Flexible composite material and preparation method thereof

Abstract

The invention provides a flexible composite material and a preparation method thereof. The flexible composite material comprises a base body, wherein the base body is derived from a wood material or a bamboo material; and a biomass fiber membrane, the biomass fiber membrane being present on at least one surface of the substrate, moreover, an elastomer material is arranged between the matrix and the biomass fiber membrane, and at least part of the elastomer material permeates into pores of the matrix. The flexible composite material disclosed by the invention does not crack, and has excellent flexibility and excellent mechanical properties. The preparation method of the flexible composite material is simple and easy to implement, raw materials are easy to obtain, and the flexible composite material is suitable for mass production.

Description

Technical Field

[0001] The invention relates to a flexible composite material and a preparation method thereof, in particular to a flexible composite material based on bamboo material or wood material and a preparation method thereof, belonging to the field of wood materials. Background Art

[0002] Sliced ​​thin bamboo veneer (hereinafter referred to as bamboo veneer) is a new type of decorative veneer material with natural bamboo texture. It has been industrialized and applied in products. Bamboo veneer is made of bamboo slices, and is processed into large-scale thin bamboo slices through a series of processes such as square material lamination, softening and slicing, and backing reinforcement. While retaining the natural texture and color of bamboo, bamboo veneer also reflects the humanistic feelings and low-carbon and environmentally friendly concepts of bamboo in traditional culture, and has the contemporary attributes of beauty, culture and green.

[0003] In addition, bamboo itself has excellent longitudinal flexibility, but it is easy to crack in the transverse direction and has low tensile strength. The common method to improve bamboo skin is to immediately fix it with non-woven fabric after planing, which can improve its cracking behavior. However, since non-woven fabric affects the aesthetics of the bamboo surface, and its opacity blocks the unique texture of bamboo, it can only be used as a backing material. Bamboo skin without non-woven fabric is still difficult to overcome the cracking problem. Summary of the invention

[0004] Problem that the invention aims to solve

[0005] In view of the technical problems existing in the prior art, the present invention first provides a flexible composite material. The flexible composite material of the present invention will not crack, has excellent flexibility, and has excellent mechanical properties.

[0006] The present invention also provides a method for preparing the flexible composite material. The preparation method is simple and easy to implement, the raw materials are easy to obtain, and the method is suitable for mass production.

[0007] Solutions for solving problems

[0008] The present invention first provides a flexible composite material, which comprises:

[0009] a substrate, the substrate being derived from a wood material or a bamboo material; and,

[0010] A biomass fiber membrane, the biomass fiber membrane being present on at least one surface of the substrate; and

[0011] There is an elastomeric material between the matrix and the biomass fiber membrane, and at least a portion of the elastomeric material penetrates into the pores of the matrix.

[0012] According to the flexible composite material of the present invention, the thickness of the substrate is 0.1-0.6 mm, preferably 0.15-0.25 mm; and / or,

[0013] The thickness of the biomass fiber membrane is less than 0.1 mm, preferably 0.04-0.06 mm; the density is 0.5 g / cm 3 Below, preferably 0.34-0.37g / cm 3 .

[0014] According to the flexible composite material of the present invention, the pores of the biomass fiber membrane are infiltrated with an elastomeric material; preferably, the biomass fiber membrane is derived from wood fiber cells and / or bamboo fiber cells; more preferably, the biomass fiber membrane is obtained by papermaking using a papermaking gauze.

[0015] According to the flexible composite material of the present invention, the elastomeric material comprises waterborne polyurethane.

[0016] The present invention also provides a method for preparing the flexible composite material according to the present invention, which comprises: using an elastomer solution to composite-form a matrix and a biomass fiber membrane to obtain a formed body.

[0017] According to the preparation method of the present invention, the preparation method of the biomass fiber membrane includes: placing biomass fibers in a solvent and dispersing them to obtain a slurry; and making paper from the slurry using a papermaking gauze to obtain a biomass fiber membrane.

[0018] According to the preparation method of the present invention, the mass concentration of the biomass fiber in the slurry is 0.05%-0.2%, preferably 0.05%-0.1%.

[0019] According to the preparation method of the present invention, the dispersion treatment includes dispersion treatment using a stirrer; preferably, the rotation speed of the stirrer is 15000-20000 rpm, and the dispersion treatment time is 1h to 2h.

[0020] According to the preparation method of the present invention, the solid content of the elastomer solution is 28-34%; and / or,

[0021] The substrate and the biomass fiber membrane are adhered to each other by applying an elastic body solution; the applying method includes one or a combination of two or more of paving, coating, casting and spraying.

[0022] According to the preparation method of the present invention, the preparation method further comprises the step of curing the molded body; preferably, the curing temperature is 70-90°C, the curing time is 5-8 minutes, and the curing pressure is 0.5-2MPa.

[0023] Effects of the Invention

[0024] The flexible composite material of the invention will not crack, has excellent flexibility and excellent mechanical properties.

[0025] The preparation method of the flexible composite material of the invention is simple and easy, the raw materials are easy to obtain, and it is suitable for mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The surface morphologies and cross-sectional morphologies of the flexible composite materials of Examples 1 to 3 of the present invention and the traditional composite material of Comparative Example 1 are shown.

[0027] Figure 2 The surface morphologies of the flexible composite materials of Examples 1-3 of the present invention and the traditional composite material of Comparative Example 1 after the transverse tensile strength is tested are shown at a magnification of 100 times (upper figure) and 200 times (lower figure). DETAILED DESCRIPTION

[0028] Various exemplary embodiments, features and aspects of the present invention will be described in detail below. The word "exemplary" used here means "used as an example, embodiment or illustrative". Any embodiment described here as "exemplary" is not necessarily interpreted as being superior or better than other embodiments.

[0029] In addition, in order to better illustrate the present invention, numerous specific details are provided in the following specific embodiments. It should be understood by those skilled in the art that the present invention can be implemented without certain specific details. In other examples, methods, means, equipment and steps well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present invention.

[0030] Unless otherwise stated, the units used in this specification are all international standard units, and the numerical values ​​and numerical ranges appearing in the present invention should be understood to include the inevitable systematic errors in industrial production.

[0031] In this specification, the word "may" means both performing a certain process and not performing a certain process.

[0032] In this specification, the references to "some specific / preferred embodiments", "other specific / preferred embodiments", "embodiments", etc., mean that the specific elements (e.g., features, structures, properties and / or characteristics) described in connection with the embodiments are included in at least one embodiment described herein, and may or may not exist in other embodiments. In addition, it should be understood that the elements may be combined in various embodiments in any suitable manner.

[0033] In this specification, the numerical range expressed using "a numerical value A to a numerical value B" means a range including the endpoints numerical values ​​A and B.

[0034] In this specification, when "normal temperature" or "room temperature" is used, the temperature may be 15-25°C.

[0035] <First aspect>

[0036] A first aspect of the present invention provides a flexible composite material comprising:

[0037] a substrate, the substrate being derived from a wood material or a bamboo material; and,

[0038] A biomass fiber membrane, the biomass fiber membrane being present on at least one surface of the substrate; and

[0039] There is an elastomeric material between the matrix and the biomass fiber membrane, and at least a portion of the elastomeric material penetrates into the pores of the matrix.

[0040] The flexible composite material of the invention will not crack, has excellent flexibility and excellent mechanical properties.

[0041] In the present invention, the matrix is ​​derived from a wood material or a bamboo material. Preferably, the matrix is ​​derived from bamboo veneer. The bamboo veneer includes common natural color and carbonized color side-pressed sliced ​​bamboo veneer, flat-pressed sliced ​​bamboo veneer or other bamboo veneer prepared by using bamboo integrated materials as sliced ​​raw materials. The bamboo veneer can also be replaced by rotary cut bamboo veneer, sliced ​​reconstituted wood veneer, sliced ​​reconstituted bamboo veneer, sliced ​​wood veneer or rotary cut wood veneer; the rotary cut bamboo veneer is a bamboo veneer material prepared from bamboo as raw material through rotary cutting technology; the sliced ​​reconstituted wood veneer is a reconstituted wood veneer material prepared from reconstituted wood as raw material through softening sliced ​​technology; the sliced ​​reconstituted bamboo veneer is a reconstituted bamboo veneer material prepared from reconstituted bamboo as raw material through softening sliced ​​technology; the rotary cut wood veneer is a veneer material prepared from the wood part obtained from trees through softening sliced ​​technology; the rotary cut wood veneer is a veneer material prepared by rotary cutting technology.

[0042] In some specific embodiments, the thickness of the substrate is 0.1-0.6 mm, preferably 0.15-0.25 mm, for example: 0.12 mm, 0.16 mm, 0.18 mm, 0.2 mm, 0.22 mm, 0.24 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.55 mm, etc.

[0043] The biomass fiber membrane of the present invention is present on at least one surface of the substrate. In the present invention, the bamboo surface that is prone to cracking and breaking is treated by bridging and repairing with biomass fibers and the flexibility of the elastomeric material is enhanced. The present invention increases the transverse connection structure between bamboo fibers by using the biomass fiber membrane, thereby hindering the cracking behavior between transverse tissues. Specifically, in the present invention, the elastomeric material includes but is not limited to elastomeric resin materials such as water-based polyurethane.

[0044] Specifically, in the present invention, the biomass fiber membrane is derived from wood fiber cells and / or bamboo fiber cells; the biomass fiber membrane of the present invention uses wood or bamboo fiber cells as the main component, and specifically, the biomass fiber membrane of the present invention can be derived from fibers formed by wood materials or bamboo materials. The wood material can be the trunk or root of various trees, and the core material in the trunk is preferably used. For bamboo materials, various bamboo materials of scattered, clumping and mixed types can be used, such as green bamboo, yellow bamboo, purple bamboo, black bamboo, spotted bamboo, bitter bamboo, sweet bamboo, laurel bamboo, dragon bamboo, square bamboo, moso bamboo, etc. Further, the biomass fiber membrane of the present invention can be derived from pulp fibers.

[0045] In some specific embodiments, the biomass fiber membrane of the present invention has a relatively thin thickness, which is about 0.1 mm or less, preferably 0.04-0.06 mm, for example: 0.01 mm, 0.02 mm, 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, 0.07 mm, etc.; and the biomass fiber membrane of the present invention also has a relatively low density, which is about 0.5 g / cm 3 Below, preferably 0.34-0.37g / cm 3 , for example 0.1 g / cm 3 , 0.2g / cm 3 , 0.3g / cm 3 , 0.32g / cm 3 , 0.33g / cm 3 , 0.35g / cm 3 , 0.36g / cm 3 ,,0.38g / cm 3 , 0.4g / cm 3 wait.

[0046] Preferably, the biomass fiber membrane is obtained by papermaking using a papermaking gauze. The biomass fiber membrane obtained by papermaking using a papermaking gauze is thinner and has a more appropriate density, which is conducive to obtaining a flexible composite material.

[0047] In the present invention, there is an elastomeric material between the substrate and the biomass fiber membrane, and at least part of the elastomeric material penetrates into the pores of the substrate. By allowing the elastomeric material to penetrate into the pores of the substrate, the flexibility of the bamboo material can be fully increased.

[0048] The present invention uses an elastomeric material, preferably an aqueous polyurethane having good compatibility with bamboo and good elasticity, as the elastomeric material, which can fill and wrap the bamboo itself and the cracks and pore structures generated during the planing process in multiple scales, thereby increasing the flexibility and lateral strength of the bamboo. Furthermore, by arranging the biomass fiber membrane and the elastomeric material layer by layer, the biomass fiber membrane and the elastomeric material can be fused with each other, and the two can be more evenly distributed and have better adhesion.

[0049] In some specific embodiments, the pores of the biomass fiber membrane are also infiltrated with an elastomeric material, that is, the pores of the substrate and the pores of the biomass fiber membrane are infiltrated with an elastomeric material. By infiltrating the pores of the biomass fiber membrane with an elastomeric material, the biomass fiber membrane and the elastomeric material are fused, making the adhesion more excellent.

[0050] In addition, the flexible composite material of the present invention has a backing layer on the side of the substrate away from the biomass fiber membrane, so as to further fix and support the substrate. Specifically, the backing layer can be a non-woven fabric.

[0051] In some specific embodiments, the pores of the backing layer are also infiltrated with an elastomeric material. By infiltrating the pores of the backing layer with an elastomeric material, the stress dispersion of the flexible composite material can be further improved.

[0052] The flexible composite material obtained after preparation and processing is a new bamboo-based material with ultra-high flexibility, which can be used in flexible packaging, flexible substrates, special-shaped decorative veneers and other fields. It expands the application scope of bamboo skin, increases product added value, and has great development space.

[0053] <Second Aspect>

[0054] The second aspect of the present invention provides a method for preparing the flexible composite material according to the first aspect of the present invention, comprising: using an elastomer solution to composite a matrix with a biomass fiber membrane to obtain a molded body. The preparation method of the present invention is simple and easy to implement, and the raw materials are easy to obtain, and is suitable for mass production.

[0055] In some specific embodiments, the preparation method of the biomass fiber membrane includes: placing the biomass fiber in a solvent and dispersing it to obtain a slurry; using a papermaking gauze to make paper from the slurry to obtain a biomass fiber membrane. The present invention obtains a biomass fiber membrane by using a papermaking gauze to make paper, and the fiber content and the thickness of the fiber membrane can be controlled according to the actual application scenario.

[0056] Specifically, in the slurry, the mass concentration of the biomass fiber is 0.05%-0.2%, preferably 0.05%-0.1%, for example, 0.06%, 0.07%, 0.08%, 0.09%, 0.11%, 0.13%, 0.15%, 0.17%, 0.19%, etc. The aperture of the mesh of the papermaking gauze can be 60-120 mesh, for example, 70 mesh, 80 mesh, 90 mesh, 100 mesh, 110 mesh, etc.

[0057] In some specific embodiments, the dispersion treatment includes dispersion treatment using a stirrer; preferably, the speed of the stirrer is 15000-20000 rpm, for example: 16000 rpm, 17000 rpm, 18000 rpm, 19000 rpm, etc.; the dispersion treatment time is 1h to 2h, for example: 1.2h, 1.4h, 1.6h, 1.8h, etc. Through the dispersion treatment, the biomass fiber can be made more uniform, which is conducive to the formation of a biomass fiber film.

[0058] Furthermore, the solid content of the elastomer solution is 28-34%, for example: 29%, 30%, 31%, 32%, 33%, etc.; and / or, the substrate and the biomass fiber membrane are adhered to each other by applying the elastomer solution; the application method includes one or a combination of more than two of paving, coating, casting and spraying.

[0059] Specifically, the present invention does not particularly limit the timing of applying the elastomer solution, and can be set as needed, as long as there is an elastomer solution between the substrate and the biomass fiber membrane of the flexible composite material. Specifically, the elastomer solution can be applied to one side of the substrate first, and then the biomass fiber membrane can be assembled on the side of the substrate with the elastomer solution. The biomass fiber membrane can also be assembled on one side of the substrate before applying the elastomer solution. The elastomer solution can also be applied to one side of the substrate first, and then the biomass fiber membrane can be assembled on the side of the substrate with the elastomer solution. In order to facilitate the elastomer solution to penetrate more evenly into the pores of the substrate and the biomass fiber membrane, the elastomer solution can be continued to be applied to the side of the biomass fiber membrane away from the elastomer solution.

[0060] The present invention does not specifically limit the amount of the elastomer solution, and can be set as needed, as long as the function of the present invention can be achieved. Specifically, the amount of the elastomer solution used each time can be 5-15 g / m 2 , preferably 8-10g / m 2 , for example: 5.5g / m 2 , 6g / m 2 , 6.5g / m 2 , 7g / m 2 , 7.5g / m 2 , 8g / m 2 , 8.5g / m 2 , 9g / m 2 , 9.5g / m 2 , 10g / m 2 , 10.5g / m 2 , 11g / m 2 , 11.5g / m 2 , 12g / m 2 , 13g / m 2 , 14g / m 2 wait.

[0061] In addition, a backing layer may be provided on the side of the substrate of the flexible composite material of the present invention away from the biomass fiber membrane, so as to further fix and support the substrate. Specifically, the backing layer may be a non-woven fabric.

[0062] Furthermore, the backing layer can be assembled on one side of the substrate first, and then the biomass fiber membrane can be assembled, or the biomass fiber membrane can be assembled on one side of the substrate first, and then the backing layer can be assembled. Specifically, the backing layer can be assembled on one side of the substrate using an adhesive. The amount of the adhesive used is not particularly limited in the present invention and can be selected as needed.

[0063] Furthermore, after the backing layer is assembled on one side of the substrate, hot pressing can be performed to tightly combine the backing layer and the substrate into one. Specifically, the temperature of hot pressing can be 70-110°C, for example: 80°C, 90°C, 100°C, etc.; the time of hot pressing can be 50-100 seconds, for example: 60 seconds, 70 seconds, 80 seconds, 90 seconds, etc.

[0064] The present invention does not impose any particular limitation on the adhesive, as long as the backing layer can be assembled on one side of the substrate, such as commercially available solid powder adhesive.

[0065] In some specific embodiments, the preparation method also includes the step of curing the molded body; preferably, the curing temperature is 70-90°C, for example: 750°C, 80°C, 85°C, etc.; the curing time is 5-8 minutes, for example: 5.5 minutes, 6 minutes, 6.5 minutes, 7 minutes, 7.5 minutes, etc.; the curing pressure is 0.5-2MPa, for example: 0.7MPa, 0.9MPa, 1.1MPa, 1.3MPa, 1.5MPa, 1.7MPa, 1.9MPa, etc.

[0066] Finally, the cured product can be polished to obtain the flexible composite material of the present invention.

[0067] Example

[0068] The embodiments of the present invention will be described in detail below in conjunction with the examples, but those skilled in the art will appreciate that the following examples are only used to illustrate the present invention and should not be considered to limit the scope of the present invention. If no specific conditions are specified in the examples, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be obtained commercially.

[0069] In the embodiment, the waterborne polyurethane used is a waterborne polyurethane of model 1926 produced by Yoshida Chemical Co., Ltd. It has a solid content of about 34%, a pH value of 6-8, and a viscosity of less than 350 mPa·s.

[0070] Example 1

[0071] (1) Non-woven fabric veneer was applied to one side of the sliced ​​bamboo veneer. The adhesive used was a commercially available three-component solid powder adhesive. The hot pressing temperature was 90°C and the hot pressing time was 80 seconds. The final thickness was 0.15 mm.

[0072] (2) Pulp fibers are prepared into an aqueous slurry at a mass concentration of 0.1%, and the pulp fibers in the aqueous slurry are dispersed using a stirrer at a stirring speed of 15000 rpm for 2 hours. Then, papermaking is performed using a papermaking gauze having a mesh size of 80 meshes, and a pulp fiber membrane is prepared for use.

[0073] (3) Injecting the aqueous polyurethane solution into a high-pressure spray gun and spraying the surface of the slicing bamboo veneer not attached with the non-woven fabric in 1) once, with a spraying amount of 10 g / m 2 ; The solid content of polyurethane in waterborne polyurethane is 34%.

[0074] (4) Assembling the pulp fiber membrane in (2) on the side of the planed bamboo veneer with waterborne polyurethane in (3), and spraying the waterborne polyurethane again, the spraying number is 1, and the spraying amount of glue is 10g / m2 The solid content of polyurethane in the waterborne polyurethane is 34%, and a molded body is obtained, and at least the waterborne polyurethane penetrates into the pores of the pulp fiber membrane, the sliced ​​bamboo skin and the non-woven fabric.

[0075] (5) The molded body in (4) is placed in a press for heating and pressurizing curing at a temperature of 80°C, a time of 8 minutes, and a pressure of 2 MPa.

[0076] (6) The cured and dried bamboo veneer is surface polished to obtain a flexible composite material.

[0077] Example 2

[0078] (1) One side of the sliced ​​bamboo veneer is veneered with non-woven fabric, and the adhesive used is a commercially available three-component solid powder adhesive, the hot pressing temperature is 90°C, and the hot pressing time is 80 seconds. The final thickness is 0.15 mm;

[0079] (2) preparing an aqueous slurry with a mass concentration of 0.1% by weight of pulp fibers, dispersing the pulp fibers in the aqueous slurry using a stirrer at a stirring speed of 15,000 rpm for 2 hours, and making paper using a papermaking gauze having a mesh size of 80 meshes to prepare a pulp fiber membrane for later use;

[0080] (3) Injecting the aqueous polyurethane solution into a high-pressure spray gun and spraying the surface of the slicing bamboo veneer not attached with the non-woven fabric in 1) once, with a spraying amount of 10 g / m 2 ; The solid content of polyurethane in waterborne polyurethane is 34%.

[0081] (4) Assembling the pulp fiber membrane in (2) on the side of the sliced ​​bamboo veneer having the waterborne polyurethane in (3) to obtain a molded body, wherein at least the waterborne polyurethane penetrates into the pores of the pulp fiber membrane and the sliced ​​bamboo veneer.

[0082] (5) The molded body in (4) is placed in a press for heating and pressurizing curing at a temperature of 80°C, a time of 8 minutes, and a pressure of 2 MPa.

[0083] (6) The cured and dried bamboo veneer is surface polished to obtain a flexible composite material.

[0084] Example 3

[0085] (1) One side of the sliced ​​bamboo veneer is veneered with non-woven fabric, and the adhesive used is a commercially available three-component solid powder adhesive, the hot pressing temperature is 90°C, and the hot pressing time is 80 seconds. The final thickness is 0.15 mm;

[0086] (2) preparing an aqueous slurry with a pulp fiber mass concentration of 0.1%, dispersing the pulp fiber in the aqueous slurry using a stirrer at a stirring speed of 15,000 rpm for 2 hours, and making paper using a papermaking gauze having a mesh size of 80 meshes to prepare a pulp fiber membrane for later use;

[0087] (3) Assemble the pulp fiber membrane in (2) on the side of the shavings of bamboo veneer not attached with the nonwoven fabric in (1).

[0088] (4) Injecting the aqueous polyurethane solution into a high-pressure spray gun and spraying the surface of the sliced ​​bamboo veneer having the pulp fiber membrane in (3) once, with a spraying amount of 10 g / m 2 The solid content of the polyurethane in the waterborne polyurethane is in the range of 34%, a molded body is obtained, and at least the waterborne polyurethane penetrates into the pores of the pulp fiber membrane and the sliced ​​bamboo skin.

[0089] (5) The molded body in (4) is placed in a press for heating and pressurizing curing at a temperature of 80°C, a time of 8 minutes, and a pressure of 2 MPa.

[0090] (6) The cured and dried bamboo veneer is surface polished to obtain a flexible composite material.

[0091] Comparative Example 1

[0092] One side of the sliced ​​bamboo veneer was veneered with non-woven fabric, the adhesive used was three-component solid powder glue, the hot pressing temperature was 90°C, and the hot pressing time was 80 seconds. Finally, the thickness was processed to 0.15mm to obtain a traditional composite material.

[0093] Performance Testing

[0094] 1. Flexibility

[0095] By winding around steel pipes with diameters of 50 mm, 30 mm, 14 mm, 13 mm, 12 mm, 11 mm, 10 mm, 9 mm, 8 mm, 7 mm, 6 mm, 5 mm, 4 mm, 3 mm, 2 mm, 1 mm, and 0.5 mm, and taking no breakage during winding as the standard, the flexibility between the three embodiments and the untreated bamboo skin was tested, and the results are shown in Table 1.

[0096] 2. Transverse tensile strength

[0097] The transverse tensile strength test between the three embodiments and the untreated bamboo skin was tested by a mechanical testing machine, and all the results are shown in Table 1.

[0098] Table 1

[0099]

[0100] As can be seen from Table 1, the mechanical flexibility and mechanical properties of the flexible composite materials of the embodiments of the present invention are significantly improved compared with the control examples, and the three embodiments can be wound around a 0.5 mm steel pipe without breaking. The transverse tensile strength of the flexible composite materials of the embodiments of the present invention is also significantly improved, and the transverse tensile strength of the embodiments 1, 2, and 3 is improved by 88.66%, 19.57%, and 40.11% respectively compared with the untreated bamboo skin.

[0101] 3. Transmission electron microscope (TEM) test

[0102] The surface structure morphology and cross-sectional structure morphology of the flexible composite materials of Examples 1-3 and the conventional composite material of Comparative Example 1 were observed by transmission electron microscopy (TEM). Figure 1 shown.

[0103] Among them, a is the surface structure morphology of the traditional composite material of comparative example 1, and d, g and j are the surface structure morphologies of Example 3, Example 2 and Example 1, respectively. It can be clearly seen from d, g and j that the water-based polyurethane penetrates into the pulp fiber membrane, while a does not contain water-based polyurethane.

[0104] b is the cross-sectional structural morphology of the conventional composite material of comparative example 1, and e, h and k are the cross-sectional structural morphologies of embodiment 3, embodiment 2 and embodiment 1, respectively. From e, h and k, it can be seen that the waterborne polyurethane also penetrates into the pore structure of the bamboo material, so that the pulp fiber membrane is closely combined with the bamboo material.

[0105] 4. Transmission electron microscope test after transverse stretching

[0106] The surface structure morphology and cross-sectional structure morphology of the flexible composite materials of Examples 1-3 and the conventional composite material of Comparative Example 1 after transverse stretching were observed by transmission electron microscope (TEM). The results are as follows: Figure 2 shown.

[0107] Depend on Figure 2 It can be seen that during the transverse stretching process, the pulp fiber membrane of Example 3 is more likely to fall off, so only a small amount of water-based polyurethane plays a reinforcing role on the sliced ​​bamboo veneer.

[0108] During the transverse stretching process, the pulp fiber membrane of Example 2 also falls off when subjected to transverse stretching. This may be due to the small amount of water-based polyurethane sprayed, which cannot completely fill the pores and tightly glue the pulp fiber membrane and slicing bamboo skin. The pulp fiber membrane is easily broken at the weak bonding point during stretching.

[0109] During the transverse stretching process, the complex structure formed by the interweaving and entanglement of the pulp fiber membranes of Example 1 disperses the stress of the sliced ​​bamboo skin. At this time, a large number of pulp fibers are dispersed and pulled out, thereby preventing the further expansion of the cracks. At the same time, the water-based polyurethane infiltrated into the non-woven fabric also has a certain stress dispersion effect.

[0110] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A flexible composite material, characterized in that: include: A substrate, wherein the substrate is derived from a wood material or a bamboo material; as well as, A biomass fiber membrane, the biomass fiber membrane being present on at least one surface of the substrate; and There is an elastomeric material between the matrix and the biomass fiber membrane, and at least a portion of the elastomeric material penetrates into the pores of the matrix.

2. The flexible composite material according to claim 1, characterized in that: The thickness of the substrate is 0.1-0.6 mm, preferably 0.15-0.25 mm; and / or, The thickness of the biomass fiber membrane is less than 0.1 mm, preferably 0.04-0.06 mm; the density is 0.5 g / cm 3 Below, preferably 0.34-0.37g / cm 3 .

3. The flexible composite material according to claim 1 or 2, characterized in that: The pores of the biomass fiber membrane are infiltrated with an elastomeric material; preferably, the biomass fiber membrane is derived from wood fiber cells and / or bamboo fiber cells; more preferably, the biomass fiber membrane is obtained by papermaking using a papermaking gauze.

4. The flexible composite material according to any one of claims 1 to 3, characterized in that: The elastomeric material includes waterborne polyurethane.

5. A method for preparing the flexible composite material according to any one of claims 1 to 4, characterized in that: include: The matrix and the biomass fiber membrane are composited and molded by using an elastomer solution to obtain a molded body.

6. The preparation method according to claim 5, characterized in that: The preparation method of the biomass fiber membrane comprises: placing biomass fibers in a solvent and dispersing them to obtain slurry; and making paper from the slurry using a papermaking gauze to obtain a biological biomass fiber membrane.

7. The preparation method according to claim 6, characterized in that: In the slurry, the mass concentration of the biomass fiber is 0.05%-0.2%, preferably 0.05%-0.1%.

8. The preparation method according to claim 7, characterized in that: The dispersion treatment includes dispersion treatment using a stirrer; preferably, the rotation speed of the stirrer is 15000-20000 rpm, and the dispersion treatment time is 1h to 2h.

9. The preparation method according to any one of claims 5 to 7, characterized in that: The solid content of the elastomer solution is 28-34%; and / or, The substrate and the biomass fiber membrane are adhered to each other by applying an elastic body solution; the applying method includes one or a combination of two or more of paving, coating, casting and spraying.

10. The preparation method according to any one of claims 5 to 9, characterized in that: The preparation method further comprises the step of curing the molded body; preferably, the curing temperature is 70-90° C., the curing time is 5-8 minutes, and the curing pressure is 0.5-2 MPa.

Images