Guard plate material with high degradation performance and preparation method thereof

Abstract

The invention relates to the technical field of environment-friendly materials, in particular to a protective plate material with high degradation performance and a preparation method of the protective plate material. The protective plate material is prepared from the following raw materials in parts by weight: 60 to 70 parts of polylactic acid, 10 to 15 parts of reinforced fibers, 5 to 10 parts of a composite toughening agent, 2 to 5 parts of a plasticizer and 12.5 to 20 parts of a functional aid, wherein the composite toughening agent comprises polyethylene glycol and polycaprolactone, and the weight m1 of the polyethylene glycol and the weight m2 of the polycaprolactone meet the relational expression: m1: m2 < = 1: 0.2. According to the protective plate material, the mechanical property and the degradation property of the protective plate material can be synchronously improved through the interaction among the polylactic acid, the reinforced fibers, the composite toughening agent, the plasticizer and the functional additive, so that the mechanical property and the degradation property of the protective plate material can be considered.

Description

Technical Field

[0001] The present application relates to the technical field of environmentally friendly materials, and in particular to a protective plate material with high degradation performance and a preparation method thereof. Background Art

[0002] Traditional auto parts use a lot of non-structural parts. For example, the material of the car's guard plate is generally polyethylene terephthalate (PET) felt or composite molded sheet materials made of polyethylene terephthalate (PET) and polypropylene (PP). Although these materials have good mechanical properties and aging resistance and low manufacturing costs, these non-structural parts are often made of petroleum-based plastic materials, which not only consumes a lot of non-renewable resources, but also has high carbon emissions. In addition, since petroleum-based plastic materials are difficult to degrade naturally, they are easy to cause environmental pollution if they are not handled properly during the waste stage. To solve this problem, research and development of new environmentally friendly materials for automotive parts has become one of the focuses in the current field of automotive materials science.

[0003] Although there are methods for preparing degradable guard plate materials using degradable materials at this stage, the mechanical properties of these degradable materials are poor, making it difficult for degradable guard plate materials to meet the use requirements of automobiles. In addition, if reinforcing materials are added, the degradation performance of the degradable materials will be affected. Summary of the invention

[0004] The present application provides a guard plate material with high degradation performance and a preparation method thereof to solve the following technical problem: how to balance the mechanical properties and degradation properties of the guard plate material.

[0005] In the first aspect, the present application provides a guard plate material with high degradation performance. The raw materials of the guard plate material include, in parts by weight: polylactic acid: 60 to 70 parts, reinforcing fiber: 10 to 15 parts, composite toughening agent: 5 to 10 parts, plasticizer: 2 to 5 parts, functional additive: 12.5 to 20 parts; wherein the composite toughening agent includes polyethylene glycol and polycaprolactone, and the weight m1 of the polyethylene glycol and the weight m2 of the polycaprolactone satisfy the relationship: m1:m2≤1:0.2.

[0006] Optionally, the weight m1 of the polyethylene glycol and the weight m2 of the polycaprolactone satisfy the relationship: m1:m2=1:(0.2-1).

[0007] Optionally, the reinforcing fiber includes glass fiber and / or modified bamboo fiber; and / or

[0008] In the case where the reinforcing fibers include glass fibers and modified bamboo fibers, the weight m3 of the glass fibers and the weight m4 of the modified bamboo fibers satisfy the relationship: m3:m4=1:(0.25-1).

[0009] Optionally, the average relative molecular mass of the polylactic acid is 80,000 to 200,000.

[0010] Optionally, the plasticizer includes castor oil derivatives and epoxidized soybean oil, and the weight m5 of the castor oil derivatives and the weight m6 of the epoxidized soybean oil satisfy the relationship: m5:m6=1:(0.25-1.5).

[0011] Optionally, the functional additive includes a lubricant and an inorganic filler, and the weight m7 of the lubricant and the weight m8 of the inorganic filler satisfy the relationship: m7:m8=(0.5-1.0):(10-15).

[0012] Optionally, the inorganic filler includes hollow alumina microspheres, and the particle size of the hollow alumina microspheres is 50 μm to 250 μm.

[0013] Optionally, the functional additive further includes an anti-ultraviolet agent, an antioxidant and an anti-hydrolysis stabilizer, and the weight m9 of the anti-ultraviolet agent, the weight m10 of the antioxidant and the weight m11 of the anti-hydrolysis stabilizer satisfy the relationship: m9:m10:m11=0.5:0.5:(1~3).

[0014] In a second aspect, the present application provides a method for preparing the guard plate material according to the first aspect, the method comprising:

[0015] The polylactic acid, reinforcing fiber, composite toughening agent, plasticizer and functional additive are mixed, and then the mixture is heated to obtain a mixed raw material;

[0016] preheating the mold to obtain a preheated mold;

[0017] The mixed raw material is compression molded using the preheated mold to obtain a guard plate material.

[0018] Optionally, the end temperature of the heating is 215°C to 225°C, and the heating time is ≥ 10 min; and / or

[0019] The preheating temperature is 80°C to 120°C; and / or

[0020] The pressure of the compression molding is 30MPa-50MPa, the temperature of the compression molding is 180°C-220°C, and the time of the compression molding is 1min-3min.

[0021] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0022] An embodiment of the present application provides a protective plate material with high degradation performance. The protective plate material uses polylactic acid, a bio-based material, as a main component, and then uses a composite toughening agent including polyethylene glycol and polycaprolactone, and the weight m1 of polyethylene glycol and the weight m2 of polycaprolactone satisfy the relationship: m1:m2≤1:0.2. Polyethylene glycol and polylactic acid are grafted and polymerized to form a copolymer containing polylactic acid and polyethylene glycol. The copolymer is subsequently subjected to a two-step ring opening with polycaprolactone to generate a plurality of block copolymers. These block copolymers have hydrophilic and lipophilic amphiphilic properties, which can improve the degree of interfacial bonding between polylactic acid and other components to enhance the overall toughness of the protective plate material. In addition, these block copolymers can also improve the controllability of the degradation rate of the protective plate material. , to improve the biodegradability of the guard plate material; in addition, the plasticizer will also undergo a cross-linking reaction with these block copolymers to introduce the macromolecular chain segments in the plasticizer into the block copolymers and generate a cross-linking structure. These cross-linking structures can not only improve the mechanical properties of the guard plate material, but also improve the biodegradability of the guard plate material; in addition, the reinforcing fibers can be stably present in the cross-linking structure through the action of functional additives, and based on the excellent toughness and strength of the reinforcing fibers, the mechanical properties of the guard plate material can be further improved; therefore, the guard plate material can simultaneously improve the mechanical properties and degradation properties of the guard plate material through the interaction between polylactic acid, reinforcing fibers, composite toughening agents, plasticizers and functional additives, thereby achieving a balance between the mechanical properties and degradation properties of the guard plate material. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0025] Figure 1 A schematic diagram of the molding principle of a copolymer of polylactic acid and polyethylene glycol in a protective plate material with high degradation performance provided in an embodiment of the present application;

[0026] Figure 2 A schematic flow chart of a method for preparing a guard plate material provided in an embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0028] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity and should not be understood as a rigid limitation on the scope of the present application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within the range; for example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which applies regardless of the range; in addition, whenever a numerical range is indicated in this document, it is meant to include any cited numbers (fractions or integers) within the indicated range.

[0029] In this article, the terms including "including" and "including" mean "including but not limited to". "And / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone; where A and B can be singular or plural. Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0030] Figure 1 The schematic diagram of the molding principle of the copolymer of polylactic acid and polyethylene glycol in a protective plate material with high degradation performance provided in an embodiment of the present application is exemplarily shown;

[0031] like Figure 1 As shown, the embodiment of the present application provides a guard plate material with high degradation performance. The raw materials of the guard plate material include, by weight: polylactic acid: 60 to 70 parts, reinforcing fiber: 10 to 15 parts, composite toughening agent: 5 to 10 parts, plasticizer: 2 to 5 parts, functional additive: 12.5 to 20 parts; wherein, the composite toughening agent includes polyethylene glycol and polycaprolactone, and the weight m1 of the polyethylene glycol and the weight m2 of the polycaprolactone satisfy the relationship: m1:m2≤1:0.2;

[0032] In these embodiments, the weight proportion of polylactic acid can be 60 to 70 parts. Polylactic acid is used as a biodegradable material to facilitate the two-step ring opening of polylactic acid, polyethylene glycol, and polycaprolactone to generate multiple block copolymers, so as to improve the mechanical properties and biodegradability of the guard plate material through these block copolymers; in addition, the weight proportion of reinforcing fiber can be 10 to 15 parts, so that the guard plate material has a sufficient amount of reinforcing fiber, and a sufficient amount of reinforcing fiber can enhance the mechanical properties of the guard plate material; in addition, the weight proportion of composite toughening agent can be 5 to 10 parts, so that the guard plate material has a sufficient amount of composite toughening agent, and the polyethylene glycol in the sufficient toughening agent will be grafted with polylactic acid to form a copolymer containing polylactic acid and polyethylene glycol, and the formed copolymer will be subsequently grafted with polycaprolactone The two-step method generates multiple block copolymers through ring opening. These block copolymers have hydrophilic and lipophilic amphiphilic properties, which can improve the interfacial bonding between polylactic acid and other components to enhance the overall toughness of the protective plate material. In addition, the weight proportion of the plasticizer can be 2 to 5 parts, so that the protective plate material contains a sufficient amount of plasticizer, and the sufficient amount of plasticizer will undergo a cross-linking reaction with these block copolymers to introduce the macromolecular segments in the plasticizer into the block copolymers and generate a cross-linking structure. These cross-linking structures can not only enhance the mechanical properties of the protective plate material, but also enhance the biodegradability of the protective plate material. In addition, the weight proportion of the functional additive can be 12.5 to 15 parts, so that the protective plate material contains a sufficient amount of functional additive, and the sufficient amount of functional additive can enhance the stability of the reinforcing fiber in the cross-linking structure.

[0033] The weight proportions of the polylactic acid can be 60 parts, 61 parts, 62 parts, 63 parts, 64 parts, 65 parts, 66 parts, 67 parts, 68 parts, 69 parts or 70 parts.

[0034] The weight proportion of the reinforcing fiber can be 10 parts, 11 parts, 12 parts, 13 parts, 14 parts or 15 parts.

[0035] The weight proportion of the composite toughening agent can be 5 parts, 6 parts, 7 parts, 8 parts, 9 parts or 10 parts.

[0036] The weight proportion of the plasticizer can be 2 parts, 3 parts, 4 parts or 5 parts.

[0037] The weight proportions of the functional additive may be 12.5, 13.0, 13.5, 14.0, 14.5, 15.0, 15.5, 16.0, 16.5, 17.0, 17.5, 18.0, 18.5, 19.0, 19.5 or 20.0 parts.

[0038] It should be noted that the multiple block copolymers formed between polylactic acid, polyethylene glycol and polycaprolactone can also improve the controllability of the degradation rate of the protective plate material, so as to adjust the degradation speed of the protective plate material and meet the use requirements of different protective plate materials.

[0039] In some optional embodiments, the weight m1 of the polyethylene glycol and the weight m2 of the polycaprolactone satisfy the relationship: m1:m2=1:(0.2-1);

[0040] In these embodiments, the weight m1 of polyethylene glycol and the weight m2 of polycaprolactone can satisfy the relationship: m1:m2=1:(0.2~1), so that the composite toughening agent contains sufficient amounts of polyethylene glycol and polycaprolactone. Sufficient amounts of polyethylene glycol will be grafted with polylactic acid to form a copolymer containing polylactic acid and polyethylene glycol. The copolymer will subsequently be ring-opened with sufficient amounts of polycaprolactone in a two-step process to generate multiple block copolymers. These block copolymers have hydrophilic and lipophilic amphiphilic properties, which can improve the interfacial bonding between polylactic acid and other components to enhance the overall toughness of the protective plate material.

[0041] The weight m1 of the polyethylene glycol and the weight m2 of the polycaprolactone may satisfy the relationship: m1:m2=1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9 or 1:1.0.

[0042] In some optional embodiments, the reinforcing fiber includes glass fiber and / or modified bamboo fiber; and / or

[0043] In the case where the reinforcing fiber includes glass fiber and modified bamboo fiber, the weight m3 of the glass fiber and the weight m4 of the modified bamboo fiber satisfy the relationship: m3:m4=1:(0.25-1);

[0044] In these embodiments, the reinforcing fibers may include glass fibers and / or modified bamboo fibers, and in the case where the reinforcing fibers include glass fibers and modified bamboo fibers, the weight m3 of the glass fibers and the weight m4 of the modified bamboo fibers may satisfy the relationship: m3:m4=1:(0.25-1), thereby ensuring that the reinforcing fibers contain sufficient amounts of glass fibers and modified bamboo fibers, and sufficient amounts of glass fibers and bamboo fibers may stably exist in a cross-linked structure through the action of functional additives, thereby further improving the mechanical properties of the guard plate material based on the excellent toughness and strength of the reinforcing fibers; in addition, sufficient amounts of bamboo fibers as bio-based degradable materials may adjust the biodegradability of the guard plate material.

[0045] The weight m3 of the glass fiber and the weight m4 of the modified bamboo fiber can satisfy the relationship: m3:m4=1:0.25, 1:0.30, 1:0.35, 1:0.40, 1:0.45, 1:0.50, 1:0.55, 1:0.60, 1:0.65, 1:0.70, 1:0.75, 1:0.80, 1:0.85, 1:0.90, 1:0.95 or 1:1.00.

[0046] In some optional embodiments, the average relative molecular mass of the polylactic acid is 80,000 to 200,000;

[0047] In these embodiments, the average relative molecular mass of polylactic acid can be 80,000 to 200,000, and the degradation rate of polylactic acid can be further adjusted to adjust the degradation rate of the guard plate material to meet the use requirements of different guard plate materials.

[0048] The average relative molecular mass of the polylactic acid can be 80,000, 90,000, 100,000, 110,000, 120,000, 130,000, 140,000, 150,000, 160,000, 170,000, 180,000, 190,000 or 200,000

[0049] In some optional embodiments, the plasticizer includes castor oil derivatives and epoxidized soybean oil, and the weight m5 of the castor oil derivatives and the weight m6 of the epoxidized soybean oil satisfy the relationship: m5:m6=1:(0.25-1.5);

[0050] In these embodiments, the plasticizer may include castor oil derivatives and epoxidized soybean oil, and the weight m5 of the castor oil derivative and the weight m6 of the epoxidized soybean oil may satisfy the relationship: m5:m6=1:(0.25~1.5), so that the plasticizer contains sufficient amounts of castor oil derivatives and epoxidized soybean oil. Sufficient amounts of castor oil derivatives and epoxidized soybean oil will undergo cross-linking reactions with the block copolymer, so that the macromolecular segments in the plasticizer are introduced into the block copolymer and generate cross-linked structures. These cross-linked structures can not only improve the mechanical properties of the guard plate material, but also improve the biodegradability of the guard plate material.

[0051] The weight m5 of the castor oil derivative and the weight m6 of the epoxidized soybean oil can satisfy the relationship: m5:m6=1:0.25, 1:0.30, 1:0.35, 1:0.40, 1:0.45, 1:0.50, 1:0.55, 1:0.60, 1:0.65, 1:0.70, 1:0.75, 1:0.80, 1:0.85, 1:0.90, 1:0.95, 1:1.00, 1:1.05, 1:1.10, 1:1.15, 1:1.20, 1:0.25, 1:1.30, 1:1.35, 1:1.40, 1:1.45 or 1:1.50.

[0052] It should be noted that the plasticizer includes ethylene glycol diacetate.

[0053] In some optional embodiments, the functional additive includes a lubricant and an inorganic filler, and the weight m7 of the lubricant and the weight m8 of the inorganic filler satisfy the relationship: m7:m8=(0.5-1.0):(10-15);

[0054] In these embodiments, the functional additive may include a lubricant and an inorganic filler, and the weight of the lubricant m7 and the weight of the inorganic filler m8 may satisfy the relationship: m7:m8=(0.5~1.0):(10~15), so that the functional additive contains sufficient lubricant and inorganic filler. A sufficient amount of lubricant can improve the compatibility of the raw materials of the guard plate material to facilitate the uniform dispersion of the inorganic filler into the guard plate material, thereby improving the strength of the guard plate material through the inorganic filler.

[0055] The weight m7 of the lubricant and the weight m8 of the inorganic filler can satisfy the relationship: m7:m8=0.5:10, 0.6:10, 0.7:10, 0.8:10, 0.9:10, 1.0:10, 0.5:12, 0.6:12, 0.7:12, 0.8:12, 0.9:12, 1.0:12, 0.5:15, 0.6:15, 0.7:15, 0.8:15, 0.9:15, 1.0:15.

[0056] It should be noted that the lubricant may be calcium stearate.

[0057] In some optional embodiments, the inorganic filler comprises hollow alumina microspheres, and the particle size of the hollow alumina microspheres is 50 μm to 250 μm;

[0058] In these embodiments, the inorganic filler may include hollow alumina microspheres, and the particle size of the hollow alumina microspheres may be 50 μm to 250 μm. The hollow alumina microspheres are used to replace traditional inorganic fillers such as calcium carbonate, talcum powder, kaolin, etc. to reduce the density of the guard plate material to maintain the mechanical properties of the guard plate material; in addition, the hollow structure of the hollow alumina microspheres can be used as a sound partition space to improve the sound insulation performance of the guard plate material, thereby improving the noise, vibration and acoustic roughness performance of the automobile to reduce the chassis noise during vehicle driving.

[0059] The particle size of the hollow alumina microspheres may be 50 μm, 70 μm, 90 μm, 110 μm, 130 μm, 150 μm, 170 μm, 190 μm, 210 μm, 230 μm or 250 μm.

[0060] In some optional embodiments, the functional additive further comprises an anti-ultraviolet agent, an antioxidant and an anti-hydrolysis stabilizer, and the weight m9 of the anti-ultraviolet agent, the weight m10 of the antioxidant and the weight m11 of the anti-hydrolysis stabilizer satisfy the relationship: m9:m10:m11=0.5:0.5:(1-3);

[0061] In these embodiments, the functional additives may also include anti-ultraviolet agents, antioxidants and anti-hydrolysis stabilizers, and the weight m9 of the anti-ultraviolet agent, the weight m10 of the antioxidant and the weight m11 of the anti-hydrolysis stabilizer may satisfy the relationship: m9:m10:m11=0.5:0.5:(1~3). The anti-ultraviolet agent, antioxidant and anti-hydrolysis stabilizer may improve the environmental resistance of the guard plate material, thereby improving the functional stability of the material.

[0062] The weight m9 of the anti-ultraviolet agent, the weight m10 of the antioxidant and the weight m11 of the anti-hydrolysis stabilizer can satisfy the relationship: m9:m10:m11=0.5:0.5:1.0, 0.5:0.5:1.5, 0.5:0.5:2.0, 0.5:0.5:2.5 or 0.5:0.5:3.0.

[0063] It should be noted that the anti-ultraviolet agent may be UV-327, the antioxidant may be BHT, and the anti-hydrolysis stabilizer may be FT-9188.

[0064] In summary, with respect to the raw material composition of the guard plate material, the inventors found that polylactic acid is a hydrophobic polymer, and many additives in the guard plate material, such as plasticizers, reinforcing fibers or fillers, may not be compatible with it, resulting in uneven dispersion of the raw materials in the guard plate material, affecting the overall performance of the guard plate material. The polyethylene glycol chain segment is hydrophilic, which can achieve bridging between the polylactic acid matrix and these additives, promote the uniform dispersion of the raw materials in the polycaprolactone matrix in the guard plate material, and thus improve the comprehensive performance of the guard plate material. In addition, the introduction of the polyethylene glycol chain segment also increases the flexibility of the guard plate material, which helps to reduce the impact of the brittleness of the polylactic acid itself on the guard plate material, thereby improving the impact strength and tear resistance of the guard plate material. In addition, polyethylene glycol can also improve the processing fluidity of the guard plate material to reduce the melt viscosity of the guard plate material, making it easier for the guard plate material to flow and fill the mold during processing, and reducing processing defects in the preparation process of the guard plate material. In addition, by adjusting the dosage and molecular weight of polyethylene glycol, the degradation rate of polylactic acid can be controlled to a certain extent. This property can be used to design automotive parts with a specific life cycle.

[0065] It should be noted that the hydroxyl group of polyethylene glycol will be grafted copolymerized with polylactic acid to form a PLA-g-PEG block copolymer dispersed phase, and then ring-opening polymerized with polycaprolactone under the action of castor oil derivatives and epoxidized soybean oil plasticizers to obtain O-[PCL-(PLA-g-PEG)n-PCL]m-CO multi-block copolymer, which makes the guard plate material simultaneously hydrophilic and hydrophobic. Since some raw materials in the guard plate material have good hydrolysis ability, the mechanical properties and biodegradation rate of the guard plate material can be affected by adjusting the content of polyethylene glycol, polycaprolactone, castor oil derivatives, epoxidized soybean oil, and reinforcing fibers in the raw materials of the guard plate material. In addition, castor oil derivatives and epoxidized soybean oil are mixed in a mass ratio of 1:(0.25-1.5) as plasticizers. Based on the good biocompatibility of castor oil derivatives and epoxidized soybean oil molecules, they will produce cross-linked structures with O-[PCL-(PLA-g-PEG)n-PCL]m-CO multi-block copolymer molecules during the processing process to introduce large molecular ester chain segments into the multi-segment block copolymer. The introduced large molecular ester chain segments are easily degraded by composting microorganisms. Therefore, the degradation rate of the guard plate material can be adjusted to meet the use requirements of different guard plate materials.

[0066] Figure 2 A schematic flow chart of a method for preparing a guard plate material provided in an embodiment of the present application is exemplarily shown;

[0067] Based on a general inventive concept, such as Figure 2 As shown, the present application provides a method for preparing the guard plate material, the method comprising:

[0068] S1. The polylactic acid, reinforcing fiber, composite toughening agent, plasticizer and functional additive are mixed, and then the mixture is heated to obtain a mixed raw material;

[0069] S2. Preheating the mold to obtain a preheated mold;

[0070] S3. Use the preheated mold to compression mold the mixed raw material to obtain a guard plate material.

[0071] This method is a method for preparing the above-mentioned guard plate material. The specific steps of the guard plate material can refer to the above-mentioned embodiment. Since this method adopts part or all of the technical solutions of the above-mentioned embodiment, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiment, which will not be repeated here one by one.

[0072] In some optional embodiments, the end temperature of the heating is 215° C. to 225° C., and the heating time is ≥ 10 min; and / or

[0073] The preheating temperature is 80°C to 120°C; and / or

[0074] The compression molding pressure is 30MPa-50Mpa, the compression molding temperature is 180°C-220°C, and the compression molding time is 1min-3min;

[0075] In these optional embodiments, the final heating temperature can be 215°C to 225°C, and the heating time can be ≥10 minutes, which can prompt the polylactic acid, reinforcing fiber, composite toughening agent, plasticizer and functional additive to undergo a preliminary chemical reaction by heating to obtain a sufficient amount of mixed raw materials; in addition, the preheating temperature can be 80°C to 120°C, which can facilitate the subsequent compression molding between the mixed raw materials and the mold to finally form the protective plate material; in addition, the compression molding pressure can be 30MPa to 50Mpa, the compression molding temperature can be 180°C to 220°C, and the compression molding time can be 1min to 3min. The compression molding method can reduce the temperature difference between the center and edge positions of the mold so that the mixed raw materials can form the protective plate material.

[0076] The endpoint temperature of the heating may be 215°C, 216°C, 217°C, 218°C, 219°C, 220°C, 221°C, 222°C, 223°C, 224°C or 225°C.

[0077] The preheating temperature may be 80°C, 90°C, 100°C, 110°C or 120°C.

[0078] The compression molding pressure may be 30 MPa, 35 MPa, 40 MPa, 45 MPa or 50 MPa.

[0079] The temperature of the compression molding may be 180°C, 185°C, 190°C, 195°C, 200°C, 205°C, 210°C, 215°C or 220°C.

[0080] The compression molding time can be 1.0 min, 1.5 min, 2.0 min, 2.5 min or 3.0 min.

[0081] The present application is further described below in conjunction with specific examples. The experimental methods in the following examples that do not specify specific conditions are usually measured according to industry standards; if there are no corresponding industry standards, they are carried out according to common international standards, conventional conditions or conditions recommended by the manufacturer.

[0082] Example 1

[0083] like Figure 1As shown, a guard plate material with high degradation performance, in terms of weight parts, the raw materials of the guard plate material include: polylactic acid: 65 parts, reinforcing fiber: 15 parts, composite toughening agent: 10 parts, plasticizer: 5 parts, functional additive: 20 parts; wherein, the composite toughening agent includes polyethylene glycol and polycaprolactone, and the weight m1 of polyethylene glycol and the weight m2 of polycaprolactone satisfy the relationship: m1:m2=7:3.

[0084] The reinforcing fibers include glass fibers and modified bamboo fibers; when the reinforcing fibers include glass fibers and modified bamboo fibers, the weight m3 of the glass fibers and the weight m4 of the modified bamboo fibers satisfy the relationship: m3:m4=1:0.5.

[0085] The average relative molecular mass of polylactic acid is 200,000.

[0086] The plasticizer includes ethylene glycol diacetate, castor oil derivatives and epoxidized soybean oil. The weight m9 of ethylene glycol diacetate, the weight m5 of castor oil derivatives and the weight m6 of epoxidized soybean oil satisfy the relationship: m9:m5:m6=3:1:1.0.

[0087] The functional additives include lubricants and inorganic fillers. The weight m7 of the lubricant and the weight m8 of the inorganic filler satisfy the relationship: m7:m8=1.0:15.

[0088] The inorganic filler comprises hollow alumina microspheres, and the particle size of the hollow alumina microspheres is 50 μm to 250 μm.

[0089] Functional additives also include anti-ultraviolet agents, antioxidants and anti-hydrolysis stabilizers. The weight m9 of the anti-ultraviolet agent, the weight m10 of the antioxidant and the weight m11 of the anti-hydrolysis stabilizer satisfy the relationship: m9:m10:m11=0.5:0.5:3.

[0090] like Figure 2 As shown, a method for preparing a guard plate material, the method comprising:

[0091] S1. The polylactic acid, reinforcing fiber, composite toughening agent, plasticizer and functional additive are mixed, and then the mixture is heated to obtain a mixed raw material;

[0092] S2. The mixed raw materials are compression molded to obtain a guard plate material.

[0093] The end point temperature of heating is 220°C and the heating time is 10 min;

[0094] The preheating temperature is 120°C;

[0095] The molding pressure was 30 MPa, the molding temperature was 220° C., and the molding time was 3 min.

[0096] Example 2

[0097] Based on the contents disclosed in Example 1, the following modifications are further made:

[0098] In terms of weight, the raw materials of the guard plate material include: polylactic acid: 70 parts, reinforcing fiber: 15 parts, composite toughening agent: 10 parts, plasticizer: 5 parts, functional additive: 14 parts; wherein, the composite toughening agent includes polyethylene glycol and polycaprolactone, and the weight m1 of polyethylene glycol and the weight m2 of polycaprolactone satisfy the relationship: m1:m2=1:(0.2~1).

[0099] The reinforcing fibers include glass fibers and modified bamboo fibers; when the reinforcing fibers include glass fibers and modified bamboo fibers, the weight m3 of the glass fibers and the weight m4 of the modified bamboo fibers satisfy the relationship: m3:m4=1:4.

[0100] The average relative molecular mass of polylactic acid is 200,000.

[0101] The weight m9 of ethylene glycol diacetate, the weight m5 of castor oil derivative and the weight m6 of epoxidized soybean oil satisfy the relationship: m9:m5:m6=4:1:1.0.

[0102] The functional additives include lubricants and inorganic fillers. The weight m7 of the lubricant and the weight m8 of the inorganic filler satisfy the relationship: m7:m8=1.0:10.

[0103] Functional additives also include anti-ultraviolet agents, antioxidants and anti-hydrolysis stabilizers. The weight m9 of the anti-ultraviolet agent, the weight m10 of the antioxidant and the weight m11 of the anti-hydrolysis stabilizer satisfy the relationship: m9:m10:m11=0.5:0.5:2.

[0104] Example 3

[0105] Based on the contents disclosed in Example 1, the following modifications are further made:

[0106] In terms of weight, the raw materials of the guard plate material include: polylactic acid: 70 parts, reinforcing fiber: 15 parts, composite toughening agent: 10 parts, plasticizer: 5 parts, functional additive: 14 parts; wherein, the composite toughening agent includes polyethylene glycol and polycaprolactone, and the weight m1 of polyethylene glycol and the weight m2 of polycaprolactone satisfy the relationship: m1:m2=1:1.0.

[0107] The reinforcing fibers include glass fibers and modified bamboo fibers; when the reinforcing fibers include glass fibers and modified bamboo fibers, the weight m3 of the glass fibers and the weight m4 of the modified bamboo fibers satisfy the relationship: m3:m4=9:6.

[0108] The average relative molecular mass of polylactic acid is 200,000.

[0109] The weight m9 of ethylene glycol diacetate, the weight m5 of castor oil derivative and the weight m6 of epoxidized soybean oil satisfy the relationship: m9:m5:m6=2:1:1.0.

[0110] The functional additives include lubricants and inorganic fillers. The weight m7 of the lubricant and the weight m8 of the inorganic filler satisfy the relationship: m7:m8=1.0:10.

[0111] Functional additives also include anti-ultraviolet agents, antioxidants and anti-hydrolysis stabilizers. The weight m9 of the anti-ultraviolet agent, the weight m10 of the antioxidant and the weight m11 of the anti-hydrolysis stabilizer satisfy the relationship: m9:m10:m11=0.5:0.5:2.

[0112] Example 4

[0113] Based on the contents disclosed in Example 1, the following modifications are further made:

[0114] In terms of weight, the raw materials of the guard plate material include: polylactic acid: 70 parts, reinforcing fiber: 15 parts, composite toughening agent: 10 parts, plasticizer: 5 parts, functional additive: 14 parts; wherein, the composite toughening agent includes polyethylene glycol and polycaprolactone, and the weight m1 of polyethylene glycol and the weight m2 of polycaprolactone satisfy the relationship: m1:m2=1:1.0.

[0115] The reinforcing fiber is glass fiber.

[0116] The average relative molecular mass of polylactic acid is 200,000.

[0117] The plasticizer is ethylene glycol diacetate.

[0118] The functional additives include lubricants and inorganic fillers. The weight m7 of the lubricant and the weight m8 of the inorganic filler satisfy the relationship: m7:m8=1.0:10.

[0119] Functional additives also include anti-ultraviolet agents, antioxidants and anti-hydrolysis stabilizers. The weight m9 of the anti-ultraviolet agent, the weight m10 of the antioxidant and the weight m11 of the anti-hydrolysis stabilizer satisfy the relationship: m9:m10:m11=0.5:0.5:2.

[0120] Example 5

[0121] Based on the contents disclosed in Example 1, the following modifications are further made:

[0122] The end point temperature of heating is 215°C;

[0123] The preheating temperature is 80°C;

[0124] The compression molding pressure was 30 MPa, the compression molding temperature was 180° C., and the compression molding time was 1 min.

[0125] Example 6

[0126] Based on the contents disclosed in Example 1, the following modifications are further made:

[0127] The end point temperature of heating is 225°C;

[0128] The preheating temperature is 120°C;

[0129] The molding pressure was 50 MPa, the molding temperature was 220° C., and the molding time was 3 min.

[0130] Comparative Example 1

[0131] Based on the contents disclosed in Example 1, the following modifications are further made:

[0132] The polyethylene terephthalate material is directly used to make the guard plate material.

[0133] Comparative Example 2

[0134] Based on the contents disclosed in Example 1, the following modifications are further made:

[0135] No polyethylene glycol is used.

[0136] Comparative Example 3

[0137] Based on the contents disclosed in Example 1, the following modifications are further made:

[0138] Polycaprolactone is not used.

[0139] Comparative Example 4

[0140] Based on the contents disclosed in Example 1, the following modifications are further made:

[0141] The weight m1 of the polyethylene glycol and the weight m2 of the polycaprolactone satisfy the relationship: m1:m2=1:0.1.

[0142] Related experiments and effect data:

[0143] The guard plate materials obtained in the embodiments and comparative examples were collected respectively, and their properties were tested. The results are shown in Table 1.

[0144] Table 1 Performance test results of the guard plate materials of various embodiments and comparative examples

[0145]

[0146]

[0147] As can be seen from Table 1, in Example 1 to Example 4, as the proportion of polyethylene glycol, castor oil derivatives, epoxidized soybean oil, and modified bamboo fiber increases, the corresponding 100-day weight loss rate increases significantly, with a high positive effect. In addition, since the degradation performance of polycaprolactone monomer is between polylactic acid and polyethylene glycol, in Example 1 and Example 2, glass fiber is used as the main reinforcing material, so it is necessary to select a lower proportion of polycaprolactone so that the degradation performance of the guard plate material meets the preset; for Example 3, as the mass ratio of modified bamboo fiber in the reinforcing fiber increases, it is necessary to select a higher proportion of polycaprolactone to reduce the degradation rate of the guard plate material, so as to promote the use cycle of the guard plate material to meet the preset, and prevent the degradation rate from being too fast, resulting in the life cycle of the guard plate material not meeting the design and use requirements. Therefore, the polyethylene glycol and polycaprolactone in the raw materials of the guard plate material are mixed in a mass ratio of 1: (0.2~1), which can synergistically adjust the degradation rate of the guard plate material to meet different design requirements.

[0148] Comparing Example 1 and Example 4, due to the presence of a large number of internal hollow structures in the hollow alumina microspheres, the surface density is lower than that of the traditional guard plate material, which is also in line with the trend of lightweight design ideas for automotive parts. At the same time, the hollow alumina microspheres have excellent heat insulation and flame retardant properties. For new energy vehicles, improving the flame retardant properties of the guard plate material will also become a future design trend, which is in line with the battery protection design concept of new energy vehicles at this stage.

[0149] In summary, the embodiments of the present application provide a guard plate material with high degradation performance. The guard plate material can simultaneously improve the mechanical properties and degradation properties of the guard plate material through the interaction between polylactic acid, reinforcing fibers, composite toughening agents, plasticizers and functional additives, thereby achieving a balance between the mechanical properties and degradation properties of the guard plate material.

[0150] In addition, an embodiment of the present application provides a guard plate material with high degradation performance. The guard plate material uses polylactic acid, a renewable bio-based material, as a main component. Polylactic acid can be widely sourced from corn starch, sugar cane, etc., and the carbon emissions during the production of polylactic acid are significantly lower than those of traditional petroleum-based plastic materials. Under specific conditions, polylactic acid can be biodegraded, which reduces the long-term pollution of the guard plate material to the environment.

[0151] In addition, a guard plate material with high degradation performance provided in an embodiment of the present application has good biocompatibility by adding a plasticizer comprising castor oil derivatives and epoxidized soybean oil, and reinforcing fibers comprising modified bamboo fibers. In addition, the guard plate material achieves high degradation performance through the interaction between polylactic acid, reinforcing fibers, composite toughening agents, plasticizers and functional additives, while various mechanical properties can also meet the requirements of automobile underbody guard plates for impact resistance and wear resistance.

[0152] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. It will be apparent to those skilled in the art that various modifications to these embodiments are possible, and the general principles defined in the present application can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown in the present application, but will conform to the widest range consistent with the principles and novel features applied for by the present application.

Claims

1. A protective plate material with high degradation performance, characterized in that: In terms of weight, the raw materials of the guard plate material include: polylactic acid: 60 to 70 parts, reinforcing fiber: 10 to 15 parts, composite toughening agent: 5 to 10 parts, plasticizer: 2 to 5 parts, functional additive: 12.5 to 20 parts; wherein the composite toughening agent includes polyethylene glycol and polycaprolactone, and the weight m1 of the polyethylene glycol and the weight m2 of the polycaprolactone satisfy the relationship: m1:m2≤1:0.

2.

2. The cover material according to claim 1, characterized in that: The weight m1 of the polyethylene glycol and the weight m2 of the polycaprolactone satisfy the relationship: m1:m2=1:(0.2-1).

3. The cover material according to claim 1, characterized in that: The reinforcing fibers include glass fibers and / or modified bamboo fibers; and / or In the case where the reinforcing fibers include glass fibers and modified bamboo fibers, the weight m3 of the glass fibers and the weight m4 of the modified bamboo fibers satisfy the relationship: m3:m4=1:(0.25-1).

4. The cover material according to claim 1, characterized in that: The average relative molecular mass of the polylactic acid is 80,000 to 200,000.

5. The cover material according to claim 1, characterized in that: The plasticizer includes castor oil derivatives and epoxidized soybean oil, and the weight m5 of the castor oil derivatives and the weight m6 of the epoxidized soybean oil satisfy the relationship: m5:m6=1:(0.25-1.5).

6. The cover material according to claim 1, characterized in that: The functional additive includes a lubricant and an inorganic filler, and the weight m7 of the lubricant and the weight m8 of the inorganic filler satisfy the relationship: m7:m8=(0.5-1.0):(10-15).

7. The cover material according to claim 6, characterized in that: The inorganic filler comprises hollow alumina microspheres, and the particle size of the hollow alumina microspheres is 50 μm to 250 μm.

8. The cover material according to claim 1, characterized in that: The functional additives also include an anti-ultraviolet agent, an antioxidant and an anti-hydrolysis stabilizer. The weight m9 of the anti-ultraviolet agent, the weight m10 of the antioxidant and the weight m11 of the anti-hydrolysis stabilizer satisfy the relationship: m9:m10:m11=0.5:0.5:(1-3).

9. A method for preparing the guard plate material according to any one of claims 1 to 8, characterized in that: The method comprises: The polylactic acid, reinforcing fiber, composite toughening agent, plasticizer and functional additive are mixed, and then the mixture is heated to obtain a mixed raw material; preheating the mold to obtain a preheated mold; The mixed raw material is compression molded using the preheated mold to obtain a guard plate material.

10. The method according to claim 9, characterized in that The end temperature of the heating is 215°C to 225°C, and the heating time is ≥ 10 min; and / or The preheating temperature is 80°C to 120°C; and / or The pressure of the compression molding is 30MPa-50MPa, the temperature of the compression molding is 180°C-220°C, and the time of the compression molding is 1min-3min.

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