Pbat / pla sheath-core composite fiber, preparation method thereof and sanitary product

Abstract

The application discloses a kind of PBAT / PLA skin-core composite fibers and preparation method and sanitary products, belong to PBAT / PLA skin-core composite fibers technical field, overcome the problem of poor compatibility of PBAT and PLA in the preparation process of PBAT / PLA skin-core composite fibers in prior art.The preparation method of the PBAT / PLA skin-core composite fibers of the application includes: S1, using one of ester group-containing furan derivatives and ester group-containing anhydride derivatives to modify PLA, to obtain modified PLA;Using the other of ester group-containing furan derivatives and ester group-containing anhydride derivatives to modify PBAT, to obtain modified PBAT;S2, using the modified PLA and the modified PBAT are spun.The skin layer and core layer of the skin-core composite fibers prepared by the application realize long-term compatibilization.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of PBAT / PLA sheath-core composite fibers, and particularly relates to a PBAT / PLA sheath-core composite fiber, a preparation method thereof and a sanitary product. BACKGROUND

[0002] With the improvement of people's living standards, sanitary materials have entered the fourth generation, that is, the direction of pursuing more relaxed, softer and more comfortable, especially in baby diapers and disposable sanitary products. High-grade hot air non-woven fabrics made of ES (Ethylene-Propylene Side By Side) fibers have become the main raw materials. ES fibers are sheath-core composite fibers composed of two different high molecular materials, which have the characteristics of good softness, low outer layer melting point, high inner layer melting point and high strength. After reprocessing heat treatment, part of the skin layer is fused and bonded, and the remaining fibers remain in a fiber state, which not only maintains the characteristics of fiber fluffiness and softness, but also does not damage the structure of the fibers, has very high strength, and is particularly suitable for producing sanitary materials, thermal insulation fillers, filter materials and other products. Currently, ES fibers on the market are mainly PE / PP composite fibers and PE / PET composite fibers. Since these materials have poor biodegradability, they will cause pollution to the environment after being discarded. Therefore, the research and development of ES fibers based on biodegradable materials and disposable sanitary products have great significance for environmental protection and the development of green and sustainable economy.

[0003] Poly(butylene terephthalate-co-ethylene terephthalate) (PBAT for short) has become a kind of biodegradable plastic composition that is currently the focus of research because of its excellent toughness and fatigue resistance, high impact strength, and excellent biodegradability. In addition, polylactic acid (PLA for short) has good biodegradability, high mechanical strength, and simple processing, and can be produced using biomass starch and other resources, making it an ideal biobased degradable engineering plastic. In order to compensate for the brittleness of PLA, flexible PBAT is currently introduced to improve the toughness of the material. Although the properties of these two materials can complement each other, it is found during use that due to the large structural difference between the two materials, the compatibility of the two after blending is poor, greatly reducing the strength of the blended material, reducing the toughening effect, and resulting in the performance of the blended material being lower than expected.

[0004] In order to improve the interaction between PLA and PBAT, the compatibility of the blend can be improved by modification methods, thereby improving the comprehensive performance of the material. The main methods for compatibilization currently adopted include adding inorganic materials, chain extenders, compatibilizers, natural polymer compounds, and nano-material modification, etc. However, considering the processing and forming of the PBAT / PLA sheath-core composite fiber, the above methods will have a great impact on the spinnability. Specifically, since the two plastics are respectively melt-extruded by a single screw extruder and then delivered to the spinning assembly by a metering pump, the two melts are combined at the spinneret plate of the composite spinning assembly and then are extruded through the spinneret holes, and then are wound at a certain spinning speed. Therefore, the reaction time of the two melts at the spinneret holes is short, and the efficient and rapid compatibilization reaction cannot occur. In addition, using the above modification methods of adding substances, new interface layers are easily generated and defects are easily produced, further reducing the spinnability and winding speed of the ES fiber.

[0005] In summary, for the compatibility problem of the ES fiber mentioned above, the prior art cannot achieve rapid compatibilization of the PBAT / PLA sheath-core composite fiber. SUMMARY

[0006] Therefore, the technical problem to be solved by the present application is to overcome the poor compatibility of PBAT and PLA in the preparation process of the PBAT / PLA sheath-core composite fiber in the prior art, so as to provide a PBAT / PLA sheath-core composite fiber, a preparation method thereof, and a sanitary product.

[0007] To this end, the present application provides the following technical solutions.

[0008] In a first aspect, the present application provides a preparation method of a PBAT / PLA sheath-core composite fiber, comprising:

[0009] S1, modifying PLA by using one of an ester group-containing furan derivative and an ester group-containing anhydride derivative to obtain modified PLA;

[0010] S2, modifying PBAT by using the other of the ester group-containing furan derivative and the ester group-containing anhydride derivative to obtain modified PBAT;

[0011] S2, spinning by using the modified PLA and the modified PBAT.

[0012] In a possible implementation, S1, PLA is modified by using an ester group-containing furan derivative to form furanized PLA;

[0013] S2, modifying PBAT by using the other of the ester group-containing furan derivative and the ester group-containing anhydride derivative to obtain modified PBAT;

[0014] S2, spinning the anhydridized PLA and the furanized PBAT.

[0015] In one possible implementation, S1, modifying the PLA with an ester group-containing anhydride derivative to form an anhydridized PLA;

[0016] modifying the PBAT with an ester group-containing furan derivative to form a furanized PBAT;

[0017] S2, spinning the anhydridized PLA and the furanized PBAT.

[0018] In one possible implementation, the step of modifying the PLA with one of the ester group-containing furan derivative and the ester group-containing anhydride derivative to obtain a modified PLA comprises: performing an ester exchange reaction between the ester group-containing furan derivative or the ester group-containing anhydride derivative and the PLA;

[0019] Preferably, the ester group-containing furan derivative or the ester group-containing anhydride derivative and the PLA are first melt blended;

[0020] Preferably, the molar ratio of the ester group-containing furan derivative or the ester group-containing anhydride derivative to the PLA is (2-8):(8-2);

[0021] Preferably, the conditions of the first melt blending comprise: a blending time of 10 min-45 min and a temperature of 150°C-210°C; further, a screw rotation speed of 60 r / min-100 r / min;

[0022] Preferably, before the first melt blending, the ester group-containing furan derivative or the ester group-containing anhydride derivative and the PLA are dried respectively;

[0023] Preferably, the drying conditions for drying the ester group-containing furan derivative or the ester group-containing anhydride derivative and the PLA respectively comprise: a temperature of 70°C-100°C and a time of 12 h-14 h.

[0024] In one possible implementation, the ester group-containing furan derivative has a structural formula as shown in the following:

[0025] wherein, R1 is selected from a substituted or unsubstituted aromatic group or a substituted or unsubstituted alkylene chain, and R2 is a substituted or unsubstituted alkylene chain;

[0026] Preferably, R1 is selected from a substituted or unsubstituted phenyl group or a substituted or unsubstituted C1-C10 alkylene chain, and R2 is a substituted or unsubstituted C1-C10 alkylene chain;

[0027] Preferably, R1 is selected from unsubstituted phenyl or unsubstituted C1-C10 alkylene chain, and R2 is unsubstituted C1-C10 alkylene chain;

[0028] More preferably, R1 is selected from unsubstituted phenyl or unsubstituted C2-C8 alkylene chain, and R2 is unsubstituted C2-C8 alkylene chain;

[0029] In a possible implementation, the ester group-containing anhydride derivative has the following structure:

[0030] wherein R3 is selected from substituted or unsubstituted aromatic group or substituted or unsubstituted alkylene chain;

[0031] Preferably, R3 is selected from substituted or unsubstituted phenyl or substituted or unsubstituted C1-C10 alkylene chain, more preferably, R3 is selected from unsubstituted phenyl or unsubstituted C1-C10 alkylene chain, and most preferably, R3 is selected from unsubstituted phenyl or unsubstituted C2-C8 alkylene chain.

[0032] In a possible implementation, the step of modifying PBAT by using the other one of the ester group-containing furan derivative and the ester group-containing anhydride derivative to obtain modified PBAT comprises: performing transesterification reaction between the ester group-containing anhydride derivative or the ester group-containing furan derivative and PBAT;

[0033] Preferably, the ester group-containing anhydride derivative or the ester group-containing furan derivative and the PBAT are subjected to a second melt blending;

[0034] Preferably, the molar ratio of the ester group-containing anhydride derivative or the ester group-containing furan derivative to the PBAT is (2-8):(8-2);

[0035] Preferably, the conditions of the second melt blending comprise: a blending time of 10 min-45 min and a temperature of 150°C-210°C; further, a screw rotation speed of 60 r / min-100 r / min;

[0036] Preferably, before the second melt blending, the ester group-containing anhydride derivative or the ester group-containing furan derivative and the PBAT are dried respectively;

[0037] Preferably, the conditions of drying the ester group-containing anhydride derivative or the ester group-containing furan derivative and the PBAT respectively comprise: a temperature of 70°C-100°C and a time of 12 h-14 h.

[0038] In a possible implementation, the core layer raw material for forming the core layer of the PBAT / PLA sheath-core composite fiber comprises the modified PLA;

[0039] The sheath material for forming the sheath layer of the PBAT / PLA sheath-core composite fiber comprises the modified PBAT;

[0040] The spinning is performed according to a bi-component spinning process.

[0041] Preferably, in the bi-component spinning process, the sheath melt extrusion temperature is 190-220 DEG C, the core melt extrusion temperature is 195-220 DEG C, the number of spinneret holes is 36-100, the spinning temperature is 195-210 DEG C, and the spinning speed is 500-3000 m / min.

[0042] In a possible implementation, the core material further comprises PLA, and the amount of the modified PLA is 2-20% of the mass of the PLA.

[0043] Preferably, the sheath material further comprises PBAT, and the amount of the modified PBAT is 2-20% of the mass of the PBAT.

[0044] Preferably, the mass ratio of the core material to the sheath material is (3:7)-(7:3).

[0045] Preferably, before the spinning, the core material and the sheath material are dried respectively.

[0046] Preferably, the drying conditions for the core material and the sheath material respectively comprise a temperature of 70-100 DEG C and a time of 12-14 h.

[0047] In a second aspect, the application provides a PBAT / PLA sheath-core composite fiber prepared by the preparation method of the PBAT / PLA sheath-core composite fiber.

[0048] In a third aspect, the application provides a sanitary product comprising the PBAT / PLA sheath-core composite fiber.

[0049] The technical scheme of the application has the following advantages:

[0050] 1. The preparation method of the PBAT / PLA sheath-core composite fiber comprises: S1, modifying PLA by using one of an ester group-containing furan derivative and an ester group-containing acid anhydride derivative to obtain modified PLA, and modifying PBAT by using the other of the ester group-containing furan derivative and the ester group-containing acid anhydride derivative to obtain modified PBAT; S2, performing spinning by using the modified PLA and the modified PBAT.

[0051] The application adopts modified PLA and modified PBAT to prepare PBAT / PLA skin-core composite fibers, when ester-based furan derivatives are used to modify PLA, ester-based anhydride derivatives are used to modify PBAT; when ester-based anhydride derivatives are used to modify PLA, ester-based furan derivatives are used to modify PBAT. Through temperature-induced DA reaction of diene on furanized PLA and monoene on anhydridized PBAT in the spinning process, or temperature-induced DA reaction of diene on furanized PBAT and monoene on anhydridized PLA in the spinning process, the problem of phase separation of PBAT and PLA segments caused by poor compatibility is effectively solved; the peeling between the skin layer and the core layer of the composite fiber in the spinning process is effectively alleviated, the rapid compatibility of the skin layer and the core layer in the melt spinning process is realized, the spinnability and the spinning speed of the skin-core composite fiber are greatly improved, which is beneficial to the industrialized continuous production; at the same time, the skin layer and the core layer of the prepared skin-core composite fiber will not separate with time, long-term compatibilization is realized; without adding additional fillers and other compatibilizers, the problems of low spinnability and safety of compatibilization materials caused by the residues of the modifiers in the fiber processing and molding process are effectively avoided. BRIEF DESCRIPTION OF DRAWINGS

[0052] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed in the following specific embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0053] Figure 1 The synthesis path of PLA-FU provided for the present application embodiment 1, embodiment 2;

[0054] Figure 2 The synthesis path of PBAT-AA provided for the present application embodiment 1, embodiment 2;

[0055] Figure 3 The reaction equation of the interface compatibilization of the PBAT / PLA skin-core composite fiber provided for the present application embodiment 1, embodiment 2;

[0056] Figure 4 The optical microscope morphology diagram of the PBAT / PLA skin-core composite fiber provided for the present application embodiment 1-embodiment 3;

[0057] Figure 5 The scanning electron microscope morphology diagram of the PBAT / PLA skin-core composite fiber provided for the present application embodiment 1-embodiment 3. DETAILED DESCRIPTION

[0058] The following examples are provided to better further understand the present application and are not limited to the best mode for carrying out the present application, and do not constitute limitations on the content and protection scope of the present application. Any product that is the same as or similar to the present application obtained by anyone under the inspiration of the present application or by combining the present application with other prior art features falls within the protection scope of the present application.

[0059] When the specific experimental steps or conditions are not indicated in the examples, the operations or conditions can be carried out according to the conventional experimental steps described in the literature in the art. When the reagents or instruments used are not indicated by the manufacturer, they are all conventional reagent products that can be obtained by purchase on the market.

[0060] In a first aspect, the present application provides a preparation method of a PBAT / PLA sheath-core composite fiber, comprising: modifying PLA by using an ester group-containing furan derivative (hereinafter referred to as FU) to form furanized PLA (hereinafter referred to as PLA-FU); modifying PBAT by using an ester group-containing anhydride derivative (hereinafter referred to as AA) to form anhydridized PBAT (hereinafter referred to as PBAT-AA); and spinning the furanized PLA and the anhydridized PBAT.

[0061] Among them, the PLA-FU includes a double bond, and the PBAT-AA contains a single bond. In the spinning process, the single and double bonds undergo temperature-induced DA reaction, so that the PLA and the PBAT can be fully connected, thereby improving the poor compatibility caused by the large structural difference between the PLA and the PBAT in the prior art, and then the phase separation problem, and finally improving the performance of the PBAT / PLA sheath-core composite fiber.

[0062] Specifically, the preparation process is as follows:

[0063] S1, forming PLA-FU;

[0064] The ester group-containing furan derivative and the PLA are subjected to an ester exchange reaction to form PLA-FU, and the specific steps include: drying FU and PLA at 70-100°C in a vacuum oven for 12-24h, and then melt blending the two, for example, using an internal mixer for melt blending, and the conditions are set as follows: the screw rotation speed is 60-100r / min; the blending time is 10-45min, and the temperature is 150-210°C; wherein the molar ratio of FU to PLA is (2-8):(8-2).

[0065] The molar mass of PLA = m1 / Mw1, where m1 is the mass of PLA, and Mw1 is the weight average molecular weight of PLA.

[0066] The structure of the ester group-containing furan derivative is as follows:

[0067] R1is selected from substituted or unsubstituted aromatic groups or substituted or unsubstituted alkylene chains, preferably R1is selected from substituted or unsubstituted phenyl groups or substituted or unsubstituted C1-C10 alkylene chains, further preferably R1is selected from unsubstituted phenyl groups or unsubstituted C1-C10 alkylene chains, more preferably R1is selected from unsubstituted phenyl groups or unsubstituted C2-C8 alkylene chains. For example, R1is phenyl or -(CH2) n n is 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10.

[0068] R2is a substituted or unsubstituted alkylene chain; preferably R2is an unsubstituted C1-C10 alkylene chain; more preferably R2is a substituted or unsubstituted C2-C8 alkylene chain.

[0069] It should be noted that the above-mentioned ester-containing furan derivative, i.e. FU, can be any ester-containing furan, and the ester-containing furan derivative of the present application is only an example of the embodiment of the present application.

[0070] The equipment used for melt blending can be a mixer, and can also be other equipment that can realize melt blending in the prior art.

[0071] S2, forming PBAT-AA;

[0072] The ester exchange reaction of the ester-containing anhydride derivative and PBAT is carried out. Specifically, the AA and PBAT resin are dried in a vacuum oven at 70-100°C for 12-24h, and the AA and the PBAT are melt blended; for example, melt blending is carried out by using a mixer, and the conditions are set as follows: the screw rotation speed is 60-100r / min; the blending time is 10-45min, and the temperature is 150-210°C; wherein the molar ratio of AA to PBAT is (2-8):(8-2).

[0073] The molar mass of PBAT = m2 / Mw2, wherein m2 is the mass of PBAT, and Mw2 is the weight average molecular weight of PBAT.

[0074] The structure of the ester-containing anhydride derivative is as follows:

[0075] R3is selected from substituted or unsubstituted aromatic groups or substituted or unsubstituted alkylene chains; preferably R3is selected from substituted or unsubstituted phenyl groups or substituted or unsubstituted C1-C10 alkylene chains, more preferably R3is selected from unsubstituted phenyl groups or unsubstituted C1-C10 alkylene chains, and most preferably R3is selected from unsubstituted phenyl groups or unsubstituted C2-C8 alkylene chains.

[0076] For example, R3is phenyl or -(CH2) n n is 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10.

[0077] It should be noted that the above-mentioned ester group-containing anhydride derivative, i.e., AA, can adopt any ester group-containing anhydride, and the ester group-containing anhydride derivative of the present application is only an example of the embodiment of the present application.

[0078] The equipment used for melt blending can be a mixer, and can also be other equipment capable of achieving melt blending in the prior art.

[0079] S3, forming a PBAT / PLA sheath-core composite fiber;

[0080] PBAT and PBAT-AA are used as the sheath layer raw materials for forming the sheath layer. Specifically, PBAT and PBAT-AA are physically blended, wherein the amount of PBAT-AA accounts for 2%-20% of the mass of PBAT.

[0081] PLA and PLA-FU are used as the core layer raw materials for forming the core layer. Specifically, PLA and PLA-FU are physically blended, wherein the amount of PLA-FU accounts for 2-20% of the mass of PLA.

[0082] The above-mentioned PBAT, PBAT-AA, PLA and PLA-FU are dried in a vacuum oven at 70-100℃ for 12-24h. It can be understood that the above-mentioned four materials can be dried respectively, or the core layer raw materials formed by physically blending PLA and PLA-FU can be dried together, or the sheath layer raw materials formed by physically blending PBAT and PBAT-AA can be dried together.

[0083] Then, a PBAT / PLA sheath-core composite fiber is prepared according to a two-component spinning process. The sheath layer extrusion temperature is 190-220℃, the core layer melt extrusion temperature is 195-220℃, the number of spinneret holes is 36-100, the spinning temperature is 195-210℃, the spinning speed is 500-3000m / min, and the mass ratio of the core layer raw materials to the sheath layer raw materials is (3:7)-(7:3).

[0084] The embodiment of the present application utilizes temperature to induce the dynamic bond between the molecular chains of PLA-FU and PBAT-AA, i.e., Diels-Alder (DA) bond, to achieve long-term compatibility of the PBAT / PLA two-component sheath-core composite fiber. Specifically, the reversible DA bond inside PLA-FU and PBAT-AA is activated under the stimulation of a given temperature and absorbs energy from the outside, so as to achieve rapid and effective compatibilization of the interface of the PBAT / PLA sheath-core composite fiber in the melt spinning process through the way of DA bond breaking and bonding, thereby making the sheath layer and the core layer of the prepared sheath-core composite fiber not to be phase-separated with the passage of time, and realizing long-term compatibilization. DThe temperature for the DA reaction is approximately 120-210℃. During the spinning and hot stretching processes, this is the reverse reaction. However, as the temperature decreases, the furan in PLA-FU and the anhydride in PBAT-AA undergo the DA reaction for compatibilization, which is the forward reaction. Furthermore, as can be seen from the above preparation method, the preparation method provided in this embodiment of the invention uses only four raw materials: PLA-FU, PBAT-AA, PBAT, and PLA, without requiring the addition of fillers or other compatibilizers. This effectively avoids problems such as low spinnability and safety of compatibilizer materials caused by residual modifiers during fiber processing.

[0085] In one possible implementation, PLA can be modified with an ester-containing acid anhydride derivative to obtain anhydride-modified PLA (i.e., PLA-AA), and PBAT can be modified with an ester-containing furan derivative to obtain furan-modified PBAT (i.e., PBAT-FU). The preparation methods will not be described in detail here.

[0086] Secondly, the present invention provides a PBAT / PLA core-sheath composite fiber, which is prepared by the preparation method of PBAT / PLA core-sheath composite fiber described in any of the foregoing embodiments.

[0087] Specifically, the PBAT / PLA core-sheath composite fiber includes a sheath layer and a core layer. The sheath layer wraps around the core layer. The raw materials forming the sheath layer are composed of PBAT-AA and PBAT, and the raw materials forming the core layer are composed of PLA-FU and PLA.

[0088] Thirdly, the present invention provides a hygiene product prepared from the PBAT / PLA core-sheath composite fibers described in the foregoing embodiments. This hygiene product can be, for example, baby diapers or feminine hygiene pads.

[0089] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0090] Source of raw materials

[0091] FU1: Shenzhen Aituo Chemical Co., Ltd.;

[0092] FU2: Shenzhen Aituo Chemical Co., Ltd.;

[0093] AA1: Shanghai Hans Chemical Co., Ltd.;

[0094] AA2: Shanghai Hans Chemical Co., Ltd.;

[0095] PLA: Mw is 80,000-100,000, Wanhua Chemical Group Co., Ltd.

[0096] PBAT: Mw is 60000-80000, Wanhua Chemical Group Co., Ltd.

[0097] Example 1

[0098] The present embodiment provides a preparation method of a PBAT / PLA sheath-core composite fiber (denoted as PBAT-PLA-1), comprising:

[0099] S1, forming PLA-FU1;

[0100] FU1 and PLA resin were dried in a vacuum oven at 70°C for 12h, and then FU1 and PLA resin were melt blended by using an internal mixer to prepare PLA-FU1, the screw rotation speed was set to 60r / min, the blending molar ratio of FU1 to PLA was 2:8, the blending time was 10min, and the blending temperature was 150°C, to obtain PLA-FU1. The structural formula of FU1 and the structural formula and synthesis path of PLA-FU1 are shown in Figure 1 .

[0101] S2, forming PBAT-AA1;

[0102] AA1 and PBAT resin were dried in a vacuum oven at 80°C for 12h, and then AA1 and PBAT resin were melt blended by using an internal mixer to prepare PBAT-AA1, the screw rotation speed was set to 60r / min, the blending mass ratio of AA1 to PBAT was 2:8, the blending time was 10min, and the blending temperature was 150°C, to obtain PBAT-AA1. The structural formula of AA1, the structural formula and synthesis path of PBAT-AA1 are shown in Figure 2 .

[0103] S3, forming PBAT / PLA sheath-core composite fiber;

[0104] PLA-FU1, PLA, PBAT-AA1 and PBAT were dried in a vacuum oven at 70°C for 12h. PBAT and PBAT-AA1 were physically blended to form a sheath layer raw material, wherein the amount of PBAT-AA1 accounted for 5% of the mass of PBAT. PLA and PLA-FU1 were physically blended to form a core layer raw material, wherein the amount of PLA-FU1 accounted for 5% of the mass of PLA.

[0105] Then, PBAT / PLA sheath-core composite fiber was prepared according to a two-component spinning process. The sheath extrusion temperature was 190°C, the core melt extrusion temperature was 195°C; the number of spinneret holes was 36, the spinning temperature was 195°C, and the spinning speed was 500m / min. The synthesis path of PLA-FU1 and PBAT-AA1 is shown in Figure 3The mass ratio of the sheath layer raw material and the core layer raw material is 3:7.

[0106] Embodiment 2

[0107] The embodiment provides a preparation method of a PBAT / PLA sheath-core composite fiber (denoted as PBAT-PLA-2), which comprises the following steps:

[0108] S1, forming PLA-FU2;

[0109] The FU2 and the PLA resin are respectively dried in a vacuum oven at 85 DEG C for 18 hours, and then the FU2 and the PLA resin are melt blended by using a banbury mixer to prepare the PLA-FU2, the screw rotation speed is set to 90 r / min, the blending molar ratio of the FU2 to the PLA is 5:5, the blending time is 30 min, and the blending temperature is 180 DEG C, so that the PLA-FU2 is obtained. Figure 1 .

[0110] S2, forming PBAT-AA2;

[0111] The AA2 and the PBAT resin are respectively dried in a vacuum oven at 85 DEG C for 18 hours, and then the AA2 and the PBAT resin are melt blended by using a banbury mixer to prepare the PBAT-AA2, the screw rotation speed is set to 60 r / min, the blending mass ratio of the AA2 to the PBAT is 5:5, the blending time is 30 min, and the blending temperature is 180 DEG C, so that the PBAT-AA2 is obtained. Figure 2 .

[0112] S3, forming a PBAT / PLA sheath-core composite fiber;

[0113] The PLA-FU2, the PLA, the PBAT-AA2 and the PBAT are respectively dried in a vacuum oven at 70 DEG C for 18 hours. The PBAT and the PBAT-AA2 are physically blended to form a sheath layer raw material, wherein the amount of the PBAT-AA2 accounts for 5% of the mass of the PBAT. The PLA and the PLA-FU2 are physically blended to form a core layer raw material, wherein the amount of the PLA-FU2 accounts for 5% of the mass of the PLA.

[0114] Then, the PBAT / PLA sheath-core composite fiber is prepared according to a double-component spinning process. The sheath layer extrusion temperature is 205 DEG C, the core layer melt extrusion temperature is 210 DEG C, the number of spinneret holes is 70, the spinning temperature is 200 DEG C, and the spinning speed is 1500 m / min. Figure 3 The mass ratio of the sheath layer raw material and the core layer raw material is 5:5.

[0115] Example 3

[0116] The embodiment provides a preparation method of a PBAT / PLA pia-core composite fiber (denoted as PBAT-PLA-3), which comprises the following steps:

[0117] S1, forming PLA-FU2;

[0118] The FU2 and the PLA resin are dried in a vacuum oven at 100 DEG C. for 24 hours respectively, and then the FU2 and the PLA resin are melt blended by using an internal mixer to prepare the PLA-FU2, the screw rotation speed is set to 100 r / min, the blending molar ratio of the FU2 to the PLA is 5:5, the blending time is 30 min, and the blending temperature is 180 DEG C., so that the PLA-FU2 is obtained.

[0119] S2, forming PBAT-AA2;

[0120] The AA2 and the PBAT resin are dried in a vacuum oven at 80 DEG C. for 24 hours respectively, and then the AA2 and the PBAT resin are melt blended by using an internal mixer to prepare the PBAT-AA2, the screw rotation speed is set to 100 r / min, the blending mass ratio of the AA2 to the PBAT is 5:5, the blending time is 30 min, and the blending temperature is 210 DEG C., so that the PBAT-AA2 is obtained.

[0121] S3, forming a PBAT / PLA pia-core composite fiber;

[0122] The PLA-FU2, the PLA, the PBAT-AA2 and the PBAT are dried in a vacuum oven at 100 DEG C. for 24 hours respectively. The PBAT and the PBAT-AA2 are physically blended to form a pia layer raw material, wherein the amount of the PBAT-AA2 accounts for 20% of the mass ratio of the PBAT. The PLA and the PLA-FU2 are physically blended to form a core layer raw material, wherein the amount of the PLA-FU2 accounts for 20% of the mass of the PLA.

[0123] Then, the PBAT / PLA pia-core composite fiber is prepared according to a double-component spinning process. The pia layer extrusion temperature is 220 DEG C., the core layer melt extrusion temperature is 220 DEG C., the number of spinneret holes is 3000, the spinning temperature is 210 DEG C., and the spinning speed is 3000 m / min. The mass ratio of the pia layer raw material to the core layer raw material is 7:3.

[0124] Example 4

[0125] The embodiment provides a preparation method of a PBAT / PLA pia-core composite fiber (denoted as PBAT-PLA-4), which comprises the following steps:

[0126] S1, forming PLA-AA1;

[0127] AA1 and PLA resin were dried in a vacuum oven at 70℃ for 12h, and then PLA-AA1 was prepared by melt blending AA1 and PLA resin using an internal mixer, with screw rotation speed of 60r / min, blending molar ratio of AA1 to PLA of 2:8, blending time of 10min and blending temperature of 150℃, to obtain PLA-AA1.

[0128] S2, forming PBAT-FU1;

[0129] FU1 and PBAT resin were dried in a vacuum oven at 80℃ for 12h, and then PBAT-FU1 was prepared by melt blending FU1 and PBAT resin using an internal mixer, with screw rotation speed of 60r / min, blending mass ratio of FU1 to PBAT of 2:8, blending time of 10min and blending temperature of 150℃, to obtain PBAT-FU1.

[0130] S3, forming PBAT / PLA sheath-core composite fiber;

[0131] PLA-AA1, PLA, PBAT-FU1 and PBAT were dried in a vacuum oven at 70℃ for 12h. PBAT and PBAT-FU1 were physically blended to form sheath layer raw material, wherein the amount of PBAT-FU1 accounted for 5% of the mass of PBAT. PLA and PLA-AA1 were physically blended to form core layer raw material, wherein the amount of PLA-AA1 accounted for 5% of the mass of PLA.

[0132] Then, PBAT / PLA sheath-core composite fiber was prepared according to the double-component spinning process. The sheath layer extrusion temperature was 190℃, and the core layer melt extrusion temperature was 195℃. The number of spinneret holes was 36, the spinning temperature was 195℃, and the spinning speed was 500m / min. The mass ratio of sheath layer raw material to core layer raw material was 3:7.

[0133] Comparative Example 1

[0134] This comparative example provides a preparation method of PBAT / PLA sheath-core composite fiber (denoted as PBAT-PLA), comprising:

[0135] PBAT and PLA were not subjected to modification treatment, the sheath layer raw material was only PBAT, and the core layer raw material was only PLA. PBAT / PLA sheath-core composite fiber was prepared according to the double-component spinning process. The sheath layer extrusion temperature was 190℃, and the core layer melt extrusion temperature was 195℃. The number of spinneret holes was 36, the spinning temperature was 195℃, and the spinning speed was 500m / min. The mass ratio of sheath layer raw material to core layer raw material was 3:7.

[0136] Comparative Example 2

[0137] PBAT / PLA sheath-core composite fibers were prepared according to the preparation method provided in Example 1, with the difference being that the sheath material was formed by PBAT and PBAT-AA1, the core material was only PLA, and other conditions and proportions were consistent with Example 1.

[0138] Comparative Example 3

[0139] PBAT / PLA sheath-core composite fibers were prepared according to the preparation method provided in Example 1, with the difference being that the sheath material was only PBAT, the core material was formed by PLA-FU1 and PLA, and other conditions and proportions were consistent with Example 1.

[0140] Test Example 1

[0141] The PBAT / PLA sheath-core composite fibers of Examples 1-3 and Comparative Example 1 were subjected to optical microscope testing, and the morphology diagram is shown in Figure 4 .

[0142] The PBAT / PLA sheath-core composite fibers of Examples 1-3 and Comparative Example 1 were subjected to scanning electron microscope testing, and the morphology diagram is shown in Figure 5 .

[0143] According to Figure 4 and Figure 5 , it can be known that the sheath-core interface of the PBAT / PLA sheath-core composite fibers of Comparative Example 1 is relatively obvious, so that phenomena such as separation of the sheath and core layers and rupture of the sheath layer will occur in subsequent heat stretching, directly affecting the mechanical properties and subsequent use performance of the sheath-core composite fibers. The PBAT / PLA sheath-core composite fibers provided by the examples of the present application obviously improve the interface between PBAT and PLA, and the interfacial compatibility between the sheath and core layers is good, and there is no visible interface gap.

[0144] Test Example 2

[0145] Examples 1-4 and Comparative Examples 1-3 were subjected to mechanical property testing, and the results are shown in Tables 1, 2 and 3. Test method: a fiber strength tester (model: XQ-1, Shanghai Xinjian Instrument Co., Ltd.) was used to test the mechanical properties of the fibers, the test temperature was 25°C, the clamping distance was 20 mm, the tensile speed was 10 mm / min, 20 single fibers were taken for testing for each group of samples, and the average value was taken as the final test result.

[0146] Table 1 Mechanical properties after 1 day

[0147]

[0148] Table 2 Fiber mechanical properties after 30 days

[0149]

[0150] Table 3 Mechanical properties of fibers after 180 days

[0151]

[0152] According to Table 1, in Comparative Examples 1-3, if PBAT / PLA sheath-core composite fibers without adding PBAT-AA or PLA-FU, the breaking strength thereof is 2.34, 2.01, 1.99 cN / dtex, and the elongation at break thereof is only 30.21%, 28.6%, 29.33%, respectively. However, the PBAT / PLA sheath-core composite fibers prepared by the present application have an elongation at break of about 2 times, and the breaking strength thereof is also improved, which indicates that the DA reaction between anhydridized PBAT and furanized PLA and between anhydridized PLA and furanized PBAT in the spinning process improves the interface compatibility of the composite fibers. In addition, the mechanical properties and elongation at break of the sheath-core composite fibers prepared in Examples 1-4 after 30 days and 180 days are comparable to the breaking strength and elongation at break data after 1 day, which indicates that the method of the present application can realize long-term compatibilization of the interface of the composite fibers.

[0153] Obviously, the above examples are only examples for clearly illustrating but not limiting the embodiments. For those skilled in the art, other different forms of changes or variations can be made on the basis of the above description. Here, all the embodiments need not and cannot be exhausted. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A method for producing a PBAT / PLA sheath-core composite fiber, characterized by, The method comprises the following steps: S1, modifying PLA by using one of an ester group-containing furan derivative and an ester group-containing anhydride derivative to obtain modified PLA; The step of modifying PLA by using one of the ester group-containing furan derivative and the ester group-containing anhydride derivative to obtain modified PLA comprises: performing first melt blending of the ester group-containing furan derivative or the ester group-containing anhydride derivative and the PLA to perform an ester exchange reaction; PBAT is modified by using the other of the ester group-containing furan derivative and the ester group-containing anhydride derivative to obtain modified PBAT; the step of modifying PBAT by using the other of the ester group-containing furan derivative and the ester group-containing anhydride derivative to obtain modified PBAT comprises: performing second melt blending of the ester group-containing anhydride derivative or the ester group-containing furan derivative and PBAT to perform an ester exchange reaction; S2, spinning the modified PLA and the modified PBAT; The core layer raw material for forming the core layer of the PBAT / PLA sheath-core composite fiber comprises the modified PLA and PLA, and the amount of the modified PLA is 2%-20% of the mass of PLA in S2; The skin layer raw material for forming the skin layer of the PBAT / PLA sheath-core composite fiber comprises the modified PBAT and PBAT, and the amount of the modified PBAT is 2%-20% of the mass of PBAT in S2; The structure of the ester group-containing furan derivative is as follows: wherein R1is selected from a substituted or unsubstituted aromatic group or a substituted or unsubstituted alkylene chain, and R2is a substituted or unsubstituted alkylene chain; The structure of the ester group-containing anhydride derivative is as follows: wherein R3is selected from a substituted or unsubstituted aromatic group or a substituted or unsubstituted alkylene chain.

2. The method of producing a PBAT / PLA sheath-core composite fiber according to claim 1, characterized by, S1, modifying PLA by using an ester group-containing furan derivative to form furanized PLA; PBAT is modified by using an ester group-containing anhydride derivative to form anhydride PBAT; S2, spinning the furanized PLA and the anhydride PBAT.

3. The method for preparing PBAT / PLA core-sheath composite fiber according to claim 1, characterized in that, S1, modifying PLA by using an ester group-containing anhydride derivative to form anhydride PLA; PBAT is modified by using an ester group-containing furan derivative to form furan PBAT; S2, spinning the anhydride PLA and the furan PBAT.

4. The method for preparing PBAT / PLA core-sheath composite fiber according to claim 1, characterized in that, The molar ratio of the ester group-containing furan derivative or the ester group-containing anhydride derivative to the PLA is (2-8):(8-2).

5. The method for preparing PBAT / PLA core-sheath composite fiber according to claim 1, characterized in that, The conditions of the first melt blending comprise: a blending time of 10 min-45 min, a temperature of 150°C-210°C, and a screw rotation speed of 60 r / min-100 r / min.

6. The method for preparing PBAT / PLA core-sheath composite fiber according to claim 1, characterized in that, Before the first melt blending, the ester group-containing furan derivative or the ester group-containing anhydride derivative and the PLA are dried respectively.

7. The method for preparing PBAT / PLA core-sheath composite fiber according to claim 6, characterized in that, The drying conditions of the ester group-containing furan derivative or the ester group-containing anhydride derivative and the PLA, which are dried respectively, comprise: a temperature of 70°C-100°C and a time of 12 h-14 h.

8. The method for preparing PBAT / PLA core-sheath composite fiber according to claim 1, characterized in that, R1 is selected from a substituted or unsubstituted phenyl or a substituted or unsubstituted C1-C10 alkylene chain, and R2 is a substituted or unsubstituted C1-C10 alkylene chain.

9. The method for preparing PBAT / PLA core-sheath composite fiber according to claim 1, characterized in that, R1 is selected from an unsubstituted phenyl or an unsubstituted C1-C10 alkylene chain, and R2 is an unsubstituted C1-C10 alkylene chain.

10. The method for preparing PBAT / PLA core-sheath composite fiber according to claim 1, characterized in that, R1 is selected from unsubstituted phenyl or unsubstituted C2-C8 alkylene chain, R2 is unsubstituted C2-C8 alkylene chain.

11. The method for preparing PBAT / PLA core-sheath composite fiber according to claim 1, characterized in that, The ester group-containing furan derivative has a structural formula of or .

12. The method for preparing PBAT / PLA core-sheath composite fiber according to claim 1, characterized in that, R3 is substituted or unsubstituted phenyl or substituted or unsubstituted C1-C10 alkylene chain.

13. The method for preparing PBAT / PLA core-sheath composite fiber according to claim 1, characterized in that, R3 is unsubstituted phenyl or unsubstituted C1-C10 alkylene chain.

14. The method for preparing PBAT / PLA core-sheath composite fiber according to claim 1, characterized in that, R3 is unsubstituted phenyl or unsubstituted C2-C8 alkylene chain.

15. The method for preparing PBAT / PLA core-sheath composite fiber according to claim 1, characterized in that, The ester group-containing anhydride derivative has a structural formula of or .

16. The method for preparing PBAT / PLA core-sheath composite fiber according to claim 1, characterized in that, The molar ratio of the ester group-containing anhydride derivative or ester group-containing furan derivative to the PBAT is (2-8):(8-2).

17. The method for preparing PBAT / PLA core-sheath composite fiber according to claim 1, characterized in that, The second melt blending condition includes: blending time is 10 min-45 min, temperature is 150℃-210℃; screw rotation speed is 60 r / min-100 r / min.

18. The method for preparing PBAT / PLA core-sheath composite fiber according to claim 1, characterized in that, Before the second melt blending, the ester group-containing anhydride derivative or ester group-containing furan derivative and the PBAT are dried respectively.

19. The method of claim 18, wherein the PBAT / PLA sheath-core composite fiber is prepared by a melt spinning method. The drying condition of the ester group-containing anhydride derivative or ester group-containing furan derivative and the PBAT respectively includes: temperature is 70℃-100℃, time is 12h-14h.

20. The method for preparing PBAT / PLA core-sheath composite fiber according to claim 1, characterized in that, The spinning is performed according to the two-component spinning process.

21. The method for preparing PBAT / PLA core-sheath composite fiber according to claim 20, characterized in that, In the two-component spinning process, the skin layer melt extrusion temperature is 190℃-220℃, the core layer melt extrusion temperature is 195℃-220℃; the spinneret hole number is 36-100, the spinning temperature is 195℃-210℃, and the spinning speed is 500 m / min-3000 m / min.

22. The method for preparing PBAT / PLA core-sheath composite fiber according to claim 1, characterized in that, The mass ratio of the core layer raw material to the skin layer raw material is (3:7)-(7:3). And / or, before the spinning, the core layer raw material and the skin layer raw material are dried respectively.

23. The method of claim 22, wherein the PBAT / PLA sheath-core composite fiber is prepared by a melt spinning method. The drying condition of the core layer raw material and the skin layer raw material respectively includes: temperature is 70℃-100℃, time is 12h-14h.

24. A PBAT / PLA sheath-core composite fiber, characterized by, The PBAT / PLA sheath-core composite fiber is prepared by the preparation method of the PBAT / PLA sheath-core composite fiber according to any one of claims 1-23.

25. A sanitary article, characterized in that The PBAT / PLA sheath-core composite fiber according to claim 24.

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