Degradable WPC base material, preparation method thereof and floor

Abstract

The invention relates to the field of wood-plastic composite floors, in particular to a degradable WPC base material, a preparation method of the degradable WPC base material and a floor. The degradable WPC base material is prepared from the following raw materials in parts by mass: 80 to 120 parts of polylactic resin, 30 to 60 parts of a modified plant-based material, 1 to 8 parts of a stabilizer, 1 to 5 parts of polyethylene wax and 1 to 6 parts of a foaming agent. The degradable floor is made of degradable materials, so that the degradable performance and the toughness of the floor can be improved.

Description

Technical Field

[0001] The present application relates to the field of wood plastic composite flooring, and in particular to a degradable WPC substrate and a preparation method thereof and a flooring. Background Art

[0002] The main raw materials for the production of wood plastic composite flooring (WPC) include wood raw materials, plastics and processing aids. Therefore, WPC not only has the hardness and environmental protection of wood, but also has many advantages of plastics, such as excellent processing performance, easy processing and molding, good water resistance, good toughness, etc.

[0003] At present, the plastics used in the production of WPC flooring are mainly based on petroleum-based materials that are not easily degradable, such as polyvinyl chloride (PVC). However, with the shortage of petroleum resources, there may be major problems in the supply and demand of its raw materials in the future. On the other hand, in order to meet the "dual carbon" goals and vigorously promote "plastic ban", it is urgent to use renewable natural resource materials to develop new composite materials and promote the replacement of non-degradable plastic products. Summary of the invention

[0004] The present application provides a degradable WPC substrate and a preparation method thereof and a floor, which can improve the degradability and toughness of the floor.

[0005] The present invention is specifically as follows:

[0006] A degradable WPC substrate, wherein the raw materials for preparing the degradable WPC substrate include, by weight:

[0007] 80-120 parts of polylactic acid resin, 30-60 parts of modified plant-based materials, 1-8 parts of stabilizer, 1-5 parts of polyethylene wax, and 1-6 parts of foaming agent.

[0008] In one embodiment of the present invention, the stabilizer includes: at least one of a hindered amine light stabilizer, a benzotriazole light stabilizer, a polyolefin light stabilizer, a benzophenone light stabilizer, and a salicylic acid light stabilizer.

[0009] In one embodiment of the present invention, the blowing agent comprises at least one of azodicarbonamide, carbon dioxide and cyclopentane.

[0010] In one embodiment of the present invention, the modified plant-based material is obtained by modifying the plant-based material through an esterification reaction using a composite modification liquid.

[0011] In one embodiment of the present invention, the composite modifying liquid is a mixed solution of glacial acetic acid and concentrated sulfuric acid in a volume ratio of 50:1.

[0012] In one embodiment of the present invention, the plant-based material includes one or more of wood powder, straw powder, rice husk powder and bagasse.

[0013] A method for preparing a degradable WPC substrate, used for preparing the above-mentioned degradable WPC substrate, comprises the following steps:

[0014] S1: weigh the raw materials in corresponding weight parts according to the preset ratio of the degradable WPC substrate, first mix the polylactic acid resin, the modified plant-based material, the stabilizer, the polyethylene wax and the foaming agent in a high-speed mixer at 100°C-120°C for 10-15 minutes;

[0015] S2: Then, the mixture is mixed in a cold mixer at 50°C for 10-15 minutes; the mixture is extruded through a twin-screw extruder, the extrusion temperature is 160°C-190°C, and the screw speed of the twin-screw extruder is 10-25r / min;

[0016] S3: The degradable WPC substrate is obtained by calendering with a calender;

[0017] In one embodiment of the present invention, the preparation steps of the modified plant-based material include: adding the plant-based material to a high-speed mixer, adding a mixed solution of glacial acetic acid and concentrated sulfuric acid in a volume ratio of 40-60:1, controlling the temperature at 40-60°C, and stirring at a high speed for 5-15 minutes, so that the cellulose in the plant fiber and the glacial acetic acid undergo an esterification reaction under the catalysis of concentrated sulfuric acid to obtain the modified plant-based material.

[0018] A degradable WPC floor, the base material of the degradable WPC floor adopts the above-mentioned degradable WPC base material.

[0019] The beneficial effects of the present invention are:

[0020] The degradable WPC substrate comprises, by weight, 80-120 parts of polylactic acid resin, 30-60 parts of modified plant-based materials, 1-8 parts of stabilizer, 1-5 parts of polyethylene wax, and 1-6 parts of foaming agent. The degradable WPC substrate is made of degradable materials, thereby improving the degradability and toughness of the floor. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 This is a schematic diagram of the structure of the degradable WPC floor provided in this application.

[0023] Icon: 200-degradable WPC floor; 210-PLA wear-resistant layer; 220-PLA color film layer; 230-degradable WPC substrate; 240-back film layer. DETAILED DESCRIPTION

[0024] 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, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0026] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0027] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0028] In the description of the embodiments of the present application, it should be noted that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the application is usually placed when in use, or the orientation or positional relationship commonly understood by those skilled in the art, or the orientation or positional relationship in which the product of the application is usually placed when in use, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0029] In the description of the embodiments of the present application, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0030] This embodiment provides a degradable WPC substrate. The raw materials for preparing the degradable WPC substrate include, by weight:

[0031] 80-120 parts of polylactic acid resin, 30-60 parts of modified plant-based materials, 1-8 parts of stabilizer, 1-5 parts of polyethylene wax, and 1-6 parts of foaming agent.

[0032] The degradable WPC substrate is made of degradable materials, thereby being able to improve the degradability of the floor and the toughness of the floor.

[0033] Specifically, in this embodiment, the stabilizer includes: at least one of a hindered amine light stabilizer, a benzotriazole light stabilizer, a polyolefin light stabilizer, a benzophenone light stabilizer, and a salicylic acid light stabilizer.

[0034] The foaming agent comprises at least one of azodicarbonamide, carbon dioxide and cyclopentane.

[0035] When preparing the modified plant-based material, the modified plant-based material is obtained by modifying the plant-based material through an esterification reaction using a composite modification liquid. In addition, in this embodiment, the composite modification liquid is a mixed solution of glacial acetic acid and concentrated sulfuric acid in a volume ratio of 50:1.

[0036] Thus, taking the modified plant-based material as modified wood powder as an example, the wood powder is added to a high-speed mixer, and a mixed solution of glacial acetic acid and concentrated sulfuric acid is added in a volume ratio of 50:1, the temperature is controlled at about 60°C, and high-speed stirring is performed for 10 minutes, so that the cellulose in the wood powder and the glacial acetic acid undergo an esterification reaction under the catalysis of concentrated sulfuric acid to obtain modified wood powder; wherein, the amount of glacial acetic acid added is 50-75mL;

[0037] Further, in this embodiment, the plant-based material includes one or more of wood powder, straw powder, rice husk powder and bagasse. That is, wood powder can be replaced with other plant fibers, including but not limited to straw powder, rice husk powder and bagasse.

[0038] It should be noted that when modifying plant-based materials, taking wood powder as the raw material, if wood powder and polylactic acid are directly blended to obtain a PLA (polylactic acid) wood-plastic composite material, although it can be mixed evenly, the interface compatibility is poor and the toughness of the composite material is not good; the main component of wood powder is cellulose, which contains a large number of functional groups such as polar hydroxyl groups and phenolic hydroxyl groups. Treating wood powder with glacial acetic acid is to esterify the polar functional groups on the wood surface to generate hydrophobic non-polar chemical functional groups, thereby reducing the repulsion between the plastic substrate and the surface of the wood material, thereby achieving the purpose of improving the interface adhesion and improving the toughness of the material.

[0039] Based on the above-mentioned degradable WPC substrate, this embodiment also provides a method for preparing a degradable WPC substrate, which is used to prepare the above-mentioned degradable WPC substrate, comprising the following steps:

[0040] S1: weigh the raw materials in corresponding weight parts according to the preset ratio of the degradable WPC substrate, first mix the polylactic acid resin, the modified plant-based material, the stabilizer, the polyethylene wax and the foaming agent in a high-speed mixer at 100°C-120°C for 10-15 minutes;

[0041] S2: Then, the mixture is mixed in a cold mixer at 50°C for 10-15 minutes; the mixture is extruded through a twin-screw extruder, the extrusion temperature is 160°C-190°C, and the screw speed of the twin-screw extruder is 10-25r / min;

[0042] S3: The degradable WPC substrate is obtained by calendering with a calender;

[0043] Furthermore, in this embodiment, the preparation steps of the modified plant-based material include: adding the plant-based material to a high-speed mixer, adding a mixed solution of glacial acetic acid and concentrated sulfuric acid in a volume ratio of 40-60:1, controlling the temperature at 40-60°C, and stirring at a high speed for 5-15 minutes, so that the cellulose in the plant fiber and the glacial acetic acid undergo an esterification reaction under the catalysis of concentrated sulfuric acid to obtain a modified plant-based material.

[0044] In summary, based on the above-mentioned degradable WPC substrate and preparation method thereof, this embodiment further provides a degradable WPC floor. The substrate of the degradable WPC floor is prepared by using the above-mentioned degradable WPC substrate.

[0045] For details, please refer to Figure 1 The degradable WPC floor 200 includes a PLA wear-resistant layer 210, a PLA color film layer 220 and a degradable WPC substrate 230; the PLA wear-resistant layer 210, the PLA color film layer 220 and the degradable WPC substrate 230 are stacked in sequence from top to bottom, and the degradable WPC floor 200 is made based on PLA resin and modified wood powder, the purpose of which is to improve the degradability of the floor and the toughness of the floor.

[0046] Since the PLA wood-plastic composite material obtained by directly blending wood powder and polylactic acid can be mixed evenly, the interfacial compatibility is poor and the toughness of the composite material is not good. In addition, the main component of wood powder is cellulose, which contains a large number of functional groups such as polar hydroxyl groups and phenolic hydroxyl groups. Therefore, this embodiment uses glacial acetic acid to treat the wood powder, which is to esterify the polar functional groups on the wood surface to generate hydrophobic non-polar chemical functional groups, thereby reducing the repulsion between the plastic substrate and the surface of the wood material, thereby achieving the purpose of improving the interfacial adhesion and improving the toughness of the material.

[0047] For further information, please refer to Figure 1 In this embodiment, the thickness of the PLA wear-resistant layer 210 is 0.3-1.5 mm; the thickness of the PLA color film layer 220 is 0.05-0.15 mm; in addition, the lower surface of the degradable WPC substrate 230 may also be provided with a back film layer 240, and the thickness of the back film layer 240 is 1-2 mm; the back film layer 240 includes one or more of cork, EVA, IXPE and PE.

[0048] Based on the above-mentioned method for preparing the degradable WPC substrate, the process for preparing the degradable WPC floor from the above-mentioned degradable WPC substrate includes:

[0049] Preparation of the degradable WPC substrate 230: weigh the raw materials in corresponding weight parts according to the preset ratio of the degradable WPC substrate 230, and mix the polylactic acid resin, modified wood powder, stabilizer, polyethylene wax and foaming agent in a high-speed mixer at 100°C-120°C for 15 minutes through a substrate production line; then mix them in a cold mixer at 50°C for 10 minutes; extrude the obtained mixture through a twin-screw extruder, the extrusion temperature is 160°C-190°C, and the screw speed of the twin-screw extruder is 10-25r / min; then, the mixture is calendered into a 3-5mm WPC foamed substrate through a calender;

[0050] The PLA wear-resistant layer 210, the PLA color film layer 220 and the WPC foam substrate are stacked from top to bottom, and the PLA wear-resistant layer 210, the PLA color film layer 220 and the WPC foam substrate are evenly laminated by a calender; wherein the temperature of the first roller and the second roller of the calender is 175-190° C.; the temperature of the third roller, the fourth roller and the fifth roller is 80-100° C., and the calendering speed is 3-5 m / min, to obtain a semi-finished floor with a set thickness;

[0051] UV roller paint, UV roller paint the semi-finished floor after extrusion;

[0052] Molding and punching: put the semi-finished floor after UV roller painting into the molding press for positioning and molding. The hot pressing temperature is 80℃-100℃ and the time is 5s-8s. The tool is heated by the heating device to perform heat preservation and pressure punching on the WPC floor to achieve arc-shaped molding chamfering and obtain the formed WPC floor.

[0053] Grooving: The formed WPC floor enters the groover through the traction system and grooves are cut around the floor.

[0054] It should be noted that this embodiment is described based on the preset ratio of the degradable WPC substrate 230 including 80-120 parts of polylactic acid resin, 30-60 parts of modified wood powder, 1-8 parts of stabilizer, 1-5 parts of polyethylene wax, and 1-6 parts of foaming agent.

[0055] For further information, please refer to Figure 1 In this embodiment, when a back film layer 240 is provided on the lower surface of the degradable WPC substrate 230 of the degradable WPC floor 200, its production steps may also include: laminating the back film layer 240 and the degradable WPC substrate 230, setting the laminating process temperature to 100℃-120℃ and the speed to 5-10m / min; the hot melt adhesive roller coating temperature is 85℃-120℃, the adhesive application amount is 30-50g / m2, and the soundproof layer is attached to the lower surface of the degradable WPC substrate 230.

[0056] In the above content, before preparing the degradable WPC substrate 230, it is necessary to prepare modified wood powder, and the preparation steps of the modified wood powder include: adding plant fiber to a high-speed mixer, adding a mixed solution of glacial acetic acid and concentrated sulfuric acid in a volume ratio of 50:1, controlling the temperature at about 60°C, and stirring at a high speed for 10 minutes, so that the cellulose in the plant fiber and the glacial acetic acid undergo an esterification reaction under the catalysis of concentrated sulfuric acid to obtain modified wood powder.

[0057] The amount of glacial acetic acid added is 50-75 mL, and the plant fiber includes one or more of wood powder, straw powder, rice husk powder and bagasse.

[0058] In summary, please refer to Figure 1 The degradable WPC floor 200 and its processing method have the following advantages:

[0059] 1. PLA has good mechanical and physical properties, excellent antibacterial and antifungal properties, and also exhibits good biocompatibility, gloss, transparency and heat resistance;

[0060] 2. PLA is a new type of biodegradable plastic. After use, it can be completely degraded by microorganisms in nature, and finally generate carbon dioxide and water, which does not pollute the environment. Using PLA to replace traditional PVC in WPC flooring is more environmentally friendly;

[0061] 3. PLA materials are safer. When PLA is burned, its calorific value is the same as that of paper, which is half of that of traditional plastics. In addition, no toxic gases such as nitrides and sulfides are released during the burning process.

[0062] 4. WPC flooring is made by mixing modified wood powder with PLA. It has the advantages of biodegradability, safety and environmental protection, good mechanical properties, and relatively light weight. It can solve the problem of high freight costs of traditional SPC flooring to a certain extent.

[0063] Based on the above, please refer to Figure 1 , provide the following embodiment 1 and embodiment 2, the specific contents are as follows:

[0064] Embodiment 1:

[0065] The structure of the degradable WPC floor is, from top to bottom, a PLA wear-resistant layer 210, a PLA color film layer 220, a degradable WPC substrate 230 and a back film layer 240; the raw materials of the degradable WPC substrate 230 are PLA material and modified wood powder; the preparation method of the modified wood powder is as follows: add the wood powder to a high-speed mixer, add a mixed solution of glacial acetic acid and concentrated sulfuric acid in a volume ratio of 50:1, wherein the amount of glacial acetic acid added is 75 mL; control the temperature at about 60°C, stir at a high speed for 10 minutes, so that the cellulose in the wood powder and the glacial acetic acid undergo an esterification reaction under the catalysis of concentrated sulfuric acid to obtain the modified wood powder.

[0066] The raw materials of the degradable WPC substrate 230, calculated by weight, include: 100 parts of polylactic acid resin, 40 parts of modified wood powder, 5 parts of stabilizer, 3 parts of polyethylene wax, and 4 parts of foaming agent; the thickness of the PLA wear-resistant layer 210 is 0.3 mm; the thickness of the PLA color film layer 220 is 0.1 mm; the back film layer 240, made of EVA, has a thickness of 1 mm.

[0067] The processing method of the degradable WPC floor comprises the following steps:

[0068] 1. Preparation of degradable WPC substrate 230: According to the formula of degradable WPC substrate 230, corresponding weight portions of raw materials are weighed, and polylactic acid resin, modified wood powder, stabilizer, polyethylene wax and foaming agent are first mixed in a 120°C high-speed mixer for 15 minutes through a substrate production line, and then mixed in a 50°C cold mixer for 10 minutes, and the mixture is extruded and formed by a twin-screw extruder at an extrusion temperature of 180°C and a screw speed of 20r / min, and then calendered into a 5mm WPC foaming substrate by a calender;

[0069] 2. From top to bottom, stack the PLA wear-resistant layer 210, the PLA color film layer 220 and the base material layer, and evenly bond the wear-resistant layer, the color film layer and the base material through a calender. The temperature of the first and second rollers is 185°C; the temperature of the third, fourth and fifth rollers is 100°C, and the calendering speed is 5m / min, to obtain a semi-finished floor with a set thickness.

[0070] 3. UV Roller Paint: Apply UV roller paint to the semi-finished floor after extrusion;

[0071] 4. Moulding and punching: Place the UV-painted WPC floor into the moulding press for positioning and moulding. The hot pressing temperature is 90°C and the time is 6 seconds. The tool is heated by the heating device to punch and cut the WPC floor with heat preservation and pressure to achieve arc-shaped moulding chamfers.

[0072] 5. Grooving: The formed floor enters the groove machine through the traction system, and grooves are cut around the floor;

[0073] 6. Film pasting: Paste the back film layer 240 and the degradable WPC substrate 230 as follows: set the temperature to 120°C and the speed to 8m / min; the hot melt adhesive roller coating temperature is 110°C and the adhesive application amount is 50g / m2, and paste the silent layer on the lower surface of the degradable WPC substrate 230.

[0074] Embodiment 2:

[0075] The structure of the degradable WPC floor is PLA wear-resistant layer 210, PLA color film layer 220, degradable WPC substrate 230 and back film layer 240 from top to bottom. The main raw materials of the degradable WPC substrate 230 are PLA material and modified wood powder; the preparation method of the modified wood powder is as follows: add the wood powder to a high-speed mixer, add glacial acetic acid and concentrated sulfuric acid mixed solution at a volume ratio of 50:1, wherein the amount of glacial acetic acid added is 50mL. Control the temperature at about 60°C, stir at high speed for 10 minutes, so that the cellulose in the wood powder and the glacial acetic acid undergo esterification reaction under the catalysis of concentrated sulfuric acid to obtain modified wood powder.

[0076] The raw materials of the degradable WPC substrate 230, calculated by weight, include: 100 parts of polylactic acid resin, 60 parts of modified wood powder, 3 parts of stabilizer, 2 parts of polyethylene wax, and 3 parts of foaming agent; the thickness of the PLA wear-resistant layer 210 is 0.3 mm; the thickness of the PLA color film layer 220 is 0.1 mm; the back film layer 240, made of IXPE, has a thickness of 2 mm.

[0077] The processing method of degradable WPC floor comprises the following steps:

[0078] 1. Preparation of the degradable WPC substrate 230: According to the formula of the degradable WPC substrate 230, corresponding weight portions of raw materials are weighed, and the polylactic acid resin, modified wood powder, stabilizer, polyethylene wax, and foaming agent are first mixed in a 100° C. high-speed mixer for 15 minutes through a substrate production line, and then mixed in a 50° C. cold mixer for 10 minutes, and the mixture is extruded through a twin-screw extruder at an extrusion temperature of 160° C. and a screw speed of 15 r / min, and then calendered into a 4 mm WPC foam substrate through a calender;

[0079] 2. From top to bottom, stack the PLA wear-resistant layer 210, the PLA color film layer 220 and the base layer, and evenly bond the wear-resistant layer, the color film layer and the base layer through a calender. The temperature of the first and second rollers is 175°C; the temperature of the third, fourth and fifth rollers is 90°C, and the calendering speed is 3m / min, to obtain a semi-finished floor with a set thickness.

[0080] 3. UV Roller Paint: Apply UV roller paint to the semi-finished floor after extrusion;

[0081] 4. Moulding and punching: Place the UV-painted WPC floor into the moulding press for positioning and moulding. The hot pressing temperature is 90°C and the time is 6 seconds. The tool is heated by the heating device to punch and cut the WPC floor with heat preservation and pressure to achieve arc-shaped moulding chamfers.

[0082] 5. Grooving: The formed floor enters the groove machine through the traction system, and grooves are cut around the floor;

[0083] 6. Film pasting: Paste the back film layer 240 and the degradable WPC substrate 230 as follows: set the temperature to 100°C and the speed to 5m / min; the hot melt adhesive roller coating temperature is 85°C, the adhesive application amount is 35g / m2, and the soundproofing layer is pasted on the lower surface of the degradable WPC substrate 230.

[0084] Comparative Example 1:

[0085] The implementation method is the same as that of Example 1, except that the wood powder in the raw material of the degradable WPC substrate 230 is ordinary wood powder.

[0086] Comparative Example 2:

[0087] The implementation method is the same as that of Example 1, except that the resin powder in the raw materials of the degradable WPC substrate 230, the wear-resistant layer, and the color film layer are all PVC resins, and 20 parts by weight of plasticizer are added to the raw materials of the substrate to promote the plasticization of PVC.

[0088] Physical properties tests were performed on the WPC finished floors made in Examples 1 and 2 and Comparative Examples 1 and 2, with the main test items being density, static bending strength, dimensional stability and high-temperature warpage.

[0089] Density: measured by water displacement method;

[0090] Static bending strength: test method refers to GB / T 17657-2022;

[0091] Dimensional stability: Test method refers to ISO 23999;

[0092] High temperature warpage: test method refers to ISO 23999;

[0093] The test results are shown in Table 1:

[0094]

[0095] Table 1 Physical properties test results of finished flooring of Examples 1, 2 and Comparative Examples 1, 2

[0096] It can be concluded from Table 1 that: 1. Compared with WPC floors made of ordinary wood powder as raw materials, the mechanical properties and stability of WPC finished floors made of modified wood powder are improved. This is because during the blending process, the interface compatibility between ordinary wood powder and PLA is poor, and wood powder will also restrict the movement of PLA macromolecular chains, resulting in a significant decrease in PLA crystallization ability. Adding a certain amount of glacial acetic acid to wood powder can increase the esterification degree of cellulose in wood powder, improve the compatibility between wood powder and PLA, and thus improve the mechanical properties of the composite material. 2. Compared with the PLA and PVC resin materials added to WPC floors, PLA has a lower density, and the finished floor is lighter in weight, and the corresponding transportation cost is also lower. In addition, PLA is a thermoplastic material, which is easier to process and has relatively good physical properties.

[0097] The mildew resistance grade of the WPC finished floors prepared in Examples 1 and 2 and Comparative Examples 1 and 2 was tested, and the test method was based on GB / T 35469-2017.

[0098] The test results are shown in Table 2:

[0099] Example 1 Example 2 Comparative Example 1 Comparative Example 2 Fungal growth Trace growth Trace growth Trace growth Moderate growth Mold growing area 5％ 8％ 8％ 35％ Mildew resistance level 1 1 1 3

[0100] Table 2 Test results of mildew resistance grade of finished floor in Examples 1, 2 and Comparative Examples 1, 2

[0101] It can be concluded from Table 2 that Example 1 has the best mildew-proof effect, and the mildew-proof grades of Example 2 and Comparative Example 1 can also reach Grade 1, and the mildew growth of Comparative Example 2 is the most. This is mainly due to the excellent antibacterial and mildew-proof properties of PLA. PLA is a polyester polymer obtained by polymerization with lactic acid as the main raw material, which can form a weakly acidic environment on the surface of the product, making it more difficult for mildew to adhere to the surface of the product.

[0102] In summary, the present invention provides a degradable WPC floor 200 made of a new biodegradable PLA resin and modified wood powder as raw materials, which has the advantages of light weight, good physical properties and excellent anti-mildew effect, and the production raw materials do not contain formaldehyde and plasticizers, which is more green, safe and environmentally friendly.

[0103] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A degradable WPC substrate, characterized in that: The raw materials for preparing the degradable WPC substrate include, by weight: 80-120 parts of polylactic acid resin, 30-60 parts of modified plant-based materials, 1-8 parts of stabilizer, 1-5 parts of polyethylene wax, and 1-6 parts of foaming agent.

2. The degradable WPC substrate according to claim 1, characterized in that: The stabilizer comprises at least one of a hindered amine light stabilizer, a benzotriazole light stabilizer, a polyolefin light stabilizer, a benzophenone light stabilizer, and a salicylic acid light stabilizer.

3. The degradable WPC substrate according to claim 1, characterized in that: The foaming agent comprises at least one of azodicarbonamide, carbon dioxide and cyclopentane.

4. The degradable WPC substrate according to claim 1, characterized in that: The modified plant-based material is prepared by modifying the plant-based material through an esterification reaction using a composite modification liquid.

5. The degradable WPC substrate according to claim 4, characterized in that: The composite modified liquid is a mixed solution of glacial acetic acid and concentrated sulfuric acid in a volume ratio of 50:

1.

6. The degradable WPC substrate according to claim 4, wherein the plant-based material comprises one or more of wood powder, straw powder, rice husk powder and bagasse.

7. The method for preparing a degradable WPC substrate according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1: weighing corresponding weight portions of raw materials according to the preset ratio of the degradable WPC substrate, firstly mixing polylactic acid resin, modified plant-based material, stabilizer, polyethylene wax and foaming agent in a high-speed mixer at 100° C.-120° C. for 10-15 minutes; S2: then mixing in a cold mixer at 50°C for 10-15 minutes; extruding the obtained mixture through a twin-screw extruder, the extrusion temperature is 160°C-190°C, and the screw speed of the twin-screw extruder is 10-25r / min; S3: The degradable WPC substrate is obtained by calendering with a calender.

8. The method for preparing a degradable WPC substrate according to claim 7, characterized in that: The preparation steps of the modified plant-based material include: adding the plant-based material to a high-speed mixer, adding a mixed solution of glacial acetic acid and concentrated sulfuric acid in a volume ratio of 40-60:1, controlling the temperature at 40-60°C, and stirring at a high speed for 5-15 minutes, so that the cellulose in the plant fiber and the glacial acetic acid undergo an esterification reaction under the catalytic action of the concentrated sulfuric acid to obtain the modified plant-based material.

9. A degradable WPC floor, characterized in that: The substrate of the degradable WPC floor is the degradable WPC substrate according to any one of claims 1 to 6.

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