Modified polylactic acid-based nonwoven fabric material, and preparation method and application thereof

Abstract

The application discloses a modified polylactic acid-based non-woven fabric material and a preparation method and application thereof, and relates to the technical field of non-woven fabrics.The components of the modified polylactic acid-based non-woven fabric material include the following preparation raw materials: first modified polylactic acid and second modified polylactic acid; the components of the first modified polylactic acid include the following preparation raw materials: a hydrophobic monomer, an initiator and a first polylactic acid resin; and the components of the second modified polylactic acid include the following preparation raw materials: an antioxidant, an ultraviolet-resistant agent and a second polylactic acid resin.The first modified polylactic acid and the second modified polylactic acid are distinguished in the raw materials of the modified polylactic acid-based non-woven fabric material, and are prepared respectively to avoid simple mixing.The modified polylactic acid-based non-woven fabric material is a hydrophobic non-woven fabric, has good hydrophobicity, can delay the penetration and hydrolysis of water to a polylactic acid matrix, improves the anti-aging performance of the material, and prolongs the service life of the material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of non-woven fabrics, in particular to a modified polylactic acid-based non-woven fabric material and a preparation method and application thereof. BACKGROUND

[0002] Plastic mulch is widely used in the process of agricultural production in China. It can effectively keep the moisture and soil of farmland, keep warm and prevent cold, and prevent pests from breeding, ensuring the normal growth of crops. However, traditional mulch is mostly PE (polyethylene), PP (polypropylene), and PET (polyethylene terephthalate) film, which is easy to age, turn white, crack and become fragments under sunlight and humid environment, making it difficult to recycle. In addition, further aging of traditional mulch will form microplastic particles, further polluting farmland.

[0003] Compared with PE, PP, PET and other traditional polymers, polylactic acid (PLA) is a new type of bio-based and biodegradable polymer. It can be completely degraded by microorganisms in the environment such as compost, avoiding microplastic pollution, and will replace traditional polymers to become an important raw material for plastic mulch in the future. There is prior art that discloses a multi-layer composite PLA mulch. However, the technology is complex, and toxic adhesives are used, making it difficult to ensure that the toxic adhesives will not pollute the farmland when the mulch degrades. There is prior art that discloses loading anti-ultraviolet agents on silica and forming a non-woven mulch by melt blending with PLA into a network. However, the technology is complex and the cost is high, and the silica is easy to agglomerate inside the PLA melt, affecting the fiber formation and network formation of PLA, and weakening the final performance of the mulch.

[0004] In addition, compared with the dense traditional plastic mulch, the breathable and moisture permeable performance of the non-woven fabric made mulch is obviously better than that of the general plastic mulch, which can prevent the occurrence of seedling burning, excessive temperature and other adverse phenomena due to exposure to sunlight, and is also an important development direction of future agricultural mulch. The prior art discloses a crop straw fiber-based special agricultural mulch made of straw fiber, waste clothing fiber, gauze, cellulose material and potato starch. However, natural materials such as starch and straw are prone to bacterial diseases that affect crop growth, and traditional polymer materials such as polyester and spandex in waste clothing can also cause microplastic pollution. The prior art discloses improving the durability of the non-woven fabric mulch by anti-ultraviolet treatment. However, this process only performs surface treatment, and the anti-ultraviolet layer has poor durability and is difficult to popularize due to large surface treatment pollution. The prior art discloses that the initiator causes free radical initiation grafting modification. However, this process needs to generate a large number of free radicals in the polylactic acid melt, which is contrary to the traditional polymer melt processing. In the traditional polymer melt processing process, in order to avoid macromolecular rupture and degradation of the polymer in a high temperature environment and ensure the final performance of the polymer material, a certain amount of anti-aging additive needs to be introduced into the melt to capture free radicals in the melt and avoid chain reaction caused by free radicals to cause polymer degradation. However, the presence of the anti-aging additive will hinder the free radical initiation grafting reaction caused by the initiator, thereby making the performance of the final product, the non-woven fabric mulch, poor.

[0005] Therefore, there is an urgent need for a new type of plastic mulch and a preparation method thereof to solve the above problems. SUMMARY

[0006] The first technical problem to be solved by the present application is:

[0007] A modified polylactic acid-based non-woven fabric material is provided.

[0008] The second technical problem to be solved by the present application is:

[0009] A preparation method of the modified polylactic acid-based non-woven fabric material is provided.

[0010] The third technical problem to be solved by the present application is:

[0011] The present application also provides a plastic mulch.

[0012] To solve the first technical problem, the technical solution adopted by the present application is:

[0013] A modified polylactic acid-based non-woven fabric material, the components of the modified polylactic acid-based non-woven fabric material include the following preparation raw materials:

[0014] The first modified polylactic acid and the second modified polylactic acid;

[0015] The components of the first modified polylactic acid include the following raw materials for preparation:

[0016] hydrophobic monomer, initiator and first polylactic acid resin;

[0017] The components of the second modified polylactic acid include the following raw materials for preparation:

[0018] antioxidant, anti-ultraviolet agent, second polylactic acid resin.

[0019] According to the embodiments of the present application, one of the technical solutions has at least one of the following advantages or beneficial effects:

[0020] In the modified polylactic acid-based non-woven fabric material, the raw materials of the first modified polylactic acid include hydrophobic monomer, initiator and first polylactic acid resin. By grafting hydrophobic monomer in the first polylactic acid resin, the hydrophobic side chain in the first polylactic acid resin after grafting can control the diffusion of water thereon and initiate the hydrolysis thereof, so as to realize the regulation of the aging mechanism of the first modified polylactic acid.

[0021] In the raw materials of the second modified polylactic acid, anti-aging additives such as antioxidant and anti-ultraviolet agent are included. Without changing the chemical structure of the second polylactic acid resin, the additives can absorb ultraviolet energy and capture oxygen-containing free radicals generated by themselves, so as to inhibit the photodegradation and thermal-oxidative degradation of the second polylactic acid resin.

[0022] In the raw materials of the modified polylactic acid-based non-woven fabric material, the first modified polylactic acid and the second modified polylactic acid are distinguished and prepared separately to avoid simple mixing. If simple mixing is adopted, the anti-aging additives such as antioxidant and anti-ultraviolet agent in the second modified polylactic acid will affect the reaction between the hydrophobic monomer, initiator and first polylactic acid resin. The presence of the anti-aging additives will hinder the generation of free radicals by the initiator to initiate grafting, and ultimately affect the hydrophobicity and anti-aging property of the product modified polylactic acid-based non-woven fabric material. In the present application, the first modified polylactic acid and the second modified polylactic acid are used as independent raw materials. In the preparation of the first modified polylactic acid, the initiator rapidly decomposes to initiate free radical polymerization and free radical grafting, and almost no initiator remains in the first modified polylactic acid. When the first modified polylactic acid and the second modified polylactic acid are mixed to prepare the modified polylactic acid-based non-woven fabric material, the initiator will not naturally contact the anti-aging additives.

[0023] The modified polylactic acid-based non-woven fabric material is a hydrophobic non-woven fabric with good hydrophobicity, which can delay the penetration and hydrolysis of water to the polylactic acid matrix and improve the anti-aging property of the material, thereby prolonging the service life thereof.

[0024] According to one embodiment of the present application, the components of the modified polylactic acid-based non-woven fabric material include the following raw materials for preparation:

[0025] 25-100 parts by weight of the first modified polylactic acid and 1-75 parts by weight of the second modified polylactic acid;

[0026] The components of the first modified polylactic acid include the following raw materials for preparation:

[0027] 1-20 parts by weight of a hydrophobic monomer, 0.005-0.01 parts by weight of an initiator, and 100-150 parts by weight of a first polylactic acid resin;

[0028] The components of the second modified polylactic acid include the following raw materials for preparation:

[0029] 0.1-1 parts by weight of an antioxidant, 0.6-1 parts by weight of an ultraviolet inhibitor, and 95-150 parts by weight of a second polylactic acid resin.

[0030] According to an embodiment of the present application, the hydrophobic monomer includes at least one of a maleic anhydride type monomer and an acrylic ester type monomer.

[0031] According to an embodiment of the present application, the hydrophobic monomer includes at least one of ethyl acrylate, butyl acrylate, octyl acrylate, hydroxyethyl acrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, and hydroxyethyl methacrylate.

[0032] According to an embodiment of the present application, the initiator includes at least one of benzoyl peroxide, azobisisobutyronitrile, and dicumyl peroxide.

[0033] According to an embodiment of the present application, the antioxidant includes at least one of a phosphite type antioxidant and a hindered phenol type antioxidant.

[0034] According to an embodiment of the present application, the phosphite type antioxidant includes at least one of 168 antioxidant and 9228 antioxidant.

[0035] According to an embodiment of the present application, the hindered phenol type antioxidant includes at least one of 1010 antioxidant and 1076 antioxidant.

[0036] According to an embodiment of the present application, the antioxidant includes the phosphite type antioxidant and the hindered phenol type antioxidant in a weight ratio of 1-2:0-2.

[0037] According to an embodiment of the present application, the components of the first modified polylactic acid and / or the second modified polylactic acid further include a polybutylene adipate terephthalate resin as a raw material for preparation. The addition of the polybutylene adipate terephthalate resin can enhance the polylactic acid matrix fiber and improve the mechanical properties without changing the biodegradable properties of the polylactic acid matrix.

[0038] According to an embodiment of the present application, the ratio of the melt indexes of the first and second polylactic acid resins is 10-20:10-20.

[0039] According to an embodiment of the present application, the first and second polylactic acid resins are spinning grade polylactic acid resins.

[0040] According to an embodiment of the present application, the anti-UV agent includes at least one of anti-UV agent 329, anti-UV agent 234 and anti-UV agent 360.

[0041] To solve the second technical problem, the present application adopts the technical solution of:

[0042] A method for preparing the modified polylactic acid-based non-woven fabric material, comprising the following steps:

[0043] Mixing a hydrophobic monomer, an initiator and a first polylactic acid resin, and extruding under heating and pressure to obtain a first mixture;

[0044] Mixing an antioxidant, an anti-UV agent and a second polylactic acid resin, and extruding under heating and pressure to obtain a second mixture;

[0045] Mixing the first mixture and the second mixture, and melt-bonding to prepare a modified polylactic acid-based non-woven fabric material.

[0046] According to an embodiment of the present application, one of the technical solutions has at least one of the following advantages or beneficial effects:

[0047] At present, the modification of existing polylactic acid non-woven fabrics is mostly achieved by introducing different additives, which cannot fundamentally change the inherent structure of polylactic acid, and too many additives will also affect the melt-bonding performance of polylactic acid. The present application changes the chemical structure of polylactic acid in a simple and low-cost way, and realizes the fundamental performance control of polylactic acid.

[0048] In the prior art, due to the poor mixing effect of the spun-bonding equipment, it is generally not used as a reaction extrusion modification reaction equipment. Therefore, if a reaction extrusion modified non-woven fabric material is used, an extrusion equipment (such as a twin-screw extruder) is needed for reaction extrusion and granulation, and then fed into a spun-bonding equipment for melt-bonding to produce a non-woven fabric. In this process, the polymer needs to undergo two heat processes, and the polymer will inevitably be further thermally degraded and aged. If no measures are taken, the performance of the polymer material will also be significantly weakened, and the reaction extrusion modification effect will also be discounted.

[0049] To avoid the above dilemma, the first mixture and the second mixture are prepared separately, two processes are carried out separately, one part of the polylactic acid resin is granulated after heating and pressurized extrusion, and the other part of the polylactic acid resin is blended and granulated with anti-aging additives such as antioxidants and ultraviolet resistance agents, so that the introduction of anti-aging additives will not affect the reaction extrusion modification. Then the first mixture and the second mixture are mixed and fed into the spunbond equipment, the anti-aging additives in the second mixture can protect the modified polylactic acid resin in the first mixture from performance loss caused by secondary heat processing, and ensure the performance of the final polylactic acid non-woven fabric.

[0050] According to an embodiment of the present application, during the preparation of the first mixture and the second mixture, the temperature during heating is 160-180℃.

[0051] According to an embodiment of the present application, during the preparation of the first mixture and the second mixture, the temperature during heating includes but is not limited to: 160℃, 170℃, 180℃.

[0052] According to an embodiment of the present application, the device used for heating and pressurized extrusion includes a double screw extruder.

[0053] According to an embodiment of the present application, the hydrophobic monomer, the initiator and the first polylactic acid resin are mixed, and then left for 12-24 hours before heating and pressurized extrusion.

[0054] According to an embodiment of the present application, examples of the standing time include but are not limited to: 12 hours, 14 hours, 15 hours, 16 hours, 18 hours, 20 hours, 21 hours, 22 hours, 24 hours.

[0055] According to an embodiment of the present application, melt-blown is carried out by using a spunbond equipment.

[0056] According to an embodiment of the present application, during the melt-blown, the temperature of the spunbond equipment is 160-180℃.

[0057] According to an embodiment of the present application, during the melt-blown, the temperature of the spunbond equipment includes but is not limited to: 160℃, 170℃, 180℃.

[0058] Another aspect of the present application also provides a plastic mulch film. The plastic mulch film comprises the modified polylactic acid-based non-woven fabric material according to the above-mentioned first aspect embodiment. Since this application uses all the technical solutions of the above-mentioned modified polylactic acid-based non-woven fabric material, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments.

[0059] Other features and advantages of the present application will be set forth in the description that follows, and in part will be apparent from the description, or can be learned by practice of the application. DETAILED DESCRIPTION

[0060] In the description of the present application, if there is a description to first, second, etc. is only for the purpose of distinguishing technical features, and can not be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or the order of the indicated technical features.

[0061] In the description of the present application, it is to be understood that, in relation to the orientation description, for example, the orientation or position relationship indicated by up, down, etc. is based on the orientation or position relationship shown in the examples, only for the convenience of describing the present application and simplifying the description, and is not to indicate or imply that the device or element indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore can not be understood as a limitation on the present application.

[0062] The words "preferably", "more preferably" and the like in the present application refer to embodiments of the present application which can provide certain benefits in certain situations. However, other embodiments can also be preferred in the same or other situations. In addition, the description of one or more preferred embodiments does not imply that other embodiments are not useful, nor does it imply that these other embodiments are excluded from the scope of the present application.

[0063] When a numerical range is disclosed herein, the above range is considered to be continuous and includes the minimum and maximum values of the range, as well as every value between the minimum and maximum values. Further, when the range refers to integers, every integer between the minimum and maximum values of the range is included. In addition, when multiple ranges are provided to describe a feature or characteristic, the ranges can be combined. In other words, unless otherwise indicated, all ranges disclosed herein should be understood to include any and all sub-ranges subsumed therein.

[0064] The technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0065] The reagents, methods and equipment used in the present application are conventional reagents, methods and equipment in the technical field, unless otherwise specified.

[0066] Example 1

[0067] A modified polylactic acid-based non-woven fabric material, the components of the modified polylactic acid-based non-woven fabric material include the following preparation raw materials:

[0068] A first modified polylactic acid and a second modified polylactic acid;

[0069] The components of the first modified polylactic acid include the following raw materials:

[0070] A hydrophobic monomer, an initiator and a first polylactic acid resin;

[0071] The components of the second modified polylactic acid include the following raw materials:

[0072] Antioxidant, anti-ultraviolet agent, polybutylene adipate / terephthalate resin and second polylactic acid resin.

[0073] Specifically, the hydrophobic monomer includes 20 parts by weight of butyl methacrylate;

[0074] The initiator is 0.005 parts by weight of benzoyl peroxide;

[0075] The polybutylene adipate / terephthalate resin is 5 parts by weight of the polybutylene adipate / terephthalate resin;

[0076] The first polylactic acid resin is 80 parts by weight of polylactic acid;

[0077] Specifically, the anti-ultraviolet agent includes 1 part by weight of anti-ultraviolet agent 329;

[0078] The antioxidant includes 1 part by weight of 168 antioxidant and 1 part by weight of 1010 antioxidant;

[0079] The polybutylene adipate / terephthalate resin is 5 parts by weight of the polybutylene adipate / terephthalate resin;

[0080] The second polylactic acid resin is 95 parts by weight of polylactic acid.

[0081] The preparation of the modified polylactic acid-based non-woven fabric material comprises the following steps:

[0082] (1) mixing an antioxidant, an anti-ultraviolet agent, a polybutylene adipate / terephthalate resin and a second polylactic acid resin, blending the mixture in a mixer, and feeding the mixture into a twin-screw extruder for granulation, wherein the temperature of the twin-screw extruder is 160° C.;

[0083] (2) The hydrophobic monomer, initiator, polybutylene adipate / terephthalate resin and the first polylactic acid resin were blended in a mixer, and after 24 hours, the mixture was fed into a twin-screw extruder for granulation at a temperature of 160° C.;

[0084] (3) The particles obtained in (1) and (2) are blended again by a blender, and the blend is fed into a spunbonding device to be melt-onto-web to produce a modified polylactic acid-based nonwoven fabric material, and the temperature of the partition of the spunbonding device is 160°C.

[0085] The modified polylactic acid-based nonwoven fabric material is taken to prepare a plastic mulch film.

[0086] Example 2

[0087] A modified polylactic acid-based nonwoven fabric material, components of the modified polylactic acid-based nonwoven fabric material include the following preparation raw materials:

[0088] The first modified polylactic acid and the second modified polylactic acid;

[0089] Components of the first modified polylactic acid include the following preparation raw materials:

[0090] The hydrophobic monomer, the initiator and the first polylactic acid resin;

[0091] Components of the second modified polylactic acid include the following preparation raw materials:

[0092] The antioxidant, the ultraviolet inhibitor, the polybutylene adipate terephthalate resin and the second polylactic acid resin.

[0093] Specifically, the hydrophobic monomer includes 15 parts by weight of butyl methacrylate and 5 parts by weight of maleic anhydride;

[0094] The initiator is 0.005 parts by weight of benzoyl peroxide;

[0095] The polybutylene adipate terephthalate resin is 5 parts by weight of polybutylene adipate terephthalate resin;

[0096] The first polylactic acid resin is 80 parts by weight of polylactic acid;

[0097] Specifically, the ultraviolet inhibitor includes 1 part by weight of ultraviolet inhibitor 329;

[0098] The antioxidant includes 1 part by weight of 168 antioxidant and 1 part by weight of 1010 antioxidant;

[0099] The polybutylene adipate terephthalate resin is 5 parts by weight of polybutylene adipate terephthalate resin;

[0100] The second polylactic acid resin is 95 parts by weight of polylactic acid.

[0101] The modified polylactic acid-based nonwoven fabric material is prepared, including the following steps:

[0102] (1) mixing the antioxidant, the anti-ultraviolet agent, the polybutylene adipate terephthalate resin and the second polylactic acid resin, blending by a blender, feeding into a twin-screw extruder for granulation, and the temperature of the twin-screw extruder is 160℃;

[0103] (2) mixing the hydrophobic monomer, the initiator, the polybutylene adipate terephthalate resin and the first polylactic acid resin, blending by a blender, feeding into a twin-screw extruder for granulation after 24 hours, and the temperature of the twin-screw extruder is 160℃;

[0104] (3) re-blending the granules obtained in (1) and (2) by a blender, and feeding the blend into a spunbonding device for melt-blowing to obtain the modified polylactic acid-based non-woven fabric material, and the temperature of the spunbonding device is 160℃.

[0105] The modified polylactic acid-based non-woven fabric material is used to prepare a plastic mulch film.

[0106] Example 3

[0107] A modified polylactic acid-based non-woven fabric material, components of the modified polylactic acid-based non-woven fabric material include the following preparation raw materials:

[0108] a first modified polylactic acid and a second modified polylactic acid;

[0109] Components of the first modified polylactic acid include the following preparation raw materials:

[0110] a hydrophobic monomer, an initiator and a first polylactic acid resin;

[0111] Components of the second modified polylactic acid include the following preparation raw materials:

[0112] an antioxidant, an anti-ultraviolet agent, a polybutylene adipate terephthalate resin and a second polylactic acid resin.

[0113] Specifically, the hydrophobic monomer includes 20 parts by weight of butyl methacrylate;

[0114] The initiator is 0.005 parts by weight of benzoyl peroxide;

[0115] The polybutylene adipate terephthalate resin is 5 parts by weight of polybutylene adipate terephthalate resin;

[0116] The first polylactic acid resin is 100 parts by weight of polylactic acid;

[0117] Specifically, the anti-ultraviolet agent includes 1 part by weight of anti-ultraviolet agent 234;

[0118] The antioxidant includes 1 part by weight of 168 antioxidant and 1 part by weight of 1010 antioxidant;

[0119] The polybutylene adipate terephthalate resin is 5 parts by weight of polybutylene adipate terephthalate resin.

[0120] The second polylactic acid resin is 100 parts by weight of polylactic acid.

[0121] The modified polylactic acid-based nonwoven material is prepared by the following steps:

[0122] (1) mixing the antioxidant, the ultraviolet inhibitor, the polybutylene adipate terephthalate resin and the second polylactic acid resin, blending by a stirrer, feeding into a twin-screw extruder for granulation, and the temperature of the twin-screw extruder is 160℃;

[0123] (2) mixing the hydrophobic monomer, the initiator, the polybutylene adipate terephthalate resin and the first polylactic acid resin, blending by a stirrer after 24 hours, feeding into a twin-screw extruder for granulation, and the temperature of the twin-screw extruder is 160℃;

[0124] (3) re-blending the granules obtained in (1) and (2) by a stirrer, feeding the blend into a spunbonding device for melt-blowing to obtain the modified polylactic acid-based nonwoven material, and the temperature of the spunbonding device is 160℃.

[0125] The modified polylactic acid-based nonwoven material is used to prepare a plastic mulch.

[0126] Example 4

[0127] A modified polylactic acid-based nonwoven material, components of the modified polylactic acid-based nonwoven material include the following preparation raw materials:

[0128] The first modified polylactic acid and the second modified polylactic acid;

[0129] Components of the first modified polylactic acid include the following preparation raw materials:

[0130] The hydrophobic monomer, the initiator and the first polylactic acid resin;

[0131] Components of the second modified polylactic acid include the following preparation raw materials:

[0132] The antioxidant, the ultraviolet inhibitor and the second polylactic acid resin.

[0133] Specifically, the hydrophobic monomer includes 20 parts by weight of butyl methacrylate;

[0134] The initiator is 0.005 parts by weight of benzoyl peroxide;

[0135] The first polylactic acid resin is 100 parts by weight of polylactic acid;

[0136] Specifically, the ultraviolet inhibitor includes 1 part by weight of ultraviolet inhibitor 329;

[0137] Antioxidant includes 1 part by weight of 168 antioxidant and 1 part by weight of 1010 antioxidant;

[0138] The second polylactic acid resin is 100 parts by weight of polylactic acid.

[0139] The modified polylactic acid-based nonwoven material is prepared by the following steps:

[0140] (1) mixing antioxidant, ultraviolet inhibitor and second polylactic acid resin, blending by a stirrer, feeding into a twin-screw extruder for granulation, the temperature of the twin-screw extruder is 160℃;

[0141] (2) mixing hydrophobic monomer, initiator and first polylactic acid resin, blending by a stirrer, feeding into a twin-screw extruder for granulation after 24 hours, the temperature of the twin-screw extruder is 160℃;

[0142] (3) re-blending the granules obtained in (1) (2) by a stirrer, feeding the blend into a spunbonding device for melt-blowing to obtain the modified polylactic acid-based nonwoven material, the temperature of the spunbonding device is 160℃.

[0143] The modified polylactic acid-based nonwoven material is used to prepare a plastic mulch.

[0144] Example 5

[0145] A modified polylactic acid-based nonwoven material, the components of the modified polylactic acid-based nonwoven material include the following preparation raw materials:

[0146] The first modified polylactic acid and the second modified polylactic acid;

[0147] The components of the first modified polylactic acid include the following preparation raw materials:

[0148] Hydrophobic monomer, initiator and first polylactic acid resin;

[0149] The components of the second modified polylactic acid include the following preparation raw materials:

[0150] Antioxidant, ultraviolet inhibitor and second polylactic acid resin.

[0151] Specifically, the hydrophobic monomer includes 20 parts by weight of butyl methacrylate;

[0152] The initiator is 0.005 parts by weight of benzoyl peroxide;

[0153] The first polylactic acid resin is 100 parts by weight of polylactic acid;

[0154] Specifically, the ultraviolet inhibitor includes 1 part by weight of ultraviolet inhibitor 329;

[0155] The antioxidant includes 0.6 parts by weight of antioxidant 168 and 1.4 parts by weight of antioxidant 1010.

[0156] The second polylactic acid resin is 100 parts by weight of polylactic acid.

[0157] The modified polylactic acid-based non-woven fabric material is prepared by the following steps:

[0158] (1) mixing the antioxidant, the ultraviolet inhibitor and the second polylactic acid resin, blending by a stirrer, feeding into a twin-screw extruder for granulation, and the temperature of the twin-screw extruder is 160°C;

[0159] (2) mixing the hydrophobic monomer, the initiator and the first polylactic acid resin by a stirrer, and after 24 hours, feeding into a twin-screw extruder for granulation, and the temperature of the twin-screw extruder is 160°C;

[0160] (3) re-blending the granules obtained in (1) and (2) by a stirrer, and feeding the blend into a spunbonding device for melt-blowing to obtain the modified polylactic acid-based non-woven fabric material, and the temperature of the spunbonding device is 160°C.

[0161] The modified polylactic acid-based non-woven fabric material is used to prepare a plastic mulch film.

[0162] Comparative Example 1

[0163] The difference between Comparative Example 1 and Example 1 is that Comparative Example 1 does not contain the second modified polylactic acid, and the amount of the first modified polylactic acid raw material is different.

[0164] A modified polylactic acid-based non-woven fabric material, the components of the modified polylactic acid-based non-woven fabric material include the following preparation raw materials:

[0165] The first modified polylactic acid;

[0166] The components of the first modified polylactic acid include the following preparation raw materials:

[0167] The hydrophobic monomer, the initiator and the first polylactic acid resin;

[0168] Specifically, the hydrophobic monomer includes 40 parts by weight of butyl methacrylate;

[0169] The initiator is 0.01 parts by weight of benzoyl peroxide;

[0170] The polybutylene adipate terephthalate resin is 10 parts by weight of polybutylene adipate terephthalate resin;

[0171] The first polylactic acid resin is 200 parts by weight of polylactic acid;

[0172] The modified polylactic acid-based non-woven fabric material is prepared by the following steps:

[0173] The hydrophobic monomer, initiator and first polylactic acid resin are blended by a blender, and after 24 hours, fed into a twin-screw extruder for granulation, with a twin-screw extruder temperature of 160°C, and fed into a spunbonding device for melt-bonding to produce a modified polylactic acid-based non-woven fabric material, with a partition temperature of the spunbonding device being 160°C;

[0174] The modified polylactic acid-based non-woven fabric material is taken to prepare a plastic mulch film.

[0175] Comparative Example 2

[0176] Comparative Example 2 differs from Example 1 in that Comparative Example 2 does not contain the first modified polylactic acid, and the amount of the second modified polylactic acid raw material is different.

[0177] A modified polylactic acid-based non-woven fabric material, components of the modified polylactic acid-based non-woven fabric material including the following preparation raw materials:

[0178] Second modified polylactic acid;

[0179] Components of the second modified polylactic acid include the following preparation raw materials:

[0180] Antioxidant, ultraviolet-resistant agent, polybutylene adipate terephthalate resin and second polylactic acid resin.

[0181] Specifically, the ultraviolet-resistant agent includes 2 parts by weight of ultraviolet-resistant agent 329;

[0182] The antioxidant includes 2 parts by weight of 168 antioxidant and 2 parts by weight of 1010 antioxidant;

[0183] The polybutylene adipate terephthalate resin is 10 parts by weight of polybutylene adipate terephthalate resin;

[0184] The second polylactic acid resin is 190 parts by weight of polylactic acid.

[0185] Preparation of the modified polylactic acid-based non-woven fabric material includes the following steps:

[0186] The antioxidant, ultraviolet-resistant agent, polybutylene adipate terephthalate resin and second polylactic acid resin are blended by a blender, fed into a twin-screw extruder for granulation, with a twin-screw extruder temperature of 160°C, and fed into a spunbonding device for melt-bonding to produce a modified polylactic acid-based non-woven fabric material, with a partition temperature of the spunbonding device being 160°C;

[0187] The modified polylactic acid-based non-woven fabric material is taken to prepare a plastic mulch film.

[0188] The amount of each component of Examples 1-5 and Comparative Examples 1-2 is shown in Table 1.

[0189] Table 1

[0190]

[0191] Performance test:

[0192] Mechanical property test standard and test method: according to GB / T 24218.3-2010 standard test, sample size: 50mm*300mm, tensile rate: 300mm / min.

[0193] Melt index is tested according to ASTM D1238, the non-woven fabric sample is cut and fed into the melt index tester.

[0194] Water contact angle test uses KRUSS DSA25 contact angle tester to measure the water contact angle of the sample, 2ul of distilled water is dropped on the sample and stays for 10 seconds, then the test software configured by the equipment is used to measure the contact angle value of the non-woven fabric sample.

[0195] The modified polylactic acid-based non-woven fabric materials of examples 1-5 and comparative examples 1-2 were tested, and the test results are shown in table 2.

[0196] Table 2

[0197]

[0198] From the above table, the tensile strength of all examples can reach 60N, and the elongation can reach more than 110%, with good mechanical properties; after 200h xenon lamp aging, the tensile strength can reach 50N, and the elongation can reach more than 90%, with good aging resistance.

[0199] The difference between example 1 and comparative example 1 is that comparative example 1 does not contain the second modified polylactic acid, and the amount of the first modified polylactic acid raw material is different, and it can be compared that the introduction of the second modified polylactic acid can improve the aging resistance of the non-woven fabric.

[0200] The difference between example 1 and comparative example 2 is that comparative example 2 does not contain the first modified polylactic acid, and the amount of the second modified polylactic acid raw material is different, and it can be compared that the introduction of the first modified polylactic acid can improve the toughness and toughness after aging of the non-woven fabric.

[0201] The difference between examples 1, 2, 3 and examples 4, 5 is that examples 4, 5 do not introduce PBAT, and it can be compared that the introduction of PBAT resin can improve the mechanical properties of the non-woven fabric before and after aging.

[0202] In summary, the first mixture and the second mixture are prepared separately, two processes are carried out separately, a part of the polylactic acid resin is granulated after being extruded by heating and pressurizing, and another part of the polylactic acid resin is granulated by blending with the anti-aging additives such as the antioxidant and the ultraviolet resistance agent, so that the introduction of the anti-aging additives does not affect the reaction extrusion modification. Then the first mixture and the second mixture are mixed and fed into the spunbonding equipment, the anti-aging additives in the second mixture can protect the modified polylactic acid resin in the first mixture from the performance loss caused by the secondary heat processing, and ensure the performance of the final polylactic acid non-woven fabric.

[0203] The above is only an embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent transformation or direct or indirect application in the related technical field by using the content of the present application is also included in the patent protection scope of the present application.

Claims

1. A modified polylactic acid-based nonwoven material, characterized by: The components of the modified polylactic acid-based nonwoven fabric material include the following raw materials by weight: 25-100 parts by weight of a first modified polylactic acid and 1-75 parts by weight of a second modified polylactic acid; The components of the first modified polylactic acid include the following raw materials: 1-20 parts by weight of a hydrophobic monomer, 0.005-0.01 parts by weight of an initiator, and 100-150 parts by weight of a first polylactic acid resin; The components of the second modified polylactic acid include the following raw materials: 0.1-1 parts by weight of an antioxidant, 0.6-1 parts by weight of an ultraviolet light resistant agent, and 95-150 parts by weight of a second polylactic acid resin.

2. The modified polylactic acid-based nonwoven material according to claim 1, wherein: The hydrophobic monomer includes at least one of a maleic anhydride-based monomer and an acrylic ester-based monomer.

3. The modified polylactic acid-based nonwoven material of claim 1, wherein: The hydrophobic monomer includes at least one of ethyl acrylate, butyl acrylate, octyl acrylate, hydroxyethyl acrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, and hydroxyethyl methacrylate.

4. The modified polylactic acid-based nonwoven material of claim 1, wherein: The initiator includes at least one of benzoyl peroxide, azobisisobutyronitrile, and dicumyl peroxide.

5. The modified polylactic acid-based nonwoven material according to claim 1, wherein: The antioxidant includes at least one of a phosphite-based antioxidant and a hindered phenol-based antioxidant.

6. The modified polylactic acid-based nonwoven material according to claim 1, wherein: The components of the first modified polylactic acid and / or the second modified polylactic acid further include the following raw material: a polybutylene adipate terephthalate resin.

7. A method of making a modified polylactic acid-based nonwoven material according to any one of claims 1 to 6, characterized in that: The method includes the following steps: mixing the hydrophobic monomer, the initiator, and the first polylactic acid resin, and extruding under heating and pressure to obtain a first mixture; mixing the antioxidant, the ultraviolet light resistant agent, and the second polylactic acid resin, and extruding under heating and pressure to obtain a second mixture; mixing the first mixture and the second mixture, and melt-bonding to produce the modified polylactic acid-based nonwoven fabric material.

8. The method of claim 7, wherein: During the preparation of the first mixture and the second mixture, the temperature during heating is 160-180°C.

9. A plastic mulch film characterized by: A modified polylactic acid-based nonwoven fabric material as claimed in any one of claims 1 to 6.

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