CN1172041C - Preparation method of pitch-based carbon membrane artificial lung - Google Patents

Abstract

The present invention relates to a method for preparing an asphalt-base carbon film artificial lung, which belongs to the technical field of biological engineering material. The present invention has the technical scheme that asphalt is used as raw material; firstly, the raw asphalt is prepared into aeolotropic refined asphalt through filtration; then, the aeolotropic refined asphalt carries out melt spinning at the certain temperature, and a hollow fiber is produced; carbonization, reinforcment and toughening are carried out on the hollow fiber; finally, anticoagulant processing is carried out on the hollow fiber, and thus, the asphalt-base artificial lung hollow fiber film material can be prepared. The material not only has strong water prevention and ventilation performance and good anticoagulant performance, but also has certain toughness and tensile strength; the material fundamentally changes the state that the industrial high molecular material is not adaptable to human bodies. The artificial lung prepared by the method can have no blood coagulation for a plurality of continuous days, even a plurality of months, the exchange capacity of oxygen and carbon dioxide is more than 80%, and the service life of the artificial lung is effectively extended.

Description

Preparation method of pitch-based carbon membrane artificial lung

technical field

The invention relates to a preparation method of a bioengineering material, in particular to a preparation of a membrane material for an artificial lung, and belongs to the technical field of bioengineering.

Background technique

It is an ideal goal of clinical treatment to quickly and effectively provide oxygen and remove carbon dioxide for patients with respiratory failure. At present, research and development of the curtain-type, rotating disc-type and membrane-type artificial lungs has been done in the prior art (Liu Qingjun, Artificial Organs, 1984: 46-48). Among them, the curtain type artificial lung is that the blood flows down from the vertical stainless steel membrane, and the oxygen is blown from the right angle direction. Rotating disc-type artificial lung is to immerse the lower half of dozens of side-by-side round plastic plates into the tank storing blood, and rotate continuously. The blood forms a thin film on the surface of the disc and oxygen is blown to oxidize the blood. These two types of artificial lungs have been gradually eliminated due to the direct contact between blood and oxygen, which are prone to air bubbles and hemolysis. Membrane-type artificial lungs first imitate the function of the lungs of the body with a silicone rubber or polytetrafluoroethylene membrane with a thickness of 10-30 μm. Since the membrane is easily broken, it must be reinforced with a polyester fiber network, and then made of silicone rubber and polypropylene into a capillary type. artificial lung. Thousands of fibers form a bundle, put into an oxygen-filled cylinder or connect with an oxygen bottle, and the blood flows through the hollow fiber, and the carbon dioxide in the blood exchanges with the oxygen in the cylinder between the capillary walls (Gu B, Du Q G, Yang Y L. Microporous hollow fiber membranes formed from blends of isotactic and tactical polypropylene. Journal of Membrane Science, 2000: 164: 59-65). However, due to the uneven distribution of pores on the hollow fiber wall, the easy penetration of blood plasma and water molecules, etc., the service life is only a few hours, and the cure rate of adult patients is only 50% (Cui Dejian, Artificial Lung Membrane, Foreign Medical Respiratory System Volume, 1995; 3(15):116-119). In addition, hollow fiber materials used in artificial lungs must undergo special anticoagulant treatment before they can be directly used in the human body. At present, the industrially used inorganic carbon membranes made of carbonized organic matter with high carbon content are generally used for the selective separation of gases at high temperatures (Czaki J, Endo N, Ohizumi K, et al.Novel preparation method for the production of mesoporous carbon fiber from a polymer blend. Carbon Vol.1997; 35(7): 1031-1033). Because the material has good waterproof, breathable and anticoagulant properties, it has been used as a hemodialysis material in the human body. However, inorganic carbon membranes, especially hollow fiber membranes, are very brittle and often need other materials to support them before they can be used. They have not been used in artificial lungs yet.

Contents of the invention

The present invention aims to propose a method for preparing a membrane material used in artificial lungs, so that the material has good waterproof, breathable, and anticoagulant properties, while increasing the exchange capacity of oxygen and carbon dioxide, and improving the service life of the artificial lung . The preparation method of pitch base artificial lung that the present invention proposes comprises the following steps:

(1) Convert asphalt from different sources into anisotropic refined asphalt after filtration, thermal condensation polymerization, hydrogenation reaction and extraction;

(2) Heat and melt the refined pitch, defoam, stand and filter, and melt-spin at 350-380°C to prepare a hollow fiber with an inner diameter of 50-150 μm and an outer diameter of 100-200 μm ;

(3) Putting the hollow fiber prepared above into an organic solution, removing the soluble fine components therein, and raising the temperature in an oxygen-enriched atmosphere to obtain an infusible pitch-based hollow fiber;

(4) Under the protection of an inert gas, carbonize the infusible pitch-based hollow fiber to obtain a hollow fiber with a wall hole diameter of 0.4-140 nm;

(5) Immerse the carbonized hollow fiber in the asphalt stock solution, or in the methanol solution of phenolic, furan, and sugar ketone thermosetting resins, make it absorb a certain amount of carbon-containing compounds, and then oxidize and carbonize to obtain a pore size of 0.2-120nm carbon-carbon composite hollow fibers;

(6) soaking the hollow fiber prepared by step (5) in the quaternary ammonium salt and the anticoagulant polymer solution respectively, and then drying;

(7) Curing and encapsulating a plurality of fixed-length hollow fibers with epoxy resin to obtain a pitch-based carbon membrane artificial lung.

Because the present invention controls the microporous structure of the hollow fiber, improves the process to prepare the ultra-fine hollow fiber, and improves its biocompatibility by oxidation and carbonization under specific temperature conditions, and through composite reinforcement, toughening, and adsorption of heparin. , so the prepared artificial lung membrane material has good waterproof, breathable and anticoagulant properties.

The present invention utilizes the oxidized or carbonized pitch-based hollow fibers with good blood compatibility for the first time, fundamentally changing various inadaptable states of the previous industrial polymer materials to the human body. By controlling the different concentrations of the raw asphalt solution, the size of the hollow fiber wall hole can be artificially controlled. The artificial lung prepared according to the invention is not only waterproof and highly air-permeable, but also can prevent blood coagulation for several days or even several months, and its oxygen and carbon dioxide exchange capacity is above 80%.

Detailed ways

The raw material asphalt used in the present invention is industrial petroleum asphalt, coal tar asphalt, pyrolysis asphalt and other synthetic asphalts. Toluene, heparin sodium, quaternary ammonium salts, high-purity nitrogen, low-carbon hydrocarbon gases, and thermosetting resins such as phenolic, furan, and sugar ketone are products of chemical plants in Shanghai, Beijing, and Changzhou. The pore diameter was measured by ASAP2010 nitrogen adsorption instrument made in the United States (nitrogen molecular cross-section: 0.162nm ² , standard tube inner diameter: 9.530mm) or mercury porosimeter (Quantachrome Autosorb-60, American), pressure range: 0-400MPa.

The specific operation steps are as follows:

(1) Refining and modulation of raw asphalt

After filtering the raw asphalt, conduct thermal polycondensation at 300-350°C under the protection of nitrogen, and then perform hydrogenation reaction at 400-450°C for 30-60 minutes; after extraction with toluene, convert asphalt raw materials from different sources into isotropic Refined bitumen of opposite sex;

(2) Formation of pitch fibers

Heat and melt the refined pitch, defoam, stand and filter, and melt-spin at 350-380°C to prepare hollow fibers with an inner diameter of 50-150 μm and an outer diameter of 100-200 μm;

(3) Non-melting treatment of pitch fibers

Put the hollow fiber prepared above into toluene, remove the soluble fine components in it, and gradually raise the temperature of the furnace from room temperature to 200-400°C in an oxygen-enriched atmosphere, and the heating rate can be controlled at 10°C/min , to produce infusible pitch-based hollow fibers;

(4) Carbonization of non-melting fibers

Under the protection of pure nitrogen, the temperature of the furnace is raised from 200-400°C to 1100-1300°C, and the heating rate is 20°C/min, so that it is carbonized, and a hollow fiber with a wall hole diameter of 0.4-140nm is obtained;

(5) Preparation of carbon-carbon composite materials

Immerse the carbonized hollow fiber in asphalt stock solution or phenolic (furan, sugar ketone) thermosetting resin liquid, make it absorb 5-25% carbon-containing compounds of the dry weight of the hollow fiber, and then slowly heat to 1000 ° C ~ 1300 ° C, A carbon-carbon composite hollow fiber with a wall pore diameter of 0.2 to 120 nm is prepared;

(6) Surface treatment

Soak the hollow fiber prepared in step (5) in 0.5-1M quaternary ammonium salt and 0.1-0.2M anticoagulant polymer material for 1-5 hours, dry, and set aside;

(7) Assembly

100-1000 hollow fibers with a length of 35-40 cm are cured and packaged with epoxy resin to obtain a pitch-based artificial lung hollow fiber membrane.

Put the prepared hollow fiber into toluene as described in step (3), and after removing the soluble fine components therein, the temperature of the furnace can also be gradually raised from room temperature to 200-400° C. under a pressure of 50KPa ( The heating rate can be controlled at 10°C/min), and the infusible pitch-based hollow fiber is produced.

The above step (4) can also be used under the protection of pure nitrogen, the temperature of the furnace is raised from 200-400°C to 2500°C, and the heating rate is 25°C/min, so that it can be graphitized to obtain a wall hole diameter of 0.4- 140nm hollow fiber. Above-mentioned step (5) also can adopt the hollow fiber after carbonization to pass into low-carbon hydrocarbon gas, low-carbon hydrocarbon gas can be methane, ethane or propane etc., make it absorb 5～25% of hollow fiber dry weight The carbon-containing compound is then slowly heated to 1000°C-1300°C to prepare a carbon-carbon composite pitch-based hollow fiber with a pore size of 0.2-120nm.

The quaternary ammonium salt described in the above step (6) is one of benzyl alkyl ammonium chloride or cetyl trimethyl ammonium chloride; the anticoagulant polymer material is sodium heparin, paclitaxel or carboxyl Any of the sulfated chitosans.

Example 1:

Raw materials Petroleum asphalt, toluene, heparin sodium, benzyl alkyl ammonium chloride, high-purity nitrogen, methane and phenolic resin used in the asphalt industry are the products of Shanghai, Beijing, Changzhou and other chemical plants (analytical pure).

(1) Refining and modulation of raw asphalt

After filtering the raw asphalt, carry out thermal polycondensation at 300°C under the protection of nitrogen, and then perform hydrogenation reaction at 400°C for 30 minutes; after extraction with toluene, convert asphalt raw materials from different sources into anisotropic refined asphalt;

(2) Formation of pitch fibers

Heat and melt the refined pitch, defoam, stand and filter, and melt-spin at 350°C to prepare hollow fibers with an inner diameter of 50-150 μm and an outer diameter of 100-200 μm;

(3) Non-melting treatment of pitch fibers

Put the hollow fiber prepared above into toluene, remove the soluble fine components in it, and gradually raise the temperature of the furnace from room temperature to 200°C in an oxygen-enriched atmosphere, and the heating rate can be controlled at 10°C/min. Obtain infusible pitch-based hollow fibers;

(4) Carbonization of non-melting fibers

Under the protection of pure nitrogen, the temperature of the furnace is raised from 200°C to 1100°C at a rate of 20°C/min, and carbonized to obtain hollow fibers with a wall hole diameter of 0.4-140nm;

(5) Preparation of carbon-carbon composite materials

Immerse the non-melting and carbonized hollow fiber into the asphalt spinning stock solution, make it adsorb 5% carbon-containing compounds of the dry weight of the hollow fiber, and slowly heat it to 1000°C to obtain a carbon-carbon composite hollow fiber with a wall hole diameter of 0.2-120nm. fiber;

(6) Surface treatment

Soak the high-performance hollow fiber prepared by (5) in 0.5M benzylalkylammonium chloride solution and 0.1M heparin sodium solution respectively for 1 hour and dry it for later use.

(7) Assembly

100 hollow fibers with a length of 40 cm are cured and packaged with epoxy resin, sterilized, connected to an oxygen cylinder and a vacuum pump, and then used.

Example 2:

The raw material pitch is pyrolysis pitch for industrial use, and toluene, heparin sodium, benzyl alkyl ammonium chloride, high-purity nitrogen, methane and phenolic resin are the products (analytical pure) of Shanghai, Beijing, Changzhou and other chemical plants respectively.

(1) Refining and modulation of raw asphalt

After the raw asphalt is filtered, thermal polycondensation is carried out under the protection of nitrogen at a temperature of 320°C, and then hydrogenated at 420°C for 30 minutes; after extraction with toluene, the asphalt raw materials from different sources are converted into anisotropic refined asphalt.

(2) Formation of pitch fibers

Heat and melt the refined pitch, defoam, stand and filter, and melt-spin at 374°C to prepare hollow fibers with an inner diameter of 50-150 μm and an outer diameter of 100-200 μm;

(3) Non-melting treatment of pitch fibers

Put the hollow fiber prepared above into toluene, remove the soluble fine components, and gradually raise the temperature of the furnace from room temperature to 300°C in an oxygen-enriched atmosphere, and the heating rate can be controlled at 10°C/min. Obtain infusible pitch-based hollow fibers;

(4) Carbonization of non-melting fibers

Under the protection of pure nitrogen, the temperature of the furnace is raised from 200°C to 1200°C at a rate of 20°C/min, and it is carbonized to obtain a hollow fiber with a wall hole diameter of 0.4-140nm;

(5) Preparation of carbon-carbon composite materials

Immerse the non-melting and carbonized hollow fiber into the asphalt spinning stock solution to make it absorb 25% of the carbon-containing compound of the dry weight of the hollow fiber, and slowly heat it to 1100°C to obtain a carbon-carbon composite hollow fiber with a wall hole diameter of 0.5-100nm. fiber;

(6) Surface treatment

Soak the high-performance hollow fiber prepared by (5) in 0.5M benzylalkylammonium chloride solution and 0.1M heparin sodium solution respectively for 1 hour and dry it for later use.

(7) Assembly

200 hollow fibers with a length of 40 cm are packaged with epoxy resin, cured, sterilized, connected to an oxygen cylinder and a vacuum pump, and then used.

Example 3

Toluene, heparin sodium, benzyl alkyl ammonium chloride, high-purity nitrogen, methane and phenolic resin are the products of Shanghai, Beijing, Changzhou and other chemical factories (analytical pure).

(1) Refining and modulation of raw asphalt

After filtering the raw asphalt, carry out thermal condensation at 330°C under the protection of nitrogen, and then hydrogenation reaction at 440°C for 60 minutes; after extraction with toluene, convert asphalt raw materials from different sources into anisotropic refined asphalt;

(2) Formation of pitch fibers

Heat and melt the refined pitch, defoam, stand and filter, and melt-spin at 374°C to prepare hollow fibers with an inner diameter of 50-150 μm and an outer diameter of 100-200 μm;

(3) Non-melting treatment of pitch fibers

Put the hollow fiber prepared above into toluene, remove the soluble fine components, and gradually raise the temperature of the furnace from room temperature to 300°C under the pressure of 50KPa, and the heating rate can be controlled at 10°C/min. Infusible pitch-based hollow fibers;

(4) Carbonization of non-melting fibers

Under the protection of pure nitrogen, the temperature of the furnace is raised from 300°C to 1200°C at a rate of 20°C/min, and carbonized to obtain hollow fibers with a wall hole diameter of 0.4-140nm;

(5) Preparation of carbon-carbon composite materials

Immerse the non-melting and carbonized hollow fiber into a methanol solution of 15% phenolic resin, make it absorb 15% carbon-containing compound of the dry weight of the hollow fiber, slowly heat to 1300°C, and obtain a carbon-carbon with a pore size of 0.4-110nm Composite hollow fibers;

(6) Surface treatment

Soak the high-performance hollow fiber prepared by (5) in 1M cetyltrimethylammonium chloride and 0.2M paclitaxel solutions for 5 hours and dry it for later use.

(7) Assembly

600 hollow fibers with a length of 40 cm are cured and packaged with epoxy resin, and then connected to an oxygen bottle base and a vacuum pump (0.025 MPa).

Example 4

The raw materials are coal tar pitch, toluene, heparin sodium, benzyl alkyl ammonium chloride, high-purity nitrogen, methane and phenolic resin are the products of Shanghai, Beijing, Changzhou and other chemical factories (analytical pure).

(1) Refining and modulation of raw asphalt

After filtering the raw asphalt, conduct thermal polycondensation at 350°C under the protection of nitrogen, and then perform hydrogenation reaction at 450°C for 60 minutes; after toluene extraction, convert asphalt raw materials from different sources into anisotropic refined asphalt;

(2) Formation of pitch fibers

Heat and melt the refined pitch, defoam, stand and filter, and melt-spin at 380°C to prepare hollow fibers with an inner diameter of 50-150 μm and an outer diameter of 100-200 μm;

(3) Non-melting treatment of pitch fibers

Put the hollow fiber prepared above into toluene, remove the soluble fine components, and gradually raise the temperature of the furnace from room temperature to 400°C in an oxygen-enriched atmosphere, and the heating rate can be controlled at 10°C/min. Obtain infusible pitch-based hollow fibers;

(4) Carbonization of non-melting fibers

Under the protection of pure nitrogen, the temperature of the furnace was raised from 400°C to 1300°C at a rate of 20°C/min, and carbonization was carried out to obtain hollow fibers with a wall hole diameter of 0.4-140nm;

(5) Preparation of carbon-carbon composite materials

Immerse the non-melting and carbonized hollow fiber into the asphalt spinning stock solution, make it absorb 5% carbon-containing compound of the dry weight of the hollow fiber, and slowly heat it to 1100°C to obtain a carbon-carbon composite hollow fiber with a pore size of 0.2-120nm ;

(6) Surface treatment

The high-performance hollow fiber prepared by (5) was soaked in 1M cetyltrimethylamine oxide and 0.2M paclitaxel solution for 5 hours and dried respectively to obtain a pitch-based artificial lung membrane material;

(7) Assembly

800 hollow fibers with a length of 40 cm are cured and packaged with epoxy resin, and then connected to an oxygen bottle base and a vacuum pump (0.055 MPa).

Example 5

The raw materials are coal tar pitch, toluene, heparin sodium, benzyl alkyl ammonium chloride, high-purity nitrogen, methane and phenolic resin are the products of Shanghai, Beijing, Changzhou and other chemical factories (analytical pure).

(1) Refining and modulation of raw asphalt

After filtering the raw asphalt, conduct thermal polycondensation at 350°C under the protection of nitrogen, and then perform hydrogenation reaction at 450°C for 60 minutes; after toluene extraction, convert asphalt raw materials from different sources into anisotropic refined asphalt;

(2) Formation of pitch fibers

Heat and melt the refined pitch, defoam, stand and filter, and melt-spin at 380°C to prepare hollow fibers with an inner diameter of 50-150 μm and an outer diameter of 100-200 μm;

(3) Non-melting treatment of pitch fibers

Put the hollow fiber prepared above into toluene, remove the soluble fine components, and gradually raise the temperature of the furnace from room temperature to 400°C in an oxygen-enriched atmosphere, and the heating rate can be controlled at 10°C/min. Obtain infusible pitch-based hollow fibers;

(4) Carbonization and graphitization of non-melting fibers

Under the protection of pure nitrogen, the temperature of the furnace is raised from 400°C to 2500°C at a rate of 20°C/min, and then carbonized and graphitized to obtain hollow fibers with a wall hole diameter of 0.4-140nm;

(5) Preparation of carbon-carbon composite materials

Immerse the hollow fiber prepared in the above (4) into the asphalt spinning stock solution, make it adsorb 5% carbon-containing compound of the dry weight of the hollow fiber, and slowly heat to 1100°C to obtain a carbon-carbon composite with a pore size of 0.2-120nm hollow fiber;

(6) Surface treatment

The high-performance hollow fiber prepared by (5) was soaked in 1M cetyltrimethylammonium chloride and 0.2M carboxylated sulfated chitosan solution for 5 hours and dried to obtain a pitch-based artificial lung. Membrane material;

(7) Assembly

The 35cm-long hollow fiber 1000 is cured and packaged with epoxy resin, and connected to the base of the oxygen bottle and the vacuum pump (0.065MPa).

Claims (5)

1. a preparation method of a pitch-based carbon membrane artificial lung, the method may further comprise the steps: (1) Convert asphalt from different sources into anisotropic refined asphalt after filtration, thermal condensation polymerization, hydrogenation reaction and extraction; (2) Heat and melt the refined pitch, defoam, stand and filter, and melt-spin at 350-380°C to prepare hollow fibers with an inner diameter of 50-150 μm and an outer diameter of 100-200 μm; (3) Putting the hollow fiber prepared above into an organic solution, removing the soluble fine components therein, and raising the temperature in an oxygen-enriched atmosphere to obtain an infusible pitch-based hollow fiber; (4) Under the protection of an inert gas, carbonize the infusible pitch-based hollow fiber to obtain a hollow fiber with a wall hole diameter of 0.4-140 nm; (5) Immerse the carbonized hollow fiber in the asphalt stock solution, or in the methanol solution of phenolic, furan, and sugar ketone thermosetting resins, make it absorb a certain amount of carbon-containing compounds, and then oxidize and carbonize to obtain a pore size of 0.2-120nm carbon-carbon composite hollow fibers; (6) soaking the hollow fiber prepared by step (5) in the quaternary ammonium salt and the anticoagulant polymer solution respectively, and then drying; (7) Curing and encapsulating a plurality of fixed-length hollow fibers with epoxy resin to obtain a pitch-based carbon membrane artificial lung. 2. according to the described preparation method of claim 1, it is characterized in that the hollow fiber made in step (3) is put into organic solvent, after removing the soluble fine component wherein, also can adopt to heat up under 50KPa pressure , to produce infusible pitch-based hollow fibers. 3. The preparation method according to claim 1, characterized in that the step (4) can also be graphitized under the protection of pure nitrogen to obtain a hollow fiber with a wall hole diameter of 0.4-140 nm. 4. according to the described preparation method of claim 1, it is characterized in that step (5) also can adopt the hollow fiber after carbonization to pass into low-carbon hydrocarbon gas, make it adsorb a certain amount of carbon-containing compound, then slowly heat carbonization , making a carbon-carbon composite hollow fiber with a pore size of 0.2 to 120 nm; 5. according to the preparation method claimed in claim 1, it is characterized in that the quaternary ammonium salt described in the step (6) is the one in benzyl alkyl ammonium chloride or cetyl trimethyl ammonium chloride; The anticoagulant polymer material is any one of heparin sodium, paclitaxel or carboxylated sulfated chitosan.