CN-122011692-A - Full-biodegradable mulching film added with straw powder and micro-fertilizer and preparation method and application thereof

Abstract

The invention relates to the field of agricultural environment-friendly materials, and discloses a full-biodegradable mulching film added with straw powder and a micro-fertilizer, and a preparation method and application thereof. The mulching film comprises 60-80 parts of poly (adipic acid)/butylene terephthalate (PBAT), 5-20 parts of polylactic acid (PLA), 5-15 parts of blocking agent, 3-8 parts of plasticizer, 3-10 parts of calcium carbonate powder (CaCO 3 ), 1-7 parts of straw powder and 1-7 parts of micro-fertilizer. The preparation process comprises drying raw materials, melt blending, granulating (one region 140-170deg.C, screw rotation speed 100-300 RPM) by a twin screw granulator, and film forming (one region 90-130deg.C, screw rotation speed 15-45 RPM) by a film blowing machine. The mulch film is used for agricultural covering, can promote crop microelement absorption, enhance stress resistance and improve soil fertility, solves the problems of insufficient mechanical property, single function and low utilization rate of agricultural wastes of the traditional mulch film, has the benefits of environmental protection and yield increase, realizes nutrient slow release in the degradation process, and promotes sustainable development of agricultural ecology.

Inventors

• FEI JIANGCHI
• MIN XIAOYE
• Ke Xianao
• Gui Shiyu
• Zheng Aocheng

Assignees

• 湖南农业大学

Dates

Publication Date

20260512

Application Date

20260205

Claims (10)

1. 1. The full-biodegradable mulching film added with the straw powder and the micro-fertilizer is characterized by comprising the following raw material components in parts by weight: 60-80 parts of poly (adipic acid)/butylene terephthalate (PBAT), 5-20 parts of polylactic acid (PLA), 5-15 parts of blocking agent, 3-8 parts of plasticizer, 3-10 parts of calcium carbonate powder (CaCO 3 ), 1-7 parts of straw powder and 1-7 parts of trace fertilizer.
2. 2. The fully biodegradable mulch film according to claim 1, characterized in that the barrier agent is polypropylene carbonate (PPC).
3. 3. The fully biodegradable mulch film according to claim 1, wherein: the plasticizer is at least one of Epoxidized Soybean Oil (ESO), ATBC, DOP, glycerol, sorbitol, xylitol, glycerol, white oil or polyethylene glycol.
4. 4. The fully biodegradable mulch film according to claim 1, wherein the calcium carbonate powder is light calcium carbonate with a particle size of 1000-5000 mesh.
5. 5. The fully biodegradable mulch film according to claim 1, wherein the straw powder is corn straw powder with a particle size of 1000-3000 meshes, and the preparation method comprises: cutting corn stalk, drying at 105deg.C for 12 hr, and pulverizing to 60-100 mesh; fine crushing to above 1000 meshes by a high-pressure pulse crusher, and screening to 1000-3000 meshes by an ultrasonic vibration screen.
6. 6. The fully biodegradable mulch film according to claim 1, wherein the micro fertilizer is powder rich in iron, zinc, boron, manganese, copper and molybdenum, and has a particle size of 1000-3000 mesh, and the preparation method comprises: (1) Drying the micro-fertilizer in an oven at 40-60 ℃ for 8 hours; (2) Fine crushing to above 1000 meshes by a high-pressure pulse crusher, and screening to 1000-3000 meshes by an ultrasonic vibration screen.
7. 7. The method for producing a fully biodegradable mulch film according to any one of claims 1 to 6, comprising the steps of: (1) Drying PBAT, PLA, calcium carbonate powder, straw powder and trace fertilizer at 30-50 ℃ for 8h; (2) Adding the dried raw materials, the blocking agent and the plasticizer into a double-screw mixing granulator, and granulating after melt blending to obtain mixed plastic particles; (3) And (3) drying the mixed plastic particles for 8 hours at 40-60 ℃, and carrying out blow molding to form a film by a film blowing machine.
8. 8. The method according to claim 7, wherein the twin-screw mixer granulator comprises the following technological parameters: The temperature of the first area is 140-170 ℃, the temperature of the second area is 140-170 ℃, the temperature of the third area is 160-190 ℃, the temperature of the fourth area is 160-190 ℃, the rotating speed of the screw is 100-300RPM, the feeding speed of the hopper is 2-8Hz, and the speed of the granulator is 1-6Hz.
9. 9. The method for preparing the film according to claim 7, wherein the technological parameters of the film blowing machine are as follows: the temperature of the first area is 90-130 ℃, the temperature of the second area is 100-150 ℃, the temperature of the third area is 100-150 ℃, the rotating speed of the screw is 15-45RPM, the traction speed is 5-15RPM, and the winding speed is 5-15RPM.
10. 10. The use of the fully biodegradable mulch film according to any one of claims 1-6, wherein the mulch film is used for ground covering in agricultural planting, and can increase the absorption of trace elements, enhance stress resistance and improve soil fertility.

Description

Full-biodegradable mulching film added with straw powder and micro-fertilizer and preparation method and application thereof Technical Field The invention relates to the technical field of agricultural environment-friendly materials, in particular to a full-biodegradable mulching film added with straw powder and a micro-fertilizer, and a preparation method and application thereof. Background The mulch film covering technology is used as an important component of modern agriculture, and plays a remarkable role in heat preservation, soil moisture preservation, weed suppression and the like. The traditional mulching film mainly comprises Polyethylene (PE), and the characteristic that the PE is difficult to degrade causes accumulation of residual soil films, so that the environmental problems of soil structural damage, crop yield reduction and the like are caused. In recent years, fully biodegradable mulch films become a research hot spot, and the problem of environmental pollution of traditional mulch films is solved by adopting degradable polymers such as PBAT, PLA and the like to prepare the mulch films. However, the prior art still has the following disadvantages: the agricultural waste is not fully utilized; Common biodegradable materials in the market are polylactic acid (PLA) and poly (butylene adipate/terephthalate) (PBAT), and in order to further reduce the preparation cost and increase the degradation speed of the biodegradable mulch film, researchers often add natural plant fibers to PLA and PBAT. As an agricultural waste, the straw has the advantages of low price, sufficient raw materials, high specific modulus, small processing energy consumption and the like. Therefore, the formation of composite materials by using straw as reinforcement and such high molecular polymers has become a current research hot spot. The addition of the straw into the mulching film can reduce cost, improve the resource utilization rate of straw waste, and is beneficial to the implementation of straw returning. At present, the addition of straw to mulching films faces a number of difficulties. Because obvious interface incompatibility exists between the straw and the polymer base material and the surface roughness of the straw fiber is higher, the mechanical property of the composite film added with the straw is generally lower than that of a commercial degradable mulch film product. The balance between mechanical properties and degradation properties is difficult The three-layer full-biodegradable composite membrane disclosed in the Chinese patent publication No. CN110091564A has the advantages that the barrier property is optimized through the formula design of different layers, but the addition of straw powder and micro-fertilizer is not involved, the preparation process is not optimized for the treatment of agricultural wastes, and the double requirements of high strength and soil improvement of the mulching film cannot be met. 3. Functional singleness limitation Although the compatibility of the blending material is improved by adding the compatibilizer in the Chinese patent publication No. CN115260720A, the compatibility is not improved by introducing straw powder as a reinforcing material and the trace element fertilizer is not used as a functional component, so that the slow release function of nutrients in the degradation process cannot be realized, and the requirement of modern agriculture on soil fertility improvement is difficult to meet. In addition, studies have shown that crops can have reduced absorption of trace elements such as iron, copper, manganese and the like under long-term film covering conditions, which can lead to reduced yield and quality of farmland crops due to lack of trace elements. The trace fertilizer is rich in iron, zinc, boron, manganese, copper, molybdenum and other elements, can improve soil fertility, increase crop yield and quality, and strengthen stress resistance of crops, and is a main measure for supplementing trace elements to crops. The micro-fertilizer is added into the mulching film product, so that adverse effects of long-term mulching film coverage on the absorption of trace elements by crops can be improved, the yield and quality of the crops can be improved, and the long-term stable development of the agricultural ecological environment can be protected. The preparation method of the mulching film added with the micro fertilizer has not been reported yet. Based on the background, the functional full-biodegradable mulching film added with the straw powder and the micro-fertilizer is developed, so that the cost of the biodegradable mulching film can be reduced, the straw resource utilization rate is improved, and the functional full-biodegradable mulching film has great significance in improving the quality of agricultural products, promoting the use of the degradable mulching film and protecting the agricultural ecological environment Disclosure of Invention The invention