil bath and magnetically stir in a collector type constant temperature heating magnetic stirrer , constant temperature reaction at 40°C for 0.5h to obtain a maleic anhydride solution;

[0042] (4) Add the above-mentioned cellulose solution and maleic anhydride solution to a 20ml iodine flask C successively, heat in an oil bath and magnetically stir ...

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