Tough full-bio-based polylactic acid / polyamide composite material and preparation method thereof

Abstract

The invention discloses a tough full-bio-based polylactic acid / polyamide composite material and a preparation method thereof, and belongs to the technical field of polymer composite material preparation. The tough polylactic acid / polyamide composite material comprises polylactic acid, bio-based polyamide, a core-shell amide modified material, a hydrolysis stabilizer, an antioxidant and a chain extender. The core-shell amide modified material is prepared by filling a functional elastomer copolymer with amino nanoparticles. The core-shell amide modified material formed on the basis of the amino nanoparticle reactive filling functional elastomer copolymer has a micro core-shell structure formed in situ and a large number of amido bonds, so that the number of hydrogen bonds between molecular chains of a blend system is increased, and entanglement and intermolecular acting force between micro molecular chains of the blend material are improved; therefore, the system compatibility is improved, the absorption of the material on external stress and energy is enhanced, more obvious plastic deformation is generated when the material is stressed and deformed, and the material is endowed with better mechanical properties.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer composite material preparation, and in particular to a strong and tough all-biobased polylactic acid / polyamide composite material and a preparation method thereof. Background Art

[0002] Biodegradable materials, due to their environmental friendliness and renewability, are becoming a key research focus in replacing petroleum-based engineering plastics. Polylactic acid, a typical bio-based polyester, boasts renewable raw material sources, excellent processing adaptability, and complete biological metabolism. It has already found industrial application in packaging film bags, clothing, and medical sutures.

[0003] However, polylactic acid materials still have significant defects in engineering applications, such as: prominent brittleness, elongation at break generally less than 10% (ASTM D638); poor impact resistance, and cantilever beam notched impact strength less than 4kJ / m 2 (ASTM D256). These significant mechanical performance defects make it difficult to meet the requirements of engineering plastic parts such as automotive parts (requires >15kJ / m 2 ) and other fields.

[0004] In the prior art, although the use of polyamide to modify polylactic acid can improve some mechanical properties, there are still systemic defects. For example, in the polylactic acid / nylon 11 system disclosed in Chinese patent CN107841131A, although the addition of high content of nylon 11 can improve the mechanical ductility of polylactic acid, the blend system has a significant phase separation phenomenon, resulting in a low impact strength of the material (maximum 5.8kJ / m 2 In addition, although Chinese patent CN102690506A uses flexible long carbon chain nylon (PA610 / PA12) to toughen polylactic acid, the elongation at break of the material is still less than 50%, and the ductility is very poor. This is also due to the poor compatibility of the blend system, and further improvement is still needed. Summary of the Invention

[0005] The present invention aims to provide a strong, all-biobased polylactic acid / polyamide composite material and its preparation method to address the aforementioned problems in the background art. The core-shell amide-modified material, formed from a functional elastomeric copolymer reactively filled with amino nanoparticles, possesses an in-situ microscopic core-shell structure and numerous amide bonds. This enhances the material's absorption of external stress and energy, resulting in more significant plastic deformation when subjected to stress, and imparts improved mechanical properties.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] One of the technical solutions of the present invention is to provide a tough polylactic acid / polyamide composite material, wherein the raw materials, calculated by weight, include:

[0008] 45-75 parts of polylactic acid, 25-50 parts of bio-based polyamide, 3-10 parts of core-shell amide modified material, 0.3-0.8 parts of hydrolysis stabilizer, 0.3-0.8 parts of antioxidant and 0.5-1.0 parts of chain extender;

[0009] The core-shell amide modified material is prepared by filling a functional elastomer copolymer with amino nanoparticles based on the same preparation process.

[0010] Preferably, the polylactic acid is PLA LX175, PLAL175, PLAL130, PLA 3001D, 3052D, 3100HP, 3251D, 6362D, PLA REVODE290, REVODE213, REVODE701, REVODE713, PLAFY201 or FY601; and / or the bio-based polyamide is nylon 410, nylon 510, nylon 610, nylon 1010, nylon 1012 or nylon 11 to improve the toughness of the polylactic acid.

[0011] Preferably, the polylactic acid is of extrusion injection molding grade, has a number average molecular weight of 60,000-90,000 Da, and a melt index range of 10-30 g / 10 min (210° C. / 2.16 kg).

[0012] Preferably, the functional elastomer copolymer chain segments contain 5-15 mol% of functional groups capable of reacting with amino groups (based on nuclear magnetic resonance results); and / or the amino nanoparticle content in the core-shell amide modified material is 5-35 wt%. When the addition amount of the core-shell amide modified material is too high, the toughening effect is not significantly improved, and the risk of filler agglomeration in the core-shell amide modified material is increased.

[0013] Preferably, the functional group of the functional elastomeric copolymer is an epoxy group or an anhydride group; and / or the glass transition temperature of the functional elastomeric copolymer is -40 to -30°C (differential scanning calorimetry test), and the soft segment content is 50-80 mol% (based on nuclear magnetic resonance results).

[0014] More preferably, the functional group content in the functional elastomeric copolymer is 5-15 mol% (calculated based on NMR results).

[0015] Preferably, the amino nanoparticles are aminocellulose nanocrystals, aminonanocellulose fibers, aminonanosilica or aminonanozinc oxide; and / or the functional elastomer copolymer is poly(ethylene-methacrylic acid-glycidyl methacrylate), poly(1,3-butadiene-ethylene-glycidyl acrylate), poly(1,3-butadiene-methacrylic acid-glycidyl methacrylate), poly(ethylene-acrylate-maleic anhydride), poly(1-decene-ethylene-glycidyl methacrylate), poly(1-decene-methacrylic acid-glycidyl methacrylate) or poly(1-decene-1,3-butadiene-glycidyl methacrylate).

[0016] Preferably, the preparation method of the core-shell amide modified material comprises the following steps: melt blending the amino nanoparticles and the functional elastomer copolymer, maintaining the temperature at 150-180° C. and stirring speed at 100-150 rpm for 4-7 minutes to obtain the core-shell amide modified material.

[0017] Preferably, the hydrolysis stabilizer is one or more of 2-oxazoline, triglycidyl isocyanate, N,N'-diisopropylcarbodiimide (DIC), polycarbodiimide (Stabaxol P 110), dicyclohexylcarbodiimide (DCC) and N,N'-bis(2,6-diisopropylphenyl)carbodiimide (TIC); and / or, the antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, octadecyl (3,5-di-tert-butyl-4-hydroxyphenyl)propionate, cyclohexyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, dilauryl thiodipropionate, an organic phosphate compound (Irganox B 225), one or more of N',N-diphenyl-p-phenylenediamine, 2,6-di-tert-butyl-4-methylphenol, vitamin E and tris(2,4-di-tert-butylphenyl)phosphite; and / or, the chain extender is one or more of JoncrylADR 4468, JoncrylADR 4400, JoncrylADR 4300, dioxazoline, epoxy soybean oil, maleic anhydride grafted styrene and 1,5-pentanediisocyanate.

[0018] The second technical solution of the present invention is to provide a method for preparing the above-mentioned tough polylactic acid / polyamide composite material, comprising the following steps:

[0019] The raw materials are mixed and melt-blended at a temperature of 190-210° C. and a stirring speed of 100-150 rpm for 5-8 minutes to obtain the tough polylactic acid / polyamide composite material.

[0020] The preparation temperature of the core-shell amide modified material is kept at the minimum temperature at which amino groups react with the functional groups of the elastomer. This allows the degree of reaction to be controlled by adjusting the amount of amino nanofiller, while allowing unreacted functional groups to continue to function during the preparation of the polylactic acid / polyamide composite. The preparation temperature of the tough polylactic acid / polyamide composite is relatively higher, primarily to ensure thorough melt mixing of the various materials. It is worth noting that the core-shell structure of the core-shell amide modified material is based on covalent bonds formed by the reaction between amino groups and functional groups, resulting in good thermal stability.

[0021] Preferably, after the melt blending, an injection molding step is further included; the injection molding parameters are: injection temperature 210-240° C., mold temperature 50-100° C., and holding time 20-60 seconds.

[0022] Preferably, the injection molding further comprises a drying step; the drying step is vacuum drying at 40-60° C. for 18-24 hours.

[0023] The technical principles of the present invention are as follows:

[0024] The core-shell amide modified material of the present invention is produced through the reaction between amino groups on the surface of amino nanoparticles and functional groups of a functional elastomeric copolymer. After reactive melt blending, the amino nanoparticles and the functional elastomeric copolymer develop a partial microscopic core-shell structure. The prepared core-shell amide modified material improves the compatibility of the polylactic acid / polyamide blend system, optimizes interfacial tension, and reduces the degree of phase separation in the system. Therefore, during the processing and preparation of the composite material, the blend interface and phase morphology can be controlled through in-situ compatibilization. The core-shell structure content in the core-shell amide modified material is determined by the amount of amino nanoparticles added.

[0025] The added hydrolysis stabilizer and antioxidant are to improve the processing stability of the polymer melt and the durability of the product, and the chain extender is to improve the melt strength during polymer processing.

[0026] The beneficial technical effects of the present invention are as follows:

[0027] In view of the poor compatibility of traditional polylactic acid / bio-based polyamide blend systems and the problem that the material strength and toughness cannot be balanced during the toughening process, the present invention creatively proposes to introduce a core-shell amide modified material of a specific structural design in the system. The core-shell amide modified material formed based on the reactive filling functional elastomeric copolymer of amino nanoparticles has a microscopic core-shell structure and a large number of amide bonds formed in situ, which simultaneously increases the number of hydrogen bonds between the molecular chains of the blend system, improves the entanglement and intermolecular force between the microscopic molecular chains of the blend material, thereby enhancing the absorption of external stress and energy, and producing more significant plastic deformation when the material is deformed by stress, giving the material better mechanical properties. At the same time, the functional groups of the unreacted elastomeric copolymer can further improve the compatibility of the polylactic acid / bio-based polyamide system. Therefore, the prepared core-shell amide modified material can have a certain reinforcing effect while realizing the toughening polylactic acid / bio-based polyamide blend system, improving the performance of the product as much as possible.

[0028] The tough polylactic acid / polyamide composite material prepared by the present invention has excellent tensile strength, elongation at break and impact resistance. Specifically, the tensile strength of the product can reach 60-75MPa, the elongation at break can reach 200-400%, and the notched impact strength can reach up to about 50kJ / m 2 , with the potential to replace some non-structural engineering plastic parts. The preparation process of the present invention is characterized by simplicity and controllable costs. The resulting composite material has excellent performance and can be applied to engineering plastics fields such as automotive parts, electronic and electrical housings, and household products, with significant environmental benefits and industrial promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 The tensile stress-strain curves of the products of Examples 1, 2, 4, 5 and Comparative Examples 1-4 are shown in Figures 1-2 and 1-2, and 2-3 are shown in Figures 2-4 and 3-4.

[0031] Figure 2 The following are SEM images of the quenched cross sections of the products of Example 1 and Comparative Examples 1-2, wherein (a) is Comparative Example 1, (b) is Comparative Example 2, and (c) is Example 1. DETAILED DESCRIPTION

[0032] Various exemplary embodiments of the present invention are now described in detail. This detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention. It should be understood that the terms used in the present invention are only for describing specific embodiments and are not intended to limit the present invention.

[0033] In addition, for numerical ranges in the present invention, it is understood that each intervening value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between any stated value or stated range, and any other stated value or intervening value in the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

[0034] Unless otherwise specified, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which the present invention pertains. Although preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention. It should be noted that any details not described herein are conventional procedures in the art and are not the focus of the present invention.

[0035] The terms “include,” “including,” “have,” “contain,” etc. used in the present invention are open-ended terms, meaning including but not limited to.

[0036] The polylactic acid (PLLA, 3001D) used in the following examples and comparative examples of the present invention was purchased from Nature Work, USA, with a number average molecular weight of 75,000, a melt index of 22 g / 10 min (210 ° C, 2.16 kg), and an L-LA content of more than 98.5%; the bio-based polyamide PA used 11 was provided by Arkema, France, with a melt index of 25 g / 10 min (210°C, 2.16 kg); the functional elastomer copolymer used was ethylene-acrylate-glycidyl methacrylate random copolymer (EMG, E), purchased from Arkema, France, with a melt index of 7 g / 10 min (190°C, 2.16 kg), the content of functional groups reactive with amino groups in its chain segments was 8 mol%, the soft segment content was 78 mol% (based on nuclear magnetic resonance results), and the glass transition temperature was -36°C (differential scanning calorimetry); the amino nano-silica, amino nano-cellulose fiber, and amino nano-zinc oxide used were provided by the Beijing Research Institute of Petrochemicals, China National Petroleum Corporation, with an amino content of approximately 1-3 wt.%, and a specific surface area of ​​approximately 300-600 m 2 The antioxidant used was Irganox B 225 produced by BASF, the hydrolysis stabilizer was Stabaxol P 110 provided by LANXESS, and the chain extender was BASF's epoxy Joncryl ADR 4468.

[0037] The core-shell amide modified material (E10) used in the present invention is prepared by reactive melt blending and extrusion of amino nano-silica filler and ethylene-acrylate-glycidyl methacrylate random copolymer using a twin-screw extruder (HAAKE Mini CTW). The specific preparation process is as follows: amino nano-silica filler and ethylene-acrylate-glycidyl methacrylate random copolymer are mixed in a mass ratio of 1:9, and melt blended at a temperature of 150°C and a stirring speed of 100 rpm for 5 minutes to obtain E10. Similarly, core-shell amide modified materials prepared from amino nano-cellulose fiber or amino nano-zinc oxide and ethylene-acrylate-glycidyl methacrylate random copolymer are labeled N10 and Z10, respectively.

[0038] By modifying the mass ratios of amino nano-silica filler (amino nano-cellulose fiber or amino nano-zinc oxide) and ethylene-acrylate-glycidyl methacrylate random copolymer in the preparation process of E10 (N10, Z10) to 2:8, 3:7, and 0:10, respectively, E20, E30, and E0 (N20, N30, E0, or Z20, Z30, and E0) were prepared, respectively.

[0039] The obtained composite material was reactively extruded by a twin-screw extruder (HAAKE Mini CTW) and injection molded by a micro injection molding machine (SZS-20, Wuhan Ruiming) to obtain standard test specimens.

[0040] The tensile test in the present invention is conducted at room temperature (25±3°C) on dumbbell-shaped specimens according to ASTM D638 Type V, with a tensile speed of 10 mm / min. The notched impact strength test of the samples in the present invention is conducted according to ASTM D256, with a notch depth of about 2 mm.

[0041] The raw materials used in the following examples and comparative examples of the present invention are all commercially available products.

[0042] Figure 1 The tensile stress-strain curves of the products of Examples 1, 2, 4, 5 and Comparative Examples 1-4 are shown in Figures 1-2 and 1-2, and 2-3 are shown in Figures 2-4 and 3-4.

[0043] Example 1

[0044] A tough polylactic acid / polyamide composite material, the raw materials, calculated by weight, are:

[0045] 65.1 parts of polylactic acid, 27.9 parts of bio-based polyamide, 5 parts of core-shell amide modified material (E10), 0.5 parts of hydrolysis stabilizer, 0.5 parts of antioxidant and 1.0 parts of chain extender.

[0046] The specific preparation process is as follows:

[0047] The raw materials were accurately weighed, mixed in a high-speed mixer, and melt-blended at 100 rpm and 200°C for 5 min using a twin-screw extruder. The mixture was extruded into granules and dried in a vacuum oven at 50°C for 48 hours. The mixture was then injection-molded using an injection molding machine at an injection temperature of 220°C, a mold temperature of 100°C, and a holding time of 30 seconds to obtain a standard test bar, which was recorded as 73 / 5E10.

[0048] From Table 1 and Figure 1 It can be seen that after adding the core-shell amide modified material E10 in the present invention, the mechanical properties of the obtained polylactic acid-based composite material, such as tensile strength and notched impact strength, are improved, while maintaining a high elongation at break, indicating that the core-shell amide modified material E10 effectively absorbs external energy when the material is subjected to stress, thereby playing a role in strengthening and toughening.

[0049] Example 2

[0050] A tough polylactic acid / polyamide composite material, the raw materials, calculated by weight, are:

[0051] 65.1 parts of polylactic acid, 27.9 parts of bio-based polyamide, 5 parts of core-shell amide modified material (E20), 0.5 parts of hydrolysis stabilizer, 0.5 parts of antioxidant and 1.0 parts of chain extender.

[0052] The specific preparation process is as follows:

[0053] The raw materials were accurately weighed, mixed in a high-speed mixer, and melt-blended at 100 rpm and 200°C for 5 min using a twin-screw extruder. The mixture was extruded into granules and dried in a vacuum oven at 50°C for 48 hours. The mixture was then injection-molded using an injection molding machine at an injection temperature of 220°C, a mold temperature of 100°C, and a holding time of 30 seconds to obtain a standard test bar, which was recorded as 73 / 5E20.

[0054] From Table 1 and Figure 1 It can be seen that after adding the core-shell amide modified material E20 in the present invention, the mechanical properties of the obtained polylactic acid-based composite material, such as tensile strength, are further improved to 68.3 MPa, while the elongation at break is maintained at 231%, indicating that the core-shell amide modified material E20 increases the toughness of the material while maintaining a certain fracture strength.

[0055] Example 3

[0056] A tough polylactic acid / polyamide composite material, the raw materials, calculated by weight, are:

[0057] 65.1 parts of polylactic acid, 27.9 parts of bio-based polyamide, 5 parts of core-shell amide modified material (E30), 0.5 parts of hydrolysis stabilizer, 0.5 parts of antioxidant and 1.0 parts of chain extender.

[0058] The specific preparation process is as follows:

[0059] The raw materials were accurately weighed, mixed in a high-speed mixer, and melt-blended at 100 rpm and 200°C for 5 min using a twin-screw extruder. The mixture was extruded into granules and dried in a vacuum oven at 50°C for 48 hours. The mixture was then injection-molded using an injection molding machine at an injection temperature of 220°C, a mold temperature of 100°C, and a holding time of 30 seconds to obtain a standard test bar, which was recorded as 73 / 5E30.

[0060] From Table 1 and Figure 1 It can be seen that after adding the core-shell amide modified material E30 in the present invention, the tensile strength of the obtained polylactic acid-based composite material increases to 71.3 MPa, but the elongation at break decreases to 136%, which indicates that the addition amount of amino nanoparticles in the core-shell amide modified material is relatively high.

[0061] Example 4

[0062] A tough polylactic acid / polyamide composite material, the raw materials, calculated by weight, are:

[0063] 46.5 parts of polylactic acid, 46.5 parts of bio-based polyamide, 5 parts of core-shell amide modified material (E10), 0.5 parts of hydrolysis stabilizer, 0.5 parts of antioxidant and 1.0 parts of chain extender.

[0064] The specific preparation process is as follows:

[0065] The raw materials were accurately weighed, mixed in a high-speed mixer, and melt-blended at 100 rpm and 200°C for 5 min using a twin-screw extruder. The mixture was extruded into granules and dried in a vacuum oven at 50°C for 48 hours. The mixture was then injection-molded using an injection molding machine at an injection temperature of 220°C, a mold temperature of 100°C, and a holding time of 30 seconds to obtain a standard test bar, which was recorded as 55 / 5E10.

[0066] From Table 1 and Figure 1 It can be seen that after adding the core-shell amide modified material E10, the mechanical properties of the obtained polylactic acid-based composite material, such as tensile strength and notched impact strength, are improved, which are 61.7 MPa and 49.8 kJ / m respectively. 2 , while the elongation at break can reach 399%.

[0067] Example 5

[0068] A tough polylactic acid / polyamide composite material, the raw materials, calculated by weight, are:

[0069] 46.5 parts of polylactic acid, 46.5 parts of bio-based polyamide, 5 parts of core-shell amide modified material (E20), 0.5 parts of hydrolysis stabilizer, 0.5 parts of antioxidant and 1.0 parts of chain extender.

[0070] The specific preparation process is as follows:

[0071] The raw materials were accurately weighed, mixed in a high-speed mixer, and melt-blended at 100 rpm and 200°C for 5 min using a twin-screw extruder. The mixture was extruded into granules and dried in a vacuum oven at 50°C for 48 hours. The granules were then injection-molded using an injection molding machine at an injection temperature of 220°C, a mold temperature of 100°C, and a holding time of 30 seconds to obtain standard test bars, which were recorded as 55 / 5E20.

[0072] From Table 1 and Figure 1 It can be seen that after adding the core-shell amide modified material E20, the mechanical properties of the obtained polylactic acid-based composite material, such as tensile strength, are further increased to 63.0 MPa, while maintaining a break elongation of 305% and a notched impact strength of about 36.5 kJ / m 2 .

[0073] Example 6

[0074] A tough polylactic acid / polyamide composite material, the raw materials, calculated by weight, are:

[0075] 46.5 parts of polylactic acid, 46.5 parts of bio-based polyamide, 5 parts of core-shell amide modified material (E30), 0.5 parts of hydrolysis stabilizer, 0.5 parts of antioxidant and 1.0 parts of chain extender.

[0076] The specific preparation process is as follows:

[0077] The raw materials were accurately weighed, mixed in a high-speed mixer, and melt-blended at 100 rpm and 200°C for 5 min using a twin-screw extruder. The mixture was extruded into granules and dried in a vacuum oven at 50°C for 48 hours. The granules were then injection-molded using an injection molding machine at an injection temperature of 220°C, a mold temperature of 100°C, and a holding time of 30 seconds to obtain standard test bars, which were recorded as 55 / 5E30.

[0078] From Table 1 and Figure 1 It can be seen that after adding the core-shell amide modified material E30, the tensile strength of the obtained polylactic acid-based composite material further increased to 65.8 MPa, while the elongation at break decreased to 207%. This may be due to the excessively high nanoparticle content in the core-shell amide modified material.

[0079] Example 7

[0080] A tough polylactic acid / polyamide composite material, the raw materials, calculated by weight, are:

[0081] 65.1 parts of polylactic acid, 27.9 parts of bio-based polyamide, 5 parts of core-shell amide modified material (N10), 0.5 parts of hydrolysis stabilizer, 0.5 parts of antioxidant and 1.0 parts of chain extender.

[0082] The specific preparation process is as follows:

[0083] The raw materials were accurately weighed, mixed in a high-speed mixer, and melt-blended at 100 rpm and 200°C for 5 min using a twin-screw extruder. The mixture was extruded into granules and dried in a vacuum oven at 50°C for 48 hours. The mixture was then injection-molded using an injection molding machine at an injection temperature of 220°C, a mold temperature of 100°C, and a holding time of 30 seconds to obtain a standard test bar, which was recorded as 73 / 5N10.

[0084] As can be seen from Table 1, after adding the core-shell amide modified material N10 in the present invention, the mechanical properties of the obtained polylactic acid-based composite material, such as tensile strength and notched impact strength, are improved, while maintaining a high elongation at break, indicating that the core-shell amide modified material N10 can also play a role in strengthening and toughening.

[0085] Example 8

[0086] A tough polylactic acid / polyamide composite material, the raw materials, calculated by weight, are:

[0087] 65.1 parts of polylactic acid, 27.9 parts of bio-based polyamide, 5 parts of core-shell amide modified material (N30), 0.5 parts of hydrolysis stabilizer, 0.5 parts of antioxidant and 1.0 parts of chain extender.

[0088] The specific preparation process is as follows:

[0089] The raw materials were accurately weighed, mixed in a high-speed mixer, and melt-blended at 100 rpm and 200°C for 5 min using a twin-screw extruder. The mixture was extruded into granules and dried in a vacuum oven at 50°C for 48 hours. The mixture was then injection-molded using an injection molding machine at an injection temperature of 220°C, a mold temperature of 100°C, and a holding time of 30 seconds to obtain a standard test bar, which was recorded as 73 / 5N30.

[0090] As can be seen from Table 1, after adding the core-shell amide modified material N30 of the present invention, the tensile strength of the obtained polylactic acid-based composite material is further improved to 65.2 MPa, and the notched impact strength is better than that of the addition of a single elastomer, indicating that the core-shell amide modified material N30 improves the toughness of the composite material.

[0091] Example 9

[0092] A tough polylactic acid / polyamide composite material, the raw materials, calculated by weight, are:

[0093] 46.5 parts of polylactic acid, 46.5 parts of bio-based polyamide, 5 parts of core-shell amide modified material (N10), 0.5 parts of hydrolysis stabilizer, 0.5 parts of antioxidant and 1.0 parts of chain extender.

[0094] The specific preparation process is as follows:

[0095] The raw materials were accurately weighed, mixed in a high-speed mixer, and melt-blended at 100 rpm and 200°C for 5 min using a twin-screw extruder. The mixture was extruded into granules and dried in a vacuum oven at 50°C for 48 hours. The granules were then injection-molded using an injection molding machine at an injection temperature of 220°C, a mold temperature of 100°C, and a holding time of 30 seconds to obtain standard test bars, which were recorded as 55 / 5N10.

[0096] As shown in Table 1, after adding the core-shell amide modified material N10, the mechanical properties of the obtained polylactic acid-based composite material, such as tensile strength and notched impact strength, are improved, which are 61.6 MPa and 31.3 kJ / m respectively. 2 , while the elongation at break can reach 295%.

[0097] Example 10

[0098] A tough polylactic acid / polyamide composite material, the raw materials, calculated by weight, are:

[0099] 46.5 parts of polylactic acid, 46.5 parts of bio-based polyamide, 5 parts of core-shell amide modified material (N30), 0.5 parts of hydrolysis stabilizer, 0.5 parts of antioxidant and 1.0 parts of chain extender.

[0100] The specific preparation process is as follows:

[0101] The raw materials were accurately weighed, mixed in a high-speed mixer, and melt-blended at 100 rpm and 200°C for 5 min using a twin-screw extruder. The mixture was extruded into granules and dried in a vacuum oven at 50°C for 48 hours. The mixture was then injection-molded using an injection molding machine at an injection temperature of 220°C, a mold temperature of 100°C, and a holding time of 30 seconds to obtain standard test bars, which were recorded as 55 / 5N30.

[0102] As shown in Table 1, after adding the core-shell amide modified material N30, the mechanical properties of the obtained polylactic acid-based composite material, such as tensile strength, are further increased to 63.4 MPa, while maintaining a break elongation of 210%, and a notched impact strength of about 25.7 kJ / m 2 .

[0103] Example 11

[0104] A tough polylactic acid / polyamide composite material, the raw materials, calculated by weight, are:

[0105] 65.1 parts of polylactic acid, 27.9 parts of bio-based polyamide, 5 parts of core-shell amide modified material (Z10), 0.5 parts of hydrolysis stabilizer, 0.5 parts of antioxidant and 1.0 parts of chain extender.

[0106] The specific preparation process is as follows:

[0107] The raw materials were accurately weighed, mixed in a high-speed mixer, and melt-blended at 100 rpm and 200°C for 5 min using a twin-screw extruder. The mixture was extruded into granules and dried in a vacuum oven at 50°C for 48 hours. The granules were then injection-molded using an injection molding machine at an injection temperature of 220°C, a mold temperature of 100°C, and a holding time of 30 seconds to obtain standard test bars, which were recorded as 73 / 5Z10.

[0108] As shown in Table 1, after adding the core-shell amide modified material Z10, the mechanical properties of the obtained polylactic acid-based composite material, such as tensile strength, increased to 63.0 MPa and notched impact strength of about 26.1 kJ / m 2 , indicating that the core-shell amide modified material Z10 effectively absorbed external energy when the material was subjected to stress, playing a role in strengthening and toughening.

[0109] Example 12

[0110] A tough polylactic acid / polyamide composite material, the raw materials, calculated by weight, are:

[0111] 65.1 parts of polylactic acid, 27.9 parts of bio-based polyamide, 5 parts of core-shell amide modified material (Z30), 0.5 parts of hydrolysis stabilizer, 0.5 parts of antioxidant and 1.0 parts of chain extender.

[0112] The specific preparation process is as follows:

[0113] The raw materials were accurately weighed, mixed in a high-speed mixer, and melt-blended at 100 rpm and 200°C for 5 min using a twin-screw extruder. The mixture was extruded into granules and dried in a vacuum oven at 50°C for 48 hours. The granules were then injection-molded using an injection molding machine at an injection temperature of 220°C, a mold temperature of 100°C, and a holding time of 30 seconds to obtain standard test bars, which were recorded as 73 / 5Z30.

[0114] As shown in Table 1, after adding the core-shell amide modified material Z30, the mechanical properties of the obtained polylactic acid-based composite material, such as tensile strength, are further increased to 64.9 MPa, and the elongation at break is 189%.

[0115] Example 13

[0116] A tough polylactic acid / polyamide composite material, the raw materials, calculated by weight, are:

[0117] 46.5 parts of polylactic acid, 46.5 parts of bio-based polyamide, 5 parts of core-shell amide modified material (Z10), 0.5 parts of hydrolysis stabilizer, 0.5 parts of antioxidant and 1.0 parts of chain extender.

[0118] The specific preparation process is as follows:

[0119] The raw materials were accurately weighed, mixed in a high-speed mixer, and melt-blended at 100 rpm and 200°C for 5 min using a twin-screw extruder. The mixture was extruded into granules and dried in a vacuum oven at 50°C for 48 hours. The mixture was then injection-molded using an injection molding machine at an injection temperature of 220°C, a mold temperature of 100°C, and a holding time of 30 seconds to obtain a standard test bar, which was recorded as 55 / 5Z10.

[0120] As shown in Table 1, after adding the core-shell amide modified material Z10, the mechanical properties of the obtained polylactic acid-based composite material, such as tensile strength and notched impact strength, are improved, which are 62.3 MPa and 34.5 kJ / m respectively. 2 , while the elongation at break can reach 305%.

[0121] Example 14

[0122] A tough polylactic acid / polyamide composite material, the raw materials, calculated by weight, are:

[0123] 46.5 parts of polylactic acid, 46.5 parts of bio-based polyamide, 5 parts of core-shell amide modified material (Z30), 0.5 parts of hydrolysis stabilizer, 0.5 parts of antioxidant and 1.0 parts of chain extender.

[0124] The specific preparation process is as follows:

[0125] The raw materials were accurately weighed, mixed in a high-speed mixer, and melt-blended at 100 rpm and 200°C for 5 min using a twin-screw extruder. The mixture was extruded into granules and dried in a vacuum oven at 50°C for 48 hours. The mixture was then injection-molded using an injection molding machine at an injection temperature of 220°C, a mold temperature of 100°C, and a holding time of 30 seconds to obtain a standard test bar, which was recorded as 55 / 5Z30.

[0126] As shown in Table 1, after adding the core-shell amide modified material Z30, the mechanical properties of the obtained polylactic acid-based composite material, such as tensile strength, are further increased to 63.4 MPa, and the notched impact strength is about 28.6 kJ / m 2 .

[0127] Comparative Example 1

[0128] The only difference from Example 1 is that the addition of the core-shell amide modifier is omitted, and the obtained product is recorded as 73.

[0129] Comparative Example 2

[0130] The only difference from Example 1 is that the core-shell amide modified material (E10) is replaced by an equal mass of unmodified functional elastomeric copolymer E0, and the obtained product is recorded as 73 / 5E0.

[0131] Figure 2 The following are SEM images of the quenched cross sections of the products of Example 1 and Comparative Examples 1-2, wherein (a) is Comparative Example 1, (b) is Comparative Example 2, and (c) is Example 1.

[0132] Figure 2 The improvement effect of the compatibility of the blend system was characterized. Figure 2 It can be seen that the core-shell amide modified material significantly improves the compatibility of the polylactic acid-based composite material system, indicating that it optimizes the phase interface of the blend components of the present invention and improves the interfacial tension, which helps to achieve good mechanical properties.

[0133] Comparative Example 3

[0134] The only difference from Example 4 is that the addition of the core-shell amide modifier is omitted, and the obtained product is recorded as 55.

[0135] Comparative Example 4

[0136] The only difference from Example 4 is that the core-shell amide modified material (E10) is replaced by an equal mass of unmodified functional elastomeric copolymer E0, and the obtained product is recorded as 55 / 5E0.

[0137] Table 1 Mechanical properties of PLA / PA composites

[0138]

[0139]

[0140] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A tough polylactic acid / polyamide composite material, characterized in that: Raw materials, calculated by mass, include: 45-75 parts of polylactic acid, 25-50 parts of bio-based polyamide, 3-10 parts of core-shell amide modified material, 0.3-0.8 parts of hydrolysis stabilizer, 0.3-0.8 parts of antioxidant and 0.5-1.0 parts of chain extender; The core-shell amide modified material is prepared by filling a functional elastomer copolymer with amino nanoparticles.

2. The tough polylactic acid / polyamide composite material according to claim 1, characterized in that: The polylactic acid is PLALX175, PLA L175, PLA L130, PLA 3001D, 3052D, 3100HP, 3251D, 6362D, PLAREVODE290, REVODE213, REVODE701, REVODE713, PLA FY201 or FY601; and / or the bio-based polyamide is nylon 410, nylon 510, nylon 610, nylon 1010, nylon 1012 or nylon 11.

3. The tough polylactic acid / polyamide composite material according to claim 1, characterized in that: The chain segments of the functional elastomer copolymer contain 5-15 mol% of functional groups capable of reacting with amino groups; and / or the content of amino nanoparticles in the core-shell amide modified material is 5-35 wt%.

4. The tough polylactic acid / polyamide composite material according to claim 3, characterized in that: The functional group is an epoxy group or an acid anhydride group; and / or the glass transition temperature of the functional elastomeric copolymer is -40 to -30°C, and the soft segment content is 50-80 mol%.

5. The tough polylactic acid / polyamide composite material according to claim 1, characterized in that: The amino nanoparticles are aminocellulose nanocrystals, aminonanocellulose fibers, aminonanosilica or aminonanozinc oxide; and / or the functional elastomer copolymer is poly(ethylene-methacrylic acid-glycidyl methacrylate), poly(1,3-butadiene-ethylene-glycidyl acrylate), poly(1,3-butadiene-methacrylic acid-glycidyl methacrylate), poly(ethylene-acrylate-maleic anhydride), poly(1-decene-ethylene-glycidyl methacrylate), poly(1-decene-methacrylic acid-glycidyl methacrylate) or poly(1-decene-1,3-butadiene-glycidyl methacrylate).

6. The tough polylactic acid / polyamide composite material according to claim 3, characterized in that: The preparation method of the core-shell amide modified material comprises the following steps: mixing the amino nanoparticles and the functional elastomer copolymer, maintaining the mixture at a temperature of 150-180° C. and a stirring speed of 100-150 rpm for 4-7 minutes to obtain the core-shell amide modified material.

7. The tough polylactic acid / polyamide composite material according to claim 1, characterized in that: The hydrolysis stabilizer is one or more of 2-oxazoline, triglycidyl isocyanate, N,N'-diisopropylcarbodiimide, polycarbodiimide, dicyclohexylcarbodiimide and N,N'-bis(2,6-diisopropylbenzene)carbodiimide; and / or, the antioxidant is one or more of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol, (3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate cyclohexyl, dilauryl thiodipropionate, N',N-diphenyl-p-phenylenediamine, 2,6-di-tert-butyl-4-methylphenol, an organic phosphate compound, vitamin E and tris(2,4-di-tert-butylphenyl)phosphite; and / or, the chain extender is one or more of JoncrylADR 4468, JoncrylADR One or more of 4400, Joncryl ADR 4300, dioxazoline, epoxidized soybean oil, maleic anhydride grafted styrene and 1,5-pentamethylene diisocyanate.

8. A method for preparing the tough polylactic acid / polyamide composite material according to any one of claims 1 to 7, characterized in that: The following steps are involved: The raw materials are mixed and melt-blended at a temperature of 190-210° C. and a stirring speed of 100-150 rpm for 5-8 minutes to obtain the tough polylactic acid / polyamide composite material.

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