CN104264257A - Method for preparing cellulose fibers by taking reed as raw material - Google Patents

Abstract

The invention discloses a method for preparing cellulose fibers by taking reed as a raw material. According to the method, the cellulose fibers are prepared by taking low-cost herb reed as the raw material and adopting an NMMO (N-methylmorpholine-N-oxide) process. The method comprises the following steps: crushing dry reed raw material into particles, and stewing the particles by using a mixed liquid of sodium hydroxide and sodium sulfide to obtain sulfate reed pulp, cleaning the sulfate reed pulp in flowing water, and dewatering; performing impregnating-pressing-flowing water washing twice alternately by using a sodium carbonate solution and dilute sulfuric acid sol to obtain reed cellulose; adding the reed cellulose into an NMMO solution for dissolving to obtain reed spinning dope; and performing spinning, solidifying, water washing, plasticizing and drying on the reed spinning dope through a dry-wet spinning machine to obtain the reed cellulose fibers. The method has the advantages that the cellulose fibers are prepared by taking low-cost herb reed as the raw material and adopting the NMMO process, so that the preparation method is low in preparation cost, non-toxic, harmless, environmentally friendly, remarkable in economic benefits, and favorable for industrialized production.

Description

A kind of method that takes reed as raw material to prepare cellulose fiber

technical field

The invention relates to a method for preparing cellulose fibers, in particular to a method for preparing cellulose fibers using reeds as raw materials.

Background technique

my country is not a country with large forests. To produce this high-grade fiber with wood pulp will consume a large amount of forest resources, and the cost is too high, which is not suitable for my country's national conditions. Herbaceous plant fiber resources are sustainable and environmentally friendly, and can participate in the ecological cycle of nature.

Our country is very rich in herbaceous plant cellulose resources, especially the output of reed is very huge. Under natural conditions, the fresh grass yield is 3.9-13.9 tons/ha, and it can be harvested 2-3 times a year. Phragmites reed is a tall grass with wide adaptability, strong stress resistance and high biomass, and most of it is used as grazing land at present. The aboveground part of the reed is tall and has strong regenerative power. The measurement shows that the cellulose content in the reed is close to that in the rice straw. If the advantages of high fiber content in reed can be fully utilized, it will be of great economic and social significance to use its high-quality fiber to prepare cellulose fiber. In recent years, the development of cellulose fiber has greatly promoted the development of the national economy.

Cellulose is difficult to dissolve directly in conventional solvents due to the strong hydrogen bond. The traditional viscose method and cuproammonia method not only have lengthy process routes, complex production processes, consume a lot of raw materials and energy, but also cause serious environmental pollution. The emergence of nitrogen methyl morpholine oxide (NMMO) technology can solve these problems well, and the mechanical properties of the product are obviously better than traditional methods. We choose the NMMO process, which is non-toxic and harmless and 99.5-99.7% recyclable, which belongs to the green cycle, environmental protection and low-carbon economy.

Contents of the invention

The object of the present invention is to address the above existing problems, and to provide a method for preparing cellulose fibers through a non-toxic, harmless and environmentally friendly NMMO process using cheap herbaceous reeds as raw materials.

Technical scheme of the present invention:

A method for preparing cellulose fiber with reed as raw material, comprising the following steps:

1) Crush the dried reeds into particles with a diameter of 0.5-1.5 cm, and soak the granular reeds in a mixture of sodium hydroxide and sodium sulfide with a concentration of 13-19 wt% for 4-6 hours, with a liquor ratio of 1 :6-10, the mass ratio of sodium hydroxide and sodium sulfide in the mixed solution of sodium hydroxide and sodium sulfide is 3:1, cook at 120-160 ℃ for 2-3 hours, after cooling to room temperature, the The solid sulfate reed cellulose is taken out, extruded and dehydrated, washed with running water until the pH value is 7-8, and then stirred and extruded with dilute sulfuric acid with a concentration of 0.1 mol/L and an aqueous solution of sodium carbonate with a concentration of 10.6 g/L Dehydrated twice to obtain a dehydrated sample;

2) Add the dehydrated sample obtained in step 1) to the NMMO solution with a concentration of 60wt%, and add 0.05-1wt% antioxidant at the same time, soak and stir for 1-3 hours, heat to 90-105°C, and pump intermittently at the same time Vacuum to -0.1Mpa to remove water until the water content is 8-13wt%. The intermittent method is to stop vacuuming for half an hour and continue vacuuming for 3-5 minutes until the cellulose is completely dissolved to obtain transparent amber reed cellulose and the spinning stock solution of NMMO, and obtain the spinning stock solution of NMMO after separation;

3) The reed cellulose NMMO spinning stock solution obtained in step 2) was directly injected into the static kettle of the dry-wet spinning machine, and kept at 95°C for 4 hours under the condition of vacuum degree of -0.1MPa, and passed through the twin-screw - After metering the spinneret assembly, solidify in a water bath containing 15-25wt% NMMO to obtain the as-spun reed cellulose fiber;

4) Rinse the reed cellulose fiber primary silk obtained in step 3) with water, and then place it at 40-45°C in an aqueous solution of 10-15% glycerol by volume and plasticize it for 55-60 minutes. 1:18-20, dehydrated and sun-dried to obtain white cellulose fiber products.

The antioxidant is one of butylated hydroxyanisole, dibutyl hydroxytoluene, propyl gallate and tert-butyl hydroquinone, or a mixture of two or more in any proportion.

The invention has the advantages that: the preparation method uses cheap herb reed as raw material, adopts NMMO technology to prepare cellulose fiber, has low preparation cost, is non-toxic, harmless and environmentally friendly, has remarkable economic benefits, and is beneficial to industrialized production.

Detailed ways

The technical scheme of the present invention will be further described below in conjunction with specific examples:

Example 1:

A method for preparing cellulose fiber with reed as raw material, comprising the following steps:

1) Crush the dried reeds into particles with a diameter of 0.5-1.5 cm, and soak the granular reeds in a mixture of sodium hydroxide and sodium sulfide with a concentration of 13wt% for 6 hours, the bath ratio is 1:6, hydrogen The mass ratio of sodium hydroxide to sodium sulfide in the mixture of sodium oxide and sodium sulfide is 3:1, cook at 120°C for 2 hours, and after cooling to room temperature, remove the solid sulfate reed cellulose in the solution, Squeeze and dehydrate, wash with running water until the pH value is 8, and then use dilute sulfuric acid with a concentration of 0.1 mol/L and an aqueous solution of sodium carbonate with a concentration of 10.6 g/L to stir and squeeze and dehydrate twice to obtain a dehydrated sample;

2) Add 15 g of the dehydrated sample obtained in step 1) to 200 mL of NMMO solution with a concentration of 60 wt%, and add 0.015 g of propyl gallate at the same time, soak and stir for 2.5 hours, heat to 90°C, and intermittently vacuum to -0.1Mpa to remove water until the water content is 13wt%. The intermittent method is to stop vacuuming for half an hour and continue vacuuming for 5 minutes until the cellulose is completely dissolved to obtain a transparent amber spinning stock solution of reed cellulose and NMMO. , after separation, the spinning dope of NMMO is obtained;

3) The reed cellulose NMMO spinning stock solution obtained in step 2) is directly injected into the static kettle of the dry-wet spinning machine, and kept at 95°C for 4 hours under the condition of vacuum degree of -0.1MPa, and then passed through the twin-screw- After metering this-spinner assembly, solidify in a water bath containing 15wt% NMMO to obtain the as-spun reed cellulose fiber;

4) Rinse the reed cellulose fiber primary silk obtained in step 3) with water, and then place it in 10% glycerin aqueous solution by volume at 40°C for 55 minutes, and dehydrate and dry it for 55 minutes. Drying yields a cellulosic fiber product.

Example 2:

A method for preparing cellulose fiber with reed as raw material, comprising the following steps:

1) Crush the dried reeds into particles with a diameter of 0.5-1.5cm, add the granular reeds to a mixture of sodium hydroxide and sodium sulfide with a concentration of 19wt%, soak for 4 hours, the bath ratio is 1:8, hydrogen The mass ratio of sodium hydroxide to sodium sulfide in the mixture of sodium oxide and sodium sulfide is 3:1, cook at 160°C for 2 hours, cool to room temperature, and remove the solid sulfate reed cellulose in the solution. Squeeze and dehydrate, wash with running water until the pH value is 8, and then use dilute sulfuric acid with a concentration of 0.1 mol/L and an aqueous solution of sodium carbonate with a concentration of 10.6 g/L to stir and squeeze and dehydrate twice to obtain a dehydrated sample;

2) Add 13 g of the dehydrated sample obtained in step 1) to 200 mL of NMMO solution with a concentration of 60 wt%, and add 0.015 g of butylhydroxyanisole at the same time, soak and stir for 2.5 hours, heat to 100 ° C, and vacuumize intermittently at the same time To -0.1Mpa to remove water by evaporation until the water content is 13wt%. The intermittent method is to stop vacuuming for half an hour and then continue vacuuming for 3 minutes until the cellulose is completely dissolved to obtain transparent amber reed cellulose and NMMO. Silk stock solution, the spinning stock solution of NMMO is obtained after separation;

3) The reed cellulose NMMO spinning stock solution obtained in step 2) is directly injected into the static kettle of the dry-wet spinning machine, and kept at 95°C for 4 hours under the condition of vacuum degree of -0.1MPa, and then passed through the twin-screw- After metering this-spinning assembly, the water bath containing 15wt% NMMO coagulates to obtain the reed cellulose fiber as-spun silk;

4) Rinse the reed cellulose fiber primary silk obtained in step 3) with water, and then place it in 15% glycerol aqueous solution at 40°C for 60 minutes to plasticize, bath ratio 1:20, dehydrate and dry Drying yields a cellulosic fiber product.

the

Example 3:

A method for preparing cellulose fiber with reed as raw material, comprising the following steps:

1) Crush the dried reeds into particles with a diameter of 0.5-1.5 cm, and soak the granular reeds in a mixture of sodium hydroxide and sodium sulfide with a concentration of 15wt% for 6 hours, the bath ratio is 1:8, hydrogen The mass ratio of sodium hydroxide to sodium sulfide in the mixture of sodium oxide and sodium sulfide is 3:1, cook at 160°C for 2 hours, cool to room temperature, and remove the solid sulfate reed cellulose in the solution. Squeeze and dehydrate, wash with running water until the pH value is 8, and then use dilute sulfuric acid with a concentration of 0.1 mol/L and an aqueous solution of sodium carbonate with a concentration of 9 g/L to stir and squeeze for dehydration twice to obtain a dehydrated sample;

2) Add 12 g of the dehydrated sample obtained in step 1) to 200 mL of NMMO solution with a concentration of 60 wt%, and add 0.015 g of dibutyl hydroxytoluene at the same time, soak and stir for 3 hours, heat to 90°C, and vacuumize intermittently at the same time To -0.1Mpa to remove water by evaporation until the water content is 13wt%. The intermittent method is to stop vacuuming for half an hour and then continue vacuuming for 3 minutes until the cellulose is completely dissolved to obtain transparent amber reed cellulose and NMMO. Silk stock solution, the spinning stock solution of NMMO is obtained after separation;

3) The reed cellulose NMMO spinning stock solution obtained in step 2) is directly injected into the static kettle of the dry-wet spinning machine, and kept at 95°C for 4 hours under the condition of vacuum degree of -0.1MPa, and then passed through the twin-screw- After metering this-spinning assembly, the water bath containing 15wt% NMMO coagulates to obtain the reed cellulose fiber as-spun silk;

4) Rinse the reed cellulose fiber primary silk obtained in step 3) with water, and then place it in 10% glycerin aqueous solution by volume at 45°C for 55 minutes, and dehydrate and dry it for 55 minutes. Drying yields a white cellulose fibrous product.

Claims (2)

1. be the method that cellulose fibre prepared by raw material with reed, it is characterized in that comprising the following steps:

1) dry reed powder is broken into the particle that diameter is 0.5-1.5cm, granular reed being joined concentration is soak 4-6 hour in the NaOH of 13-19wt% and the mixed liquor of vulcanized sodium, bath raio is 1:6-10, in the mixed liquor of NaOH and vulcanized sodium, the mass ratio of NaOH and vulcanized sodium is 3:1, boiling 2-3 hour at 120-160 DEG C, after being cooled to room temperature, solids sulfate reed fiber element in solution is pulled out, extrusion dehydration, water displacement wash to pH value is 7-8, extrusion dehydration is stirred respectively twice again with the aqueous sodium carbonate of concentration to be the dilute sulfuric acid of 0.1 mol/L and concentration be 10.6 g/L, obtain dehydrated sample,

2) dehydrated sample that step 1) obtains being joined concentration is in the NMMO solution of 60wt%, add the antioxidant of 0.05-1wt% simultaneously, to soak and after stirring 1-3 hour, be heated to 90-105 DEG C, interval is evacuated to-0.1Mpa to dewater to moisture as 8-13wt% simultaneously, discontinuous method is after often stopping vacuumizing half an hour, vacuumize 3-5 minute continuously, until cellulose dissolves completely, obtain the reed fiber element of clear amber in color and the spinning solution of NMMO, after separation, obtain the spinning solution of NMMO;

3) by step 2) in the reed fiber element NMMO spinning solution that obtains, be directly injected in the static still of dry wet spinning machine, under vacuum is-0.1MPa condition, 95 DEG C are incubated 4 hours, after twin-screw-metering basis-spinning pack, solidify through the water-bath containing 15-25wt% NMMO again, obtain reed fiber cellulose fiber spun filament;

4) reed fiber cellulose fiber spun filament step 3) obtained, NMMO is rinsed with water, it being placed at 40-45 DEG C volumn concentration is 10-15% glycerine water solution plasticizing 55-60 minute, bath raio 1:18-20 again, and dehydration is dried and obtained white fiber cellulose fiber product.

2. be the method that cellulose fibre prepared by raw material with reed according to claim 1, it is characterized in that: described antioxidant is the mixture of one or more arbitrary proportions in butylated hydroxy anisole, dibutyl hydroxy toluene, n-propyl gallate and ditert-butylhydro quinone etc.