CN101538371B - Preparation method of high-strength degradable polysaccharide blend film - Google Patents

Abstract

The invention discloses a preparation method of a high-strength degradable polysaccharide blend film. Chitosan, β-cyclodextrin and sodium benzoate are used as main film-forming substances. The specific preparation method includes: film liquid preparation, decompression Degassing, film making, freeze drying, heat drying, drying, softening, finished product packaging. Compared with the prior art, the present invention has the advantages of simple process and cheap and easy-to-obtain raw materials. There are only three components of the membrane, which greatly improves the compatibility of the components of the membrane, improves its mechanical properties, and reduces the mechanical properties of the membrane. The production cost; and micropores are formed by the freeze-drying method, which improves the air permeability of the film and also improves the fresh-keeping ability of the film.

Description

The preparation method of high-strength degradable polysaccharide blend film

Technical field

The present invention relates to a kind of film, specifically, is the preparation method of the composite membrane of a kind of chitin and beta-cyclodextrin.

Background technology

Gel-film generally is to be covered in the thin layer that material surface constitutes by forms such as parcel, dipping, coating, sprinklings.Gel-film can be divided into: solid film, mobile film etc.Wherein solid film can be divided into the fully bio-degradable film again, medical film and coating.Mobile film can be divided into food preservative, chemical fertilizer, pesticide slow-releasing agent and makeup again.

" daily chemical industry " 2000 the 1st phases have been delivered people's such as Zhang Donghua article " the composite product film forming research of natural polymer Rhizoma amorphophalli glucomannan ", Rhizoma amorphophalli glucomannan and modification thereof or composite product (carrageenin, carrageenin and xanthan gum, xanthan gum) membrane formation mechanism are inquired into, and the performance of film analyzed and researched, film-forming method has been proposed.Concrete operations are as follows: water-bath after 0.5g Rhizoma amorphophalli glucomannan and 5g carrageenin and the abundant swelling of 3g xanthan gum adding 500ml distilled water is boiled, be cooled to 50～60 ℃ then, pick a small amount of glue with glass stick, evenly spread upon on the sheet glass, get product after the film forming.

" Food science " 2000 the 21st the 2nd phases of volume have been delivered Li Bo's article " investigation of materials of Rhizoma amorphophalli glucomannan edible film ", introduced a kind of blend film, i.e. the preparation method of Rhizoma amorphophalli glucomannan and natural polysaccharide-xanthan gum blend: (1) konjaku powder purifying: konjaku powder → 50% washing with alcohol → 95% ethanol dehydration → 70 ℃ oven drying gets pure powder; (2) blend film preparation: 1. 0.9g xanthan gum → add 100ml water in 2 hours → colloidal sol of 45 ℃ of swellings filter → colloidal sol; 2. 0.9g konjaku powder → add 100ml water in 50 ℃ of swellings 1 hour → colloidal sol; 3. above-mentioned two kinds of colloidal sols are mixed with certain proportion, under 55 ℃, stir → film on sheet glass → 80 ℃ of oven drying film forming.And the structure of film analyzed.

Above-mentioned several film does not have germ resistance, and its physical strength is relatively poor, water resisting property a little less than, and exist degradation problem under the film strength.In order to address this problem, " membrane science and technology " 2007 the 27th the 6th phases of volume have delivered and have been permitted elegant genuine article " development of Rhizoma amorphophalli glucomannan antimicrobial compound film and application thereof ", introduced a kind of blend film, that is: with the Rhizoma amorphophalli glucomannan matrix, the film-forming method that adds softening agent, lipid, emulsifying agent, antiseptic-germicide and biostats blend: the preparation of (1) Rhizoma amorphophalli glucomannan water-sol: take by weighing a certain amount of KGM, add 500mL distilled water, 45 ℃ of following swelling 0.5h obtain konjac sol.(2) preparation of the chitosan water-sol: take by weighing certain amount of chitosan, add the acetic acid solution of 500mL2%, with 45 ℃ of heating in water bath 0.5h, make it to dissolve fully, solution filters with 100 order nylon and obtains chitosan aqueous solution.(3) preparation of Rhizoma amorphophalli glucomannan-chitosan composite antibiotic film: two kinds of top colloidal sols are mixed by a certain percentage, and add an amount of softening agent, waterproofing agent and antiseptic-germicide, even 45 ℃ of stirred in water bath, cooling, leave standstill 24h, evenly coat natural casting film-forming on the slick sheet glass then, dry at a certain temperature, take off film.And the performance and the structure of film observed and measure.This film also adds except that 2 kinds of main components: softening agent, lipid, emulsifying agent, antiseptic-germicide and biological inhibition the, totally 7 kinds of compositions; The composition of film is many, causes group partition inter-capacitive poor; Consistency is poor, causes physical strength not high; Composition has too much also caused the cost of system film to improve simultaneously.

Chinese patent CN1781978 discloses a kind of " preparation method of edible water resistant, high temperature resistant composite gel antibiotic film ", promptly with the preparation method of chitosan and konjac glucomanna esterification modified product, cycloheptaamylose, xanthan gum and carrageenin blend, its concrete preparation method comprises: the preparation of film liquid, heating, the centrifugal degassing, a kind of rhyme scheme in Chinese operas serving as the prelude to a complete score for voices system film, oven dry, sam ease back, take off film, finished product packing.Because there is the not high and high problem of cost of manufacture of physical strength equally in nearly 8 kinds of the components of this film.

Summary of the invention

Technical problem to be solved by this invention is to provide the preparation method of the high-strength degradable polysaccharide blend film that a kind of component is few, cost is low, the film physical strength height that is obtained by this preparation method.

In order to address the above problem, technical scheme of the present invention is: a kind of preparation method of high-strength degradable polysaccharide blend film, carry out as follows: chitosan is dissolved in to be configured to massfraction in the acetic acid solution of pH3～4 be 2～3% solution, add the aqueous solution that contains massfraction 2.5～5% cycloheptaamyloses and massfraction 0.018～0.035% Sodium Benzoate again, in Ultrasonic Cleaners, mix blended liquid, the mass ratio of chitosan, beta-cyclodextrin and Sodium Benzoate is 225～450: 75～250 in the blended liquid: 1; With blended liquid vacuum deaerator 30～40 minutes, the blended liquid with deaeration injected the film that Die and mould plate is made thickness 0.05～1.0mm again, lyophilize 60～90 minutes in freeze drying box earlier, dry 10～25min in 60～90 ℃ of loft drier again; After treating the film drying, be transferred in the basic solution of pH 9～10 and soaked 2～3 minutes, shift out, the pH value that is washed till washing water with distilled water is 7.0～7.5, seasoning or be placed in 40～50 ℃ of loft drier is dried, and the film with oven dry takes out again, in the environment of relative humidity 〉=80%, placed 30～60 minutes, and cut apart packing at last.

As the preferred embodiment of technique scheme, the condition of chitosan, beta-cyclodextrin and Sodium Benzoate blend in Ultrasonic Cleaners is: ultrasonic frequency 15～40KHz, and vibration mixing time 1.5～2h, the temperature of mixed solution is 25～30 ℃; The vacuum tightness of vacuum deaerator is 0.03～0.06MPa; The lyophilize temperature is :-10～-25 ℃, vacuum tightness is: 1.5～5.0KPa; Described loft drier is the far-infrared radiation loft drier.

As another preferred embodiment of technique scheme, described chitosan, cycloheptaamylose and Sodium Benzoate are food grade materials, and the film by the present invention's preparation can be used for food fresh keeping membrane like this.

The present invention is a main raw material with chitosan and beta-cyclodextrin, it is big that chitosan has tensile strength, good toughness, have stronger alkali resistance and organic solvent resistance, and, beta-cyclodextrin has hydrophobic inside and hydrophilic external structure, soluble in waterly can form stable inclusion compound with the interaction of hydrophobic chitosan molecule by non covalent bond, effect with synergy, reached compatible effect, thereby the performance that makes the composite membrane antibacterial film that the present invention prepares is significantly improved and improves, simultaneously, composite antibacterial film of the present invention has clathration to antiseptic-germicide, can reach the effect of long-acting bacteriostatic.

The film of the present invention's preparation can be used for food packaging film, has good water preventing ability, can delay the migration and the diffusion of food Zhong Shui and oil and other composition, has selectable ventilation property and impermeabilisation ability, can stop the volatilization of flavour substances in the food; This film also can be used for the absorption of heavy metal ion, can be used as degradable surrounding purifying material and uses.

Compared with prior art, the present invention has following beneficial effect:

(1) technology of the present invention is simple, and raw material is cheap and easy to get, and the component of film has only 3 kinds, greatly reduces the cost of manufacture of film; Improve simultaneously the component compatibility of film greatly, improved its mechanical property;

(2) become micropore by freeze-drying, improved the ventilation property of this film, also improved the preservativity of this film simultaneously;

(3) the ultrasonic cavitation effect of utilizing ultrasonic technology adopts Freeze Drying Technique with chitosan, cyclodextrin, Sodium Benzoate three blend, has prepared a kind of novel degradable antimicrobial compound film;

(4) last, the mechanical property of this composite membrane, anti-microbial property, the humidity resistance of preserving moisture and ventilation property are all fine.

Embodiment

Embodiment 1

The 4.5g chitosan is dissolved in to be configured to massfraction in the acetic acid solution of pH 3 be 2.5% solution.2.5g beta-cyclodextrin and 0.018g Sodium Benzoate are mixed, be added to the water, heating makes it dissolving, the fixed molten mixing solutions that must contain massfraction 2.5% cycloheptaamylose and massfraction 0.018% Sodium Benzoate to 100mL of cooling back water, this mixing solutions is added in the chitosan, place Ultrasonic Cleaners, at ultrasonic frequency 15KHz, ultra-sonic oscillation time 2h, mix under the condition that mixeding liquid temperature is 25 ℃ blended liquid; With blended liquid vacuum deaerator 30 minutes under vacuum tightness 0.06MPa, blended liquid with deaeration injects the film that Die and mould plate is made thickness 0.1mm again, (the pre-freeze temperature is 5.0KPa for-10 ℃, vacuum tightness in lyophilize 60 minutes in freeze drying box earlier, the pre-freeze time is 3h, pumpdown time is 0.5h), dry 20min in 90 ℃ of loft drier again; After treating the film drying, be transferred in the sodium hydroxide solution of pH 9 and soaked 2 minutes, shift out, the pH value that is washed till washing water with distilled water is 7.0～7.5, is placed in 40 ℃ of loft drier to dry, and the film with oven dry takes out again, in the environment of relative humidity 80%, placed 40 minutes, to guarantee the flexibility of film, last size is as required cut apart packing.

Embodiment 2

The 11.5g chitosan is dissolved in to be configured to massfraction in the acetic acid solution of pH 3 be 3% solution.5g beta-cyclodextrin and 0.035g Sodium Benzoate are mixed, be added to the water, heating makes it dissolving, the fixed molten mixing solutions that must contain massfraction 5% cycloheptaamylose and massfraction 0.035% Sodium Benzoate to 100mL of cooling back water, this mixing solutions is added in the chitosan, place Ultrasonic Cleaners, at ultrasonic frequency 30KHz, the ultra-sonic oscillation time is 1.5h, mix under the condition that water temperature is 30 ℃ blended liquid; With blended liquid vacuum deaerator 40 minutes under vacuum tightness 0.03MPa, blended liquid with deaeration injects the film that Die and mould plate is made thickness 0.5mm again, (the pre-freeze temperature is 2.5KPa for-20 ℃, vacuum tightness in lyophilize 90 minutes in freeze drying box earlier, the pre-freeze time is 4h, pumpdown time is 1h), dry 20min in 90 ℃ of loft drier again; After treating the film drying, be transferred in the sodium hydroxide solution of pH 9 and soaked 2 minutes, shift out, the pH value that is washed till washing water with distilled water is 7.0～7.5, seasoning, and the film with oven dry takes out again, in the environment of relative humidity 85%, placed 30 minutes, to guarantee the flexibility of film, last size is as required cut apart packing.

Claims (6)

1. a kind of preparation method of high-strength degradable polysaccharide blend film is characterized in that carrying out as follows: chitosan is dissolved in the acetic acid solution of pH3～4 and is mixed with the solution that mass fraction is 2～3%, then Add an aqueous solution containing 2.5 to 5% β-cyclodextrin and 0.018 to 0.035% sodium benzoate in mass fraction, and mix in an ultrasonic cleaning machine to obtain a blend, in which chitosan, β-cyclodextrin and The mass ratio of sodium benzoate is 225～450:75～250:1; degassing the blended solution under reduced pressure for 30～40 minutes, then injecting the degassed blended solution into the mold plate to make a film with a thickness of 0.05～1.0mm, first Freeze-dry in a freeze-drying oven for 60-90 minutes, then dry in a drying oven at 60-90°C for 10-25 minutes; after the film is dry, transfer it to an alkaline solution with a pH of 9-10 and soak for 2-3 minutes, remove it, and use Wash with distilled water until the pH of the washing water is 7.0-7.5, dry naturally or in a drying oven at 40-50°C, then take out the dried film and place it in an environment with a relative humidity ≥ 80% for 30 ~60 minutes, and finally divide and pack. 2. the preparation method of high-strength degradable polysaccharide blend film according to claim 1 is characterized in that: the condition of chitosan, β-cyclodextrin and sodium benzoate blending in ultrasonic cleaning machine is: ultrasonic frequency 15 ～40KHz, shaking and mixing time 1.5～2h, the temperature of the mixture is 25～30℃. 3. The method for preparing a high-strength degradable polysaccharide blend film according to claim 1, characterized in that: the vacuum degree of degassing under reduced pressure is 0.03-0.06 MPa. 4. The method for preparing a high-strength degradable polysaccharide blend film according to claim 1, characterized in that the freeze-drying temperature is -10-25°C, and the vacuum degree is 1.5-5.0KPa. 5. The method for preparing a high-strength degradable polysaccharide blend film according to claim 1, characterized in that: the drying oven is a far-infrared radiation drying oven. 6. The preparation method of high-strength degradable polysaccharide blend film according to claim 1, characterized in that: said chitosan, β-cyclodextrin and sodium benzoate are food-grade raw materials.