Polyethylene composition for greenhouse film and preparation method of polyethylene composition

Abstract

The invention relates to a polyethylene composition for a greenhouse film. The polyethylene composition is prepared from the following raw materials in parts by weight: 100 parts of mLLDPE resin, 0.03to 0.05 parts of peroxide, 6 to 14 parts of maleic anhydride master batch, 0.1 to 0.5 part of antioxidant, 0.04 to 0.07 part of rheological agent, 1 to 1.5 parts of heat preserving additives, and 0.05 to 0.10 part of lubricating agents. The composition has higher melt viscosity, and the prepared greenhouse film has thermal insulation properties.

Description

technical field [0001] The invention belongs to the field of polymer material modification, and in particular relates to a polyethylene composition for greenhouse film and a preparation method thereof. Background technique [0002] Compared with conventional linear polyethylene resin (LLDPE), mLLDPE has high physical and mechanical strength, excellent tear resistance and puncture resistance, and good optical transparency. It is mainly used to produce thinner and lighter agricultural films and packaging film and other film fields; however, the molecular structure of mLLDPE makes its melt viscosity relatively high, and it is not sensitive to shear during processing, resulting in obvious "stick-slip phenomenon" at the die during extrusion blow molding, and easy to stack films , the film bubble swings, melt fracture is prone to occur, and the film bubble stability is poor; in addition, because the mLLDPE molecular chain has fewer long-chain branches and less chain entanglement, ...

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Problems solved by technology

[0002] Compared with conventional linear polyethylene resin (LLDPE), mLLDPE has high physical and mechanical strength, excellent tear resistance and puncture resistance, and good optical transparency. It is mainly used to produce thinner and lighter agricultural films and packaging film and other film fields; however, the molecular structure of mLLDPE makes its melt viscosity relatively high, and it is not sensitive to shear during processing, resulting in obvious "stick-slip phenomenon" at the die during extrusion blow molding, and easy to stack films , the film bubble swings, melt fracture is prone to occur, and the film bubble stability is poor; in addition, because the mLLDPE molecular chain has fewer long-chain branches and less chain entanglement, the melt strength is low, resulting in poor stability of the blown film bubble , so that the production of metallocene polyethylene greenhouse film is more difficult, and it is impossible to produce wide-format greenhouse film with excellent performance alone. It is only produced in the form of multi-layer composite, which limits its application field. At present, the main method to improve the processing performance of mLLDPE is to add high melt Strong polymers such as LDPE, but this will reduce the physical and mechanical properties of mLLDPE

[0003] Moreover, the polyethylene greenhouse film also has the following problems: due to the heating effect of sunlight during the day, the temperature in the shed can be maintained at a higher temperature, which is beneficial to the growth of crops, but at night or when there is no sunlight, when the temperature difference between day and night is large. , due to the loss of heat in the film, the temperature will drop a lot, which is not conducive to the growth of crops; therefore, it is necessary to develop a thermal insulation greenhouse film that can effectively avoid temperature drop, which is conducive to the promotion and use of mLLDPE greenhouse film