Toughened polyglycolic acid modified material and preparation method thereof

Abstract

The invention provides a toughened polyglycolic acid modified material and a preparation method thereof. Polyurethane and polyglycolic acid are physically blended, polyurethane can be uniformly dispersed in a polyglycolic acid matrix, and a sea island structure is formed to improve the toughness of polyglycolic acid. In order to further improve the compatibility of the polyglycolic acid and the polyurethane, a functional compatilizer can be optionally added, the compatibilization of the polyglycolic acid and the polyurethane is realized through chemical bonding, and the interface interaction is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high polymer materials, and particularly relates to a toughened polyglycolic acid modified material and a preparation method thereof. BACKGROUND

[0002] In recent years, with the wide use of disposable plastic products in daily life, most of the plastic products are derived from petroleum-based polymers, and the non-biodegradability and resistance to microbial degradation of petroleum-based polymers lead to their continuous storage in the environment. Today, the "white pollution" caused by plastic waste has caused a great burden on the environment. With the continuous promotion of the "plastic restriction order", biobased degradable plastics will inevitably become a new application trend. It is predicted that by 2030, the production of biobased degradable plastics will account for more than 40% of the plastic market. From food packaging, pharmaceuticals, electronics, agriculture to textiles, biobased degradable plastics will gradually replace traditional, non-degradable petrochemical plastics. Biobased polymer materials from renewable resources are an ideal choice to reduce dependence on fossil fuel-based plastics, but many biobased polymer materials themselves have insufficient mechanical properties and use performance, and often need to be modified to achieve their industrial application value. Polyglycolic acid (PGA) is a renewable polymer material with outstanding biodegradability and biocompatibility, which can ultimately be degraded into non-toxic and harmless water and carbon dioxide in both natural environment and seawater. PGA is the best polymer material in terms of degradation performance among the currently known biobased degradable plastics, and has good seawater degradability. However, PGA material itself has high brittleness and low toughness, and the elongation at break is usually less than 10%. Such low elongation at break greatly limits the application of PGA material, and the toughened PGA will have a very broad market space.

[0003] Currently, there are few studies on the toughening modification of polyglycolic acid. The most common modification methods are physical blending and chemical copolymerization, both of which choose to modify with some flexible materials. Physical blending is simple and easy to operate. By adding flexible materials to PGA, the flexible materials form an island structure in the PGA matrix, which acts as a stress concentration point when subjected to external force impact, thereby improving the toughness of PGA. In chemical copolymerization, to improve the compatibility of flexible materials with the PGA matrix, a compatibilizer is usually added to form a block copolymer at the interface of the blend, improving compatibility. For example, existing studies on the toughening modification of PGA include: ①Ling Fei Chang (Chang L F, et al. Toughening Effect of Physically Blended Polyethylene Oxide on Polyglycolic Acid [J]. Journal of Polymers and the Environment, 2020(2)) et al. blended PGA with polyethylene oxide (PEO) to achieve toughening. The presence of continuous polyethylene oxide phase in the PGA matrix promotes the formation of cavities between partially compatible PGA and PEO, improving the tensile toughness of PGA. When 15wt% PEO is added, the elongation at break increases from 3.7% for pure PGA to 54.1% for PGA / PEO, an increase of 1475.2%. ②Han Wu (Xu P, et al. Highly Toughened Sustainable Green Polyglycolic Acid / Polycaprolactone Blends with Balanced Strength: Morphology Evolution, Interfacial Compatibilization, and Mechanism [J]. [2024-06-24]) et al. blended PGA with flexible material polycaprolactone (PCL) and selected multifunctional epoxy polymers (MEPs) as a reactive compatibilizer. The terminal hydroxyl and carboxyl groups of PGA and PCL can react with MEPs in situ, greatly improving the compatibility of PGA and PCL. When 0.75wt% MEPs are added, the fracture toughness of PGA / PCL increases by 370%.③Christopher Ellingford (Reactive extrusion of biodegradable PGA / PBAT blends to enhance flexibility and gas barrier properties[J].Journal of Applied Polymer Science, 2022, 139(6)) et al. melt blended PGA with polybutylene adipate (PBAT) and compatibilized with ethylene, acrylic ester and glycidyl methacrylate (EMA-GMA), the addition of EMA-GMA enables interfacial bonding between PGA and PBAT, improving the compatibility, when adding 20wt% of EMA-GMA, the elongation at break of PGA / PBAT blends increases from 10.7% to 145%.

[0004] With the introduction of the national "plastic limit order" policy, traditional petroleum-based non-degradable plastics will be gradually replaced by biobased degradable plastics. In recent years, some degradable materials such as polylactic acid, polyhydroxyalkanoate and polyglycolic acid have developed rapidly. Polyglycolic acid has the remarkable characteristics of high strength, high barrier property, excellent biocompatibility, fast degradation rate and seawater degradability, and has obvious advantages in degradable materials. If polyglycolic acid can be applied to plastic products, it will have very good market prospects. However, polyglycolic acid itself is brittle and has low toughness, and the elongation at break is less than 10%, which greatly limits the wide application of polyglycolic acid. At present, there are few studies on the toughening of polyglycolic acid. If some simple and effective methods can be used to toughen polyglycolic acid, the toughened polyglycolic acid material can be more widely used in daily life, and has good biodegradability, which will have great significance for reducing plastic waste in the environment and protecting the environment. SUMMARY

[0005] In order to solve the technical problems existing in the prior art, the present application provides a toughened polyglycolic acid modified material, which physically blends polyurethane elastomer (PU) with polyglycolic acid (PGA). PU can be uniformly dispersed in the matrix of PGA to form an island structure to improve the toughness of PGA. In order to further improve the compatibility of PGA and PU, a functional compatibilizer is optionally added to achieve the compatibilization of PGA and PU through chemical bonding, thereby improving the interfacial interaction.

[0006] One of the objects of the present application is to provide a toughened polyglycolic acid modified material, which comprises a mixture of components including polyglycolic acid, polyurethane, and optionally added compatibilizer, and / or reaction products thereof.

[0007] Polyurethane elastomer (PU) is a block copolymer formed by alternating soft and hard segments. It exhibits high elongation at break and excellent reprocessability, making it a typical flexible material. Physical blending of PU elastomer and polyglycolic acid (PGA) creates a simple binary blend. The PU elastomer is uniformly dispersed within the PGA matrix, forming an island structure. When the blend is subjected to external stress, the PU dispersed within the PGA matrix acts as stress concentration points, absorbing external energy and enhancing the toughness of the PGA. Furthermore, to improve the compatibility between PGA and PU, a compatibilizer (preferably a multifunctional epoxy polymer) can be optionally added. The hydroxyl groups at the ends of PU and the hydroxyl and carboxyl groups at the ends of PGA achieve interfacial bonding through the compatibilizer, improving compatibility and enhancing interfacial interactions. During the PU-PGA blending process, a vulcanizing agent can also be added to dynamically vulcanize the PU. The PU dispersed within the PGA matrix is ​​vulcanized, forming a cross-linked network that effectively toughens the PGA, acting as a stress concentration point when subjected to external impact. The polyurethane elastomers used in this invention include, but are not limited to: thermoplastic polyurethane elastomers (TPU), compounded polyurethane elastomers (MPU), cast polyurethane elastomers (CPU), and waterborne polyurethane elastomers (WPU).

[0008] In the toughened polyglycolic acid modified material provided by the present invention, the polyglycolic acid is 50-95 parts by weight, the polyurethane is 5-50 parts by weight, and the compatibilizer is 0-8 parts by weight; preferably, the polyglycolic acid is 60-90 parts by weight, the polyurethane is 10-40 parts by weight, and the compatibilizer is 0-3 parts by weight.

[0009] In the toughened polyglycolic acid modified material provided by the present invention, the compatibilizer is selected from at least one of compounds containing unsaturated double bonds and compounds containing epoxy groups, preferably from at least one of polyfunctional epoxy polymers (such as ADR multi-epoxy compounds, CE multi-epoxy compounds, MEPs), ethylene, acrylates, and glycidyl methacrylate (EMA-GMA).

[0010] In the polyurethane used in this invention, segments comprising polyester glycol and / or polyether glycol and / or hydroxyl-terminated polymers are designated as soft segments, and segments comprising diisocyanate compounds and chain extenders are designated as hard segments. The polyurethane contains 10–50 wt% hard segments and 50–90 wt% soft segments; preferably, the polyurethane contains 20–45 wt% hard segments and 55–80 wt% soft segments.

[0011] Specifically, the segments in the soft segment are selected from at least one of polycaprolactone diol, polycaprolactone carbonate copolyol, hydroxyl-terminated polybutadiene, hydroxyl-terminated hydrogenated polybutadiene, hydroxyl-terminated polybutadiene-acrylonitrile, hydroxyl-terminated styrene-butadiene rubber, polylactic acid diol, polytetramethylene ether diol (PTMEG), polypropylene oxide diol (PPG), polytrimethylene ether diol (PO3G), tetrahydrofuran-propylene oxide copolyol, polycaprolactone (PCDL), polyhexyl adipate diol (PHA), polyethylene adipate diol (PEA), poly(1-4-butylpentyl adipate) diol (PBA), and poly(neopentyl adipate) diol (PNA).

[0012] The diisocyanate compounds mentioned are selected from hexamethylene diisocyanate (HDI), pentamethylene diisocyanate (PDI), diphenylmethane diisocyanate (MDI), toluene diisocyanate (TDI), isophorone diisocyanate (IPDI), and dicyclohexylmethane diisocyanate (HDI). 12 At least one of MDI, 1,5-naphthalene diisocyanate (NDI), terephthalic diisocyanate (PPDI), 1,4-cyclohexane diisocyanate (CHDI), trimethyl-1,6-hexamethylene diisocyanate (TMHDI), and dimethylbiphenyl diisocyanate (TODI);

[0013] The chain extender is selected from at least one of 1,4-butanediol, 1,3-butanediol, trimethylolpropane monoallyl ether, glyceryl allyl ether, trimethylolpropane (TME), 3-allyloxy-1,2-propanediol (APD), and glyceryl monomethacrylate.

[0014] The second objective of this invention is to provide a method for preparing the above-mentioned toughened polyglycolic acid modified material, comprising a step of melt blending polyglycolic acid, polyurethane and optionally added compatibilizer.

[0015] According to the present invention, in the preparation method of the toughened polyglycolic acid modified material, the melt blending conditions are: temperature 210-240°C and rotation speed 50-200 rpm; preferably, the melt blending includes first melting the polyglycolic acid, then adding polyurethane and blending for 3-6 minutes when the temperature reaches at least 220°C, and optionally adding a compatibilizer and blending for 3-6 minutes at a temperature not lower than 220°C to obtain the toughened polyglycolic acid modified material.

[0016] According to the present invention, the polyurethane can be prepared by designing the ratio of soft segments to hard segments using a synthesis method commonly used in the prior art. Specifically, the preparation method of the polyurethane includes:

[0017] (1) The polyester diol and / or polyether diol and / or hydroxyl-terminated polymer and diisocyanate compound are subjected to a prepolymerization reaction to obtain a polyurethane prepolymer;

[0018] (2) Add a chain extender to the polyurethane prepolymer obtained in step (1) to carry out a chain extension reaction, and then cure the polyurethane to obtain the polyurethane.

[0019] Wherein, the polyester glycol and / or polyether glycol and / or hydroxyl-terminated polymer is selected from at least one of polycaprolactone glycol, polycaprolactone carbonate copolyol, hydroxyl-terminated polybutadiene, hydroxyl-terminated hydrogenated polybutadiene, hydroxyl-terminated polybutadiene-acrylonitrile, hydroxyl-terminated styrene-butadiene rubber, polylactic acid glycol, polytetramethylene ether glycol (PTMEG), polypropylene oxide glycol (PPG), polytrimethylene ether glycol (PO3G), tetrahydrofuran-propylene oxide copolyol, polycaprolactone (PCDL), polyhexyl adipate glycol (PHA), polyethylene adipate glycol (PEA), poly(1-4-butylpentyl adipate) glycol (PBA), and poly(neopentyl adipate) glycol (PNA).

[0020] The diisocyanate compounds mentioned are selected from hexamethylene diisocyanate (HDI), pentamethylene diisocyanate (PDI), diphenylmethane diisocyanate (MDI), toluene diisocyanate (TDI), isophorone diisocyanate (IPDI), and dicyclohexylmethane diisocyanate (HDI). 12 At least one of MDI, 1,5-naphthalene diisocyanate (NDI), terephthalic diisocyanate (PPDI), 1,4-cyclohexane diisocyanate (CHDI), trimethyl-1,6-hexamethylene diisocyanate (TMHDI), and dimethylbiphenyl diisocyanate (TODI);

[0021] The chain extender is selected from at least one of 1,4-butanediol, 1,3-butanediol, trimethylolpropane monoallyl ether, glyceryl allyl ether, trimethylolpropane (TME), 3-allyloxy-1,2-propanediol (APD), and glyceryl monomethacrylate.

[0022] The molar ratio of the diisocyanate compound to the chain extender is 1:(0.3-10);

[0023] The conditions for the prepolymerization reaction in step (1) are: 60-100℃ for 1-2 hours;

[0024] The chain extension reaction conditions in step (2) are: 60-100℃ for 1-15 min;

[0025] The curing conditions in step (2) are: curing at 80-100℃ for 12-18 hours.

[0026] According to a specific embodiment of the present invention, the polyurethane can be prepared by the following specific steps:

[0027] After weighing the polyester glycol and / or polyether glycol and / or hydroxyl-terminated polymer corresponding to a soft segment content of 50-90 wt%, pour them into a three-necked flask, heat them in an oil bath at a temperature of 110-150℃, stir them at 100-200 rpm, and remove water under vacuum at -0.1 MPa for 1-2 hours.

[0028] When the temperature inside the three-necked flask cools to 50-80°C, add a diisocyanate compound with a hard segment content of 10-50 wt%. Adjust the rotation speed to 200-400 rpm / min, place a thermometer inside the three-necked flask, and record the temperature in real time. The reaction is rapid immediately after the diisocyanate compound is added, and the temperature will rise to 60-100°C within 30 minutes. Perform the prepolymerization reaction for 1-2 hours.

[0029] After the prepolymerization reaction is completed, a chain extender is added for chain extension. The rotation speed is adjusted to 400-600 rpm / min. After the chain extension reaction is carried out for 1-15 minutes, the synthesized PU is poured out and post-cured in an oven at 80-100℃ for 12-18 hours.

[0030] This invention synthesizes polyurethane by designing the ratio of soft segments to hard segments, blends the synthesized polyurethane with polyglycolic acid (PGA), and toughens and modifies the PGA. During the melt blending process, a small amount of functional compatibilizer is optionally added to enable in-situ copolymerization of polyurethane and PGA, further improving interfacial interactions and compatibility, thereby achieving toughening of PGA.

[0031] This invention utilizes a simple and effective preparation process to toughen and modify polyglycolic acid (PGA). The toughened PGA material can be used more extensively in daily life (e.g., biodegradable heat-resistant tableware in restaurants, infusion bags in medical supplies, biodegradable mulch films in agriculture, and can also be used as timber in forestry, aquaculture, soil, and water-retaining materials for desert greening). It exhibits excellent biodegradability, which is of great significance for reducing plastic waste in the environment and promoting ecological and environmental protection. The raw materials used in this invention are readily available, and the preparation process is simple, facilitating industrial production. Attached Figure Description

[0032] Figure 1 The images shown are infrared spectra of PU with 20% and 40% hard segment content in the examples. From the infrared spectrum of PU with 20% hard segment content, it can be seen that at 3321 cm⁻¹... -1 The characteristic absorption peak of NH in the urethane group (-NH-COO-) appeared at 1717 cm⁻¹. -1The presence of a characteristic absorption peak of the carbonyl group in the urethane group at 2270 cm⁻¹ confirms the reaction between the isocyanate group and the hydroxyl group. -1 The absence of characteristic peaks for -NCO groups at this point confirms the complete reaction between the isocyanate groups and the hydroxyl groups at both ends of the chain extender, indicating the successful synthesis of PU. Similarly, the infrared spectrum of PU with a hard segment content of 40% shows a peak at 3324 cm⁻¹. -1 The characteristic absorption peak of NH in the urethane group (-NH-COO-) appeared at 1730 cm⁻¹. -1 The presence of a characteristic absorption peak of the carbonyl group in the urethane group at the specified location confirms the successful synthesis of PU.

[0033] Figure 2 The image shown is a scanning electron microscope image of Example 1 after etching with N,N-dimethylformamide. The PU in the blend was etched away by DMF, while the PGA was retained. As can be seen from the image, the PU is uniformly dispersed in the PGA matrix, and the particle size difference is not large. There is no agglomeration phenomenon, and the PU can withstand uniform stress in mechanical testing. Detailed Implementation

[0034] The present invention will now be described in detail with reference to specific embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0035] The testing instruments and conditions used in this embodiment are as follows:

[0036] Infrared testing: The prepared polyurethane elastomer was analyzed using a TENSOR 27 Fourier transform infrared spectroscopy system from Bruker (Germany), with a testing range of 4000-600 cm⁻¹. -1 The chemical structure of the polyurethane elastomer was tested and recorded using attenuated total reflectance (ATR) mode.

[0037] Mechanical blending: Blending was carried out in a Haake Rheomix 600OS internal mixer at a melting temperature of 220°C. PGA, which has a high melting point and is difficult to melt, was added to the Haake. When the real-time temperature rose to 220°C, TPU and ADR were added. The mixture was then taken out after blending for 4 minutes.

[0038] Mechanical property testing: Pure PGA, PGA / PU, and PGA / PU / ADR blends were injection molded into tensile test specimens according to ASTM D638, Type IV standard. The specimens were then subjected to tensile testing at 20 mm / min on a tensile testing machine (SANS CMT 4104, China) at 25°C. Each specimen underwent at least 5 tensile tests. Impact test specimens were also injection molded into 80*10*4mm, Type A standard according to GB / T1843-2008. These specimens were then tested using a cantilever beam impact testing machine (TF-XBL) at 25°C. Each specimen underwent at least 5 impact tests.

[0039] DSC test: Differential scanning calorimetry was performed using the STARe system from Mettler Toledo, Switzerland. The sample was heated from 25°C to 250°C, held at 250°C for 3 min, cooled to -70°C, held for 3 min, and then heated back to 250°C. The heating and cooling rates were set to 10°C / min during the test, which was conducted in an N2 atmosphere.

[0040] Dynamic mechanical properties test: Dynamic mechanical properties were tested using DMA Q800 (TAInstruments) in single cantilever mode, within the range of -100℃ to 250℃. The specific test conditions were: strain 1%, frequency 1Hz, heating rate 3℃ / min, and N2 atmosphere.

[0041] SEM testing: PGA / PU and PGA / PU / ADR blends were frozen in liquid nitrogen for 15 min for quenching, etched with N,N-dimethylformamide (DMF) for 5 days, and the cross-sectional morphology of the gold-sprayed samples was measured using a scanning electron microscope (SEM, Hitachi S4800, Japan) with an accelerating voltage of 5 kV.

[0042] Unless otherwise specified, the raw materials used in the examples and comparative examples are all publicly available in the prior art, such as those that can be directly purchased or prepared according to publicly available methods. The polyglycolic acid (PGA) used in the examples and comparative examples was purchased from Shanghai Pujing Chemical Co., Ltd., with a weight-average molecular weight of 100,000-150,000, a melting point of 225°C, and a crystallinity of 30-45%. The compatibilizer was BASF ADR-4468, with nine active epoxy groups on each ADR-4468 molecule and a density of 1.08 g / cm³. 3 It has a molecular weight of 6800, a glass transition temperature of 54℃, a melting point of 59℃, and an epoxy equivalent of 310 g / mol. Polyglycolic acid should be dried in a vacuum oven at 80℃ for 12 hours before use.

[0043] Preparation of polyurethane (PU)

[0044] The soft segment used in the synthesis of polyurethane is polycaprolactone diol, the diisocyanate is hexamethylene diisocyanate (HDI), and the chain extender is 1,4-butanediol (BDO).

[0045] First, 300g of polycaprolactone diol was poured into a three-necked flask, and the liquid level in the flask was completely submerged in an oil bath at 120℃. Vacuum treatment was performed at -0.1MPa for one and a half hours. The oil bath temperature was then adjusted to 65℃ for cooling. After cooling, 79.2g of HDI was added, and prepolymerization was carried out at 65℃ for one and a half hours. After prepolymerization, 20.8g of BDO was added for chain extension. The oil bath temperature was not changed, and chain extension was performed at 65℃ for 6 minutes. After chain extension, the prepared PU was poured out and post-cured in an oven at 80℃ for 12 hours to obtain polyurethane (PU1) with a hard segment content of 20%.

[0046] By changing the amounts of polycaprolactone diol, HDI, and BDO, a polyurethane (PU2) with a hard segment content of 40% was prepared using 220g of polycaprolactone diol, 127.5g of HDI, and 52.5g of BDO, following the above preparation process.

[0047] Example 1

[0048] Without adding ADR, PU1 with a hard segment content of 20% was blended with PGA. The melting temperature of the plastic mixer was set to 220°C and the rotation speed to 100 rpm. 10 parts of PU1 and 90 parts of PGA were blended. When the real-time temperature of the plastic mixer reached 220°C, PGA, which has a high melting point and is difficult to melt, was added first. As the PGA was sheared and stirred in the mixer, the temperature gradually increased. When the real-time temperature reached 220°C, PU1 was added. Immediately after the addition of PU1, the torque increased instantaneously and the temperature dropped. As the mixture was sheared and stirred, the temperature rose again. When the temperature reached 220°C again, the timer was started, and the mixture was stirred for 4 minutes.

[0049] Example 2

[0050] Without adding ADR, PU1 with a hard segment content of 20% was blended with PGA. The melting temperature of the plastic mixer was set to 220°C and the rotation speed to 100 rpm. 20 parts of PU1 and 80 parts of PGA were blended. When the real-time temperature of the plastic mixer reached 220°C, PGA, which has a high melting point and is difficult to melt, was added first. As the PGA was sheared and stirred in the mixer, the temperature gradually increased. When the real-time temperature reached 220°C, PU1 was added. Immediately after the addition of PU1, the torque increased instantaneously and the temperature dropped. As the mixture was sheared and stirred, the temperature rose again. When the temperature reached 220°C again, the timer was started, and the mixture was stirred for 4 minutes.

[0051] Example 3

[0052] Without adding ADR, PU2 with a hard segment content of 40% was blended with PGA. The melting temperature of the plastic mixer was set to 220°C and the rotation speed to 100 rpm. 10 parts of PU2 and 90 parts of PGA were blended. When the real-time temperature of the plastic mixer reached 220°C, PGA, which has a high melting point and is difficult to melt, was added first. As the PGA was sheared and stirred in the mixer, the temperature gradually increased. When the real-time temperature reached 220°C, PU2 was added. Immediately after the addition of PU2, the torque increased instantaneously and the temperature dropped. As the mixture was sheared and stirred, the temperature rose again. When the temperature reached 220°C again, the timer was started, and the mixture was stirred for 4 minutes.

[0053] Example 4

[0054] Without adding ADR, PU2 with a hard segment content of 40% was blended with PGA. The melting temperature of the plastic mixer was set to 220°C and the rotation speed to 100 rpm. 20 parts of PU2 and 80 parts of PGA were blended. When the real-time temperature of the plastic mixer reached 220°C, PGA, which has a high melting point and is difficult to melt, was added first. As the PGA was sheared and stirred in the mixer, the temperature gradually increased. When the real-time temperature reached 220°C, PU2 was added. Immediately after the addition of PU2, the torque increased instantaneously and the temperature dropped. As the mixture was sheared and stirred, the temperature rose again. When the temperature reached 220°C again, the timer was started, and the mixture was stirred for 4 minutes.

[0055] Example 5

[0056] With the addition of ADR, PU2 with a hard segment content of 40% was blended with PGA. The melting temperature of the plastic mixer was set to 220°C and the rotation speed to 100 rpm. 10 parts of PU2 and 90 parts of PGA were blended. When the real-time temperature of the plastic mixer reached 220°C, PGA, which has a high melting point and is difficult to melt, was added first. As the PGA was sheared and stirred in the mixer, the temperature gradually increased. When the real-time temperature reached 220°C, PU2 was added. Immediately after the addition of PU2, the torque increased instantaneously and the temperature dropped. With shearing and stirring, the temperature rose again. When the temperature reached 220°C again, 0.1 parts of ADR were added, and the timer was started. The mixture was stirred for 4 minutes.

[0057] Example 6

[0058] With the addition of ADR, PU2 with a hard segment content of 40% was blended with PGA. The melting temperature of the plastic mixer was set to 220°C and the rotation speed to 100 rpm. 10 parts of PU2 and 90 parts of PGA were blended. When the real-time temperature of the plastic mixer reached 220°C, PGA, which has a high melting point and is difficult to melt, was added first. As the PGA was sheared and stirred in the mixer, the temperature gradually increased. When the real-time temperature reached 220°C, PU2 was added. Immediately after the addition of PU2, the torque increased instantaneously and the temperature dropped. With shearing and stirring, the temperature rose again. When the temperature reached 220°C again, 3.0 parts of ADR were added, and the timer was started. The mixture was stirred for 4 minutes.

[0059] Example 7

[0060] With the addition of ADR, PU2 with a hard segment content of 40% was blended with PGA. The melting temperature of the plastic mixer was set to 220°C and the rotation speed to 100 rpm. 20 parts of PU2 and 80 parts of PGA were blended. When the real-time temperature of the plastic mixer reached 220°C, PGA, which has a high melting point and is difficult to melt, was added first. As the PGA was sheared and stirred in the mixer, the temperature gradually increased. When the real-time temperature reached 220°C, PU2 was added. Immediately after the addition of PU2, the torque increased instantaneously and the temperature decreased. With shearing and stirring, the temperature increased again. When the temperature reached 220°C again, 0.1 parts of ADR were added, and the timer was started. The mixture was stirred for 4 minutes.

[0061] Example 8

[0062] With the addition of ADR, PU2 with a hard segment content of 40% was blended with PGA. The melting temperature of the plastic mixer was set to 220°C and the rotation speed to 100 rpm. 20 parts of PU2 and 80 parts of PGA were blended. When the real-time temperature of the plastic mixer reached 220°C, PGA, which has a high melting point and is difficult to melt, was added first. As the PGA was sheared and stirred in the mixer, the temperature gradually increased. When the real-time temperature reached 220°C, PU2 was added. Immediately after the addition of PU2, the torque increased instantaneously and the temperature decreased. With shearing and stirring, the temperature increased again. When the temperature reached 220°C again, 3.0 parts of ADR were added, and the timer was started. The mixture was stirred for 4 minutes.

[0063] Comparative Example 1

[0064] Without adding polyurethane or ADR, the melting temperature of the plastic hacker was set to 220°C and the rotation speed to 100 rpm. When the real-time temperature of the plastic hacker reached 220°C, 100 parts of PGA were added to the plastic hacker. As the PGA was sheared and stirred in the hacker, the temperature gradually increased. When the real-time temperature reached 220°C, the mixture was stirred for 6 minutes.

[0065] Table 1

[0066] Hard segment content (%) PGA content (%) PU content (%) ADR content (%) Example 1 20 90 10 0 Example 2 20 80 20 0 Example 3 40 90 10 0 Example 4 40 80 20 0 Example 5 40 90 10 0.1 Example 6 40 90 10 3.0 Example 7 40 80 20 0.1 Example 8 40 80 20 3.0 Comparative Example 1 0 100 0 0

[0067] Table 2

[0068] Tensile strength (MPa) Elongation at break (%) Impact strength (kJ / m 2 ) Crystallinity (%) Example 1 92.4 31.1 4.6 33.5 Example 2 81.3 45.5 5.8 32.1 Example 3 109.1 47.8 4.5 34.5 Example 4 93.6 60.9 6.2 32.2 Example 5 86.6 55.5 7.6 31.7 Example 6 75.7 62.7 12.3 30.8 Example 7 80.2 69.4 8.7 31.3 Example 8 69.5 75.8 14.6 30.5 Comparative Example 1 140.3 5.7 2.9 35.4

[0069] The tensile strength of pure PGA is around 140 MPa, but its elongation at break is only 5.7%, and its impact strength is only 2.9 kJ / m. 2 PGA is a typical brittle material. When PGA is blended with polyurethane (PU) and then blended with PU1 containing 20% ​​hard segments, adding 10% PU1 results in a tensile strength of 92.4 MPa. While the tensile strength decreases somewhat, the elongation at break increases to 31.1%, a significant improvement of 5.5 times compared to pure PGA. This is because polyurethane can form a uniformly dispersed island structure within the PGA matrix, which, under stress, can induce cavitation and absorb energy, thereby increasing the elongation at break. Impact strength is also improved. When the amount of PU is increased to 20% PU1 blended with PGA, the tensile strength further decreases to 81.3 MPa due to the dilution effect of polyurethane, while the elongation at break increases to 45.5%, an 8-fold improvement compared to pure PGA. When the hard segment content of polyurethane is increased, and PU2 with a hard segment content of 40% is blended with PGA, the PU2 with a hard segment content of 40% has higher tensile strength and elongation at break than PU1 with a hard segment content of 20% when blended with PGA in the same proportion. In addition, the change in crystallinity can also reflect the mechanical properties of PGA in some aspects. As the polyurethane content in the blend increases, the crystallinity gradually decreases.

[0070] PU2 with a hard segment content of 40% was blended with PGA. ADR was added to improve compatibility. When 10% PU2 was blended with PGA and 0.1% ADR was added, the tensile strength decreased slightly due to the toughening effect of ADR small molecules. The tensile strength was 86.6 MPa, the elongation at break was 55.5%, an increase of 9.7 times, and the impact strength was 7.6 kJ / m. 2 The tensile strength was increased by 2.6 times. With the addition of 3.0% ADR, the tensile strength was 75.7 MPa, the elongation at break was 62.7%, an increase of 11 times, and the impact strength was 12.3 kJ / m. 2 The results showed a 4.2-fold increase. When 20% PU2 was blended with PGA and 0.1% ADR was added, the elongation at break increased by 12.2 times and the impact strength increased by 3 times. When 3.0% ADR was added, the elongation at break increased by 13.3 times and the impact strength increased by 5 times.

[0071] As shown in Table 2, the mechanical properties of the modified polyglycolic acid material are significantly improved, exhibiting both high rigidity and high toughness, as well as good stability. The processing is simple, easy to operate, and readily repeatable.

[0072] This invention describes in detail the experimental process and scheme for toughening modified polyglycolic acid materials. However, this invention includes, but is not limited to, this invention. Within the scope of the concept involved in this invention, simple combinations of the experimental scheme and other methods in this invention are all considered to be the content disclosed in this invention and are within the protection scope of this invention.

Claims

1. A toughened polyglycolic acid modified material comprising a mixture and / or reaction product of polyglycolic acid, polyurethane, and optionally a compatibilizer.

2. The toughened polyglycolic acid modified material according to claim 1, wherein the polyglycolic acid is 50 to 95 parts by weight, the polyurethane is 5 to 50 parts by weight, and the compatibilizer is 0 to 8 parts by weight; preferably, the polyglycolic acid is 60 to 90 parts by weight, the polyurethane is 10 to 40 parts by weight, and the compatibilizer is 0 to 3 parts by weight.

3. The toughened polyglycolic acid modified material according to claim 1 or 2, wherein the compatibilizer is at least one selected from the group consisting of an unsaturated double bond-containing compound, an epoxy group-containing compound, and preferably at least one selected from the group consisting of a multifunctional epoxy group-containing polymer, ethylene, an acrylate, and glycidyl methacrylate.

4. The toughened polyglycolic acid modified material according to claim 1 or 2, wherein the polyurethane has a segment comprising a polyester diol and / or a polyether diol and / or a hydroxyl-terminated polymer as a soft segment, and a segment comprising a diisocyanate compound and a chain extender as a hard segment, and wherein the content of the hard segment is 10 to 50% by weight and the content of the soft segment is 50 to 90% by weight; preferably, the content of the hard segment is 20 to 45% by weight and the content of the soft segment is 55 to 80% by weight.

6. The toughened polyglycolic acid modified material according to claim 4, wherein the segment in the soft segment is at least one selected from the group consisting of polycaprolactone diol, polycaprolactone carbonate copolydiol, hydroxyl-terminated polybutadiene, hydroxyl-terminated hydrogenated polybutadiene, hydroxyl-terminated polybutadiene-acrylonitrile, hydroxyl-terminated butadiene styrene rubber, polylactic acid diol, polytetramethylene ether diol, polypropylene oxide diol, polytrimethylene ether diol, tetrahydrofuran-propylene oxide copolydiol, polycaprolactone, polyhexandiol adipate diol, polyethylene glycol adipate diol, poly1-4 butylene glycol adipate diol, and polyneopentyl glycol adipate diol; and / or the diisocyanate compound is at least one selected from the group consisting of hexamethylene diisocyanate, pentamethylene diisocyanate, diphenylmethane diisocyanate, toluene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, 1,5-naphthalene diisocyanate, p-phenylene diisocyanate, 1,4-cyclohexane diisocyanate, trimethyl-1,6-hexamethylene diisocyanate, and dimethyl diphenyl diisocyanate; and / or the chain extender is at least one selected from the group consisting of 1,4-butanediol, 1,3-butanediol, trimethylolpropane monomethallyl ether, glycerol monomethallyl ether, trimethylolpropane, 3-allyloxy-1,2-propanediol, and glycerol monomethacrylate.

7. A method for producing the toughened polyglycolic acid modified material according to any one of claims 1 to 6, comprising a step of melt blending the polyglycolic acid, the polyurethane, and the optional compatibilizer.

8. The method for producing according to claim 7, wherein 5. The toughened polyglycolic acid modified material according to claim 4, wherein, ​ ​ ​ ​ ​ ​ ​ The melt blending is carried out at a temperature of 210-240℃ and a rotation speed of 50-200rpm. Preferably, the melt blending comprises melting the polyglycolic acid, adding the polyurethane and blending for 3-6 minutes when the temperature reaches at least 220℃, and optionally adding the compatilizer and blending for 3-6 minutes when the temperature is not lower than 220℃, to obtain the toughened polyglycolic acid modified material.

9. The preparation method according to claim 7, characterized in that, The polyurethane is prepared by the following steps: (1) pre-polymerizing the polyester diol and / or polyether diol and / or hydroxyl-terminated polymer, a diisocyanate compound, to obtain a polyurethane pre-polymer; (2) adding a chain extender to the polyurethane pre-polymer obtained in step (1) to carry out chain extension reaction, and curing to obtain the polyurethane.

10. The preparation method of claim 9, wherein, the molar ratio of the diisocyanate compound and the chain extender is 1:(0.3-10); and / or, the pre-polymerization in step (1) is carried out at a temperature of 60-100℃ for 1-2h; and / or, the chain extension reaction in step (2) is carried out at a temperature of 60-100℃ for 1-15min; and / or, the curing reaction in step (2) is carried out at a temperature of 80-100℃ for 12-18h.

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