A kind of preparation method of surface functionalized cellulose nanospheres

Abstract

The present invention relates to a method for preparing surface-functionalized cellulose nanospheres, which comprises (1) adding cellulosic fibers to the alkali liquor, swelling, filtering the solution, washing the product with water for several times until pH is 7, and drying to constant weight; (2) then adding the above product into mixed acid for fully infiltrating, reacting the above solution under stirring for 2-10 hours at 60-90 DEG C, naturally cooling the reaction products, adding an alkali solution until the pH of the solution is adjusted to 7 to obtain a dispersion liquid of cellulose nanospheres, then centrifuging the dispersion liquid, washing with water for three times, carrying out ultrasonic treatment, and then carrying out freeze drying to constant weight to obtain a cellulose nanospheres. The preparation method has advantages of low raw material cost, simple preparation process and mild preparation conditions; the surfaces of the cellulose nanospheres have functional groups, so that thermal stability and hydrophobicity are improved, self-aggregation is reduced, dispersion is easy, size is small, distribution is narrow, control is easy, specific surface area is large, reactivity is high and etc.

Description

technical field

[0001] The invention belongs to the field of preparation of cellulose nanocrystals, in particular to a preparation method of surface functionalized cellulose nanospheres. Background technique

[0002] Due to the high aspect ratio, excellent mechanical properties, fully degradable and renewable properties of cellulose nanowhiskers or nanocrystals, their use has been proposed as a main component for the development of new inexpensive biomaterials (SturcovaA, DaviesGR, EichhornSJ . Elastic modulus and stress-transfer properties soft unicate cellular whiskers. Biomacromolecules 2005;6:1055-1061.). Cellulose nanocrystals have some additional advantages for biopolymers due to their non-abrasive processability, allowing high filler content and significant cost savings, including their extensive resources, if compared to other inorganic reinforcing fillers Availability, low energy consumption, easy recycling including combustion, high sound attenuation and fairly si...

Examples

Embodiment 1

[0021] Add the microcrystalline cellulose fiber to the calcium hydroxide solution with a concentration of 1mol / L, and swell at room temperature for 4 hours, wherein the mass-volume ratio of the fiber to the lye is 0.02g / mL, filter the above mixed solution, and wash the product several times with water. until PH=7, at 50 o C to dry to constant weight; then the above product is added to the mixed acid solution obtained by mixing hydrochloric acid and formic acid with a concentration of 2mol / L and a ratio of 1:9 to fully infiltrate, wherein the mass volume ratio of fiber to acid solution is 0.008g / mL, put the above solution into the reaction vessel, at 65 o C, reacted for 6 hours under stirring with a tetrafluoroethylene stirring paddle, after the above reaction product was cooled naturally, added 2mol / L ammonia solution, adjusted the pH value of the solution to 7, and obtained a uniformly distributed cellulose nanosphere dispersion, and then After centrifuging and washing the ...

Embodiment 2

[0023] Add the lyocell fibers to a sodium hydroxide solution with a concentration of 2 mol / L, and swell at room temperature for 6 hours, wherein the mass-volume ratio of the fibers to the alkali solution is 0.1 g / mL, filter the above mixed solution, and wash the product with water for several times until the pH = 7 at 75 oC and dried to constant weight; then the above product was added to the mixed acid solution obtained by mixing hydrochloric acid and formic acid with a concentration of 5 mol / L in a ratio of 1:9, and the mass volume ratio of the fiber to the acid solution was 0.016g / mL, put the above solution into the reaction vessel, at 75 o C, reacted for 8 hours under stirring with a tetrafluoroethylene stirring paddle, after the above-mentioned reaction product was naturally cooled, 3mol / L hydrazine hydrate was added, and the pH value of the solution was adjusted to 7 to obtain a uniformly distributed cellulose nanosphere dispersion, and then After centrifuging and wash...

Embodiment 3

[0025] Add the waste cotton fiber to the barium hydroxide solution with a concentration of 1mol / L, and swell for 4 hours at room temperature, wherein the mass-volume ratio of the fiber to the lye is 0.04g / mL, filter the above mixed solution, and wash the product with water for several times until the pH =7 at 65 o C and dried to constant weight; then the above product was added to the mixed acid solution obtained by mixing hydrochloric acid and acetic acid with a concentration of 7mol / L and a ratio of 1:9 to fully infiltrate, wherein the mass volume ratio of fiber to acid solution was 0.012g / mL, put the above solution into the reaction vessel, at 70 o C, reacted for 7 hours under stirring with a tetrafluoroethylene stirring paddle, after the above reaction product was naturally cooled, add 1mol / L sodium hydroxide solution, adjust the pH value of the solution to 7, and obtain a uniformly distributed cellulose nanosphere dispersion , and then the dispersion liquid was centrifu...

technical field

[0001] The invention belongs to the field of preparation of cellulose nanocrystals, in particular to a preparation method of surface functionalized cellulose nanospheres. Background technique

[0002] Due to the high aspect ratio, excellent mechanical properties, fully degradable and renewable properties of cellulose nanowhiskers or nanocrystals, their use has been proposed as a main component for the development of new inexpensive biomaterials (SturcovaA, DaviesGR, EichhornSJ . Elastic modulus and stress-transfer properties soft unicate cellular whiskers. Biomacromolecules 2005;6:1055-1061.). Cellulose nanocrystals have some additional advantages for biopolymers due to their non-abrasive processability, allowing high filler content and significant cost savings, including their extensive resources, if compared to other inorganic reinforcing fillers Availability, low energy consumption, easy recycling including combustion, high sound attenuation and fairly si...

Examples

Embodiment 1

[0021] Add the microcrystalline cellulose fiber to the calcium hydroxide solution with a concentration of 1mol / L, and swell at room temperature for 4 hours, wherein the mass-volume ratio of the fiber to the lye is 0.02g / mL, filter the above mixed solution, and wash the product several times with water. until PH=7, at 50 o C to dry to constant weight; then the above product is added to the mixed acid solution obtained by mixing hydrochloric acid and formic acid with a concentration of 2mol / L and a ratio of 1:9 to fully infiltrate, wherein the mass volume ratio of fiber to acid solution is 0.008g / mL, put the above solution into the reaction vessel, at 65 o C, reacted for 6 hours under stirring with a tetrafluoroethylene stirring paddle, after the above reaction product was cooled naturally, added 2mol / L ammonia solution, adjusted the pH value of the solution to 7, and obtained a uniformly distributed cellulose nanosphere dispersion, and then After centrifuging and washing the ...

Embodiment 2

[0023] Add the lyocell fibers to a sodium hydroxide solution with a concentration of 2 mol / L, and swell at room temperature for 6 hours, wherein the mass-volume ratio of the fibers to the alkali solution is 0.1 g / mL, filter the above mixed solution, and wash the product with water for several times until the pH = 7 at 75 oC and dried to constant weight; then the above product was added to the mixed acid solution obtained by mixing hydrochloric acid and formic acid with a concentration of 5 mol / L in a ratio of 1:9, and the mass volume ratio of the fiber to the acid solution was 0.016g / mL, put the above solution into the reaction vessel, at 75 o C, reacted for 8 hours under stirring with a tetrafluoroethylene stirring paddle, after the above-mentioned reaction product was naturally cooled, 3mol / L hydrazine hydrate was added, and the pH value of the solution was adjusted to 7 to obtain a uniformly distributed cellulose nanosphere dispersion, and then After centrifuging and wash...

Embodiment 3

[0025] Add the waste cotton fiber to the barium hydroxide solution with a concentration of 1mol / L, and swell for 4 hours at room temperature, wherein the mass-volume ratio of the fiber to the lye is 0.04g / mL, filter the above mixed solution, and wash the product with water for several times until the pH =7 at 65 o C and dried to constant weight; then the above product was added to the mixed acid solution obtained by mixing hydrochloric acid and acetic acid with a concentration of 7mol / L and a ratio of 1:9 to fully infiltrate, wherein the mass volume ratio of fiber to acid solution was 0.012g / mL, put the above solution into the reaction vessel, at 70 o C, reacted for 7 hours under stirring with a tetrafluoroethylene stirring paddle, after the above reaction product was naturally cooled, add 1mol / L sodium hydroxide solution, adjust the pH value of the solution to 7, and obtain a uniformly distributed cellulose nanosphere dispersion , and then the dispersion liquid was centrifu...

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