CN114790329B - High mechanical property linear shape memory polyurethane/cellulose nanocrystalline composite material and preparation method and application thereof - Google Patents

High mechanical property linear shape memory polyurethane/cellulose nanocrystalline composite material and preparation method and application thereof Download PDF

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CN114790329B
CN114790329B CN202210609108.5A CN202210609108A CN114790329B CN 114790329 B CN114790329 B CN 114790329B CN 202210609108 A CN202210609108 A CN 202210609108A CN 114790329 B CN114790329 B CN 114790329B
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cncs
iso2
shape memory
composite material
memory polyurethane
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CN114790329A (en
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罗彦凤
王远亮
杨伟
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Chongqing University
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Abstract

The invention provides a high mechanical property linear shape memory polyurethane/cellulose nanocrystalline composite material and a preparation method and application thereof, belonging to the field of biological materials. The composite material is prepared from shape memory polyurethane and cellulose nanocrystals, wherein the content of the cellulose nanocrystals is 0.5-20wt%. The composite material of the invention not only maintains excellent shape memory performance, but also greatly improves mechanical property and osteoinductive effect, and has wide application prospect in preparing bone tissue engineering biological materials.

Description

High mechanical property linear shape memory polyurethane/cellulose nanocrystalline composite material and preparation method and application thereof
Technical Field
The invention belongs to the field of biological materials, and particularly relates to a high-mechanical-property linear shape memory polyurethane/cellulose nanocrystalline composite material, and a preparation method and application thereof.
Background
Bone defects caused by severe wounds, tumors, deformities and the like are always important and difficult points of clinical orthopedics treatment. In recent years, with rapid development of tissue engineering, various bone tissue engineering biomaterials have emerged. Among them, linear Shape Memory Polyurethanes (SMPUs) have been considered as a promising bone tissue engineering biomaterial due to their unique chemical structure and shape memory effect. The features of alternating soft segments and alternating hard segments present in the SMPUs result in microphase separation, forming nano-to micro-scale islands-in-the-sea hard segment aggregation regions distributed in the continuous soft regions. This phase-separated structure can promote osteoblast differentiation and calcification, thereby promoting bone formation. The shape memory effect of the SMPus can be used for minimally invasive implantation and complete filling of bone defects, promoting bone formation. However, biodegradable linear shape memory polyurethanes with glass transition temperatures between 37 and 45 ℃ have been reported to have low strength and elastic modulus at room temperature (Chun b., et al, eur Polym j.,2006,12,3367;Marzec M,et al, materials Science and Engineering: c.2017,80,736; cn201010239463.5). When the temperature is increased to the physiological temperature (37 ℃) of the human body, the mechanical property of the polyurethane is further reduced due to the enhanced molecular chain mobility of the polyurethane, and the use requirement cannot be met.
Chinese patent application No. 202010081133.1 discloses a biodegradable linear shape memory polyurethane having a shape memory temperature (glass transition temperature) between 38 and 44 ℃ due to the double ring rigid structure and long chain hard segments of isosorbide. The linear shape memory polyurethane has a tensile strength of 32.3-52.9 MPa at 25 ℃ and 18.1-32.3 MPa at 37 ℃. The linear shape memory polyurethane has higher mechanical properties at room temperature and physiological temperature of human body, and solves the problems of insufficient mechanical properties or overhigh shape recovery temperature of the traditional biodegradable linear shape memory polyurethane at physiological temperature of human body to a certain extent. However, on one hand, the mechanical property of the linear shape memory polyurethane at the physiological temperature (37 ℃) of a human body still cannot meet the use requirement and needs to be further improved; on the other hand, the osteoinductive properties of the linear shape memory polyurethane are also to be further improved.
In order to further improve the mechanical properties of the shape memory polyurethane material, chinese patent application No. 201910355538.7 discloses a preparation method of a shape memory aqueous polyurethane/cellulose nanocrystalline composite material, comprising: a) Heating and dehydrating macromolecular dihydric alcohol, and then stirring the dehydrated macromolecular dihydric alcohol with diisocyanate to react to obtain a first prepolymer; b) Reacting the first prepolymer with a solvent, a small molecular diol chain extender, a hydrophilic chain extender, a blocking agent and a catalyst to obtain a second prepolymer; c) Neutralizing the second prepolymer with a neutralizing agent, reacting with a diamine chain extender in deionized water, dispersing and emulsifying, and removing the solvent to obtain the shape memory aqueous polyurethane emulsion; d) And mixing the cellulose nanocrystalline powder dispersion liquid with the shape memory aqueous polyurethane emulsion, and uniformly dispersing by ultrasonic to obtain the shape memory aqueous polyurethane/cellulose nanocrystalline composite material. According to the method, the shape memory aqueous polyurethane is prepared, and the fixing rate and the recovery rate of the shape memory aqueous polyurethane are improved by compounding the shape memory aqueous polyurethane with cellulose nanocrystals, so that the tensile strength (up to 552.6-582.6 MPa) of the material is further improved. However, the mechanical property of the shape memory aqueous polyurethane/cellulose nanocrystalline composite material still cannot meet the requirement of bone repair, because the Young modulus of the composite material is only 5.0-21.3MPa, which is far lower than the Young modulus of cortical bone and cancellous bone of human body (3000-30000 MPa and 50-5000 MPa respectively).
In order to promote the application of polyurethane in the field of bone tissue engineering, in particular to the application of repairing a bearing part, the development of a linear shape memory polyurethane material with more excellent mechanical property and osteoinductive property is of great significance.
Disclosure of Invention
The invention aims to provide a linear shape memory polyurethane/cellulose nanocrystalline composite material with excellent mechanical property and osteoinductive property, and a preparation method and application thereof.
The invention provides a shape memory polyurethane composite material, which is prepared from shape memory polyurethane and cellulose nanocrystals, wherein the content of the cellulose nanocrystals is 0.5-20wt%;
the shape memory polyurethane is prepared by taking cyanate coupling agent, macromolecular diol and catalyst as raw materials for reaction, wherein the cyanate coupling agent is aliphatic diisocyanate blocked isosorbide coupling agent.
Further, the content of the cellulose nanocrystals is 1wt% to 15wt%, preferably 10wt%.
Further, the molar ratio of the cyanate coupling agent, the macromolecular diol and the catalyst is (1.1-2.0): 1: (0.1-0.8), preferably 1.5:1:0.5.
further, the preparation method of the cyanate coupling agent comprises the following steps: adding aliphatic diisocyanate and isosorbide into a reaction device, adding a solvent for dissolution, adding a catalyst, and reacting in an inert gas environment to obtain the catalyst;
wherein the molar ratio of the aliphatic diisocyanate to the isosorbide is (3-5): 1, preferably 4:1; the solvent is an organic solvent, preferably DMF; the molar ratio of isosorbide to catalyst (400-600): 1, preferably 500:1; the temperature of the reaction is 55-95 ℃, preferably 75 ℃ and the time is 0.5-2h, preferably 1h; the aliphatic diisocyanate is preferably 1, 6-hexamethylene diisocyanate.
Further, the macromolecular diol is a product obtained by taking lactide, polyethylene glycol and a catalyst as raw materials for reaction, wherein the molar ratio of the lactide to the polyethylene glycol to the catalyst is (4000-6000): (50-150): 1, preferably 5000:100:1; the lactide is preferably D, L-lactide, and the polyethylene glycol is preferably PEG400; the temperature of the reaction is 120-160 ℃, preferably 140 ℃ for 12-36 hours, preferably 24 hours.
Further, the catalyst is stannous octoate.
Further, the particle size of the cellulose nanocrystalline is 100nm-35 mu m.
The invention also provides a method for preparing the shape memory polyurethane composite material, which comprises the following steps:
(1) Uniformly mixing shape memory polyurethane and cellulose nanocrystals to obtain a mixture;
(2) And (3) fusing, mixing and molding the mixture to obtain the shape memory polyurethane composite material.
Further, in the step (1), the uniform mixing mode is that a grinder is used for mixing for 3-7 minutes;
in the step (2), the temperature of the fusion mixing is 90-130 ℃ and the time is 3-7 minutes; the molding mode is injection molding or hot press molding.
The invention also provides application of the shape memory polyurethane composite material in preparing bone tissue engineering biological materials.
According to the invention, CNCs particles and ISO2-PU powder are physically premixed, then are subjected to melt extrusion in a counter-rotating double-screw extruder, and are molded, so that the CNCs/ISO2-PU composite material is prepared, and has the following beneficial effects:
(1) compared with the ISO2-PU material, the mechanical property of the CNCs/ISO2-PU composite material is greatly improved, especially sigma when tested at physiological temperature (37 ℃), and the composite material is prepared from the CNCs/ISO2-PU composite material t And E is t The maximum increases are 36.7% and 89.7%, respectively.
(2) Compared with ISO2-PU, the CNCs/ISO2-PU composite material has improved heat stability.
(3) T of CNCs/ISO2-PU composite material compared with ISO2-PU g The composite material of the invention maintains an excellent shape without significant changes and still within the ideal temperature range of the biomedical shape memory polymeric materialMemory performance.
(4) Compared with the PDLLA material and the ISO2-PU material approved by the FDA for bone tissue engineering, the CNCs/ISO2-PU composite material with the CNCs content of 10 weight percent has obviously enhanced osteoinductive effect and osteogenic capacity.
(5) The CNCs particles in the CNCs/ISO2-PU composite material can be better dispersed in a matrix due to the fact that the CNCs particles have a lower specific surface area when being fused and compounded with the thermoplastic polymer, and experimental results also show that the CNCs particles in the CNCs/ISO2-PU composite material are very uniformly dispersed in the ISO2-PU matrix, and hydrogen bonds are not formed between the CNCs particles and the ISO2-PU long hard segments.
(6) The method for preparing the CNCs/ISO2-PU composite material avoids the use of a large amount of organic solvents, is more environment-friendly and is easier for industrial production.
In conclusion, the CNCs/ISO2-PU composite material provided by the invention has wide application prospect in preparing bone tissue engineering biological materials.
It should be apparent that, in light of the foregoing, various modifications, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.
The above-described aspects of the present invention will be described in further detail below with reference to specific embodiments in the form of examples. It should not be understood that the scope of the above subject matter of the present invention is limited to the following examples only. All techniques implemented based on the above description of the invention are within the scope of the invention.
Drawings
FIG. 1 shows a synthetic route diagram of PDLLA-PEG400-PDLLA macrodiol.
FIG. 2 is a schematic illustration of the preparation of CNCs/ISO2-PU composites.
FIG. 3 shows the IR spectra of CNCs, ISO2-PU and CNCs/ISO2-PU composites, with (a) and (c) being the enlargement of the corresponding regions in (b), respectively.
FIG. 4.110 shows the change in storage modulus (G') of ISO2-PU and CNCs/ISO2-PU composites (5 wt% and 15 wt%) with strain.
FIG. 5.110C (a) of ISO2-PU and CNCs/ISO2-PU composites: storage modulus (G') and (b): complex viscosity (η) versus shear frequency curve.
SEM pictures of cncs particles.
SEM (a-e) and optical microscope pictures (f-j) of CNCs/ISO2-PU composite materials, the CNCs content was: 0wt% (a, e), 1wt% (b, f), 5wt% (c, g), 10wt% (d, h) and 15wt% (e, j).
FIG. 8 tensile stress strain curves for ISO2-PU and CNCs/ISO2-PU composites at 25deg.C (a) and 37deg.C (b).
FIG. 9 shows the storage modulus (a) and tan delta (b) curves of ISO2-PU and CNCs/ISO2-PU composites (CNCs content 5wt%,10wt% and 15 wt%) obtained by DMA test.
DSC curve (a), TGA curve (b) and DTG curve (c) of ISO2-PU and CNCs/ISO2-PU composites.
FIG. 11 is a 2D shape memory process diagram of a CNCs/ISO2-PU composite material with an ISO2-PU (a) and CNCs content of 5wt% (b), 10wt% (c) and 15wt% (D).
FIG. 12 is a 3D shape memory process diagram of a CNCs/ISO2-PU composite material with an ISO2-PU (a) and CNCs content of 5wt% (b), 10wt% (c) and 15wt% (D).
FIG. 13 illustrates the shape memory process of CNCs/ISO2-PU composite material (CNCs content 10 wt%) at 60 ℃.
ALP activity after 4, 7 and 14 days of co-culture of OBs with PDLLA, ISO2-PU and CNCs/ISO2-PU composites (CNCs content 10 wt.%) (< 0.05, (< 0.001) p).
FIG. 15 ARS staining (scale 500 μm) of calcium deposition after 21 days of co-cultivation of OBs with PDLLA, ISO2-PU and CNCs/ISO2-PU composites (CNCs content 10 wt%).
FIG. 16 SEM pictures of the surface morphology of films used in vitro mineralization experiments (a) PDLLA, (b) ISO2-PU and (c) CNCs/ISO2-PU composites (CNCs content 10 wt%).
Detailed Description
The raw materials and equipment used in the invention are all known products and are obtained by purchasing commercial products.
D, L-lactide: the laboratory is self-made, and the purity is more than or equal to 99 percent; isosorbide (ISO): sigma-Aldrich, inc., america, analytical grade; stannous octoate (Sn (Oct) 2 ) Beauty of the designNational Sigma-Aldrich company, analytical grade; 1, 6-Hexamethylene Diisocyanate (HDI): analytical grade, alatin Biochemical technologies Co., ltd; n, N-Dimethylformamide (DMF): anatine Biochemical technologies Co., ltd, anhydrous grade; cellulose Nanocrystalline (CNCs) particles are purchased from Ciscow technology nanomaterials Inc., zeta potential about-50 eV.
Example 1: preparation of CNCs/ISO2-PU composite material
Step 1: preparation of coupling agent HDI-ISO-HDI
HDI and ISO were added to a round bottom single neck flask in a molar ratio of 4:1 while placing a magnetic stirrer at m (ISO, g): v (DMF, mL) =1:6 ratio anhydrous grade DMF was added to a single-port flask, and magnetic stirring was performed to completely dissolve ISO; and then ISO and Sn (Oct) 2 Sn (Oct) is added in a molar ratio of 500:1 2 After nitrogen is replaced for three times, the mixture is reacted for 1h at 75 ℃ under the protection of nitrogen; after the reaction is finished, cooling to room temperature, and placing unreacted HDI by using n-hexane dried by a molecular sieve to obtain white powder, and drying to constant weight to obtain the novel diisocyanate coupling agent of the HDI end-capped ISO, which is named as HDI-ISO-HDI.
Step 2: preparation of macromolecular diol PDLLA-PEG400-PDLLA
D, L-lactide, PEG400, sn (Oct) 2 Adding a round bottom single-mouth bottle with a magnetic stirrer according to the mol ratio of 5000:100:1, vacuumizing for 30min, and sealing; placing the single-mouth bottle into an oil bath pot at 140 ℃, starting magnetic stirring after the mixture is completely melted, uniformly stirring a reaction system, and continuously reacting for 24 hours; repeatedly purifying the product for three times by adopting a dichloromethane/ice absolute ethyl alcohol (-15 ℃ and the volume ratio of dichloromethane to ice absolute ethyl alcohol is 1:10) coprecipitation system after the reaction is finished, and purifying once by adopting a dichloromethane/ice n-hexane (-15 ℃ and the volume ratio of dichloromethane to ice n-hexane is 1:8) coprecipitation system; vacuum drying at room temperature for 72 hr to obtain target macromolecular diol named PDLLA-PEG400-PDLLA. The synthetic route of PDLLA-PEG400-PDLLA is schematically shown in FIG. 1.
Step 3: preparation of polyurethane Material ISO2-PU
Adding HDI-ISO-HDI and PDLLA-PEG400-PDLLA into a circle with a stirring rod according to a molar ratio of 1.5:1.0A bottom four-necked flask with m (PDLLA-PEG 400-PDLLA, g): v (DMF, mL) =5:4, anhydrous DMF was added, and stirred to completely dissolve the solid; then PDLLA-PEG400-PDLLA and Sn (Oct) 2 Sn (Oct) is added in a molar ratio of 500:1 2 Reacting for 3 hours at 75 ℃ under the protection of nitrogen; finally, adding ISO into the mixture according to the ratio of PDLLA-PEG400-PDLLA to ISO in a molar ratio of 1.0:0.5, and continuing to react for 16 hours; after the reaction, cooling to room temperature, diluting with dichloromethane, precipitating and purifying the product in absolute ethyl alcohol twice (the volume ratio of the diluted solution to the absolute ethyl alcohol is 1:10), and purifying the product once by using a dichloromethane/normal hexane coprecipitation system (the volume ratio of dichloromethane to normal hexane is 1:8). And (3) vacuum drying the purified product to constant weight to obtain the polyurethane material, which is named as ISO-PUs.
Step 4: injection molding process for preparing CNCs/ISO2-PU composite material
The powdery CNCs particles were dried under vacuum at 60℃for 2 days and the ISO2-PU powder was dried under vacuum at 40℃for 5 days. Then, ISO2-PU powders of different proportions were mixed with CNCs at 1800rpm for 5min using a grinder to obtain a mixture, and the contents of CNCs in the final mixture were controlled to be 1wt%, 3wt%, 5wt%, 7wt%, 10wt%, 15wt%, respectively. Next, the mixture was melt-mixed in a counter-rotating twin-screw extruder, and the mixing process was performed at a speed of 60rpm for 5 minutes at a temperature of 110 ℃. Finally, injection molding is carried out by an injection molding machine to obtain the CNCs/ISO2-PU composite material, wherein the injection molding conditions are as follows: preserving heat at 120 ℃ for 30s while keeping the pressure at 10MPa and the temperature of the die at 30 ℃.
Example 2: preparation of CNCs/ISO2-PU composite material
Step 1-3: as in example 1.
Step 4: preparation of CNCs/ISO2-PU composite material by hot press molding process
The powdery CNCs particles were dried under vacuum at 60℃for 2 days and the ISO2-PU powder was dried under vacuum at 40℃for 5 days. Then, ISO2-PU powders of different proportions were mixed with CNCs at 1800rpm for 5min using a grinder to obtain a mixture, and the contents of CNCs in the final mixture were controlled to be 1wt%, 3wt%, 5wt%, 7wt%, 10wt%, 15wt%, respectively. Next, the mixture was melt-mixed in a counter-rotating twin-screw extruder, and the mixing process was performed at a speed of 60rpm for 5 minutes at a temperature of 110 ℃. Finally, the mixture is hot-pressed for 5min at 120 ℃ by using a heating plate to form the membranous CNCs/ISO2-PU composite material.
The following experiments prove the beneficial effects of the invention.
Experimental example 1: infrared spectroscopy testing
1. Test sample
Pure CNCs, ISO2-PU and the CNCs/ISO2-PU composite material prepared by hot press molding.
2. Experimental method
The samples were recorded at 400-4000 cm using a Fourier transform infrared spectrometer (Nicolet iS50, thermo Fisher Scientific Co.) -1 FT-IR (transmittance) spectrum in the range with resolution of 4cm -1 Each sample was scanned 16 times.
3. Experimental results
FIG. 3 is the FT-IR spectrum of pure CNCs, ISO2-PU and CNCs/ISO2-PU composites. 3250-3500 cm of pure CNCs -1 The strong absorption peak of (2) is the stretching vibration peak of-OH group on the surface of CNCs, 2897cm -1 The absorption peak at this point is-CH in CNCs 2 -stretching vibration peak of group 1647cm -1 The absorption peak at this point is that of the adsorbed water in CNCs. 1754cm for ISO2-PU spectrogram -1 The absorption peak at the position belongs to the stretching vibration peak of the ester-C=O group, and is 2800 cm to 3040cm -1 The absorption peak at the site is-CH in PDLLA-PEG400-PDLLA triblock macrodiol (being the soft segment of ISO 2-PU) 2 -and-CH 3 Stretching vibration peaks of the groups. At the same time at 3300-3400cm -1 、1600-1731cm -1 And 1526cm -1 The peaks at these belong to the characteristic absorption peaks of the-NH group, the amide I band (-c=o group) and the amide II band (-NH group) in the urethane bond, respectively. 1731cm -1 The absorption peak at this point is a characteristic absorption peak of free-c=o in the urethane bond, and 1630cm -1 And 1650cm -1 Peaks at ordered and disordered hydrogen bonding carbamate-c=o, respectively, which are 1754cm apart -1 The stretching vibration peaks of the ester-c=o groups at the positions partially overlap. 1630-1650cm after adding CNCs particles into ISO2-PU -1 Where (a)The peak intensity gradually decreases with increasing content, and the CNCs content almost disappears after exceeding 5wt%. At the same time, 3320cm in the spectrum of pure ISO2-PU -1 (formation of ordered hydrogen bond-NH) and 3340cm -1 The absorption peak at (disordered hydrogen bond-NH) is significantly higher than 3400cm -1 An absorption peak at (free-NH). The CNCs are added to a volume of 3320cm -1 The peak intensity at this point gradually decreases and almost disappears after the CNCs content exceeds 5wt%. Furthermore, with further increase in the CNCs content, 3340cm -1 The peak at the position is gradually higher than 3400cm -1 The peak at this point, probably due to the large increase in-OH groups in the composite.
The result shows that the invention successfully synthesizes the CNCs/ISO2-PU composite material added with CNCs.
Experimental example 2: rheological Performance test
1. Test sample
CNCs, ISO2-PU and the CNCs/ISO2-PU composite material prepared by hot press molding.
2. Experimental method
Rheometry was performed on an AR-G2 rotarheometer (TA Instruments, USA) equipped with parallel plates 25mm in diameter. The composite material for rheometry was processed in an injection-molded manner into a sheet of 25mm diameter and 1mm thickness. The sample was melted for 3 minutes at the measured temperature before the measurement began.
3. Experimental results
The rheology test temperatures of the ISO2-PU and CNCs/ISO2-PU composites (CNCs content 5wt% and 10 wt%) were set to 110℃and the dynamic strain sweep curves obtained are shown in FIG. 4. It can be seen that the strain curves for the three materials are linear from 0% to 100% and therefore the subsequent dynamic frequency sweep test selects 10% strain, i.e. at 110 ℃ and 10% strain.
The storage modulus (G') and complex viscosity (η) of the ISO2-PU and CNCs/ISO2-PU composite melts obtained by dynamic frequency sweep test as a function of angular frequency are shown in FIG. 5. In fig. 5 (a), the G' curve as a whole gradually tends to be a straight line with an increase in CNCs content, and the slope gradually decreases. In the low frequency region, G 'is also significantly enhanced by the addition of 1wt% CNCs, and G' increases slowly with further addition of CNCs (1 wt% to 5 wt%). However, when CNCs increased from 5 to 7wt%, G' suddenly increased sharply, and the increase became slow after the content exceeded 7wt%, until the CNCs content reached 15wt%. In fig. 5 (b), η of a pure ISO2-PU shows newtonian fluid behaviour at lower frequencies, characterized by η being independent of shear rate (response unchanged with change in shear rate) and shows a pronounced shear thinning behaviour at higher frequencies. The addition of CNCs particles gradually reduces the Newton plateau, while a stronger shear thinning behavior in the high frequency region than that of pure ISO2-PU can be observed for all CNCs/ISO2-PU composites. When the CNCs content reached 7wt%, the plateau completely disappeared and the curve tended to be straight. In addition, η of the composite material increases with increasing CNCs content as with G' in the low frequency region, but increases relatively slowly with CNCs content of 1-5wt% until CNCs content reaches 7wt%.
Experimental example 3: microcosmic topography characterization
1. Test sample
CNCs, ISO2-PU, injection molded CNCs/ISO2-PU composite material bars (standard dog bone shape, effective size 20.0X4.0X2.0 mm (according to ISO 527-2-5A), annealing at 50deg.C for 20 min) and hot press molding to obtain CNCs/ISO2-PU composite material sheet (thickness about 20 μm).
2. Experimental method
SEM test: the cross-sectional profile of the composite samples (bars for mechanical testing) was observed by a Quattro S Scanning Electron Microscope (SEM) (ThermoFisher Scientific, usa) at a voltage of 8 kV. The section of the sample is broken by liquid nitrogen and is plated with gold before testing.
Optical microscopy test: the dispersion of spherical CNCs agglomerate particles in an ISO2-PU matrix was also observed and recorded using a camera-equipped optical microscope (photoperiod) for CNCs/ISO2-PU composite sheets.
3. Experimental results
In order to observe the dispersion of CNCs particles in an ISO2-PU matrix, SEM was used to observe the morphology of the liquid nitrogen brittle fracture cross section of the CNCs/ISO2-PU film. The SEM morphology of CNCs particles is shown in FIG. 6, the particles are spherical, and the diameter distribution is between 100nm and 35 μm. The cross-sectional morphology of the pure ISO2-PU and CNCs/ISO2-PU composites is shown in FIG. 7. ISO2-PU (FIG. 7 (a)) exhibited a smooth cross section, whereas the composite material (FIG. 7 (b)) having a CNCs content of 1% by weight had a roughened cross section, but no significant agglomeration of CNCs particles occurred. As the CNCs content further increased to 5wt% (fig. 7 (c)) the cross section became coarser, the CNCs particles were tightly packed in the ISO2-PU matrix. When the CNCs content reached 10wt% (fig. 7 (d)), more spherical particles were observed and significant cracks were observed on the section, indicating that the obtained CNCs/ISO2-PU composite became significantly brittle. For composites with 15wt% CNCs (fig. 7 (e)), some significant aggregation of matrix fragments and CNCs particles was observed at the brittle fracture face, with the appearance of fragments indicating a further increase in brittleness of the composite.
Furthermore, CNCs particles have a high degree of crystallinity, whereas ISO2-PU is amorphous, and the light transmittance of both are significantly different, so that they can be observed as a dispersion under an optical microscope. The soft and hard segments of pure ISO2-PU exhibit a typical phase separation morphology (fig. 7 (f)) in which the hard segments form round aggregates of size 2-8 μm and are homogeneously dispersed in the soft segment phase. The phase separation in ISO2-PU was severely destroyed after 1wt% of CNCs particles were added, and no hard segment aggregates were observed in the composite (fig. 7 (g)), but it could be observed that individual CNCs spherical particles were uniformly dispersed in the ISO2-PU matrix. Little aggregation of spherical particles was observed at a CNCs content of 5wt% (fig. 7 (h)). As the CNCs content increased to 10wt% (fig. 7 (i)), more CNCs particles could be observed to aggregate, but the number of particles that aggregate was still much less than that of the individual dispersed particles. When the CNCs content was increased to 15wt% (fig. 7 (j)), significant CNCs particle aggregation occurred.
The experimental result shows that when the addition amount of the CNCs is less than 15wt%, the CNCs particles in the CNCs/ISO2-PU composite material are dispersed very uniformly in the ISO2-PU matrix.
Experimental example 4: characterization of mechanical and thermo-mechanical Properties
1. Test sample
ISO2-PU and CNCs/ISO2-PU composite materials. The mechanical test specimens were injection molded in the shape of standard dog bones with effective dimensions of 20.0X14.0X12.0 mm (according to ISO 527-2-5A). The thermo-mechanical property (DMA) test sample was a film prepared by hot pressing and had dimensions of 0.1X15.0X150.0 mm.
2. Experimental method
The mechanical properties of the composite materials were carried out on a UTM5305SYXL electronic Universal materials tester (Shen three Si) equipped with a heating cavity plate and an electronic extensometer. The loading rates for the tests were 5.0mm/min, the test temperatures were 25℃and 37℃and the final results were the average of 5 replicates. DMA testing of the composites was performed in tensile mode on a DMA-Q800 (TA Instruments, usa) dynamic mechanical analyzer. The test conditions were constant frequency: 1Hz; prestressing: 0.01N; strain: 0.1%; test temperature range: -10-90 ℃; rate of temperature rise: 2 ℃/min.
3. Experimental results
TABLE 1 mechanical Properties of ISO2-PU and CNCs/ISO2-PU composites at 25℃and 37 ℃
*σ t Tensile strength; e (E) t Young's modulus; epsilon t Elongation at break.
The tensile stress strain curves of the ISO2-PU and CNCs/ISO2-PU composites at 25℃and 37℃are shown in FIG. 8, while the mechanical properties calculated from the corresponding stress-strain curves are listed in Table 1. The addition of CNCs particles significantly improved the mechanical properties of ISO2-PU when tested at 25 ℃ (fig. 8 (a)), and this trend of enhancement continued as the CNCs content increased. Young's modulus of pure ISO2-PU (E t ) And tensile strength (sigma) t ) 3498.3MPa and 50.1MPa respectively, E when the content of CNCs in the CNCs/ISO2-PU composite material is 15wt% t Sum sigma t Respectively increaseTo 4569.2MPa and 62.5MPa. Elongation at break at the same time (. Epsilon.) t ) Gradually decreasing from 6.8% to 3.4% of pure ISO2-PU (15 wt% CNCs). Furthermore, all samples showed a significant yield in the tensile stress-strain curve at 25 ℃, but did not exhibit a complete necking stage and plateau.
In contrast to the tensile stress-strain curve at 25℃in FIG. 8 (a), the curve at 37℃in FIG. 8 (b) shows typical ductile polymer characteristics, i.e., the curve has a pronounced yield point, long neck-in phase, and other composites and pure ISO2-PU have a very long plateau region, except for composites with 10wt% and 15wt% CNCs content. Epsilon for all samples t The values are all significantly higher than those at 25 ℃ (Table 1), and the ISO2-PU and CNCs contents are from 1% to 5% by weight t The difference in values is not large, but epsilon when the CNC content exceeds the penetration threshold (between 5wt% and 7 wt%) t The value drops sharply from 190% to 25%. E at 37℃compared with 25 ℃ t Sum sigma t Is significantly reduced. However, the E of the CNCs/ISO2-PU composite material t Sum sigma t Still much higher than pure ISO2-PU, the CNCs content 15wt% of the sigma of the composite material t Is 40.6MPa, E t Is 2021.1MPa.
Based on the above mechanical properties, the thermodynamic properties of pure ISO2-PU and CNCs/ISO2-PU composites (CNCs content 5wt%,10wt% and 15 wt%) were further investigated using DMA. Fig. 9 (a) is a graph showing the change of storage modulus (E') with temperature. Obviously, the addition of CNCs particles in the glassy state significantly increases the E' of ISO2-PU, and the higher the CNCs content in the composite material, the more significant the transition to T g The higher the temperature of the zone. Meanwhile, at 25 ℃ (glassy zone), the E' of the composite material with 15wt% of CNCs is significantly higher than that of the composite material with 10wt% of CNCs; however, when at 37℃C (T g Region) the E 'curves of the two composites almost completely coincide and they differ from the E' of the pure ISO2-PU by more than 25℃which is consistent with the results of the tensile mechanical test. In addition, the higher the CNCs content of the composite material at T g The faster zone E' drops, the T of the pure ISO2-PU and CNCs/ISO2-PU composites g The zones all ending at 60 DEG C. Thus, the temperature (T tran ) Can be selected to be 60 DEG C [31] Shape fixing temperature (T fix ) Set to 20 ℃. FIG. 9 (b) is a graph showing the variation of tan delta with temperature, and only one tan delta peak was observed for each sample, T being derived from this peak g The value does not change obviously with the addition and the content increase of CNCs, and the T of the pure ISO2-PU and CNCs/ISO2-PU composite material g The values are all between 54℃and 57 ℃. However, the intensity of tan delta peak continuously decreases with increasing CNCs content.
The experimental result shows that compared with the ISO2-PU material, the mechanical property of the CNCs/ISO2-PU composite material is greatly improved, especially sigma when tested at physiological temperature (37 ℃), the composite material is prepared t And E is t The maximum increases are 36.7% and 89.7%, respectively. In the CNCs/ISO2-PU composite material, the mechanical properties of the composite material with the CNCs content of 10 weight percent and 15 weight percent are better.
Experimental example 5: characterization of thermal properties
1. Test sample
ISO2-PU and CNCs/ISO2-PU composite materials.
2. Experimental method
DSC test N on DSC-Q100 (TA Instruments, USA) 2 In an atmosphere. The sample was first heated from room temperature to 150℃at a ramp rate of 20℃per minute, isothermal for 3 minutes, and then cooled to-20℃at a ramp rate of-20℃per minute. Finally, the sample was heated again to 150℃at a heating rate of 10℃per minute. Glass transition temperature (T) g ) Determined by a second heating scan curve. Thermogravimetric analysis (TGA) was performed on TGA-Q50 (TA Instruments, USA) with samples at N 2 The temperature was increased from 25℃to 600℃in the atmosphere at a heating rate of 10℃per minute.
3. Experimental results
FIG. 10 (a) is a DSC curve of pure ISO2-PU and CNCs/ISO2-PU composites, T being obtained from the curve g Value and heat capacity variation (ΔC) p ) The values are shown in table 2. T of ISO2-PU g The value is 42.2 ℃, and when CNCs particles are added, the T of the composite material is obtained g The values increased slightly but not significantly, the CNCs content increased from 1wt% to 15wt% of composite T g The value is only atFluctuation between 43.0℃and 43.7 ℃. At the same time, ΔC of ISO2-PU p 0.501J/(g.K), with increasing CNCs content, ΔC of the composite material p Gradually decreasing, when the CNCs content is 15%, the delta C of the composite material is p Down to 0.398J/(g.K).
TABLE 2 thermal Properties of ISO2-PU and CNCs/ISO2-PU composites
T g : glass transition temperature; ΔC p : a hot melting change; t (T) 0 : an initial decomposition temperature; t (T) fastest : the fastest decomposition temperature.
The thermal stability of ISO2-PU and CNCs/ISO2-PU composites was evaluated by TGA test, and the TGA and DTG curves obtained are shown in FIGS. 10 (b) and (c). There are two weight loss stages in each curve of the CNCs/ISO2-PU composite, while ISO2-PU has only one weight loss stage. The first weight loss stage of the CNCs/ISO2-PU composite material occurs at 100-150 ℃, and the second weight loss stage is highly coincident with the weight loss stage of the ISO2-PU, and both occur at 260-420 ℃. Corresponding initial decomposition temperatures (T) obtained from TGA and DTG curves 0 5% of weight loss) and the fastest decomposition temperature (T) fastest ) As shown in table 2.
The experimental results show that compared with ISO2-PU, the T of the CNCs/ISO2-PU composite material g No significant changes, still within the ideal temperature range for biomedical shape memory polymeric materials; meanwhile, the thermal stability of the CNCs/ISO2-PU composite material is improved.
Experimental example 6: shape memory performance characterization
1. Test sample
ISO2-PU and CNCs/ISO2-PU composite materials.
2. Experimental method
Shape memory experiments were performed on DMA with strain control in tension mode, sample sizes of 0.1 x 5.0 x 50.0mm. The specific procedure is as follows: at 5 ℃/m under conditions of a loading strain of 0.1%The in heating rate is increased from 25 ℃ to the shape memory temperature (T tran ) The method comprises the steps of carrying out a first treatment on the surface of the (ii) increasing the strain to 50% at a rate of 5%/min after 5min isothermally and holding for 5min; (III) cooling to below T at a cooling rate of 5 ℃/min tran Shape fixation temperature (T) at 30 DEG C fix ) Also for 5min; (IV) stress is removed and the temperature is raised again to T at a temperature rise rate of 5 ℃/min tran And finishing the recovery process at an isothermal temperature for 40 min. Shape memory properties of the samples were measured at a shape retention rate (R f ) And shape recovery (R) r ) And (3) evaluating, wherein the calculation formulas of the evaluation are shown in the formula (1) and the formula (2).
Wherein ε is 1 Epsilon for strain applied to the sample 2 To be cooled to T fix And relieving the strain epsilon after stress 3 The recovered strain was completed for 40min isothermally.
3. Experimental results
Based on the above DMA test results, the shape memory temperature (T tran ) Is set to 60 ℃, and the shape fixing temperature (T fix ) Set to 20 ℃. The 2D and 3D shape-fixing-recovery cycle diagrams of the pure ISO2-PU and CNCs/ISO2-PU composites (CNCs content 5wt%,10wt% and 15 wt%) are shown in fig. 11 and 12, respectively. Fixed ratio (R) of ISO2-PU f ) 99.8% of CNCs added to R of the composite material f Epsilon of 5wt%,10wt% and 15wt% CNCs/ISO2-PU composite material without significant effect 2 49.8%, 49.9% and 49.9%, respectively, i.e. R thereof f The values were 99.6%, 99.8% and 99.8% in this order. However, recovery of CNCs/ISO2-PU composite material (R r ) The effect of CNCs particles is evident. Epsilon of a composite material containing 5wt%,10wt% and 15wt% CNCs 3 11.0%, 13.6% and 15.1%, respectively, i.e. R thereof r The values were 78.0%, 72.8% and 69.8% in this order, with the exception ofR is substantially lower than that of pure ISO2-PU r Value (91.2%). At the same time, it is apparent that lower stress is required to achieve 50.0% strain for composites with higher CNCs content, which is more apparent in the 2D form-fix-recovery cycle diagram shown in fig. 11.
The shape memory process demonstration of the CNCs/ISO2-PU composite material (CNCs content 10 wt%) film is shown in figure 13. The sample film was curled into a spiral shape (temporary shape) after heating at 60 ℃ for 3 min; then cooled at 20 ℃ to fix the shape; then placing the deformed sample in the environment of 60 ℃ again; and finally returns to the original shape almost completely within 30 seconds.
According to the above results, it can be seen that the particles are uniformly dispersed when the content of CNCs in the CNCs/ISO2-PU composite material is 10wt% or less, but obvious particle agglomeration occurs when the content of CNCs is increased to 15wt%; the mechanical properties of the composite material with the CNCs content of 10 weight percent and the composite material with the CNCs content of 15 weight percent are close to each other and are obviously higher than those of other composite materials; the shape memory performance of the composite material with the CNCs content of 10 weight percent is obviously superior to that of the composite material with the CNCs content of 15 weight percent; the composite material with the CNCs content of 10 weight percent has the CNCs addition amount less than the composite material with the CNCs content of 15 weight percent. Therefore, the comprehensive properties of the CNCs/ISO2-PU composite material with the CNCs content of 10 weight percent are optimal by comprehensively considering the addition amount, the dispersibility, the mechanical property and the shape memory property of the CNCs. The composite material of the component is selected for further in vitro mineralization capability test.
Experimental example 7: characterization of mineralization in vitro
1. Test sample
ISO2-PU and CNCs/ISO2-PU composite material
2. Experimental method
The in vitro mineralization capacity of the samples was assessed by alkaline phosphatase (ALP) activity and Alizarin Red S (ARS) staining. Briefly, the material was dissolved in chloroform to make a 30wt% solution, and then cast into a thin film on a glass plate having a diameter of 15mm, and vacuum-dried under a 40 glass plate for 7 days before use to thoroughly remove chloroform. Samples were placed on both sides of the plate after uv irradiation for 30min respectively in 24 well plates (material film facing up), skull Osteoblasts (OBs) of neonatal SD rat rats were inoculated at a cell density of material/cm 2 in 1 plate, and co-cultured in high sugar medium supplemented with 10% fetal bovine serum and 1% penicillin-streptomycin after 4, 7, 14 days, medium was aspirated from 24 well plates, washed 3 times with PBS, then samples were carefully removed to clean fresh wells, each sample was 250, triton X-100 lysis buffer at a concentration of 0.2vol% was extracted for 10min at 4 solutions, and supernatant was collected for about 200. ALP activity was measured by an ALP assay kit and absorbance calculation at nm using an enzyme labeling instrument (Bio-Rad 550, california, usa), medium was aspirated from 24 well plates after 21 days, and washed with 4.0% formaldehyde in 4 plates, fixed with 8% formaldehyde at room temperature, and three times with a microscope for 4 days, and the sample was washed with pure water for three times (three times a three-phase staining experiment, and a three-phase staining procedure was performed).
3. Experimental results
While in vitro mineralization capacity of neonatal rat Osteoblasts (OBs) cultured on PDLLA, ISO2-PU and CNCs/ISO2-PU composites (10 wt%) was assessed by detecting ALP activity and ARS staining with ISO2-PU and FDA approved PDLLA for bone tissue engineering as controls. ALP activity of OBs and materials after co-cultivation for 4, 7 and 14 days is shown in FIG. 14, and in general, ALP activity of OBs on three materials is continuously increased along with the extension of cultivation time, ALP activity of OBs on ISO2-PU is higher than PDLLA, and ALP activity of OBs can be further remarkably improved by adding CNCs particles. Specifically, there was no significant difference in ALP activity of the OBs on PDLLA and ISO2-PU after 4 days of co-culture, but the ALP activity of the OBs on CNCs/ISO2-PU composite (10 wt%) was significantly higher than that on both groups (p > 0.05); after 7 days of co-cultivation, the ALP activity of the OBs on ISO2-PU was significantly higher than that of the PDLLA group (P > 0.05), while that of the CNCs/ISO2-PU composite material (10 wt%) was further significantly higher than that of the PDLLA and ISO2-PU groups (P > 0.01); ALP activity was further increased in all three groups after 14 days of co-culture, and the difference in ALP activity between the groups was consistent with day 7.
ARS staining after 21 days of OBs co-incubation on 3 sets of sample films and corresponding optical images are shown in fig. 15, all taken at the same light intensity. The shade of color on the surface of the ARS-stained samples represents how much calcium was deposited, red deposits were observed on the film surfaces of PDLLA, ISO2-PU and CNCs/ISO2-PU composites (10 wt%), but the ISO2-PU film was visually darker than the PDLLA film surface, and the CNCs/ISO2-PU composite surfaces were significantly more strongly stained than the two groups, indicating significantly more calcium deposition on the CNCs/ISO2-PU composites (10 wt%) film surfaces.
In the in-vitro mineralization experiment, three materials are dissolved by chloroform and cast into a film, and the film is thoroughly removed from the solvent and then used, instead of directly using a hot-pressed or injection-molded sample for the experiment, the purpose of avoiding the influence of lines on the surface of the hot-pressed or injection-molded sample, caused by a mold, on the cell behavior of an OBs is achieved. Meanwhile, in order to avoid enrichment of CNCs particles on the surface of a CNCs/ISO2-PU composite material (CNCs 10 wt%) film due to the fact that the density of CNCs is far smaller than that of chloroform, all three materials are prepared into a high-concentration solution with the concentration of 30wt%, and the CNCs particles are stabilized by using high viscosity in the composite material solution. The surface morphology of the three material films is shown in fig. 16, the surfaces of the PDLLA and ISO2-PU films are totally very flat except for a few microcracks caused by solvent volatilization, and the surfaces of the CNCs/ISO2-PU composite materials (CNCs 10 wt%) films can see that the CNCs particles are uniformly distributed, and agglomeration or enrichment phenomenon does not occur. Thus, the OBs cell behavior of such sample surfaces can be quite representative of the nature of the material.
Materials with more polar and hydrophilic groups on the surface are generally considered to promote better cell attachment, diffusion and proliferation. Furthermore, in addition to a few cases (including joints and some soft tissue implants), the biomaterial surface should generally have a certain roughness to promote cell attachment. For osteoblasts, surface roughness is not only an important factor for initial adhesion but also an important factor affecting the activity and mineralization of cells thereof. It can be seen from fig. 16 that the addition of CNCs particles significantly increases the surface roughness of the material, while CNCs surfaces are also rich in-OH, which is beneficial for the adhesion, proliferation and mineralization of OBs.
The above experimental results show that the CNCs/ISO2-PU composite material with the CNCs content of 10wt% has significantly enhanced osteoinductive effect and osteogenic capacity compared with the PDCLA material and the ISO2-PU material approved by the FDA for bone tissue engineering.
In summary, the invention provides a high mechanical property linear shape memory polyurethane/cellulose nanocrystalline composite material, and a preparation method and application thereof. The composite material is prepared from shape memory polyurethane and cellulose nanocrystals, wherein the content of the cellulose nanocrystals is 0.5-20wt%. The composite material of the invention not only maintains excellent shape memory performance, but also greatly improves mechanical property and osteoinductive effect, and has wide application prospect in preparing bone tissue engineering biological materials.

Claims (8)

1. A shape memory polyurethane composite, characterized by: the composite material is prepared from shape memory polyurethane and cellulose nanocrystals, wherein the content of the cellulose nanocrystals is 10-15 wt%;
the shape memory polyurethane is prepared by taking cyanate coupling agent, macromolecular diol and catalyst as raw materials for reaction, wherein the cyanate coupling agent is aliphatic diisocyanate blocked isosorbide coupling agent; the molar ratio of the cyanate coupling agent to the macromolecular diol to the catalyst is (1.1-2.0): 1: (0.1-0.8);
the preparation method of the cyanate coupling agent comprises the following steps: adding aliphatic diisocyanate and isosorbide into a reaction device, adding a solvent for dissolution, adding a catalyst, and reacting in an inert gas environment to obtain the catalyst; wherein the molar ratio of the aliphatic diisocyanate to the isosorbide is (3-5): 1, a step of; the solvent is an organic solvent; the molar ratio of isosorbide to catalyst (400-600): 1, a step of; the reaction temperature is 55-95 ℃ and the reaction time is 0.5-2h;
the macromolecular diol is a product obtained by taking lactide, polyethylene glycol and a catalyst as raw materials for reaction, wherein the molar ratio of the lactide to the polyethylene glycol to the catalyst is (4000-6000): (50-150): 1, a step of; the lactide is D, L-lactide, and the polyethylene glycol is PEG400; the reaction temperature is 120-160 ℃ and the reaction time is 12-36h;
the grain diameter of the cellulose nanocrystalline is 100nm-35 mu m.
2. The shape memory polyurethane composite of claim 1, wherein: the content of the cellulose nanocrystalline is 10wt%.
3. The shape memory polyurethane composite of claim 1, wherein: the molar ratio of the cyanate coupling agent to the macromolecular diol to the catalyst is 1.5:1:0.5.
4. the shape memory polyurethane composite of claim 1, wherein: the molar ratio of the aliphatic diisocyanate to the isosorbide is 4:1; the solvent is DMF; the molar ratio of the isosorbide to the catalyst is 500:1; the reaction temperature of the preparation method of the cyanate coupling agent is 75 ℃ and the reaction time is 1h; the aliphatic diisocyanate is 1, 6-hexamethylene diisocyanate.
5. The shape memory polyurethane composite of claim 1, wherein: the molar ratio of the lactide to the polyethylene glycol to the catalyst is 5000:100:1; the reaction temperature of the preparation method of the macromolecular diol is 140 ℃ and the time is 24 hours.
6. The shape memory polyurethane composite of claim 1, wherein: the catalyst is stannous octoate.
7. A method of making the shape memory polyurethane composite of any of claims 1-6, characterized by: the method comprises the following steps:
(1) Uniformly mixing shape memory polyurethane and cellulose nanocrystals to obtain a mixture;
(2) And (3) fusing, mixing and molding the mixture to obtain the shape memory polyurethane composite material.
8. The method according to claim 7, wherein: in the step (1), the uniform mixing mode is that a grinder is used for mixing for 3-7 minutes;
in the step (2), the temperature of the fusion mixing is 90-130 ℃ and the time is 3-7 minutes; the molding mode is injection molding or hot press molding.
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Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102423506A (en) * 2011-12-09 2012-04-25 东华大学 Medicine sustained release nanofiber membrane for treating periodontitis and preparation method for medicine sustained release nanofiber membrane
CN105148324A (en) * 2015-08-31 2015-12-16 中原工学院 Bone bionic materials built by mineralized nano cellulose whiskers and production method of bone bionic materials
CN109414523A (en) * 2016-07-08 2019-03-01 墨尼克医疗用品有限公司 Medical dressing including carrier and composite material
CN110028782A (en) * 2019-04-29 2019-07-19 中国科学院长春应用化学研究所 A kind of shape memory aqueous polyurethane/Cellulose nanocrystal composite material and preparation method
CN110028781A (en) * 2019-04-29 2019-07-19 中国科学院长春应用化学研究所 A kind of selfreparing aqueous polyurethane/Cellulose nanocrystal composite material and preparation method
CN111171351A (en) * 2020-02-05 2020-05-19 上海大学 Hierarchical structure nano hybrid material with thermal response and preparation method thereof
CN111518377A (en) * 2019-08-22 2020-08-11 四川大学 Biomedical shape memory polymer material and preparation method thereof
CN112533652A (en) * 2018-03-07 2021-03-19 格兰生物科技知识产权控股有限责任公司 Nanocellulose-containing bio-ink for 3D bio-printing, methods of making and using the same, and 3D biological structures obtained thereby
CN112853758A (en) * 2021-03-08 2021-05-28 广东工业大学 Shape memory driver with rapid photo-thermal response and preparation method and application thereof

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8541001B2 (en) * 2009-05-18 2013-09-24 Cornell University Bacterial cellulose based ‘green’ composites
JP6335197B2 (en) * 2013-02-15 2018-05-30 エフピーイノベイションズ Cellulose nanocrystal-thermosetting resin system, uses thereof, and articles made therefrom
CN103539922B (en) * 2013-09-10 2015-05-27 中国林业科学研究院林产化学工业研究所 Cellulose nano-whisker (CNW) compounded bi-component terpenyl waterborne polyurethane and preparation method and use thereof
CN111205429B (en) * 2020-02-06 2022-03-01 重庆大学 Polyurethane material and preparation method thereof
KR102517908B1 (en) * 2020-02-19 2023-04-04 강원대학교 산학협력단 A composition for tissue engineering comprising Alginate, Gelatin and Cellulose Nanocrystals and use of the same
CN112043871A (en) * 2020-08-31 2020-12-08 西南交通大学 Preparation method of bionic oriented double-layer hydrogel for bone/cartilage repair
CN113288320A (en) * 2021-07-07 2021-08-24 哈尔滨工业大学 Ligation clip with shape memory function

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102423506A (en) * 2011-12-09 2012-04-25 东华大学 Medicine sustained release nanofiber membrane for treating periodontitis and preparation method for medicine sustained release nanofiber membrane
CN105148324A (en) * 2015-08-31 2015-12-16 中原工学院 Bone bionic materials built by mineralized nano cellulose whiskers and production method of bone bionic materials
CN109414523A (en) * 2016-07-08 2019-03-01 墨尼克医疗用品有限公司 Medical dressing including carrier and composite material
CN112533652A (en) * 2018-03-07 2021-03-19 格兰生物科技知识产权控股有限责任公司 Nanocellulose-containing bio-ink for 3D bio-printing, methods of making and using the same, and 3D biological structures obtained thereby
CN110028782A (en) * 2019-04-29 2019-07-19 中国科学院长春应用化学研究所 A kind of shape memory aqueous polyurethane/Cellulose nanocrystal composite material and preparation method
CN110028781A (en) * 2019-04-29 2019-07-19 中国科学院长春应用化学研究所 A kind of selfreparing aqueous polyurethane/Cellulose nanocrystal composite material and preparation method
CN111518377A (en) * 2019-08-22 2020-08-11 四川大学 Biomedical shape memory polymer material and preparation method thereof
CN111171351A (en) * 2020-02-05 2020-05-19 上海大学 Hierarchical structure nano hybrid material with thermal response and preparation method thereof
CN112853758A (en) * 2021-03-08 2021-05-28 广东工业大学 Shape memory driver with rapid photo-thermal response and preparation method and application thereof

Non-Patent Citations (5)

* Cited by examiner, † Cited by third party
Title
An interpenetrating-network-like structure in cellulose nanocrystal/polyurethane composites and the relative strengthening mechanism;yang LD等;cellulose;第29卷(第9期);第5007-5019页 *
Biomimetic Hydroxyapatite Mineralization on the Thermoplastic Polyurethane Fibrous Scaffold Modified with Cellulose Nanocrystal;Si, JH等;JOURNAL OF BIOBASED MATERIALS AND BIOENERGY;第12卷(第4期);第387-391页 *
Cellulose nanocrystals (CNC) reinforced shape memory polyurethane ribbons for future biomedical applications and design;Garces, IT等;JOURNAL OF THERMOPLASTIC COMPOSITE MATERIALS;第33卷(第3期);第377-392页 *
形状记忆聚氨酯及其在生物医学材料中的应用;孙芙蓉;何屹;魏燕红;李娟娟;赵丽娟;;塑料工业(第04期);第11-14+25页 *
纤维素纳米晶的制备、改性及功能化应用;刘莹;刘钰娇;孟凡浩;刘井来;;现代化工(第04期);第64-68页 *

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