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CN-122008673-A - PBST three-layer co-extrusion biodegradable film, preparation method thereof and biodegradable mulching film

CN122008673ACN 122008673 ACN122008673 ACN 122008673ACN-122008673-A

Abstract

The invention discloses a PBST three-layer co-extrusion biodegradable film, a preparation method thereof and a biodegradable mulching film, and belongs to the technical field of biodegradable films; according to parts by weight, the preparation raw materials of the core layer comprise 75-95 parts of PBST, 10-20 parts of heavy calcium carbonate, 10-20 parts of other fillers and 1-2 parts of toughening agents, and the preparation raw materials of the surface layer comprise 65-90 parts of PBST, 10-35 parts of PBAT and 0.5-2 parts of compatible toughening agents. The invention realizes excellent mechanical property and heat preservation and soil moisture preservation property of the biodegradable film by selecting the types/compositions of main resin of the core layer and the surface layer of the PBST three-layer co-extrusion biodegradable film.

Inventors

  • CHEN ZHENDONG
  • CHEN YAN
  • CHEN HUA

Assignees

  • 佛山安亿纳米材料有限公司

Dates

Publication Date
20260512
Application Date
20260413

Claims (10)

  1. 1. The PBST three-layer co-extrusion biodegradable film is characterized by comprising a core layer and a surface layer, wherein the surface layer comprises a first surface layer and a second surface layer which are respectively positioned at two sides of the core layer; According to parts by weight, the preparation raw materials of the core layer comprise 75-95 parts of PBST, 10-20 parts of heavy calcium carbonate, 10-20 parts of other fillers and 1-2 parts of toughening agents, and the preparation raw materials of the surface layer comprise 65-90 parts of PBST, 10-35 parts of PBAT and 0.5-2 parts of compatible toughening agents.
  2. 2. The PBST three-layer co-extruded biodegradable film according to claim 1, wherein the core layer is prepared from 1-4 parts of plant fiber, and the surface layer is prepared from 0.1-1 part of ultraviolet inhibitor and 0.1-1 part of antioxidant.
  3. 3. The PBST three-layer co-extruded biodegradable film according to claim 2, wherein the plant fiber is selected from bamboo powder and hemp stalk powder, the anti-ultraviolet agent is selected from at least one of nano titanium dioxide and nano cerium oxide, and the antioxidant is selected from hindered phenols.
  4. 4. The PBST three-layer co-extruded biodegradable film according to claim 2, wherein the plant fiber is selected from bamboo powder and coconut powder, the anti-ultraviolet agent is selected from at least one of nano titanium dioxide and nano cerium oxide, and the antioxidant is selected from hindered phenols and phosphites.
  5. 5. The PBST three-layer co-extruded biodegradable film according to any one of claims 1 to 4, wherein the heavy calcium is selected from activated heavy calcium, and/or the other filler is selected from at least one of talc powder, mica, kaolin, barium sulfate, zinc sulfide, aluminum sulfide, and calcium sulfide, and/or the toughening agent is selected from at least one of POE-g-GMA, POE-g-MAH, TPEE, and/or the compatible toughening agent is selected from at least one of POE-g-GMA, POE-g-MAH.
  6. 6. The PBST three-layer co-extruded biodegradable film according to any one of claims 1 to 4, wherein the raw materials for preparing the surface layer further comprise 0.5 to 3 parts of an opening slipping agent; And/or the ratio of the thickness of the core layer to the thickness of the surface layer is 1-1.2:1.
  7. 7. The method for preparing the PBST three-layer co-extrusion biodegradable film according to any one of claims 1-6, which is characterized by comprising the steps of respectively heating and melting preparation raw materials of a core layer and a surface layer, conveying the raw materials to a co-extrusion die head, extruding, performing inflation molding, traction and rolling to obtain the PBST three-layer co-extrusion biodegradable film.
  8. 8. The method according to claim 7, wherein the temperature of the heating and melting is 120-160 ℃ and the temperature of the co-extrusion die is 143-147 ℃, or the temperature of the heating and melting is 125-165 ℃ and the temperature of the co-extrusion die is 148-152 ℃.
  9. 9. The method according to claim 7, wherein the inflation ratio of the inflation molding is 2.5 to 3.0, and/or the traction ratio of the traction is 3.5 to 4.2.
  10. 10. A PBST three-layer co-extruded biodegradable mulch film comprising the PBST three-layer co-extruded biodegradable film of any one of claims 1 to 6.

Description

PBST three-layer co-extrusion biodegradable film, preparation method thereof and biodegradable mulching film Technical Field The invention belongs to the technical field of biodegradable films, and particularly relates to a PBST three-layer co-extrusion biodegradable film, a preparation method thereof and a biodegradable mulching film. Background The plastic film mulching technology is an important means for agricultural yield increase in arid and semiarid areas. The traditional Polyethylene (PE) mulching film is widely applied in the area, so that the problems of soil moisture conservation, temperature increase and the like are effectively solved, but the PE mulching film is difficult to degrade naturally. In recent years, fully biodegradable mulch films have become an important direction to replace PE mulch films. Biodegradable materials such as polybutylene adipate terephthalate (PBAT) and polylactic acid (PLA) have been gradually applied to the production of mulching films. However, the existing biodegradable mulching film has obvious defects that firstly, the mechanical strength is low, particularly the tensile strength and the wind and sand abrasion resistance are insufficient, the invasion of strong wind and sand weather in spring is difficult to resist, tearing and breakage are easy to occur during covering, secondly, the heat preservation and soil moisture preservation performances are required to be improved, and the heat preservation and soil moisture preservation functions are difficult to fully play. Further, the planting of cotton in Xinjiang requires a mulch protection period of about 140 days, and the full-biodegradable mulch in the prior art is difficult to realize accurate membrane rupture in the Xinjiang for about 140 days. Therefore, how to develop a biodegradable film with improved mechanical properties and heat preservation and soil moisture preservation properties, and even further can further meet the requirement of accurate film rupture in the Xinjiang area for about 140 days, is a technical problem to be solved in the field. Disclosure of Invention Aiming at the defects in the prior art, the PBST three-layer co-extrusion biodegradable film, the preparation method thereof and the biodegradable mulching film are provided, and at least the problem that the biodegradable film is poor in mechanical property and heat preservation and soil moisture preservation is solved. Specifically, the invention realizes excellent mechanical property and heat preservation and soil moisture conservation property of the biodegradable film by selecting the types/compositions of main resin of the core layer and the surface layer of the PBST three-layer co-extrusion biodegradable film. The first object of the present invention is to provide a PBST three-layer co-extrusion biodegradable film, which comprises a core layer and a surface layer, wherein the surface layer comprises a first surface layer and a second surface layer which are respectively positioned at two sides of the core layer; According to parts by weight, the preparation raw materials of the core layer comprise 75-95 parts of PBST, 10-20 parts of heavy calcium carbonate, 10-20 parts of other fillers and 1-2 parts of toughening agents, and the preparation raw materials of the surface layer comprise 65-90 parts of PBST, 10-35 parts of PBAT and 0.5-2 parts of compatible toughening agents. In order to further realize the controllable membrane rupture time of the mulching film formed by the biodegradable film in Xinjiang, in some preferred embodiments of the invention, the preparation raw materials of the core layer further comprise 1-4 parts of plant fibers, and the preparation raw materials of the surface layer further comprise 0.1-1 part of ultraviolet resistant agent and 0.1-1 part of antioxidant. By adding biodegradable plant fibers in the core layer and adding anti-ultraviolet and antioxidant components in the surface layer, the two components are mutually influenced, and the film breaking time of the film formed by the biodegradable film can be controlled in Xinjiang areas. In some preferred embodiments of the present invention, for example, for northern Jiang regions where low-temperature and high-weather conditions are evident, the plant fiber is selected from bamboo powder and hemp stalk powder, the mass ratio of the bamboo powder to the hemp stalk powder is preferably 1:0.1-1, more preferably 1:0.4-0.8, the anti-ultraviolet agent is selected from at least one of nano titanium dioxide and nano cerium oxide, and the antioxidant is selected from hindered phenols. In the invention, the plant fiber, the ultraviolet resistant agent and the antioxidant are selected to adapt to the climate in northern Jiang region, so that the accurate membrane rupture of about 140 days is further realized, and the planting requirements of crops such as cotton are met. In other preferred embodiments of the present invention, for example, for southern Xinjiang re