Degradable plastic-wood composite board and preparation method thereof

Abstract

The present application relates to a kind of degradable plastic wood composite material plate and its preparation method, suitable for making buried flowerpot, gift packaging box, disposable lunch box and other products, belong to ecological environment material and composite material technical field.A kind of degradable plastic wood composite material plate, from top to bottom by upper starch-based composite material plate layer, upper polycaprolactone-based composite material plate layer, middle starch-based composite material plate layer, lower polycaprolactone-based composite material plate layer and lower starch-based composite material plate layer in turn.The present application adopts multilayer composite mode to prepare plate, and the structure is unique;Starch is used to make plastic wood material plate, and the raw material source is extensive, and the price is cheap, and the obtained plastic wood plate can be degraded by 100%;Polycaprolactone-based composite material plate is molded between two layers of starch-based composite material plate, and the integrity of the plate is good, while the brittleness and low strength of pure starch-based composite material plate can be overcome, and the comprehensive performance of plastic wood composite material plate is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to a composite material plate, in particular to a degradable plastic-wood composite material plate and a preparation method thereof, which is suitable for making products such as buried flower pots, gift packaging boxes, disposable lunch boxes, and belongs to the technical field of ecological environment materials and composite materials. BACKGROUND

[0002] If fresh flowers (seedlings) are purchased from the market for transplanting, disposable flower pots can be used to cultivate fresh flowers (seedlings), and the user can bury the fresh flowers (seedlings) together with the flower pots in the soil after purchasing them. With the passage of time, the disposable flower pots will degrade, and the fresh flowers (seedlings) can grow well in the soil, which can reduce the mortality rate during the transplanting process of fresh flowers (seedlings). Packaging boxes are widely used in packaging gifts. Traditionally, packaging boxes are generally made of hard paper, plastic, wood or metal. These materials have certain limitations. For example, hard paper packaging boxes have low strength and waste a large amount of paper resources during use; plastic packaging boxes are not easy to degrade and can pollute the environment after being discarded; wooden packaging boxes have high costs and must be made by cutting down trees, which is not conducive to ecological protection; metal packaging boxes are heavy, have poor touch, and have high costs; and disposable lunch boxes are traditionally made of foamed plastic, which is not degradable and can pollute the environment. In recent years, wooden disposable lunch boxes have appeared, which can degrade after being discarded, but will cause damage to forest resources.

[0003] In summary, there is an urgent need for a material that is degradable, environmentally friendly, safe and sanitary, and relatively inexpensive on the market for making various products.

[0004] Plastic-wood composite material is a new type of chemical material that has developed rapidly in recent years. It is mainly made of waste plastic, wood powder, and agricultural and forestry by-products such as rice chaff, with the addition of a small amount of additives, and is extruded at high temperature. It combines the main advantages of thermoplastic polymers and wood, has the advantages of corrosion resistance, moisture resistance, insect resistance, high dimensional stability, no cracking, no warping, no toxic components, etc., and has been widely used as outdoor floor, swimming pool edge, flower box, tree pool, fence, garbage can, sunshade, stool, chair strip, backrest strip, leisure table top, signboard, bulletin board, beam, wharf deck, waterway, handrail, guardrail, fence, partition, flower rack corridor, outdoor pavilion, outdoor platform, bathroom board, door and window frame, sound-absorbing board, ceiling, etc. However, traditional plastic-wood composite materials generally use polyethylene, polypropylene and other non-degradable plastics as the matrix. Although the amount of degradable wood powder and other plant fibers used is much larger than the amount of plastic, the material still cannot be completely degraded and will have some impact on the environment after being discarded.

[0005] Therefore, it is necessary to provide a degradable plastic-wood composite material plate and a manufacturing method thereof, which can replace traditional hard paper, plastic, wood or metal materials and conventional plastic-wood composite materials, fully exert the advantages of plastic-wood materials, and realize 100% degradability of the materials. SUMMARY

[0006] The present application is aimed at the above-mentioned purpose, and provides a degradable plastic-wood composite material plate and a manufacturing method thereof.

[0007] A degradable plastic-wood composite material plate, which is composed of an upper starch-based composite material plate layer, an upper polycaprolactone-based composite material plate layer, a middle starch-based composite material plate layer, a lower polycaprolactone-based composite material plate layer and a lower starch-based composite material plate layer from top to bottom.

[0008] The upper starch-based composite material plate layer, the middle starch-based composite material plate layer and the lower starch-based composite material plate layer are each composed of one layer of starch-based composite material plate; and the upper polycaprolactone-based composite material plate layer and the lower polycaprolactone-based composite material plate layer are each composed of one to three layers of polycaprolactone-based composite material plate.

[0009] The starch-based composite material plate is made by calendering starch, glycerol and modified wood powder.

[0010] The polycaprolactone-based composite material plate is made by melting polycaprolactone, uniformly coating the two sides of a hemp fiber cloth and solidifying.

[0011] A manufacturing method of the degradable plastic-wood composite material plate comprises the following steps:

[0012] (1) 100 parts by weight of wood powder, 100-300 parts of polyformaldehyde and 300-500 parts of dimethyl sulfoxide are weighed and added into a reaction container, and stirred uniformly, and then heated to 125-135 DEG C within 16-20 minutes, and then cooled to 80-90 DEG C after 5-15 minutes, and then 100-200 parts by weight of polyformaldehyde is added and mixed uniformly, and then heated to 125-135 DEG C again, and then stirred and dispersed for 10-20 minutes, and then cooled to room temperature; and then 10-30 parts by weight of maleic anhydride and 0.6-1 part by weight of p-dimethylaminopyridine are added into the mixed solution, and mixed uniformly, and then heated to 70-90 DEG C, and then reacted for 60-90 minutes under stirring, and then cooled to room temperature;

[0013] (2) 12-36 parts by weight of diethylene triamine and 0.1-0.5 parts by weight of phosphoric acid are weighed and added into the mixed solution of step (1), and mixed uniformly, and then reacted at room temperature for 40-80 minutes;

[0014] (3) 20-40 parts by weight of maleic anhydride is weighed and added into the solution of step (2), and stirred uniformly, and then reacted for 50-70 minutes under stirring at 70-90 DEG C, and then cooled to room temperature.

[0015] (4) Weigh 25-65 parts by weight of diethylenetriamine, add it to the mixed solution in step (3), mix well, and react at room temperature for 120-150 minutes.

[0016] (5) After the reaction is complete, filter to remove dimethyl sulfoxide and obtain the treated wood powder. Wash the treated wood powder with water 3-7 times, then dry it and heat it to 120-160℃. React for 60-80 minutes and cool it to room temperature to obtain the modified wood powder.

[0017] (6) Weigh 100 parts by weight of starch, 20-40 parts by weight of glycerol and 80-100 parts by weight of modified wood flour respectively, mix them evenly, and process them into starch-based composite material boards with a thickness of 2-4 mm by calendering.

[0018] (7) Weigh 100 parts by weight of polycaprolactone and 100-200 parts by weight of hemp fiber cloth respectively. After melting the polycaprolactone, coat it evenly on both sides of the hemp fiber cloth. After curing, a polycaprolactone-based composite material board is obtained.

[0019] (8) Cut starch-based composite material plates and polycaprolactone-based composite material plates according to the size of the molding die cavity;

[0020] (9) In the mold cavity, lay 1 layer of starch-based composite material board, 1-3 layers of polycaprolactone-based composite material board, 1 layer of starch-based composite material board, 1-3 layers of polycaprolactone-based composite material board and 1 layer of starch-based composite material board from bottom to top, close the mold, and press at 10-30MPa and 60-80℃ for 30-50 minutes. During the pressing process, perform venting operation 1-5 times. After the pressing is completed, cool to room temperature, open the mold, and take out the board to obtain a biodegradable wood-plastic composite board.

[0021] The wood flour has a particle size of 40-160 mesh.

[0022] The hemp fiber cloth mentioned is one of ramie fiber cloth, flax fiber cloth, hemp fiber cloth or sisal fiber cloth, with a single weight of 100-300 grams per square meter.

[0023] This invention:

[0024] (1) A biodegradable wood-plastic composite board with a unique structure was prepared by a multi-layer composite method;

[0025] (2) Starch is used to make wood-plastic composite boards. The raw materials are widely available and inexpensive, and the resulting wood-plastic boards can be 100% degraded.

[0026] (3) The polycaprolactone-based composite material plate is molded between the two layers of starch-based composite material plates, which can improve the bonding effect between the polycaprolactone-based composite material plate and the upper and lower starch-based composite material plates, and ensure the integrity of the degradable plastic-wood composite material plate.

[0027] (4) The polycaprolactone-based composite material plate and the starch-based composite material plate are compounded, which can overcome the brittleness and low strength of the pure starch-based composite material plate, and improve the comprehensive performance of the plastic-wood composite material plate. DETAILED DESCRIPTION

[0028] A degradable plastic-wood composite material plate is composed of an upper starch-based composite material plate layer, an upper polycaprolactone-based composite material plate layer, a middle starch-based composite material plate layer, a lower polycaprolactone-based composite material plate layer, and a lower starch-based composite material plate layer from top to bottom.

[0029] The starch-based composite material plate is made of starch, glycerol, and modified wood powder.

[0030] The polycaprolactone-based composite material plate is made by melting polycaprolactone, uniformly coating it on both sides of the hemp fiber cloth, and solidifying it.

[0031] Embodiment 1: A degradable plastic-wood composite material plate, the manufacturing method thereof includes the following steps:

[0032] (1) Take 100 parts by weight of wood powder, 200 parts of polyformaldehyde, and 400 parts of dimethyl sulfoxide, add them to a reaction container, stir them evenly, and heat them to 130℃ within 18 minutes. After 10 minutes, cool them to 85℃, add 150 parts by weight of polyformaldehyde, mix them evenly, heat them to 130℃ again, stir and disperse them for 15 minutes, and then cool them to room temperature. Then add 20 parts by weight of maleic anhydride and 0.8 parts by weight of p-dimethylaminopyridine to the mixed solution, mix them evenly, heat them to 80℃, stir and react them for 75 minutes, and then cool them to room temperature;

[0033] (2) Take 24 parts by weight of diethylenetriamine and 0.3 parts by weight of phosphoric acid, add them to the mixed solution of step (1), mix them evenly, and react them at room temperature for 60 minutes;

[0034] (3) Take 30 parts by weight of maleic anhydride, add it to the solution of step (2), stir it evenly, heat it to 80℃, stir and react it for 60 minutes, and then cool it to room temperature;

[0035] (4) Take 45 parts by weight of diethylenetriamine, add it to the mixed solution of step (3), mix it evenly, and react it at room temperature for 135 minutes;

[0036] (5) After the reaction is completed, the dimethyl sulfoxide is removed by filtration to obtain the treated wood powder, the treated wood powder is washed with water for 5 times, and then is dried and heated to 140℃, and reacts for 70 minutes, and after being cooled to room temperature, the modified wood powder is obtained;

[0037] (6) 100 parts by weight of starch, 30 parts by weight of glycerol and 90 parts by weight of modified wood powder are weighed respectively, uniformly mixed, and then processed into a starch-based composite material plate with a thickness of 3 mm by using a calendering forming method;

[0038] (7) 100 parts by weight of polycaprolactone and 150 parts by weight of hemp fiber cloth are weighed respectively, the polycaprolactone is melted, and then uniformly coated on both sides of the hemp fiber cloth, and after being solidified, a polycaprolactone-based composite material plate is obtained;

[0039] (8) The starch-based composite material plate and the polycaprolactone-based composite material plate are cut according to the size of the cavity of the mold die;

[0040] (9) In the mold cavity, 1 layer of the starch-based composite material plate, 2 layers of the polycaprolactone-based composite material plate, 1 layer of the starch-based composite material plate, 2 layers of the polycaprolactone-based composite material plate and 1 layer of the starch-based composite material plate are sequentially laid from bottom to top, the mold is closed, and the mold pressing is performed at 20 MPa and 70℃ for 40 minutes, the exhaust operation is performed 3 times during the pressing process, after the mold pressing is completed, the mold is cooled to room temperature, the mold is opened, and the plate is taken out, thereby obtaining a degradable plastic-wood composite material plate;

[0041] The wood powder has a particle size of 100 mesh;

[0042] The hemp fiber cloth is flax fiber cloth with a single weight of 200 g / m2.

[0043] Embodiment 2: A degradable plastic-wood composite material plate is prepared by the following method:

[0044] (1) 100 parts by weight of wood powder, 100 parts of polyformaldehyde and 300 parts of dimethyl sulfoxide are weighed and added into a reaction container, and stirred uniformly, heated to 125℃ within 16 minutes, and then cooled to 80℃ after 5 minutes, 100 parts by weight of polyformaldehyde is added, mixed uniformly, heated to 125℃ again, and stirred and dispersed for 10 minutes, and then cooled to room temperature; then 10 parts by weight of maleic anhydride and 0.6 parts by weight of p-dimethylaminopyridine are added into the mixed solution, mixed uniformly, heated to 70℃, stirred and reacted for 60 minutes, and then cooled to room temperature;

[0045] (2) 12 parts by weight of diethylenetriamine and 0.1 parts by weight of phosphoric acid are weighed and added into the mixed solution of step (1), mixed uniformly, and then reacted at room temperature for 40 minutes;

[0046] (3) take 20 parts by weight of maleic anhydride, add to the solution of step (2), stir evenly, 70℃, stirring under reaction for 50 minutes after falling to room temperature;

[0047] (4) take 25 parts by weight of diethylene triamine, add to the mixed solution of step (3), mix evenly, after normal temperature reaction 120 minutes;

[0048] (5) after the reaction, filter out dimethyl sulfoxide, get the treated wood powder, water washing after the wood powder 3 times, then dry, and heat to 120℃, reaction 60 minutes, cooling to room temperature, get the modified wood powder;

[0049] (6) take 100 parts by weight of starch, 20 parts by weight of glycerol and 80 parts by weight of modified wood powder respectively, mix evenly, adopt calendering forming way to process into starch-based composite material board with thickness of 2 millimeters;

[0050] (7) take 100 parts by weight of polycaprolactone and 100 parts by weight of hemp fiber cloth respectively, melt polycaprolactone, evenly coated on both sides of hemp fiber cloth, solidification after get polycaprolactone-based composite material board;

[0051] (8) according to the size of the cavity of the mold, cut the starch-based composite material board and polycaprolactone-based composite material board;

[0052] (9) in the mold cavity, from bottom to top, lay 1 layer of starch-based composite material board, 1 layer of polycaprolactone-based composite material board, 1 layer of starch-based composite material board, 1 layer of polycaprolactone-based composite material board and 1 layer of starch-based composite material board, clamp, under 10MPa, 60℃, mold pressing 30 minutes, exhaust operation once during the pressing process, after the mold pressing, cooling to room temperature, open the mold, take out the board, get a degradable plastic-wood composite material board;

[0053] The particle size of the wood powder is 40 mesh;

[0054] The hemp fiber cloth is ramie fiber cloth, single weight 100g / m2.

[0055] Example 3: a degradable plastic-wood composite material board, its manufacturing method includes the following steps:

[0056] (1) take 100 parts by weight of wood powder, 300 parts of polyformaldehyde and 500 parts of dimethyl sulfoxide, add to the reaction container, stir evenly, heat to 135℃ within 20 minutes, 15 minutes later, cool to 90℃, add 200 parts by weight of polyformaldehyde, mix evenly, heat to 135℃ again, stir and disperse for 20 minutes, then cool to room temperature; then add 30 parts by weight of maleic anhydride and 1 part by weight of p-dimethylaminopyridine to the mixed solution, mix evenly, heat to 90℃, stirring under reaction for 90 minutes, then cool to room temperature;

[0057] (2) Weigh 36 parts by weight of diethylene triamine and 0.5 parts by weight of phosphoric acid, add to the mixed solution of step (1), mix uniformly, and react at room temperature for 80 minutes;

[0058] (3) Weigh 40 parts by weight of maleic anhydride, add to the solution of step (2), stir uniformly, react at 90°C for 70 minutes under stirring, and then cool to room temperature;

[0059] (4) Weigh 65 parts by weight of diethylene triamine, add to the mixed solution of step (3), mix uniformly, and react at room temperature for 150 minutes;

[0060] (5) After the reaction is completed, filter out the dimethyl sulfoxide to obtain treated wood powder, wash the treated wood powder with water for 7 times, then dry and heat to 160°C, react for 80 minutes, cool to room temperature, and obtain modified wood powder;

[0061] (6) Weigh 100 parts by weight of starch, 40 parts by weight of glycerol and 100 parts by weight of modified wood powder respectively, mix uniformly, and process into a starch-based composite material plate with a thickness of 4 mm by using calendering molding;

[0062] (7) Weigh 100 parts by weight of polycaprolactone and 200 parts by weight of hemp fiber cloth respectively, melt the polycaprolactone, uniformly coat on both sides of the hemp fiber cloth, and obtain a polycaprolactone-based composite material plate after solidification;

[0063] (8) According to the size of the mold cavity of the mold, cut the starch-based composite material plate and the polycaprolactone-based composite material plate;

[0064] (9) In the mold cavity, place 1 layer of starch-based composite material plate, 3 layers of polycaprolactone-based composite material plate, 1 layer of starch-based composite material plate, 3 layers of polycaprolactone-based composite material plate and 1 layer of starch-based composite material plate from bottom to top in sequence, clamp, mold press at 30 MPa and 80°C for 50 minutes, perform exhaust operation 5 times during the pressing process, cool to room temperature after the mold pressing is completed, open the mold, and take out the plate to obtain a degradable plastic-wood composite material plate;

[0065] The wood powder has a particle size of 160 mesh;

[0066] The hemp fiber cloth is a sisal fiber cloth with a single weight of 300 g / m2.

[0067] Example 4: A degradable plastic-wood composite material plate, and a manufacturing method thereof, includes the following steps:

[0068] (1) take 100 parts by weight of wood powder, 100 parts of polyformaldehyde and 400 parts of dimethyl sulfoxide, add to the reaction vessel, stir evenly, heat to 125℃ in 20 minutes, after 10 minutes, cool to 90℃, add 100 parts by weight of polyformaldehyde, mix evenly, heat to 130℃ again, stir and disperse for 20 minutes, then cool to room temperature; then add 10 parts by weight of maleic anhydride and 0.8 parts by weight of p-dimethylaminopyridine to the mixed solution, mix evenly, heat to 90℃, stir and react for 60 minutes, then cool to room temperature;

[0069] (2) take 24 parts by weight of diethylenetriamine and 0.5 parts by weight of phosphoric acid, add to the mixed solution of step (1), mix evenly, and react at room temperature for 40 minutes;

[0070] (3) take 30 parts by weight of maleic anhydride, add to the solution of step (2), stir evenly, heat to 90℃, stir and react for 50 minutes, then cool to room temperature;

[0071] (4) take 45 parts by weight of diethylenetriamine, add to the mixed solution of step (3), mix evenly, and react at room temperature for 150 minutes;

[0072] (5) after the reaction is completed, filter out the dimethyl sulfoxide to obtain treated wood powder, wash the treated wood powder 3 times with water, then dry it, heat to 140℃, react for 80 minutes, cool to room temperature, and obtain modified wood powder;

[0073] (6) take 100 parts by weight of starch, 20 parts by weight of glycerol and 90 parts by weight of modified wood powder respectively, mix evenly, and process into a starch-based composite material plate with a thickness of 4mm by calendering;

[0074] (7) take 100 parts by weight of polycaprolactone and 100 parts by weight of hemp fiber cloth respectively, melt the polycaprolactone, evenly coat it on both sides of the hemp fiber cloth, solidify to obtain a polycaprolactone-based composite material plate;

[0075] (8) according to the size of the mold cavity of the mold, cut the starch-based composite material plate and the polycaprolactone-based composite material plate;

[0076] (9) place 1 layer of starch-based composite material plate, 2 layers of polycaprolactone-based composite material plate, 1 layer of starch-based composite material plate, 3 layers of polycaprolactone-based composite material plate and 1 layer of starch-based composite material plate in the mold cavity from bottom to top, clamp, mold at 10MPa and 70℃ for 50 minutes, perform exhaust operation once during the pressing process, cool to room temperature after the molding is completed, open the mold, and take out the plate to obtain a degradable plastic-wood composite material plate;

[0077] The wood powder has a particle size of 100 mesh;

[0078] The hemp fiber cloth is hemp fiber cloth, and the single weight is 100 g / m2.

[0079] Embodiment 5: A degradable plastic-wood composite material plate, and a manufacturing method thereof, comprising the following steps:

[0080] (1) 100 parts by weight of wood powder, 200 parts of polyformaldehyde and 500 parts of dimethyl sulfoxide were weighed and added into a reaction container, and stirred uniformly, and then heated to 130 DEG C within 16 minutes, and after 15 minutes, cooled to 80 DEG C, and then 150 parts by weight of polyformaldehyde was added and mixed uniformly, and then heated to 135 DEG C again, and after stirring and dispersing for 10 minutes, cooled to room temperature; then 20 parts by weight of maleic anhydride and 1 part by weight of p-dimethylaminopyridine were added into the mixed solution, and mixed uniformly, and heated to 70 DEG C, and after stirring for 75 minutes, cooled to room temperature;

[0081] (2) 36 parts by weight of diethylene triamine and 0.1 parts by weight of phosphoric acid were weighed and added into the mixed solution of step (1), and after mixing uniformly, reacted at room temperature for 60 minutes;

[0082] (3) 40 parts by weight of maleic anhydride was weighed and added into the solution of step (2), and stirred uniformly, and after heating to 70 DEG C, reacted for 60 minutes under stirring, and then cooled to room temperature;

[0083] (4) 65 parts by weight of diethylene triamine was weighed and added into the mixed solution of step (3), and after mixing uniformly, reacted at room temperature for 120 minutes;

[0084] (5) After the reaction was completed, the dimethyl sulfoxide was removed by filtration to obtain the treated wood powder, and the wood powder was washed with water for 5 times, and then dried, and heated to 160 DEG C, and reacted for 60 minutes, and then cooled to room temperature to obtain the modified wood powder;

[0085] (6) 100 parts by weight of starch, 30 parts by weight of glycerol and 100 parts by weight of modified wood powder were respectively weighed and mixed uniformly, and then processed into a starch-based composite material plate with a thickness of 2 mm by using a calendering forming method;

[0086] (7) 100 parts by weight of polycaprolactone and 150 parts by weight of hemp fiber cloth were respectively weighed, and the polycaprolactone was melted and uniformly coated on both sides of the hemp fiber cloth, and after solidification, a polycaprolactone-based composite material plate was obtained;

[0087] (8) According to the size of the cavity of the mold die, the starch-based composite material plate and the polycaprolactone-based composite material plate were cut;

[0088] (9) in the mold cavity, from bottom to top, lay 1 layer of starch-based composite material plate, 3 layers of polycaprolactone-based composite material plate, 1 layer of starch-based composite material plate, 1 layer of polycaprolactone-based composite material plate and 1 layer of starch-based composite material plate, clamp, mold at 20 MPa, 80℃ for 30 minutes, exhaust operation 3 times during the pressing process, after the end of the molding, cooling to room temperature, open the mold, take out the plate, a kind of degradable plastic wood composite material plate is obtained;

[0089] The wood powder has a particle size of 160 mesh.

[0090] The hemp fiber cloth is a linen fiber cloth, and the single weight is 200 g / m2.

[0091] Example 6: a kind of degradable plastic wood composite material plate, its manufacturing method includes the following steps:

[0092] (1) take 100 parts by weight of wood powder, 300 parts of polyformaldehyde and 300 parts of dimethyl sulfoxide, add to the reaction container, stir uniformly, heat to 135℃ in 18 minutes, 5 minutes later, reduce to 85℃, add 200 parts by weight of polyformaldehyde, mix evenly, heat to 125℃ again, stir and disperse for 15 minutes, then reduce to room temperature;Then add 30 parts by weight of maleic anhydride and 0.6 parts by weight of p-dimethylaminopyridine to the mixed solution, mix evenly, heat to 80℃, stir for 90 minutes, then reduce to room temperature;

[0093] (2) take 12 parts by weight of diethylene triamine and 0.3 parts by weight of phosphoric acid, add to the mixed solution of step (1), mix evenly, then react at room temperature for 80 minutes;

[0094] (3) take 20 parts by weight of maleic anhydride, add to the solution of step (2), stir evenly, 80℃, stir for 70 minutes, then reduce to room temperature;

[0095] (4) take 25 parts by weight of diethylene triamine, add to the mixed solution of step (3), mix evenly, then react at room temperature for 135 minutes;

[0096] (5) after the reaction is finished, filter out dimethyl sulfoxide to obtain treated wood powder, wash the wood powder 7 times, then dry it, heat to 120℃, react for 70 minutes, cool to room temperature, and obtain modified wood powder;

[0097] (6) take 100 parts by weight of starch, 40 parts by weight of glycerol and 80 parts by weight of modified wood powder respectively, mix evenly, and then process into a starch-based composite material plate with a thickness of 3 mm by calendering molding;

[0098] (7) respectively take 100 parts by weight of polycaprolactone and 200 parts by weight of hemp fiber cloth, melt the polycaprolactone, and uniformly coat the polycaprolactone on both sides of the hemp fiber cloth, and obtain a polycaprolactone-based composite material plate after solidification;

[0099] (8) according to the size of the cavity of the mold, cut the starch-based composite material plate and the polycaprolactone-based composite material plate;

[0100] (9) in the mold cavity, sequentially place 1 layer of the starch-based composite material plate, 1 layer of the polycaprolactone-based composite material plate, 1 layer of the starch-based composite material plate, 2 layers of the polycaprolactone-based composite material plate, and 1 layer of the starch-based composite material plate from bottom to top, clamp, and press at 30 MPa and 60°C for 40 minutes, perform exhaust operation 5 times during the pressing process, after the pressing is completed, cool to room temperature, open the mold, and take out the plate, to obtain a degradable plastic-wood composite material plate;

[0101] The wood powder has a particle size of 40 mesh.

[0102] The hemp fiber cloth is hemp fiber cloth with a single weight of 300 g / m2.

[0103] Example 7: A degradable plastic-wood composite material plate, and a manufacturing method thereof, includes the following steps:

[0104] (1) take 100 parts by weight of wood powder, 180 parts of polyformaldehyde, and 320 parts of dimethyl sulfoxide, add them to a reaction container, stir uniformly, heat to 127°C in 17 minutes, cool to 86°C after 7 minutes, add 160 parts by weight of polyformaldehyde, mix uniformly, heat to 126°C again, stir and disperse for 14 minutes, and then cool to room temperature; then add 14 parts by weight of maleic anhydride and 0.9 parts by weight of p-dimethylaminopyridine to the mixed solution, mix uniformly, heat to 79°C, and react for 68 minutes under stirring, and then cool to room temperature;

[0105] (2) take 18 parts by weight of diethylenetriamine and 0.2 parts by weight of phosphoric acid, add them to the mixed solution of step (1), mix uniformly, and react at room temperature for 42 minutes;

[0106] (3) take 23 parts by weight of maleic anhydride, add it to the solution of step (2), stir uniformly, react at 73°C for 55 minutes under stirring, and then cool to room temperature;

[0107] (4) take 26 parts by weight of diethylenetriamine, add it to the mixed solution of step (3), mix uniformly, and react at room temperature for 125 minutes;

[0108] (5) after the reaction is completed, filter out the dimethyl sulfoxide to obtain treated wood powder, wash the wood powder 6 times after water treatment, then dry it, heat to 126°C, react for 66 minutes, cool to room temperature, and obtain modified wood powder;

[0109] (6) Respectively take 100 parts by weight of starch, 23 parts by weight of glycerol and 83 parts by weight of modified wood powder, after mixing uniformly, use calendering forming method to process into starch-based composite material board with thickness of 2.5 millimeters;

[0110] (7) Respectively take 100 parts by weight of polycaprolactone and 170 parts by weight of hemp fiber cloth, after melting polycaprolactone, uniformly coat on both sides of hemp fiber cloth, after solidification, obtain polycaprolactone-based composite material board;

[0111] (8) According to the size of the cavity of the mold, cut the starch-based composite material board and polycaprolactone-based composite material board;

[0112] (9) In the mold cavity, from bottom to top, lay 1 layer of starch-based composite material board, 2 layers of polycaprolactone-based composite material board, 1 layer of starch-based composite material board, 3 layers of polycaprolactone-based composite material board and 1 layer of starch-based composite material board, clamp, mold at 18 MPa, 68℃ for 38 minutes, carry out exhaust operation 4 times during pressing process, after the end of molding, cool to room temperature, open the mold, take out the board, thus obtain a degradable plastic-wood composite material board;

[0113] The wood powder has a particle size of 80 mesh;

[0114] The hemp fiber cloth is ramie fiber cloth with single weight of 165 grams per square meter.

[0115] The effect of example 1 is proved by the following experiment.

[0116] According to the method of example 1, make test board, bury in soil, test the related performance before soil burial and after soil burial for 15 days and 30 days respectively, soil environment: loess, average moisture content 30%, average pH value 7.6, average soil temperature 10.2℃.

[0117] After detection, the bending strength of the degradable plastic-wood composite material board before soil burial is 10.82 MPa, the bending modulus is 425.31 MPa, the shear strength in the middle layer is 3.02 MPa, after soil burial for 15 days, the bending strength is 5.68 MPa, the bending modulus is 189.92 MPa, the mass loss is 25.16%; after soil burial for 30 days, the sample degrades and breaks, the mass loss is 61.50%, and the bending strength and bending modulus cannot be measured.

[0118] The detection results show that the obtained degradable plastic-wood composite material board has good mechanical properties, can meet the needs of daily use, such as flowerpot, disposable lunch box, etc., at the same time, has excellent degradability, short degradation period.

Claims

1. A method for preparing a degradable plastic-wood composite board, characterized in that The manufacturing method comprises the following steps: (1) take 100 parts by weight of wood powder, 100-300 parts of polyformaldehyde and 300-500 parts of dimethyl sulfoxide, add them into a reaction container, stir them uniformly, heat them to 125-135 DEG C within 16-20 minutes, cool them to 80-90 DEG C after 5-15 minutes, add 100-200 parts by weight of polyformaldehyde, mix them uniformly, heat them to 125-135 DEG C again, cool them to room temperature after stirring and dispersing for 10-20 minutes; then add 10-30 parts by weight of maleic anhydride and 0.6-1 part by weight of p-dimethylaminopyridine into the mixed solution, mix them uniformly, heat them to 70-90 DEG C, cool them to room temperature after reacting for 60-90 minutes under stirring; (2) take 12-36 parts by weight of diethylenetriamine and 0.1-0.5 parts by weight of phosphoric acid, add them into the mixed solution of step (1), mix them uniformly, and react for 40-80 minutes at room temperature; (3) take 20-40 parts by weight of maleic anhydride, add it into the solution of step (2), stir them uniformly, heat them to 70-90 DEG C, cool them to room temperature after reacting for 50-70 minutes under stirring; (4) take 25-65 parts by weight of diethylenetriamine, add it into the mixed solution of step (3), mix them uniformly, and react for 120-150 minutes at room temperature; (5) after the reaction is completed, filter out the dimethyl sulfoxide to obtain the treated wood powder, wash the treated wood powder for 3-7 times, then dry it, heat it to 120-160 DEG C, react for 60-80 minutes, cool it to room temperature to obtain the modified wood powder; (6) take 100 parts by weight of starch, 20-40 parts by weight of glycerol and 80-100 parts by weight of the modified wood powder respectively, mix them uniformly, and process them into starch-based composite material plates with a thickness of 2-4 mm by using calendering forming mode; (7) take 100 parts by weight of polycaprolactone and 100-200 parts by weight of hemp fiber cloth respectively, melt the polycaprolactone, uniformly coat it on both sides of the hemp fiber cloth, solidify it to obtain polycaprolactone-based composite material plates; (8) according to the size of the cavity of the mold die, cut the starch-based composite material plates and the polycaprolactone-based composite material plates; (9) place 1 layer of the starch-based composite material plate, 1-3 layers of the polycaprolactone-based composite material plate, 1 layer of the starch-based composite material plate, 1-3 layers of the polycaprolactone-based composite material plate and 1 layer of the starch-based composite material plate in the cavity of the mold die from bottom to top, clamp the mold, mold press at 10-30 MPa and 60-80 DEG C for 30-50 minutes, carry out exhaust operation for 1-5 times during the pressing process, cool the mold to room temperature after the mold pressing is completed, open the mold, and take out the plate to obtain a degradable plastic-wood composite material plate; The wood powder has a particle size of 40-160 mesh; The hemp fiber cloth is one of ramie fiber cloth, flax fiber cloth, hemp fiber cloth and sisal fiber cloth, and the single weight is 100-300 g / m2.