CN113416313A

CN113416313A - Biodegradable compatilizer and preparation method and application thereof

Info

Publication number: CN113416313A
Application number: CN202110571446.XA
Authority: CN
Inventors: 柯渔; 付鹏程
Original assignee: Jinan University
Current assignee: Jinan University
Priority date: 2021-05-25
Filing date: 2021-05-25
Publication date: 2021-09-21
Anticipated expiration: 2041-05-25
Also published as: CN113416313B

Abstract

The invention belongs to the field of functional materials, and discloses a biodegradable compatilizer, and a preparation method and application thereof. The preparation method of the biodegradable compatilizer comprises the following steps: (1) under the protection of nitrogen, adding isocyanic acid modified graphene oxide into a dispersing agent to obtain isocyanic acid modified graphene oxide dispersion liquid; (2) under the protection of nitrogen, dissolving the telechelic polymer with the end-capped hydroxyl groups at two ends in a solvent to prepare a solution of the telechelic polymer with the end-capped hydroxyl groups at two ends; (3) and (3) under the protection of nitrogen, mixing the dispersion liquid prepared in the step (1) with the solution prepared in the step (2), and reacting under the action of a catalyst to obtain the biodegradable compatilizer. The A-B type compatilizer prepared by the invention is beneficial to effective dispersion of GO, improves the phase separation phenomenon of a biodegradable aliphatic polyester containing a component B and a GO blend, and is also suitable for a biodegradable aliphatic polyester containing a component C and a GO blend compatible with the component B.

Description

Biodegradable compatilizer and preparation method and application thereof

Technical Field

The invention belongs to the field of functional materials, and particularly relates to a biodegradable compatilizer, and a preparation method and application thereof.

Background

The widespread use of synthetic resins has led to a series of environmental pollution problems, with large quantities of waste plastics eventually being burned or buried in the soil. Biodegradable materials have been produced, and among them, aliphatic polyesters are attracting attention because of their good biodegradability. The aliphatic polyester is a high molecular compound with an easily hydrolyzed ester bond in the main chain, the main chain is flexible and easy to be degraded into nontoxic water-soluble oligomers or monomers by enzymes in microorganisms or animals and plants, and then the nontoxic water-soluble oligomers or monomers are converted into energy, carbon dioxide and water by the microorganisms. Aliphatic polyesters such as polyhydroxyalkanoates (e.g., PHB, PHBV), polyhydroxyalkanoates (PLA, PGA, PLGA), Polycaprolactone (PCL), and the like are nontoxic and have excellent biodegradability, and play an increasingly important role in the fields of nonwovens, medical devices, high-value-added human-affinity medical materials, and the like. However, the aliphatic polyester has many defects of low melting point, poor mechanical properties, high cost and the like exposed in the using process, and the aliphatic polyester is limited to be used in a large amount in degradable products.

Graphene and graphene oxide are special two-dimensional materials and have excellent performances such as high specific surface area, high strength, high thermal stability and strong electrical conductivity. The graphene oxide sheet (GO) layer structure contains a large number of oxygen-containing groups such as hydroxyl, carboxyl, epoxy and the like, and is often used as a filler to improve the mechanical strength, thermal stability, conductivity and other properties of the biodegradable polyester. When the GO is blended with biodegradable polyester, the hydrophilicity and the roughness of the surface can be effectively improved, the transportation of water molecules on the membrane is facilitated, and the adsorption and deposition of dirt on the surface of the membrane can be slowed down; GO has a contact-mediated antimicrobial mechanism that can improve the ability of the composite membrane to resist biofouling. However, strong pi-pi interaction between GO sheets makes the GO easy to agglomerate, so that the GO is not easy to be uniformly dispersed in a biodegradable matrix, and the comprehensive performance of the composite membrane is reduced.

The biodegradable polyester component in the biodegradable polyester/GO mixed film is chemically inert and has weak interaction with the graphene oxide interface. One of the effective methods to improve the interfacial compatibility of biodegradable polyesters and GO and to increase the interaction between the two phases is to use a compatibilizer, which acts as a "bridge" to effectively link GO and biodegradable polyesters. Common graft type compatilizers are classified into A-B type, A-C type and the like according to the structure, wherein A and B are two component structures in a blend, and the structure of C is different from that of component B in the blend in terms of chemical structure, but has good compatibility with B. The A-B type and A-C type compatilizers can improve the agglomeration phenomenon of the blended film, influence the morphological structure of the film and improve the comprehensive performance of the composite film. No GO-g-PHBV graft type compatilizer is reported in the prior art.

Disclosure of Invention

In order to overcome the disadvantages and shortcomings of the prior art, the invention provides a preparation method of a biodegradable compatilizer.

The invention also aims to provide the biodegradable compatilizer prepared by the method.

The invention further aims to provide application of the biodegradable compatilizer in preparation of biodegradable aliphatic polyester/GO blends, in particular application in preparation of biodegradable polyester/GO mixed films.

The purpose of the invention is realized by the following scheme:

a preparation method of a biodegradable compatilizer mainly comprises the following steps:

(1) under the protection of nitrogen, adding isocyanic acid modified graphene oxide into a dispersing agent, and performing ultrasonic dispersion to obtain isocyanic acid modified graphene oxide dispersion liquid;

(2) under the protection of nitrogen, dissolving the telechelic polymer with the end-capped hydroxyl groups at two ends in a solvent, and uniformly stirring to prepare a solution of the telechelic polymer with the end-capped hydroxyl groups at two ends;

(3) and (3) under the protection of nitrogen, mixing the dispersion liquid prepared in the step (1) with the telechelic polymer solution with the two end hydroxyl groups blocked prepared in the step (2), reacting under the action of a catalyst, purifying, and freeze-drying to obtain the biodegradable compatilizer.

The dispersant in the step (1) is at least one of anhydrous N, N-dimethylformamide and anhydrous dichloromethane, and is preferably N, N-dimethylformamide;

the concentration of the isocyanic acid modified graphene oxide dispersion liquid in the step (1) is 0.001-0.01 g/mL, and preferably 0.005 g/mL;

the ultrasonic dispersion in the step (1) is ultrasonic treatment for 10-60 min under 200-500W; preferably, ultrasonic treatment is carried out for 30min under the power of 400W;

the telechelic polymer with two hydroxyl-terminated ends in the step (2) is at least one of telechelic polyhydroxyalkanoate with two hydroxyl-terminated ends, telechelic polyhydroxyalkanoate with two hydroxyl-terminated ends and the like, preferably telechelic polyhydroxyalkanoate with two hydroxyl-terminated ends, and more preferably poly [ (3-hydroxybutyrate) -co- (3-hydroxyvalerate) ];

the number average molecular weight of the telechelic polymer with the two hydroxyl end capping ends in the step (2) is 2000-4000 g/mol, and the molecular weight polydispersity coefficient is 1.1-1.6;

the solvent in the step (2) is preferably at least one of anhydrous N, N-dimethylformamide, anhydrous dichloroethane and anhydrous dimethyl sulfoxide;

the concentration of the telechelic polymer solution with the two end hydroxyl groups blocked in the step (2) is 0.005-0.05 g/mL, and preferably 0.01 g/mL;

stirring in the step (2) is carried out at a stirring speed of 20-600 r/min, and stirring is carried out for 20-40 min at room temperature; preferably stirring at 200r/min for 25 min;

the mixing mode in the step (3) is as follows: adding isocyanic acid modified graphene oxide dispersion liquid into telechelic polymer solution with two hydroxyl groups blocked; preferably dropwise adding under magnetic stirring;

the catalyst in the step (3) is at least one of dibutyltin dilaurate and stannous octoate; the catalyst and the telechelic polymer with the end-capped hydroxyl groups at two ends are mixed according to the mass ratio of (0.15-0.25) to 1, and are further preferably dropwise added under the condition of magnetic stirring;

the reaction in the step (3) is carried out at the speed of 20-500 r/min and at the temperature of 50-100 ℃ for 8-48 h; preferably reacting for 24 hours at 400r/min and 80 ℃;

the volume ratio of the isocyanic acid modified graphene oxide dispersion liquid to the telechelic polymer solution with two hydroxyl groups blocked in the step (3) is (5-1: 1);

the telechelic polymer with two hydroxyl groups blocked in the step (3) and the isocyanic acid modified graphene oxide are mixed according to the mass ratio of 1 (1-3), and the preferred ratio is 1: 2.

The purification in the step (3) adopts anhydrous N, N-dimethylformamide or a mixed solution of the anhydrous N, N-dimethylformamide and the anhydrous dichloroethane for centrifugal washing, and the centrifugal washing is repeated for 3-8 times, preferably 5 times; the volume ratio of the anhydrous N, N-dimethylformamide to the anhydrous dichloroethane in the mixed solution is (3-0.5): 1, preferably 1: 1;

the freeze drying treatment time in the step (3) is 18-48 h, preferably 24 h.

The biodegradable compatilizer is a graft compatilizer.

The application of the biodegradable compatilizer in preparing biodegradable aliphatic polyester/GO blends.

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

(1) according to the invention, the A-B type compatilizer is prepared by grafting the biodegradable telechelic polymer terminated by hydroxyl groups at two ends with the graphene oxide, so that the effective dispersion of GO is facilitated, the phase separation phenomenon of the biodegradable aliphatic polyester containing the component B and the GO blend is improved, and the A-B type compatilizer is also suitable for the biodegradable aliphatic polyester containing the component C and the GO blend compatible with the component B. The biodegradable compatilizer is convenient to use and easy to control.

(2) The biodegradable compatilizer has the capability of resisting biological dirt, the encapsulation rate and the drug-loading rate of loaded antibacterial drugs are 1.67 times of those of GO, and the biodegradable compatilizer has an obvious drug slow-release effect.

(3) The biodegradable compatilizer is non-toxic and has no hemolysis.

Drawings

FIG. 1 is an infrared spectrum of GO (a) and compatibilizer (b).

Figure 2 is an X-ray diffraction pattern of go (a) and compatibilizer (b).

Fig. 3 is a raman spectrum of go (a) and compatibilizer (b).

FIG. 4 is a transmission electron micrograph of GO (a) and compatibilizer (b).

Fig. 5 is a graph of the bactericidal rate of the compatibilizer for e.

FIG. 6 is a cytotoxicity plot of a compatibilizing agent.

FIG. 7 is a chart of analysis of the hemolytic effect of the compatibilizer (A) photographs of the hemolytic effect of the compatibilizer at different times; (B) after incubation for 3h with compatilizers of different concentrations, the hemolysis rate of the erythrocytes is improved; (C) hemolysis rate of erythrocytes after incubation with 1mg/mL of compatabilizer for various periods of time.

FIG. 8 is the drug release profile of GO (a) and GO-g-PHBV (b) compatibilizers.

FIG. 9 is a morphology of biodegradable aliphatic polyester and GO blend films (a) PHBV/GO blend films; (b) PHBV/GO/GO-g-PHBV blend membrane; (c) a PLA/GO blend film; (d) PLA/GO/GO-g-PHBV blend film.

FIG. 10 is the surface contact angle of biodegradable aliphatic polyester and GO blend films (a) PHBV/GO blend films; (b) PHBV/GO/GO-g-PHBV blend membrane; (c) a PLA/GO blend film; (d) PLA/GO/GO-g-PHBV blend film.

Detailed Description

The present invention will be described in further detail with reference to examples and drawings, but the embodiments of the present invention are not limited thereto. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

The reagents used in the examples are commercially available without specific reference.

Example 1: synthesis of biodegradable compatilizer GO-g-PHBV

Placing 0.1g of isocyanic acid modified graphene oxide (Xianfeng nanometer, cat # 101343) in a round-bottom flask, introducing nitrogen, adding 20mL of anhydrous N, N-dimethylformamide, and performing ultrasonic treatment for 30min under the power of 400W to obtain isocyanic acid modified graphene oxide dispersion liquid; 0.1g of telechelic poly [ (3-hydroxybutyrate) -co- (3-hydroxyvalerate) with two hydroxyl end-capped](OH-PHBV-OH, Western reagent, number average molecular weight 3.4×10³Molecular weight polydispersity index of 1.4), placing in a small glass bottle, introducing nitrogen, adding 10mL of anhydrous N, N-dimethylformamide, and magnetically stirring at 200r/min at room temperature for 25min until completely dissolving to obtain telechelic poly [ (3-hydroxybutyrate) -co- (3-hydroxyvalerate) with two hydroxyl end caps]The solution of (1); dropping the dispersion liquid of the graphene oxide modified by isocyanic acid into an OH-PHBV-OH solution under the protection of nitrogen, adding 0.1g of dibutyltin dilaurate, reacting at 80 ℃ at a stirring speed of 400r/min for 24h, cooling to room temperature, repeatedly washing the anhydrous N, N-dimethylformamide and anhydrous dichloroethane mixed solution (the volume ratio is 1:1) for 5 times, and freeze-drying the product to obtain the biodegradable compatilizer GO-g-PHBV.

Example 2: structural characterization of a biodegradable compatilizer GO-g-PHBV.

The infrared spectrums of GO and the biodegradable compatilizer GO-g-PHBV are shown in figure 1.GO is at 3400.0cm^-1、1740.2cm^-1And 1630.4cm^-1The peaks in (b) correspond to a resonance peak of a hydroxyl group (-OH), a stretching vibration peak of a carbonyl group (C ═ O), and a stretching vibration peak of a carbon (C ═ C) in the surface aromatic structure, respectively. Furthermore, 1220.3cm^-1And 1080.5cm^-1Characteristic absorption peaks of epoxy groups and alkoxy groups. The biodegradable compatilizer GO-g-PHBV is 2900cm^-1A methyl double peak appears nearby, which indicates that OH-PHBV-OH is successfully introduced. Notably, the isocyanate group is 2323.7cm^-1The nearby characteristic absorption peak disappears, which shows that the isocyanic acid modified graphene oxide and the telechelic PHBV with the hydroxyl groups at the two ends blocked have a grafting reaction.

The X-ray diffraction patterns of GO and the biodegradable compatilizer GO-g-PHBV are shown in figure 2. A sharp diffraction peak of GO appears at 10.32 ° 2 θ, which is a characteristic diffraction peak of GO, and a characteristic peak of graphite at 26.5 ° 2 θ does not appear in the figure. The diffraction peak 2 theta of the biodegradable compatilizer GO-g-PHBV is 9.59 degrees, and the interlayer spacing is larger than that of GO.

The Raman spectrum of GO and the biodegradable compatilizer GO-g-PHBV is shown in figure 3. The D band and the G band of GO respectively appear at 1344.5cm^-1And 1595.2cm^-1Nearby. The D band of the biodegradable compatilizer GO-g-PHBV appears at 1345.1cm^-1Near, the G band goes outNow 1594.0cm^-1Nearby. Compared with GO, the D band and the G band of the biodegradable compatilizer GO-G-PHBV do not shift obviously, but the intensity ratio of the D band peak and the G band peak is increased, which shows that the original stacking structure lamella of GO is disordered gradually from the ordered structure, and the molecules are toughened gradually.

A transmission electron microscope image of GO and a biodegradable compatilizer GO-g-PHBV is shown in figure 4. GO is of a lamellar structure with sharp edges. The GO sheets in the biodegradable compatilizer GO-g-PHBV are stacked, and the edges are passivated.

Example 3: and (3) antibacterial experiments of the biodegradable compatilizer.

The biodegradable compatibilizer GO-g-PHBV obtained in example 1 was used for antibacterial analysis by colony counting. 100 μ L of activated E.coli and S.aureus (ATCC8099 and ATCC6538, available from the institute of microbiology, Guangdong province) suspension, at OD 0.1, were placed in 10mL of 1.5mg/mL GO-g-PHBV compatibilizer in water to ensure that the bacteria concentration was CFU 10⁵～10⁶The mixture was shaken in a shaker at 37 ℃ for 24 hours. Taking 1mL of bacterial liquid in a test tube A containing 9mL of physiological saline, shaking uniformly, taking 1mL of bacterial liquid in a test tube B containing 9mL of physiological saline again, diluting in a gradient manner, and respectively taking CFU (carbon fiber unit) ═ 10¹And CFU 10²The bacterial suspension 100 mu L is placed on an agar plate, is evenly coated by a coater, is marked, is placed upside down in a bacterial incubator and is cultured for 18h at 37 ℃, and the number of colonies is calculated. Physiological saline added with bacterial suspension was used as a positive Control group (Control). Before the test, normal saline without adding bacterial suspension is used as a negative control group, and the test is regarded as aseptic operation if no bacterial colony appears. The sterilization rate (R) was calculated according to the following formula:

wherein N is₀And N is the average colony number of the positive control group and the experimental group, respectively. The test results are shown in fig. 5. The sterilization rate of GO and the biodegradable compatilizer GO-g-PHBV to E.coli is 93.33 percent and 71.33 percent respectively, and the sterilization rate to S.aureus is 91.44 percent and 62.90 percent respectively. The biodegradable compatilizer GO-g-PHBV has a good bactericidal effect.

Example 4

Toxicity test of the biodegradable compatilizer. The biodegradable compatilizer GO-g-PHBV in example 1 was used to study cytotoxicity by the CCK-8 method. Soaking the GO-g-PHBV compatilizer for 24 hours by adopting a DMEM culture medium to obtain a GO-g-PHBV compatilizer leaching liquor, wherein the concentration of the compatilizer is 200 mug/mL. Taking mouse fibroblast (3T3) cells in logarithmic growth phase, discarding culture medium, washing with PBS, adding 2mL of pancreatin for digestion for 2min, adding 2mL of complete culture medium (containing DMEM, 10% FBS and 1% double antibody), centrifuging, discarding supernatant, adding 2mL of PBS to clean cells, and discarding PBS; 2mL of complete medium was added and the cells gently pipetted evenly. 10 μ L of cell suspension was counted in a cell counting plate and the cell density was diluted to 5X 10 with fresh complete medium⁴one/mL. 100 μ L of the cell suspension was seeded in 96-well plates at a concentration of 5000 cells per well in CO₂Culturing in incubator for 24h, sucking off original culture medium, adding 200 μ L GO-g-PHBV compatilizer leaching solution and FBS mixed solution (volume ratio of FBS to GO-g-PHBV compatilizer leaching solution in mixed solution is 1:9), and adding into CO₂Culturing in an incubator for 24h, 48h and 72 h. The well plate was removed at the corresponding time point, the original medium was aspirated off the well, 100. mu.L complete medium was added, 10. mu.L LCCK-8 solution was added, and CO at 37 ℃ was added₂Incubating in an incubator for 4h in the absence of light, measuring the absorbance (OD value) at a wavelength of 450nm by using a microplate reader, and calculating the relative proliferation rate (RGR) of 3T3 cells according to the following formula: RGR (%) ═ (OD)_{Experimental group}-OD_{Blank group})/(OD_{Negative control group}-OD_{Blank group}) X 100%. The relative proliferation rates of GO cells were compared by the same method, and the results are shown in FIG. 6, where only cell suspension and DMEM medium were used as negative Control groups (controls) and only DMEM medium was used as blank Control groups, and each group had 3 duplicate wells. RGRs of GO at 24h, 48h and 72h are 72.88%, 67.20% and 60.40%, respectively, and the cytotoxicity grade is grade II, and the cytotoxicity is mild; the RGRs of the GO-g-PHBV compatilizer are 86.36%, 81.40% and 78.38% respectively, the cytotoxicity grade is I, and the compatibility agent has no cytotoxicity. The results show that the cells of the compatibilizer are non-toxic and have cytotoxicity levels significantly lower than those of cells that can degrade component GO in aliphatic polyester/GO blendsToxicity.

Example 5: hemolysis test of biodegradable compatilizer

And (3) adding 8mL of PBS into 2mL of fresh anticoagulated whole blood, gently blowing and uniformly mixing, centrifuging at 3000rpm for 6min, discarding supernatant, adding the PBS, gently mixing, centrifuging again to wash erythrocytes, and repeating the same method for 5 times. The washed erythrocyte pellet was diluted with fresh PBS to prepare an erythrocyte suspension with a concentration of 5% by volume fraction. The GO-g-PHBV compatibilizer in example 1 was dispersed in PBS, and 500. mu.L of the compatibilizer dispersion was mixed with 500. mu.L of the above red blood cell suspension to give final concentrations of 100, 200, 500, and 1000. mu.g/mL of compatibilizer. The mixture of the compatilizer and the red blood cells is respectively incubated for 15min, 60min, 2h, 4h and 8h in a shaking table at 37 ℃, and centrifuged for 6min at 3000 rpm. A150. mu.L portion of the supernatant was transferred to a 96-well plate, and the OD at 490nm of the sample was measured using a microplate reader, and the hemolysis rate was calculated according to the following formula:

wherein A is the OD value of the experimental group, B is the OD value of a negative control group (PBS), and C is the OD value of a positive control group (deionized water). Meanwhile, the hemolysis rate of GO was compared, and 3 sets of parallel experiments were set for each set, with the results shown in fig. 7. GO-g-PHBV compatibilizer at a concentration of 200. mu.g/mL did not cause hemolysis when incubated with red blood cells for 480min (FIG. 7A). The hemolysis rate of erythrocytes after 3h incubation of GO-g-PHBV compatilizer with different concentrations and the hemolysis rate of erythrocytes after 1mg/mL GO-g-PHBV compatilizer incubation for different times are shown in FIGS. 7B and 7C. The GO with the concentration of 500 mu g/mL and 1mg/mL has hemolysis, while the hemolysis rate of different GO-g-PHBV compatilizers is lower than 5% without hemolysis.

Example 6: drug loading and release experiments of biodegradable compatibilizers.

Taking 2mg of the GO-g-PHBV compatilizer in the embodiment 1, respectively mixing with 1mg, 2mg and 5mg of Roxithromycin (ROX), dissolving in 10mL of dimethyl sulfoxide, carrying out ultrasonic treatment for 10min, centrifuging at 10000rpm for 30min, discarding the supernatant to obtain a medicine-loaded GO-g-PHBV compatilizer, and carrying out vacuum drying to obtain the GO serving as a control group. The absorbance of the free ROX in the supernatant was measured using an ultraviolet-visible spectrophotometer, and the amount of free ROX was calculated from the standard curve, and the resulting encapsulation efficiency and drug loading were as shown in table 1. As the concentration of ROX increases, the encapsulation efficiency and drug loading of GO-g-PHBV compatibilizer increases, and GO sheets as a control also tend to increase. Under the condition of the same concentration, the encapsulation efficiency and the drug loading of the GO-g-PHBV compatilizer are far higher than those of a control group GO. At ROX concentrations of 0.2mg/mL and 0.5mg/mL, the encapsulation efficiency and drug loading of the GO-g-PHBV compatilizer are 1.67 times that of the GO in the control group. The drug release of the GO-g-PHBV compatibilizer is shown in FIG. 8. The GO-g-PHBV compatilizer loaded with the medicine releases 65-88% of the medicine in the first 9 hours and 75-95% in 24 hours, and the concentration of the medicine is increased along with the initial ROX concentration. The GO of the control group rapidly releases 48-85% of the drug in the first 3 hours, and then slowly releases the drug to 55-85% in 24 hours. As can be seen, the GO-g-PHBV compatilizer has an obvious drug slow-release effect.

TABLE 1 encapsulation efficiency and drug loading of GO and GO-g-PHBV compatibilizers

Example 7

And (3) preparing a degradable aliphatic polyester/GO/GO-g-PHBV compatilizer blending film. 200mg of PHBV (number average molecular weight 1.85X 10) was taken⁵Shanghai Michelin Biochemical technology Ltd.) and polylactic acid (PLA, weight average molecular weight 8.00X 10⁴Shanghai Michelin Biochemical technology Co., Ltd.) are respectively placed in a small glass bottle, 10mL of chloroform is added, magnetic stirring is carried out, 15mg of GO and 5mg of GO-g-PHBV in the embodiment 1 are sequentially added, magnetic stirring is carried out for 30min at the speed of 200r/min until the PHBV and the PLA are dissolved, chloroform suspensions of the PHBV/GO/GO-g-PHBV and the PLA/GO/G-PHBV are respectively obtained, 200 mu L of the above-mentioned PHBV/GO/GO-g-PHBV and PLA/GO/GO-g-PHBV suspensions are respectively dropped on a round glass slide, and natural air drying is carried out for 20min to prepare PHBV/GO/GO-g-PHBV and PLA/GO/G-PHBV blend membranes respectively. Respectively weighing 200mg of PHBV and PLA by a similar method, and blending with 20mg of GO to obtain a PHBV/GO and PLA/GO blended film. GO in the PHBV/GO and PLA/GO blended film is obviously agglomerated, the size of GO aggregates is large, and fine cracks are formed at the phase interface of the GO aggregates and PHBV or PLA matrixes. After the GO-g-PHBV interface compatilizer is added, the agglomeration phenomenon of GO is obviously improved, and the PH value is higherThe GO aggregate size in BV/GO/GO-g-PHBV and PLA/GO/GO-g-PHBV blend membranes is obviously reduced, and the compatibility of two-phase interfaces is obviously improved (figure 9). Because the PHBV is compatible with the PLA, the GO-g-PHBV can be used as an interface compatilizer of a PLA and GO blending film. The surface contact angles of the four blend films are shown in fig. 10. The surface water contact angles of the PHBV/GO and PLA/GO blended films are 81 degrees and 78 degrees, and the water contact angles of the blended films are reduced to 49 degrees and 51 degrees after the GO-g-PHBV compatilizer is added. The surface hydrophilicity of the blend membrane containing the GO-g-PHBV compatilizer is increased due to the uniform distribution of GO.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.

Claims

1. A preparation method of a biodegradable compatilizer is characterized by mainly comprising the following steps:

2. The method for preparing a biodegradable compatibilizer according to claim 1, comprising the steps of:

the dispersant in the step (1) is at least one of anhydrous N, N-dimethylformamide and anhydrous dichloromethane;

the concentration of the isocyanic acid modified graphene oxide dispersion liquid in the step (1) is 0.001-0.01 g/mL.

3. The method for preparing a biodegradable compatibilizer according to claim 1, comprising the steps of:

the telechelic polymer with the two hydroxyl end caps in the step (2) is at least one of telechelic polyhydroxyalkanoate with the two hydroxyl end caps and telechelic polyhydroxyalkanoate with the two hydroxyl end caps; preferably a double-end hydroxyl-terminated poly [ (3-hydroxybutyrate) -co- (3-hydroxyvalerate) ];

the number average molecular weight of the telechelic polymer with the two end hydroxyl groups being terminated in the step (2) is 2000-4000 g/mol, and the molecular weight polydispersity coefficient is 1.1-1.6.

4. The method for preparing a biodegradable compatibilizer according to claim 1, comprising the steps of:

the solvent in the step (2) is at least one of anhydrous N, N-dimethylformamide, anhydrous dichloroethane and anhydrous dimethyl sulfoxide;

the concentration of the telechelic polymer solution with the two end hydroxyl groups being terminated in the step (2) is 0.005-0.05 g/mL.

5. The method for preparing a biodegradable compatibilizer according to claim 1, comprising the steps of:

the catalyst in the step (3) is at least one of dibutyltin dilaurate and stannous octoate; the catalyst and the telechelic polymer with two end hydroxyl end capping are mixed according to the mass ratio (0.15-0.25) to 1.

6. The method for preparing a biodegradable compatibilizer according to claim 1, comprising the steps of:

the reaction in the step (3) is carried out for 8-48 h at 50-100 ℃.

7. The method for preparing a biodegradable compatibilizer according to claim 1, comprising the steps of:

the telechelic polymer with two hydroxyl groups blocked in the step (3) and the isocyanic acid modified graphene oxide are mixed according to the mass ratio of 1 (1-3).

8. The method for preparing a biodegradable compatibilizer according to claim 1, comprising the steps of:

the purification in the step (3) adopts anhydrous N, N-dimethylformamide or a mixed solution of the anhydrous N, N-dimethylformamide and the anhydrous dichloroethane for centrifugal washing, and the washing is repeated for 3-8 times; the volume ratio of the anhydrous N, N-dimethylformamide to the anhydrous dichloroethane in the mixed solution is (3-0.5) to 1;

and (4) carrying out freeze drying treatment for 18-48 h in the step (3).

9. A biodegradable compatibilizer prepared according to the method of any one of claims 1-8.

10. Use of the biodegradable compatibilizer of claim 9 in preparing a biodegradable aliphatic polyester/GO blend.