阅读说明：本技术 一种碱木质素聚乳酸树脂复合环保板材及其制备方法 (Alkali lignin polylactic acid resin composite environment-friendly board and preparation method thereof ) 是由 李荣杰 冯杰 何玉春 周廷保 谢军 于 2019-11-09 设计创作，主要内容包括：本发明属于建筑材料技术领域,具体公开了一种碱木质素聚乳酸树脂复合环保板材,同时还公开了其制备方法。该碱木质素聚乳酸树脂复合环保板材由依次层叠设置的第一外表层、缓冲层、内层、第二外表层热压共挤压制成型,第一外表层、缓冲层、内层、第二外表层分别由不同配比的碱木质素聚乳酸树脂颗粒、粉体颗粒、聚乳酸树脂颗粒制成。本发明通过将碱木质素与聚乳酸结合开发得到了新型的可降解板材,既可以实现碱木质素的高值化利用,又能满足建筑、家装产业的使用需求,同时可降低建筑材料中木材的使用量,实现低碳、环保的绿色经济。(The invention belongs to the technical field of building materials, and particularly discloses an alkali lignin polylactic acid resin composite environment-friendly board and a preparation method thereof. The alkali lignin polylactic acid resin composite environment-friendly board is formed by hot-pressing, co-extruding and pressing a first outer surface layer, a buffer layer, an inner layer and a second outer surface layer which are sequentially stacked, wherein the first outer surface layer, the buffer layer, the inner layer and the second outer surface layer are respectively made of alkali lignin polylactic acid resin particles, powder particles and polylactic acid resin particles in different proportions. The novel degradable board is developed by combining the alkali lignin and the polylactic acid, so that the high-value utilization of the alkali lignin can be realized, the use requirements of building and home decoration industries can be met, the use amount of wood in building materials can be reduced, and the low-carbon, environment-friendly and green economy can be realized.)

1. The alkali lignin polylactic acid resin composite environment-friendly board is characterized by comprising a first outer surface layer, a buffer layer, an inner layer and a second outer surface layer which are sequentially stacked;

the first outer surface layer is prepared from the following raw materials in parts by weight: 40-50 parts of alkali lignin polylactic resin particles, 20-30 parts of powder particles and 10-40 parts of polylactic resin particles;

the buffer layer is prepared from the following raw materials in parts by weight: 50-60 parts of alkali lignin polylactic resin particles, 10-25 parts of powder particles and 10-40 parts of polylactic resin particles;

the inner layer is prepared from the following raw materials in parts by weight: 60-70 parts of alkali lignin polylactic resin particles, 10-20 parts of powder particles and 10-40 parts of polylactic resin particles;

the second outer surface layer is prepared from the following raw materials in parts by weight: 60-70 parts of alkali lignin polylactic resin particles, 10-30 parts of powder particles and 10-40 parts of polylactic resin particles;

the alkali lignin polylactic resin particles are obtained by mixing alkali lignin and polylactic resin particles and then extruding and granulating.

2. The alkali lignin polylactic acid resin composite environment-friendly board as claimed in claim 1, wherein the thickness ratio of the first outer surface layer, the buffer layer, the inner layer and the second outer surface layer is (0.2-0.5): (0.5-1): (1-2): (0.2-0.3).

3. The alkali lignin polylactic acid resin composite environment-friendly board as claimed in claim 1, wherein the first outer surface layer is made of the following raw materials in parts by weight: 40-45 parts of alkali lignin polylactic resin particles, 20-30 parts of powder particles and 25-40 parts of polylactic resin particles;

the buffer layer is prepared from the following raw materials in parts by weight: 50-60 parts of alkali lignin polylactic resin particles, 20-25 parts of powder particles and 10-20 parts of polylactic resin particles;

the inner layer is prepared from the following raw materials in parts by weight: 60-70 parts of alkali lignin polylactic resin particles, 15-20 parts of powder particles and 10-20 parts of polylactic resin particles;

the second outer surface layer is prepared from the following raw materials in parts by weight: 60-70 parts of alkali lignin polylactic resin particles, 10-30 parts of powder particles and 10-30 parts of polylactic resin particles.

4. The alkali lignin polylactic acid resin composite environment-friendly board as claimed in any one of claims 1 to 3, wherein the weight average molecular weight of the polylactic acid resin particles is 5 to 20 ten thousand, and the melt index is 2 to 10g/10 min.

5. The alkali lignin polylactic acid resin composite environment-friendly board as claimed in claim 1, wherein the alkali lignin polylactic acid resin particles are prepared by mixing (10-12) alkali lignin and polylactic acid resin particles in a mass ratio of: (5-7) mixing, extruding and granulating to obtain the product; preferably, the temperature of extrusion granulation is 110-180 ℃, and the diameter of the granulation is 1-3 mm.

6. The alkali lignin polylactic acid resin composite environment-friendly board as claimed in claim 5, wherein when the alkali lignin and the polylactic acid resin particles are mixed, an auxiliary agent with the total mass of 0-7% of the alkali lignin and the polylactic acid resin particles is added, and then extrusion granulation is carried out; preferably, the auxiliary agent is at least one of epoxidized soybean oil, tributyl citrate and acetyl tri-n-butyl citrate.

7. The alkali lignin polylactic acid resin composite environment-friendly board as claimed in claim 1, wherein the powder particles are at least one selected from talc powder, mica powder, silica, kaolin, calcium carbonate, calcium sulfate and magnesium carbonate.

8. The method for preparing the alkali lignin polylactic acid resin composite environment-friendly board as claimed in any one of claims 1 to 7, is characterized in that the first outer surface layer, the buffer layer, the inner layer and the second outer surface layer are respectively made into single boards, and then the board is pressed into the board through hot-pressing and co-extrusion by adopting a board multilayer extruder in a stacking arrangement mode of the first outer surface layer, the buffer layer, the inner layer and the second outer surface layer from top to bottom.

9. The method for preparing the alkali lignin polylactic acid resin composite environment-friendly board as claimed in claim 8, wherein the hot-pressing co-extrusion conditions are as follows: the hot-pressing co-extrusion temperature is controlled to be 110-180 ℃, and the multi-plate pressing forming pressure is 10-20 MPa.

10. The method for preparing the alkali lignin polylactic acid resin composite environment-friendly board as claimed in claim 8 or 9, wherein the pre-pressing pressure for preparing the veneer is 5-15 MPa, and the temperature is controlled to be 140-170 ℃.

Technical Field

The invention relates to the technical field of building materials, in particular to an alkali lignin polylactic acid resin composite environment-friendly board and a preparation method thereof.

Background

The boards used in the current buildings mainly comprise solid boards and artificial boards, wherein the artificial boards can be divided into solid boards, clamping boards, fiber boards, decorative panels, fireproof boards, shaving boards and the like according to the forming classification.

Solid wood boards are wood boards made of whole wood. The boards are firm and durable, have natural grains, and are the best choice in decoration. However, the plates are not used in decoration because of high cost and high requirement on construction process. Except that the floor and the door leaf can be made of solid wood boards, the commonly used boards are all artificial boards processed by manpower. Plywood in the artificial board is formed by gluing and hot-pressing three or more layers of veneers or sheets with the thickness of one millimeter, and is the most common material for manually manufacturing furniture at present. The decorative panel is a decorative plate with single-sided decoration effect, which is made by precisely slicing a solid wood board into micro veneer with the thickness of about 0.2mm, taking a splint as a base material and performing an adhesive process. The shaving board is a thin board which is made by pressing wood particles as main raw materials, adding glue and additives, and the pressing method can be divided into an extrusion shaving board and a flat pressing shaving board.

The artificial board has low price, so the artificial board is widely applied to buildings and decorations. But has the defects that the artificial board uses a large amount of substances such as adhesive and the like, has great pollution to the environment and is not environment-friendly enough; in addition, the artificial board has poor water resistance and mechanical property, and is not suitable for occasions with large or strong mathematical requirements.

Disclosure of Invention

The invention mainly solves the technical problem of providing an alkali lignin polylactic acid resin composite environment-friendly board and a preparation method thereof.

In order to solve the technical problems, the invention adopts a technical scheme that: an alkali lignin polylactic acid resin composite environment-friendly board comprises a first outer surface layer, a buffer layer, an inner layer and a second outer surface layer which are sequentially stacked;

the first outer surface layer is prepared from the following raw materials in parts by weight: 40-50 parts of alkali lignin polylactic resin particles, 20-30 parts of powder particles and 10-40 parts of polylactic resin particles;

the buffer layer is prepared from the following raw materials in parts by weight: 50-60 parts of alkali lignin polylactic resin particles, 10-25 parts of powder particles and 10-40 parts of polylactic resin particles;

the inner layer is prepared from the following raw materials in parts by weight: 60-70 parts of alkali lignin polylactic resin particles, 10-20 parts of powder particles and 10-40 parts of polylactic resin particles;

the second outer surface layer is prepared from the following raw materials in parts by weight: 60-70 parts of alkali lignin polylactic resin particles, 10-30 parts of powder particles and 10-40 parts of polylactic resin particles;

the alkali lignin polylactic resin particles are obtained by mixing alkali lignin and polylactic resin particles and then extruding and granulating.

In a preferred embodiment, the thickness ratio of the first outer surface layer, the cushioning layer, the inner layer, and the second outer surface layer is (0.2 to 0.5): (0.5-1): (1-2): (0.2-0.3).

Preferably, the first outer surface layer is made of the following raw materials in parts by weight: 40-45 parts of alkali lignin polylactic resin particles, 20-30 parts of powder particles and 25-40 parts of polylactic resin particles;

the buffer layer is prepared from the following raw materials in parts by weight: 50-60 parts of alkali lignin polylactic resin particles, 20-25 parts of powder particles and 10-20 parts of polylactic resin particles;

the inner layer is prepared from the following raw materials in parts by weight: 60-70 parts of alkali lignin polylactic resin particles, 15-20 parts of powder particles and 10-20 parts of polylactic resin particles;

the second outer surface layer is prepared from the following raw materials in parts by weight: 60-70 parts of alkali lignin polylactic resin particles, 10-30 parts of powder particles and 10-30 parts of polylactic resin particles.

In a preferred embodiment, the polylactic acid resin particles have a weight average molecular weight of 5 to 20 ten thousand and a melt index of 2 to 10g/10min (2.16kg, 210 ℃, GB/T3682).

Preferably, the alkali lignin polylactic acid resin particles are prepared by mixing alkali lignin and polylactic acid resin particles in a mass ratio of (10-12): (5-7) mixing, extruding and granulating to obtain the product; preferably, the temperature of extrusion granulation is 110-180 ℃, and the diameter of the granulation is 1-3 mm.

Preferably, when the alkali lignin and the polylactic resin particles are mixed, an auxiliary agent accounting for 0-7% of the total mass of the alkali lignin and the polylactic resin particles is added, and then the mixture is extruded and granulated by a screw; wherein the auxiliary agent is preferably at least one of Epoxidized Soybean Oil (ESO), tributyl citrate (TBC) and acetyl tributyl citrate (ATBC). Liquid auxiliary agents are selected for selection of the auxiliary agents, and the addition of the liquid auxiliary agents is beneficial to better attachment of alkali lignin powder to the surfaces of polylactic resin particles in a mixing stage, so that the mixing is more uniform; meanwhile, the addition of the auxiliary agent is beneficial to the lubrication among a screw, a charging barrel and raw materials in the granulation process, and the local overheating caused by friction is reduced; and also contributes to the improvement of the processability of the granules.

Preferably, the powder particles are selected from at least one of talcum powder, mica powder, silicon dioxide, kaolin, calcium carbonate, calcium sulfate and magnesium carbonate. The addition of the powder particles can enhance the heavy feeling of the processed plate, improve the strength and simultaneously improve the wear resistance of the plate.

The invention also provides a preparation method of the alkali lignin polylactic acid resin composite environment-friendly board, which comprises the steps of firstly manufacturing the first outer surface layer, the buffer layer, the inner layer and the second outer surface layer into single boards respectively, and then adopting a board multilayer extruder to press the board through hot-pressing and co-extrusion according to the stacking arrangement mode of the first outer surface layer, the buffer layer, the inner layer and the second outer surface layer from top to bottom.

As a preferred embodiment, the hot-press co-extrusion conditions are as follows: the hot-pressing co-extrusion temperature is controlled to be 110-180 ℃, and the multi-plate pressing forming pressure is 10-20 MPa.

Preferably, the prepressing pressure of the prepared veneer is 5-15 MPa, and the temperature is controlled to be 140-170 ℃.

In the invention, the alkali lignin polylactic acid resin particles and the polylactic acid resin particles need to be subjected to vacuum drying treatment before use, and the vacuum drying conditions are as follows: the drying temperature is 30-70 ℃, the drying time is 2-4 h, and the vacuum degree is-0.05 to-0.1 MPa.

Polylactic acid (PLA) is a degradation material which is relatively widely researched and applied at present, is an environment-friendly material prepared by taking lactic acid obtained by starch fermentation (or chemical synthesis) as a basic raw material, has good physical properties, good biocompatibility and degradation performance, and is non-toxic and non-irritant to human bodies. Lignin is the natural substance with the most abundant aromatic components, and is the second most abundant natural polymer on earth next to cellulose, and is also the largest contributor to soil humus. As a natural polymer which is rich and cheap, the lignin has high thermal stability, rigidity, biodegradability, oxidation resistance and ultraviolet radiation absorption capacity, and can be widely applied to various fields. For a long time, most lignin is directly combusted to provide heat for factories, so that the lignin is not efficiently utilized, which not only causes resource waste, but also aggravates environmental pollution, and therefore, an efficient, reasonable and high-valued lignin utilization mode is sought, and the method has important significance for environment, resources and economy.

The novel degradable board is developed by combining lignin and polylactic acid, so that high-value utilization of the lignin can be realized, the use requirements of building and home decoration industries can be met, the use amount of wood in building materials can be reduced, and low-carbon and environment-friendly green economy is realized.

The alkali lignin polylactic resin environment-friendly board provided by the invention has high density (1.2-1.4 g/cm)³) High strength and uneasy deformation. The surface layer uses high-proportion polylactic resin particles, so that the surface layer has higher surface strength, and meanwhile, the surface strength is increased by adding inorganic mineral powder such as talcum powder, silicon dioxide, kaolin, calcium sulfate and the like, so that the surface layer has the scratch resistance similar to stone; the high-density buffer layer has a good sound insulation effect, and the three-phase three-dimensional structure of the alkali lignin, the inorganic mineral powder and the polylactic resin particles endows the board with impact buffer performance; the inner layer uses high-content alkali lignin which is used as a natural antioxidant to provide high oxidation resistance for the board, zero oxidation in the service cycle of the product can be realized, and the service cycle of the product is prolonged; the adhesive system of polylactic acid and lignin is used to replace adhesive containing a large amount of formaldehyde used in the existing board processing process, so that no formaldehyde is generated in the production process, and the board is nontoxic, odorless and free of volatile gas in the use process and can be directly used as a material for furniture and interior decoration.

The alkali lignin polylactic resin composite environment-friendly board has the characteristics of high strength, shock resistance, flame resistance, low smoke, no toxicity, water resistance, moisture resistance, corrosion resistance, high temperature resistance, insulation, aging resistance, wear resistance and the like, and the material has complete degradability, and does not pollute the environment after being manufactured, used and abandoned.

Detailed Description

The technical solution of the present invention will be described in detail by specific examples.