CN110669236B

CN110669236B - Reinforced carboxymethyl cellulose membrane

Info

Publication number: CN110669236B
Application number: CN201911092837.2A
Authority: CN
Inventors: 曹一平; 黄园; 尤庆亮
Original assignee: Jianghan University
Current assignee: Jianghan University
Priority date: 2019-11-11
Filing date: 2019-11-11
Publication date: 2021-10-22
Anticipated expiration: 2039-11-11
Also published as: CN110669236A

Abstract

The invention discloses a reinforced carboxymethyl cellulose membrane, which is prepared by the following method: 1. dissolving carboxymethyl cellulose in water to prepare carboxymethyl cellulose solution; 2. adding the pyro-paulic acid into the carboxymethyl cellulose solution, uniformly stirring to obtain a mixed solution, pouring the mixed solution into a film forming mold, and heating the film forming mold for 6-10 hours at 20-60 ℃ to obtain a film; 3. and dropwise adding a ferric nitrate solution to the thin film in the film forming mold, removing redundant liquid after the dropwise adding is finished, and placing the thin film until the thin film is completely dried to obtain the reinforced carboxymethyl cellulose film. The preparation method of the cellulose membrane is simple, can be carried out at a lower temperature, and has high strength and good toughness.

Description

Reinforced carboxymethyl cellulose membrane

Technical Field

The invention belongs to the technical field of cellulose membrane preparation, and particularly relates to an enhanced carboxymethyl cellulose membrane and application thereof.

Background

Carboxymethyl cellulose (CMC) is a derivative of carboxymethylation of cellulose, is a natural polysaccharide polymer with the largest yield and the widest application, has good biodegradability, biocompatibility and film-forming property, and is widely applied to chemical industry, food and packaging industry due to safety and non-toxicity. Carboxymethyl cellulose, a hydrophilic polysaccharide polymer, has a common CMC film quality, a brittle film, a poor moisture barrier property, and a common thermal stability.

Generally, one can modify the cellulose film by adding a modifier to improve the properties of the cellulose film. The modifier is divided into an inorganic modifier and an organic modifier, the inorganic modifier comprises inorganic reinforced particles, and common inorganic reinforced particles comprise glass fibers, graphene oxide, silicon carbide, aluminum oxide, mica, talcum powder, clay and the like.

Graphene is a simple substance of carbon, and has a two-dimensional monoatomic layer structure. The unique structure enables the graphene to integrate various excellent properties, and the graphene becomes a nano material with good mechanical property, heat conduction property, permeability and electron mobility. The graphene oxide is a product obtained after graphene is oxidized, and because the graphene oxide contains more oxygen-containing functional groups, the graphene oxide has many excellent properties of graphene and properties which graphene does not have, and the mechanical properties of the graphene oxide can be better enhanced by using the graphene oxide in the composite material.

For example, the chinese patent application "a graphene modified cellulose film and a method for preparing the same" (application No. 201710719572.9) discloses a method for modifying a cellulose film with graphene, which specifically comprises "dissolving a graphene material in an ionic liquid, adding swollen cellulose thereto, dissolving and mixing the cellulose uniformly, and then obtaining the cellulose film by film casting, water washing, plasticization and drying. The method has the advantages of complex process and troublesome operation, and cellulose and graphene materials used in the method need to be pretreated, heated and stirred in the later period, ultrasonically dispersed and spray-dried, and then subjected to film casting, washing, plasticizing and drying to obtain the cellulose film.

The organic modifier is a cross-linking agent generally used, for example, chinese patent application "a high-strength cellulose membrane and a preparation method and application thereof" (application No. 201810794984.3) discloses a method for modifying a graphene membrane, which specifically comprises: dissolving cellulose in a solvent system, adding a cross-linking agent p-benzyl dichloride to prepare a cellulose membrane casting solution, and preparing the membrane casting solution into a membrane by a phase inversion method to obtain a cellulose primary membrane; and treating the primary membrane with alkali liquor to perform etherification crosslinking reaction, and washing with deionized water to obtain the high-strength cellulose membrane. The method needs longer heating time and higher heating temperature, for example, cellulose dissolution needs to be stirred and activated for 1.5-5 h at the temperature of 130-150 ℃, and stirring needs to be carried out for 30-60min after the temperature is reduced to 80-100 ℃.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides the reinforced carboxymethyl cellulose membrane and the application thereof.

The technical scheme adopted for realizing the above purpose of the invention is as follows:

a reinforced carboxymethyl cellulose membrane prepared by the following method:

1. dissolving carboxymethyl cellulose in water to prepare carboxymethyl cellulose solution;

2. adding the pyro-paulic acid into the carboxymethyl cellulose solution, uniformly stirring to obtain a mixed solution, pouring the mixed solution into a film forming mold, and heating the film forming mold for 6-10 hours at 20-60 ℃ to obtain a film;

3. and dropwise adding a ferric nitrate solution to the thin film in the film forming mold, removing redundant liquid after the dropwise adding is finished, and placing the thin film until the thin film is completely dried to obtain the reinforced carboxymethyl cellulose film.

Further, the mass percentage concentration of the carboxymethyl cellulose solution is 1-10%.

Further, the added mass of the pyro-acid is 2-18% of the mass of the carboxymethyl cellulose.

Further, the concentration of the ferric nitrate is 15mg/mL, and the mass of the ferric nitrate added is 1-4% of the mass of the carboxymethyl cellulose.

Compared with the prior art, the invention has the beneficial effects and advantages that:

1. the cellulose membrane has the advantages of simple preparation method, wide raw material source, relatively low price, few process steps, low energy consumption and low preparation cost, can be prepared at relatively low temperature, and is suitable for industrial production.

2. The cellulose membrane has high strength and good toughness, the tensile strength is up to 25.59MPa, and the elongation at break is up to 39.96%.

3. The cellulose film is electrically conductive in the presence of moisture.

Drawings

FIG. 1 is a stress-strain graph of the cellulose film prepared in example 1.

Fig. 2 is a stress-strain graph of the cellulose film prepared in comparative example 1.

Fig. 3 is a stress-strain graph of the cellulose film prepared in comparative example 2.

Fig. 4 is a stress-strain graph of the cellulose film prepared in comparative example 3.

Fig. 5 is a stress-strain graph of the cellulose film prepared in comparative example 4.

Fig. 6 is a stress-strain graph of the cellulose film prepared in comparative example 5.

Fig. 7 is a stress-strain graph of the cellulose film prepared in comparative example 6.

Detailed Description

The present invention will be described in detail with reference to specific examples.

The following examples and comparative examples used the following sources of raw materials:

carboxymethyl cellulose was purchased from alatin with a viscosity of: 800-1200 mPas;

graphene Oxide (GO) dispersion was purchased from Bailingwei technologies, Inc. at a concentration of 4 mg/ml;

pyrobenzoic acid and sodium tetraborate are both available from Aladdin, and ferric nitrate nonahydrate is available from national pharmaceutical group Chemicals, Inc.

Example 1

1. Dissolving 320mg of carboxymethyl cellulose in 8ml of water to prepare a carboxymethyl cellulose solution with the mass percentage concentration of 4%;

2. adding 14.4mg of pyro-pakci into the carboxymethyl cellulose solution, uniformly stirring, pouring into a polytetrafluoroethylene mold, wherein the polytetrafluoroethylene mold is square, 8cm in length, 2cm in width and 0.5cm in thickness, and then putting the polytetrafluoroethylene mold into a vacuum drying oven at 40 ℃ to heat for 8 hours to obtain a film;

3. and (3) dropwise adding 0.5ml of 15mg/ml ferric nitrate solution onto the film in the polytetrafluoroethylene mold, removing the redundant ferric nitrate solution after dropwise adding is finished, standing at room temperature for 8 hours, and finally cutting the film to obtain the reinforced carboxymethyl cellulose film.

Comparative example 1

2. pouring the carboxymethyl cellulose solution into a polytetrafluoroethylene mold, wherein the polytetrafluoroethylene mold is square, 8cm in length, 2cm in width and 0.5cm in thickness, then putting the polytetrafluoroethylene mold into a vacuum drying oven at 40 ℃ to heat for 8 hours, and finally cutting the film to obtain the common carboxymethyl cellulose film.

Comparative example 2

2. adding 0.56mL of graphene oxide dispersion liquid into the carboxymethyl cellulose solution, uniformly stirring, pouring into a polytetrafluoroethylene mold, heating the polytetrafluoroethylene mold in a vacuum drying oven at 40 ℃ for 8 hours, and finally cutting the film to obtain the graphene modified carboxymethyl cellulose film, wherein the polytetrafluoroethylene mold is square, 8cm in length, 2cm in width and 0.5cm in thickness.

Comparative example 3

2. adding 14.4mg of pyro-octalic acid into the carboxymethyl cellulose solution, uniformly stirring, pouring into a polytetrafluoroethylene mold, heating the polytetrafluoroethylene mold in a vacuum drying oven at 40 ℃ for 8 hours, and finally cutting the film to obtain the pyro-octalic acid modified carboxymethyl cellulose film, wherein the polytetrafluoroethylene mold is square, 8cm in length, 2cm in width and 0.5cm in thickness.

Comparative example 4

2. adding 68.9mg of sodium tetraborate into a carboxymethyl cellulose solution, uniformly stirring, pouring into a polytetrafluoroethylene mold, heating the polytetrafluoroethylene mold in a vacuum drying oven at 40 ℃ for 8 hours, and finally cutting the film to obtain the sodium tetraborate modified carboxymethyl cellulose film, wherein the polytetrafluoroethylene mold is square, 8cm in length, 2cm in width and 0.5cm in thickness.

Comparative example 5

2. adding 68.9mg of sodium tetraborate into the carboxymethyl cellulose solution, uniformly stirring, then adding 14.4mg of scorch acid, continuously stirring for 15min, then pouring the obtained mixed solution into a polytetrafluoroethylene mold, then placing the polytetrafluoroethylene mold in a vacuum drying oven at 40 ℃ to heat for 8 hours, and finally cutting the film to obtain the mixed modified carboxymethyl cellulose film.

Comparative example 6

2. adding 68.9mg of sodium tetraborate into a carboxymethyl cellulose solution, uniformly stirring, then adding 14.4mg of scorch acid, continuously stirring for 15min, then adding 0.56ml of graphene oxide dispersion, continuously stirring for 15min, then pouring the obtained mixed solution into a polytetrafluoroethylene mold, then placing the polytetrafluoroethylene mold in a vacuum drying oven at 40 ℃ to heat for 8 hours, and finally cutting the film to obtain the composite modified carboxymethyl cellulose film.

The stress-strain (refer to national standard GB/T1040.3-2006) of the cellulose films prepared in example 1 and comparative examples 1-6 is tested by a plastic-film tensile property tester (model CMT6503), the obtained stress-strain curves are respectively shown in figures 1-7, and the tensile strength and elongation at break data of each cellulose film are obtained at the same time, and are specifically shown in the following table 1:

table 1 stress-strain test results

Cellulose membrane sample	Modifying agent	Tensile strength/MPa	Elongation at break/%
				Example 1	Pyro-bylic acid, ferric nitrate	25.59	39.96
Comparative example 1	-	11.84	3.31
				Comparative example 2	Graphene oxide	26.17	2.30
Comparative example 3	Jobecic acid	39.04	3.01
				Comparative example 4	Sodium tetraborate	3.09	1.40
Comparative example 5	Pyro-bylic acid, sodium tetraborate	7.18	1.15
				Comparative example 6	Graphene oxide, sodium tetraborate and pyro-biac acid	9.71	4.52

As can be seen from table 1, the tensile strength of the cellulose film prepared in comparative example 3 was the largest, and the tensile strength of the cellulose film prepared in comparative example 4 was the smallest. The cellulose films prepared in comparative examples 3 and 2 had a greater tensile strength than the cellulose film prepared in comparative example 1, thus demonstrating that the strength of the cellulose films was enhanced by graphene oxide and pyro-pakc. The cellulose film prepared in comparative example 6 had a tensile strength greater than that of the cellulose film prepared in comparative example 5, thereby also demonstrating that graphene oxide has an enhancing effect on the strength of the cellulose film. The tensile strength of the cellulose film prepared in comparative example 5 is greater than that of the cellulose film prepared in comparative example 4, indicating that Borate causes the cellulose film to be too highly crosslinked, which has a negative reinforcing effect on the strength of the cellulose film, while pyromucic acid has a reinforcing effect on the strength of the cellulose film.

As can be seen from table 1, the elongation at break of the obtained cellulose film was increased from 3.01% to 39.96% and increased by 12.28 times, while the strength was decreased by only 34.45% after the introduction of ferric ions, as compared with comparative example 3.

The carboxymethyl cellulose films prepared in example 1 and comparative examples 1 to 3 were subjected to conductivity test using RTS-8 four-point probe, and before the test, the carboxymethyl cellulose was in a wet state by spraying water on the carboxymethyl cellulose film using a small watering can, as shown in Table 2 below:

table 1 results of conductivity tests

Cellulose membrane sample	Modifying agent	conductivity/S.m^-1
			Example 1	Pyro-bylic acid, ferric nitrate	2.313
Comparative example 1	-	4.104
			Comparative example 2	Graphene oxide	6.443
Comparative example 3	Jobecic acid	3.304

As can be seen from table 2, the conductivity was reduced by only 30% after the introduction of ferric ions, as compared to comparative example 3.

Claims

1. A reinforced carboxymethyl cellulose membrane, characterized by being prepared by the following method:

1.1, dissolving carboxymethyl cellulose in water to prepare carboxymethyl cellulose solution;

1.2, adding pyro-acid into the carboxymethyl cellulose solution, wherein the added pyro-acid accounts for 2-18% of the weight of the carboxymethyl cellulose, uniformly stirring to obtain a mixed solution, pouring the mixed solution into a film forming mold, and heating the film forming mold for 6-10 hours at 20-60 ℃ to obtain a film;

1.3, dropwise adding a ferric nitrate solution on the thin film in the film forming mold, wherein the concentration of the ferric nitrate is 15mg/mL, the mass of the ferric nitrate solution is 1-5% of that of the carboxymethyl cellulose, removing redundant liquid after the dropwise adding is finished, and placing the thin film until the thin film is completely dried to obtain the reinforced carboxymethyl cellulose film.

2. The reinforced carboxymethylcellulose film of claim 1, wherein: the mass percentage concentration of the carboxymethyl cellulose solution is 1-10%.