CN108048954A - A kind of method that carrageenin fibre is directly prepared by red algae extracting solution - Google Patents

Abstract

The invention discloses a kind of methods that carrageenin fibre is directly prepared by red algae extracting solution, comprise the following steps：（1）After fresh red algae is removed impurity, washing is clean, be cut into small pieces or by dry seaweed deionized water impregnate 24 it is small when more than；（2）Taking treated, red algae adds in 5 10wt%NaOH solution of 10 20 times of frond quality, heating temperature to 50 80 DEG C of 0.5 2h of processing；（3）Red algae after oxygenation pretreatment is taken out to the water of 25 times of addition, 85 100 DEG C of 1 4h of heating extraction, extract adds in NaOH while hot makes its concentration reach 5 15wt%；（4）Said extracted object is filtered, obtains extracting solution；（5）Extracting solution is poured into spinning kettle, into spinning head after deaeration, using 2 15% coagulating bath, wet spinning prepares carrageenin fibre；（6）As-spun fibre drawn, washing, then with 95% ethanol dehydration, finally dry.The method of the present invention has the advantages of simple for process, energy-saving, reduces production procedure, realizes the production technology of a line of the carrageenin fibre from seaweed raw material to carrageenin fibre.

Description

A method for directly preparing carrageenan fiber from red algae extract

technical field

The invention relates to a method for preparing carrageenan fiber, in particular to a method for directly preparing carrageenan fiber from red algae extract.

Background technique

Carrageenan is a natural linear sulfated polysaccharide extracted from red algae. Carrageenan solution is in a gel state that cannot flow at room temperature. Therefore, traditionally, carrageenan is mainly used as a stabilizer, thickener and gelling agent. And other forms are widely used in food, cosmetics and medicine and other fields.

In recent years, with the rapid rise of seaweed fiber, the linear molecule of carrageenan, which is similar in structure to sodium alginate, has also been excavated for its characteristics and application in fiber formation. However, due to the gel structure characteristics of the carrageenan solution, it needs to be transformed into a flowing solution state before solution spinning can be carried out. Xia Yanzhi et al. (CN 102304772 A) used alkaline solution as a solvent to dissolve carrageenan at room temperature and spin it at room temperature. The obtained carrageenan fiber had bright color, uniform fineness and high strength, which opened up a simple and feasible way for the industrial production of carrageenan the way.

However, the current preparation method of carrageenan fiber is still to use hot water to extract carrageenan powder (that is, seaweed is removed from impurities, hot water is extracted, filtered, and dried to obtain carrageenan powder), and then the carrageenan powder is dissolved by wet method. Spinning (that is, dissolving carrageenan powder in hot water or alkali to make a carrageenan solution, and then passing through a coagulation bath to form carrageenan fibers) to prepare fibers. This is because the extract obtained by extracting carrageenan under normal conditions is in a gel state at room temperature and cannot be wet-spun, so it is necessary to freeze-dry the carrageenan gel into a powder, and then recycle the carrageenan powder during the spinning process. dissolve into solution. This process requires precipitation, drying, and re-dissolution. The process is complex and consumes too much water, ethanol, and energy.

Contents of the invention

For the problems referred to above, the purpose of this invention is to provide a kind of method that directly prepares carrageenan fiber by extracting solution of red algae, directly convert extracting solution into spinning solution without powder state in the process of preparing carrageenan fiber, will shorten greatly Process flow, reducing water and energy consumption, can realize the integrated process from seaweed to carrageenan spinning solution to carrageenan fiber under low energy and water consumption conditions, and realize the seaweed fiber industry to be more environment-friendly and resource-saving Transformation, thereby further reducing product prices and enhancing the product competitiveness of seaweed fiber.

The method of the present invention is that the extract obtained in the carrageenan extraction process, by adding NaOH, destroys the gel structure of the carrageenan solution at room temperature, so it can be dried into a powder state without precipitation, and the extract can be directly It is converted into a spinning solution to ensure that the carrageenan solution is in a fluid state at room temperature, thereby greatly shortening the preparation process.

The specific technical scheme of the present invention includes: seaweed cleaning, alkali pretreatment, extraction, filtration, wet spinning, fiber drying and other steps:

(1) Cleaning: After removing impurities from fresh red algae, wash them with water, cut them into small pieces or soak the dried seaweed in deionized water for more than 24 hours;

(2) Alkali pretreatment: take the treated red algae and add 5-10wt% NaOH solution which is 10-20 times the weight of the algal body, and heat the temperature to 50-80°C for 0.5-2h;

(3) Extraction: take out the red algae after alkali pretreatment and add 2-5 times of water, heat and extract at 85-100°C for 1-4h, add NaOH to the extract while it is hot to make the concentration reach 5-15wt%;

(4) Filtration: filter the above extract to obtain the extract;

(5) Wet spinning: Pour the extract into the spinning kettle, enter the spinneret after defoaming, and then go through a 2-15% coagulation bath to prepare carrageenan fibers by wet spinning;

(6) Fiber drying: The primary fiber is stretched, washed with water, dehydrated with 95% ethanol, and finally dried.

The red algae is the red algae of the genus Carrageenan, including carrageenan, sauerkraut or Eucheuma etc.

In the step (3), the alkali-pretreated red algae can also be directly added to 2-5 times of 5-15wt% NaOH solution, and extracted by heating at 85-100° C. for 1-4 hours.

The filtering in the step (4) is filtering with 200 mesh gauze.

A stretching bath stage is also included after the coagulation bath in the step (5).

The coagulation bath and stretching bath are solutions containing monovalent K ⁺ or divalent Ba ²⁺ , Cu ²⁺ , Zn ²⁺ , Ni ²⁺ , Ca ²⁺ metal ions.

The method of the present invention may also include a step of fiber crosslinking: changing the stretching bath of wet spinning into ethanol, and adding a crosslinking agent therein, to prepare crosslinked carrageenan fibers.

The crosslinking agent is epichlorohydrin or aldehyde, dialdehyde, acid anhydride.

Compared with the present preparation carrageenan fiber technology, the present invention has the following advantages:

The present invention uses red algae extract to directly prepare carrageenan fiber, greatly shortens the process flow, reduces water and energy consumption, and realizes the integration of seaweed, carrageenan spinning solution and carrageenan fiber under low energy and water consumption conditions The process has realized the transformation of the seaweed fiber industry to a more environment-friendly and resource-saving type, thereby further reducing product prices and improving the product competitiveness of seaweed fiber. In the spinning process, by adding a cross-linking agent to the stretching bath, the strength of the fiber can be improved in the form of online cross-linking without increasing the operation steps.

The method of the invention has the advantages of simple process, energy saving and consumption reduction, reduces the production process, and realizes the one-line production process of the carrageenan fiber from the seaweed raw material to the carrageenan fiber.

Description of drawings

Figure 1 is a process roadmap for preparing carrageenan fibers by traditional methods.

Fig. 2 is a process roadmap for preparing carrageenan fibers by the method of the present invention.

Detailed ways

The present invention is described in detail below through specific examples, but the present invention is not limited only to the following examples. All technical solutions and their improvements that do not deviate from the spirit and scope of the invention shall be covered by the claims of the present invention.

Example 1:

Take 100g of cleaned fresh carrageenan, cut it into small pieces of about 1cm, add 1000ml of 6% NaOH solution, heat in a water bath and adjust the temperature to 70°C for 1h pretreatment. Take out the pretreated red algae, then add 200ml of 8% NaOH solution, heat in a water bath at 95°C for 2 hours, and filter the extracted solution containing impurities with two layers of 200-mesh gauze to obtain the extracted solution. Pour the extract into the spinning kettle, enter the spinneret after defoaming, and use 15% BaCl ₂ solution as a coagulation bath to prepare carrageenan fibers by wet spinning. The as-spun fibers are stretched and washed with 95% Ethanol dehydration, and finally the carrageenan fiber was dried in a ventilated place.

Example 2:

Take 70g of cleaned fresh sand vegetables, cut them into pieces, add 1000ml of 6% NaOH solution, heat in a water bath and adjust the temperature to 60°C for 2h pretreatment. Add 210ml of 10% NaOH to the pretreated red algae, heat and extract in a water bath at 90°C for 2.5h, and filter with two layers of 200-mesh gauze to obtain the extract. Pour the extract into the spinning kettle, enter the spinneret after defoaming, use 7% KCl solution as the coagulation bath, and 7% _CaCl solution as the stretching bath, and prepare carrageenan fibers by wet spinning. Stretch, wash, and dehydrate with 95% ethanol, and finally dry the carrageenan fiber in a ventilated place.

Example 3:

Take 8.5g cleaned dry Eucheuma, cut into pieces, soak in 1000ml of deionized water for 24 hours, take it out and add 1000ml of 10% NaOH solution, heat in a water bath and adjust the temperature to 80°C for 0.5h, wash with water, add 300ml of deionized water , heating and extracting in a water bath at 85°C for 3 hours, adding 2.4g NaOH to the extract while it was hot, stirring evenly, filtering the extract containing impurities with two layers of 200-mesh gauze to obtain the extract. Pour the extract into the spinning kettle, enter the spinneret after defoaming, use 10% CuCl ₂ solution as a coagulation bath, and prepare carrageenan fibers by wet spinning. Ethanol dehydration, and finally the carrageenan fiber was dried in a ventilated place.

Example 4:

Take 100g of cleaned fresh Eucheuma, cut it into pieces, add 1000ml of 8% NaOH solution, heat in a water bath and adjust the temperature to 60°C for pretreatment for 1 hour, wash with water, add 400ml of deionized water, heat and extract in a water bath at 90°C for 3 hours, and extract Add 3.2g NaOH while it is hot, stir evenly, filter the extract containing impurities with two layers of 200-mesh gauze to obtain the extract. Pour the extract into the spinning kettle, and enter the spinneret after defoaming, use 5% BaCl ₂ solution as the coagulation bath, and the stretching bath is epichlorohydrin and ethanol (1:20, V/V), wet method The carrageenan fiber is prepared by spinning, the primary fiber is stretched, washed with water, dehydrated with 95% ethanol, and finally the carrageenan fiber is dried in a ventilated place.

Comparative example 1:

Get ι-carrageenan powder 21g, add 300ml 8% NaOH and be mixed with 7% carrageenan solution, pour the carrageenan solution into the spinning kettle, enter the spinneret after defoaming, use 10% BaCl _solution as coagulation bath , to prepare carrageenan fibers by wet spinning. The primary fibers are stretched, washed with water, dehydrated with 95% ethanol, and finally the carrageenan fibers are dried in a ventilated place.

Carrageenan fibers obtained in Examples 1, 2, 3, 4 and Comparative Example 1 were tested for mechanical properties, and the results are shown in Table 1.

Table 1 Dry tensile strength of carrageenan fibers prepared by wet spinning

fiber sample Strength (cN/dtex) Example 1 1.65 Example 2 1.58 Example 3 1.61 Example 4 1.76 Comparative example 1 1.63

It can be seen from Table 1 that the strength of the carrageenan fiber spun directly from the spinning solution is not much different from that of the carrageenan fiber prepared by the traditional method, and the strength of the carrageenan fiber can be improved after crosslinking.

Claims (8)

1. A kind of 1. method that carrageenin fibre is directly prepared by red algae extracting solution, it is characterised in that comprise the following steps：

   （1）Cleaning：After fresh red algae is removed impurity, washing is clean, is cut into small pieces or impregnates dry seaweed with deionized water 24 it is small when more than；

   （2）Oxygenation pretreatment：Taking treated, red algae adds in the 5-10wt% NaOH solutions of 10-20 times of frond quality, heating temperature To 50-80 DEG C of processing 0.5-2h；

   （3）Extraction：Red algae after oxygenation pretreatment is taken out to the water of 2-5 times of addition, 85-100 DEG C of heating extraction 1-4h, extract is taken advantage of Heat, which adds in NaOH, makes its concentration reach 5-15wt%；

   （4）Filtering：Said extracted object is filtered, obtains extracting solution；

   （5）Wet spinning：Extracting solution is poured into spinning kettle, into spinning head after deaeration, using the coagulating bath of 2-15%, wet method Spinning prepares carrageenin fibre；

   （6）Fiber drying：As-spun fibre drawn, washing, then with 95% ethanol dehydration, finally dry.
2. 2. the method as described in claim 1, it is characterised in that the red algae is carragheen category red algae, including pelvetia silquosa, husky dish Or Eucheuma.
3. 3. the method as described in claim 1, it is characterised in that the step（3）The middle red algae by after oxygenation pretreatment is directly added into The NaOH solution of 2-5 times of 5-15wt%, 85-100 DEG C of heating extraction 1-4h.
4. 4. the method as described in claim 1, it is characterised in that the step（4）In be filtered into using 200 mesh filtered through gauze.
5. 5. the method as described in claim 1, it is characterised in that the step（5）Stretch bath rank is further included after middle coagulating bath Section.
6. 6. the method as described in claim 1 or 5, it is characterised in that the coagulating bath and stretch bath is contain monovalence K⁺Or divalent Ba²⁺、Cu²⁺、Zn²⁺、Ni²⁺、Ca²⁺The solution of metal ion.
7. 7. the method as described in claim 1, it is characterised in that the step of further including fiber crosslinking：By the stretch bath of wet spinning It changes ethyl alcohol into, and adds in crosslinking agent wherein, crosslinking carrageenin fibre is made.
8. 8. the method for claim 7, it is characterised in that the crosslinking agent is epoxychloropropane or aldehyde, dialdehyde, acid anhydrides.