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CN-122011721-A - Special carbon dioxide-based mulch film opening agent master batch and preparation method thereof

CN122011721ACN 122011721 ACN122011721 ACN 122011721ACN-122011721-A

Abstract

The invention provides a carbon dioxide-based mulch film special-purpose opening agent master batch and a preparation method thereof. The master batch of the opening agent is prepared from a lubricant, silicon dioxide, a plasticizer and a biodegradable polymer which are used as raw materials in specific parts by mass. The practical application shows that the carbon dioxide-based cold-mixed blown mulching film has obvious anti-sticking effect and impact resistance. The determination of the anti-blocking method B of the film and the sheet of the GB/T39935-2021 plastic product shows that the carbon dioxide base plastic film separation average load of the carbon dioxide base plastic film prepared by the special opening agent master batch for the carbon dioxide base mulch according to the adding amount of 3 percent is 0.28N. The impact strength of the system reaches over 17.71 KJ/m 2 and can reach 22.54 KJ/m 2 by the measurement of the impact strength of GB/T1843-2008 plastic cantilever Liang Moque opening.

Inventors

  • HE PENGYU
  • JU HONGYAN
  • GAO FENGXIANG
  • WANG XIANHONG
  • WU RUI
  • ZHAO DI

Assignees

  • 中国科学院长春应用化学研究所

Dates

Publication Date
20260512
Application Date
20260327

Claims (10)

  1. 1. The special carbon dioxide-based mulch film opening agent master batch is characterized by being prepared from the following raw materials in parts by mass: 10-20 parts of a slipping agent; 20-30 parts of silicon dioxide; 3-5 parts of plasticizer; 50-70 parts of biodegradable polymer; Wherein the plasticizer is selected from one or more of epoxidized soybean oil, acetyl tributyl citrate, tributyl citrate or PPC dihydric alcohol.
  2. 2. The carbon dioxide-based mulch dedicated opening agent master batch according to claim 1, wherein the silica is amorphous silica, the average particle size is 4-6 μm, the particle size distribution is less than 6 μm, and the water content is less than 2%.
  3. 3. The carbon dioxide-based mulch dedicated opening agent masterbatch according to claim 1 or 2, characterized in that the slipping agent is selected from any one or more of oleamide, ethylene bis-stearamide, erucamide or pentaerythritol stearate.
  4. 4. The carbon dioxide-based mulch dedicated opening agent masterbatch according to any one of claims 1 to 3, wherein the biodegradable polymer is selected from PPC and/or PBAT.
  5. 5. The carbon dioxide-based mulch dedicated opening agent masterbatch according to any one of claims 1 to 4, characterized in that the biodegradable polymer exists in the form of powder; The particle size of the PPC is smaller than 0.9 mm, the number average molecular weight is 100-150 kDa, the molecular weight distribution is 2.2-3, the melt index is 0.3-1.5 g/min, and the melt index is measured at the temperature of 170 ℃ and the weight mass of 2.160-kg; the particle size of the PBAT is smaller than 0.9 mm, the number average molecular weight is 60-80 kDa, the molecular weight distribution is 2.2-3, the melt index is 3-5 g/min, and the melt index is measured at the temperature of 190 ℃ and the weight mass of 2.160-kg.
  6. 6. The carbon dioxide-based mulch dedicated opening agent masterbatch according to any one of claims 1 to 5, characterized in that the impact strength of the carbon dioxide-based mulch dedicated opening agent masterbatch is 17.50 KJ/m2 or more, and the membrane separation load is 0.65N or less.
  7. 7. A method for preparing the carbon dioxide-based mulch dedicated opening agent master batch according to any one of claims 1 to 6, characterized by comprising the following steps: And (3) carrying out melt granulation on the mixture of the slipping agent, the silicon dioxide, the plasticizer and the biodegradable polymer in a double-screw extruder to obtain the master batch of the special carbon dioxide-based mulch film.
  8. 8. The preparation method according to claim 7, wherein the silica and the plasticizer are stirred and mixed uniformly, and then stirred and mixed with the slipping agent and the biodegradable polymer to obtain a mixture.
  9. 9. The method of claim 7 or 8, wherein the silica and plasticizer are mixed by a staged variable speed stirring process; the staged variable speed stirring process comprises the steps of mixing for 0.5-5 min at 30-60 r/min and mixing for 0.5-5 min at 500-800 r/min.
  10. 10. The method according to any one of claims 7 to 9, wherein the processing temperature of the twin screw extruder is 130 to 170 ℃.

Description

Special carbon dioxide-based mulch film opening agent master batch and preparation method thereof Technical Field The invention belongs to the field of biodegradable materials, and particularly relates to a carbon dioxide-based special opening agent master batch for a mulch film and a preparation method thereof. Background Compared with the traditional polyethylene mulching film, the carbon dioxide-based mulching film has the outstanding technical advantages that the carbon dioxide-based mulching film takes polymethyl ethylene carbonate (PPC) as a main raw material, and has the characteristic of complete biodegradability, and degradation products are only water and carbon dioxide, so that a feasible technical scheme is provided for fundamentally solving the problem of white pollution of farmlands. In the preparation process of carbon dioxide-based mulch films, cold mix blow molding technology has been attracting attention because of its unique process advantages. The process directly carries out melt blow molding after physical mixing of the raw materials of each component of the mulch film, and omits an intermediate granulating link for preparing the modified master batch in the traditional process. The simplification of the process route not only reduces the molecular weight loss of the biodegradable material in the repeated hot working process and ensures the mechanical property of the mulching film, but also has the characteristics of short process flow, low energy consumption and controllable cost, and has good industrialized application prospect. However, the technology still faces a key technical bottleneck in the popularization and application process. Because of the inherent high rebound viscoelasticity and electrostatic adsorption characteristics of the PPC material, the film is easy to be tightly adhered between layers in the rolling process. The problem directly causes the difficulty and the easy breakage of unwinding the mulch film in the subsequent mechanized paving operation, severely restricts the automatic mulch film covering efficiency of the agricultural machine, and influences the practical application effect of the mulch film serving as the functional agricultural covering material. In order to solve the above problems, the conventional plastic processing field generally adopts a scheme of adding a slipping agent and an opening agent to reduce the surface friction coefficient of the film, thereby improving adhesion. However, in the implementation of a cold mix blow molding process, uniform mixing of the raw materials and the auxiliary agents is typically achieved by a high speed mixer. The existing commercial smooth opening agent particles are easily sheared, crushed and even pulverized by high-speed rotating metal paddles in the process, so that the particle size distribution of the auxiliary agent in the mixed system is out of control, the components are layered, the screw slipping and extrusion fluctuation in the extrusion process are further caused, and the quality stability of a mulching film product is finally affected. At present, the application technology of the silicon dioxide as a common opening agent in the traditional plastic processing is relatively mature, but the application in a biodegradable material system still has obvious technical barriers. The main reason is that the silicon dioxide has the characteristics of large specific surface area and high surface energy, and high requirements are put on the preparation process of the dispersion carrier and the master batch. The lack of special master batch for silicon dioxide with biodegradable polymer as carrier in the current market makes it difficult to realize uniform dispersion and stable opening function in biodegradable systems such as carbon dioxide-based mulching films, and becomes a key bottleneck for limiting the development of the technology. Disclosure of Invention In view of the above, the invention aims to provide a carbon dioxide-based mulch film special-purpose opening agent master batch and a preparation method thereof. The master batch of the opening agent is matched with silicon dioxide by introducing a plasticizer, so that the master batch has excellent impact strength and anti-sticking effect. In order to achieve the purpose, the invention adopts the following technical scheme: In a first aspect, the invention provides a carbon dioxide-based mulch dedicated opening agent master batch, which is prepared from the following raw materials in parts by mass: 10-20 parts of a slipping agent; 20-30 parts of silicon dioxide; 3-5 parts of plasticizer; 50-70 parts of biodegradable polymer; Wherein the plasticizer is selected from one or more of epoxidized soybean oil, acetyl tributyl citrate, tributyl citrate or PPC dihydric alcohol. Preferably, the silica is amorphous silica, the average particle diameter is 4-6 μm, the particle diameter distribution is less than 6 μm (100% particle diameter is less than 6 μm),