Medical polycaprolactone composition capable of being heated by microwaves as well as preparation method and application of medical polycaprolactone composition

Abstract

The invention relates to a medical polycaprolactone composition capable of being heated by microwaves as well as a preparation method and application of the medical polycaprolactone composition, belonging to the field of medical polymer materials. The medical polycaprolactone composition capable of being heated by microwaves is prepared from the following blended components in parts by weight: 40 to 90 parts of polycaprolactone, 10 to 60 parts of nano filler, 1 to 6 parts of microwave absorbent and 0 to 10 parts of heat conducting agent, wherein the sum of the weight of the polycaprolactone and the nano filler is 100 parts. The odor of the polycaprolactone composition can reach grade 3.5 or below, the microwave heating performance is greatly improved, meanwhile, the mechanical property of the material is good, and the polycaprolactone composition can be applied to the field of medical surgical materials.

Description

Technical Field

[0001] This invention relates to the field of medical polymer materials, and more specifically, to a microwave-heatable medical polycaprolactone composition, its preparation method, and its application. Background Technology

[0002] Polycaprolactone (PCL), also known as poly-ε-caprolactone, is a high-molecular-weight organic polymer synthesized by ring-opening polymerization of ε-caprolactone monomers under the catalysis of a metal anion complexing catalyst. Different molecular weights can be obtained by controlling the polymerization conditions. It appears as a white solid powder, is non-toxic, and insoluble in water. PCL exhibits good biocompatibility, good compatibility with other organic polymers, and good biodegradability, making it suitable as a cell growth support material. It is compatible with many conventional plastics and completely degrades under natural conditions within 6-12 months. Furthermore, PCL possesses excellent shape memory and temperature control properties, making it widely used in medical materials. Currently, medical fixation materials mainly include plaster, polymeric plaster, and thermoplastic sheets. Among these, thermoplastic sheets have better application prospects due to their reusability, environmental friendliness, and ease of low-temperature molding. The caprolactone used in thermoplastic sheets has a melting point of around 60-65℃. It exhibits good mechanical strength below its melting point, but softens rapidly above it. It can remain softened for shaping once the temperature drops to around 45℃, without harming the patient's skin, making it ideal for medical fixation. However, PCL softens too quickly above its melting point, and prolonged heating can easily cause it to sag due to gravity, even losing its shape. Improper handling can lead to it sticking together and becoming unusable. Furthermore, its strength at room temperature is suitable for fixing fingers or upper limbs, but insufficient for lower limbs or the torso, falling short compared to plaster casts. To address these shortcomings, domestic and international methods typically involve filler modification to improve strength and reduce cost to some extent, but the compatibility of fillers with the PCL matrix resin still needs improvement. Additionally, current PCL medical fixation materials often soften by heating with water at 60-65℃, which is unsuitable for microwave ovens commonly used in hospitals. Therefore, developing a medical fixation material that can improve material strength and processing plasticity, and can also be directly used for microwave heating, would have significant application value. Summary of the Invention

[0003] To address the aforementioned problems in the prior art, this invention proposes a microwave-heatable medical polycaprolactone composition. Specifically, it relates to a microwave-heatable medical polycaprolactone composition, its preparation method, and its applications. The polycaprolactone composition of this invention can be directly used for microwave heating, and its rigidity is improved while its odor is significantly reduced, reaching an odor level below 3.5. This effectively solves the shortcomings of the prior art. Furthermore, the operation process is simple and reliable, with low input costs, making it suitable for the field of medical fixation materials.

[0004] One objective of this invention is to provide a microwave-heatable medical polycaprolactone composition comprising the following blended components: polycaprolactone, nanofiller, microwave absorber, and optionally a thermal conductive agent.

[0005] Of which, based on a weight ratio of 100 parts by weight of polycaprolactone and nanofillers,

[0006] Polycaprolactone 40-90 parts by weight,

[0007] 10-60 parts by weight of nanofiller

[0008] 1-5 parts by weight of microwave absorber

[0009] 0-10 parts by weight of thermal conductive agent.

[0010] in,

[0011] The polycaprolactone has a number-average molecular weight of 40,000 to 90,000, a melt index ≥2 g / 10 min (2.16 kg, 160 °C), and a melting point of 58–65 °C. Preferably, the molecular weight distribution index of the polycaprolactone is ≤2.5. The color of the polycaprolactone is preferably <80 Hazen. The polycaprolactone has a suitable molecular weight, high toughness, good processing performance, and low odor and volatile organic compound content.

[0012] The amount of polycaprolactone used may be 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 82, 85, 86, or 90 parts by weight, or any value between the above values, or a range between any two of the above values.

[0013] The nanofiller can be selected from one or more combinations of nano-silica, nano-calcium carbonate, nano-talc, nano-calcium sulfate, montmorillonite, glass microspheres, glass fiber, carbon fiber, mica, kaolin, and silica. Preferably, it is selected from one or more of nano-silica, nano-calcium carbonate, nano-talc, and nano-calcium sulfate. The average particle size of the nanofiller is preferably 10-300 nanometers. The nanofiller has good dispersibility and compatibility, which can further improve the mechanical properties of the material.

[0014] The specific amount of the nanofiller may be 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, or 60 parts by weight, or any value between the above values, or a range between any two of the above values.

[0015] The microwave absorber may be selected from one or more combinations of silicon carbide, iron oxide, barium sulfate, nanocellulose crystals, titanium dioxide, hydrated magnesium hydroxide, pentaerythritol, and melamine. Preferably, it is selected from one or more of hydrated magnesium hydroxide, titanium dioxide, nanocellulose crystals, or melamine.

[0016] The amount of microwave absorber can be 1, 2, 3, 4, 5, or 6 parts by weight, or any value between the above values, or a range between any two of the above values.

[0017] The thermally conductive agent can be selected from one or more combinations of magnesium oxide, aluminum oxide, boron nitride, aluminum nitride, silicon carbide, graphite, carbon nanotubes, carbon black, and graphene. Preferably, it is selected from one or more of aluminum oxide, aluminum nitride, carbon nanotubes, magnesium oxide, or graphite.

[0018] The amount of the thermal conductive agent can be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 parts by weight, or any value between the above values, or a range between any two of the above values.

[0019] The microwave absorber and thermal conductive agent described herein have good compatibility with polycaprolactone and good microwave heating function, making the material suitable for microwave heating and shaping.

[0020] Specifically, the microwave-heatable medical polycaprolactone composition may also contain an odor adsorbent.

[0021] The odor adsorbent can be a cage-like silsesquioxane; specifically, it can be selected from one or more combinations of octavinylsilsesquioxane, octaphenylsilsesquioxane, octaisobutylsilsesquioxane, octaisooctylsilsesquioxane, and octaepoxysilsesquioxane. More preferably, it is one or more of octaisobutylsilsesquioxane, octavinylsilsesquioxane, octaphenylsilsesquioxane, or octaepoxysilsesquioxane. The odor adsorbent has good synergistic adsorption and barrier effects, which can further suppress the generation of odor in polycaprolactone materials.

[0022] Preferably, based on 100 parts by weight of the sum of the weights of the polycaprolactone and the nanofiller, the amount of the odor adsorbent can be 0.05 to 1.8 parts by weight, more preferably 0.2 to 1.5 parts by weight, and even more preferably 0.5 to 1.5 parts by weight. Specifically, the amount of the odor adsorbent can be 0.05, 0.1, 0.15, 0.20, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, or 1.8 parts by weight, or any value between the above values, or a range between any two of the above values.

[0023] Specifically, the microwave-heatable medical polycaprolactone composition may further include an antioxidant; by weight, the polycaprolactone composition is 100 parts by weight, and the antioxidant is 0.05 to 1 part by weight, preferably 0.1 to 0.6 parts by weight. The antioxidant may be selected from at least one or two of hindered phenolic antioxidants 1098, 1076, 2246, CA, 168, 626, or 636; preferably, it is a combination of antioxidant 1010 and antioxidant 168, with a mass ratio of 10:1 to 1:10.

[0024] A second objective of this invention is to provide a method for preparing the microwave-heatable medical polycaprolactone composition, which may include the following steps:

[0025] The components, including the polycaprolactone, nanofiller, microwave absorber, optional thermal conductive agent, and optional odor adsorbent, are mixed and melt-blended; the melt-blending temperature can be 80℃~180℃, preferably 100~130℃.

[0026] Specifically, the preparation method may include the following steps:

[0027] (1) The nanofiller, microwave absorber, optional thermal conductive agent, optional odor adsorbent and optional antioxidant are mixed evenly to obtain a mixture;

[0028] (2) The mixture and the polycaprolactone are mixed to obtain a premix;

[0029] (3) The premix is ​​melt-blended to obtain the polycaprolactone resin composition.

[0030] In step (2), the polycaprolactone may specifically be dried polycaprolactone. The mixing in steps (1) and (2) is preferably dry mixing.

[0031] To better remove odors, it is preferable to maintain the vacuum level of the equipment vacuum system at -0.05 MPa or higher during the melt blending process, and more preferably at -0.08 MPa or higher.

[0032] In addition, during the processing, various molding processes can be carried out after melt blending according to the needs of actual applications, so that the microwave-heatable medical polycaprolactone composition can be in granular form (such as by extrusion granulation), sheet form, etc.

[0033] In the preparation method of this invention, the material melt blending temperature is the blending temperature commonly used in the processing of polycaprolactone. It should be selected within a range that ensures the matrix resin is completely melted without causing it to decompose, generally 80℃~180℃, and preferably 100~130℃; the screw speed of the melt blending equipment is 300~450rpm.

[0034] In the preparation method of the present invention, the mixing equipment for each material can be various mixing equipment used in the prior art, such as mixers, kneaders, etc.; the melt blending equipment used is a general blending equipment in the rubber and plastics processing industry, such as a twin-screw extruder, a BUSS mixing unit, etc.

[0035] A third objective of this invention is to provide a polycaprolactone composition obtained by the preparation method described in the second objective of this invention.

[0036] The fourth objective of this invention is to provide the application of the microwave-heatable medical polycaprolactone composition described in the first objective of this invention, or the product prepared by the preparation method described in the second objective of this invention, preferably in medical surgical materials, such as medical fixation materials, medical shaping materials, etc.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1. The polycaprolactone used in this invention has a suitable molecular weight, high toughness and good processing performance, and low odor and volatile organic compound content.

[0039] 2. The nanofiller used in this invention has good dispersion performance and compatibility, which can further improve the mechanical properties of the material.

[0040] 3. The present invention selects specific microwave absorbers and thermal conductive agents that have good compatibility with polycaprolactone and good microwave heating function, making the material suitable for microwave heating and shaping.

[0041] 4. The odor adsorbent used in this invention has good synergistic adsorption and barrier effects, which can further suppress the generation of odor in polycaprolactone materials.

[0042] 5. The odor of the polycaprolactone composition of the present invention can be significantly reduced to below level 3.5, the microwave heating performance is greatly improved, and the rigidity of the material is effectively improved. It solves the shortcomings of the prior art. Moreover, the operation process is simple and reliable, the investment cost is low, and it is suitable for the field of medical surgical materials. Detailed Implementation

[0043] The present invention will be further described below with reference to embodiments. However, the present invention is not limited to these embodiments. The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0044] Source of raw materials

[0045] Polycaprolactone: PCL-8080, melt index 2-4 g / 10 min (2.16 kg, 160 ℃), color < 75 Hazen, melting point 58-60 ℃, monomer content < 0.5%, number average molecular weight 80,000, molecular weight distribution < 1.65, Sinopec Baling Petrochemical Branch.

[0046] Nanofillers: Nano silica (average particle size 10-60nm), nano calcium carbonate (average particle size 15-40nm), nano calcium sulfate (average particle size 30-100nm), and nano talc (average particle size 50-150nm), all of which are commercially available.

[0047] Microwave absorbers: all commercially available;

[0048] Thermal conductive agent: commercially available;

[0049] Cage-type silsesquioxanes, Hybrid Plastics, USA: Octaphenyl silsesquioxane, Octaphenyl POSS (MS0840); Octavinyl silsesquioxane, Octavinyl POSS (OL1170); Octaisobutyl silsesquioxane, Octaisobutyl POSS (MS0825); Octaepoxy silsesquioxane, Octaepoxy POSS (EP0409).

[0050] Antioxidant 1010 and Antioxidant 168, BASF, Germany;

[0051] Unless otherwise specified, the raw materials used in the examples and comparative examples are all disclosed in the prior art, such as those that can be directly purchased or prepared according to the preparation methods disclosed in the prior art.

[0052] Examples 1-5

[0053] Examples 1-5 illustrate the microwave-heatable medical polycaprolactone composition and its preparation method of the present invention. Nanofillers, microwave absorbers, cage-type silsesquioxanes, and antioxidants were placed in a high-speed mixer and stirred at 300 rpm for 2 minutes to ensure thorough and uniform mixing. This mixture was then mixed uniformly with polycaprolactone granules. The mixture was then extruded and granulated using a BUSS mixing mill (MKD-30, BUSS, Switzerland) at a temperature of 100°C–120°C under a vacuum of -0.08 MPa to obtain the microwave-heatable medical polycaprolactone composition. Specific formulations are shown in Tables 1 and 2, where the content of each component is by weight. The extruded granules were dried in a 40°C constant-temperature oven for 2 hours, and then subjected to various tests. The resulting granules were then injection molded to obtain injection-molded samples, and their performance was tested. Bending strength was tested according to GB / T9341-2000; microwave heating performance was tested by placing the sample in a microwave oven and heating it on high for 1 minute, then measuring the sample surface temperature; odor was tested according to VDA270. Specific performance results are shown in Table 2.

[0054] Examples 6-10

[0055] Examples 6-10 illustrate the microwave-heatable medical polycaprolactone composition and its preparation method of the present invention. Nanofillers, microwave absorbers, thermal conductive agents, cage-like silsesquioxanes, and antioxidants were placed in a high-speed mixer and stirred at 300 rpm for 2 minutes to ensure thorough and uniform mixing. This mixture was then mixed uniformly with polycaprolactone granules. The mixture was then extruded and granulated using a BUSS mixing mill (MKD-30, BUSS, Switzerland) at a temperature of 100°C–120°C under a vacuum of -0.08 MPa to obtain the microwave-heatable medical polycaprolactone composition. Specific formulations are shown in Tables 1 and 2, where the content of each component is by weight. The extruded granules were dried in a 40°C constant-temperature oven for 2 hours, and then various tests were performed. The resulting granules were then injection molded to obtain injection-molded samples, and their performance was tested. Bending strength was tested according to GB / T9341-2000; microwave heating performance was tested by placing the sample in a microwave oven and heating it on medium power for 1 minute, and the surface temperature of the sample was then measured. Odor was tested according to VDA270. Specific performance results are shown in Table 2.

[0056] Comparative Examples 1-5

[0057] Nanofillers, thermal conductive agents, and antioxidants were placed in a high-speed mixer and stirred at 300 rpm for 2 minutes to ensure thorough and uniform mixing. This mixture was then mixed evenly with polycaprolactone granules. The mixture was subsequently extruded and granulated using a BUSS mixing mill (MKD-30, BUSS, Switzerland) at a temperature of 100°C–120°C under a vacuum of -0.08 MPa to obtain a microwave-safe medical-grade polycaprolactone composition. Specific formulations are shown in Tables 1 and 2, where all component contents are by weight.

[0058] The extruded granules were dried in a 40℃ constant temperature oven for 2 hours, and then various tests were performed. The resulting granules were then added to an injection molding machine to produce injection molded samples, and their properties were tested. Flexural strength was tested according to GB / T9341-2000; microwave heating performance was tested by placing the sample in a microwave oven and heating it on medium power for 1 minute, and then testing the surface temperature of the sample; odor was tested according to VDA270.

[0059] Table 1. Component types of Examples 1-10 and Comparative Examples 1-5

[0060]

[0061]

[0062] Table 2. Component ratios and performance test results of Examples 1-10 and Comparative Examples 1-5

[0063]

[0064]

[0065] As can be seen from the results of the comparative examples and embodiments in Table 2, the polycaprolactone compositions prepared in Examples 1-10 of this invention reached temperatures between 47 and 60°C after microwave heating, which were significantly higher than the materials prepared in Comparative Examples 1-5. This demonstrates that the products of this application have excellent microwaveability and can be used for microwave heating. Furthermore, the polycaprolactone compositions of this invention also exhibit good rigidity and low odor, making them suitable for the field of medical surgical materials.

[0066] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A microwave-heatable medical polycaprolactone composition comprising a blend of the following components: Based on a weight ratio of 100 parts by weight of polycaprolactone and nanofillers, Polycaprolactone 40-90 parts by weight, 10-60 parts by weight of nanofiller 1-6 parts by weight of microwave absorber 0-10 parts by weight of thermal conductive agent.

2. The microwave-heatable medical polycaprolactone composition according to claim 1, characterized in that: The polycaprolactone has a number-average molecular weight of 40,000 to 90,000, a melt index ≥2 g / 10 min (2.16 kg, 160 °C), and a melting point of 58 to 65 °C. Preferably, the polycaprolactone has a molecular weight distribution index ≤ 2.5; and the polycaprolactone preferably has a color intensity < 80 Hazen.

3. The microwave-heatable medical polycaprolactone composition according to claim 1, characterized in that: The nanofiller is selected from one or more of nano silica, nano calcium carbonate, nano talc, nano calcium sulfate, nano montmorillonite, glass microspheres, glass fiber, carbon fiber, mica, kaolin, and silica; preferably, it is selected from one or more of nano silica, nano calcium carbonate, nano talc, and nano calcium sulfate.

4. The microwave-heatable medical polycaprolactone composition according to claim 1, characterized in that: The average particle size of the nanofiller is 10-300 nanometers.

5. The microwave-heatable medical polycaprolactone composition according to claim 1, characterized in that: The microwave absorber is selected from one or more of silicon carbide, iron oxide, barium sulfate, nanocellulose crystals, titanium dioxide, hydrated magnesium hydroxide, pentaerythritol, and melamine; preferably, it is selected from one or more of hydrated magnesium hydroxide, titanium dioxide, nanocellulose crystals, or melamine.

6. The microwave-heatable medical polycaprolactone composition according to claim 1, characterized in that: The thermally conductive agent is selected from one or more of magnesium oxide, aluminum oxide, boron nitride, aluminum nitride, silicon carbide, graphite, carbon nanotubes, carbon black, and graphene; preferably, it is selected from one or more of aluminum oxide, aluminum nitride, carbon nanotubes, magnesium oxide, or graphite.

7. The microwave-heatable medical polycaprolactone composition according to claim 1, characterized in that... It also contains odor absorbers; The odor adsorbent is a cage-like silsesquioxane; preferably one or more of octavinylsilsesquioxane, octaphenylsilsesquioxane, octaisobutylsilsesquioxane, octaisooctylsilsesquioxane, and octaepoxysilsesquioxane; more preferably one or more of octaisobutylsilsesquioxane, octavinylsilsesquioxane, octaphenylsilsesquioxane, or octaepoxysilsesquioxane. Preferably, the amount of the odor adsorbent is 0.05 to 1.8 parts by weight, more preferably 0.2 to 1.5 parts by weight, based on a total weight of 100 parts by weight of the polycaprolactone and the nanofiller.

8. The method for preparing the microwave-heatable medical polycaprolactone composition according to any one of claims 1 to 7, characterized in that... Includes the following steps: The components, including the polycaprolactone, nanofiller, microwave absorber, optional thermal conductive agent, and optional odor adsorbent, are mixed and melt-blended; the melt-blending temperature is preferably 80-180°C, more preferably 100-130°C.

9. The polycaprolactone composition prepared by the method for preparing the microwave-heatable medical polycaprolactone composition according to claim 8.

10. Application of the microwave-heatable medical polycaprolactone composition according to any one of claims 1 to 7 or the product prepared by the method according to claim 8, preferably in medical surgical materials.

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