CN-122008466-A - Continuous forming method of functionalized high-strength polyethylene film material

CN122008466ACN 122008466 ACN122008466 ACN 122008466ACN-122008466-A

Abstract

The invention relates to a continuous forming method of a functionalized high-strength polyethylene film, which comprises the following steps of S1, mixing a photosensitizer and a grafting monomer to prepare a suspension, spraying the suspension into polyethylene to be stirred and dispersed to obtain a composite material, S2, adding the composite material in S1 into a screw extruder to extrude to obtain a thick film, continuously and isobarically pressing the thick film to obtain a thin film, S3, carrying out multiple heat stretching on the thin film in S2 to obtain a film product, carrying out ultraviolet irradiation under an inert atmosphere, and then rolling the film product to obtain the functionalized high-strength polyethylene film. Compared with the prior art, the method can realize continuous molding of the high-strength UHMWPE film material at low temperature, does not need solvents in the preparation process, is environment-friendly, has polarity on the surface of the product, has strong interfacial adhesion when manufacturing the composite material product, and the like.

Inventors

ZHAO WENJING
LI ZHI
CAO YUCAI
XIA JINCHENG
FENG LINGYING
HU YILUN
HONG WEI

Assignees

上海化工研究院有限公司
上海联乐化工科技有限公司

Dates

Publication Date: 20260512
Application Date: 20260330

Claims (10)

1. The continuous forming method of the functionalized high-strength polyethylene film material is characterized by comprising the following steps of: s1, mixing a photosensitizer and a grafting monomer to prepare a suspension, and then spraying the suspension into polyethylene, stirring and dispersing to obtain a composite material; S2, adding the composite material in the S1 into a screw extruder for extrusion to obtain a thick film material, and then continuously performing isostatic pressing to obtain a thin film material; s3, carrying out multiple heat stretching on the thin film material in the S2 to obtain a film material product, carrying out ultraviolet irradiation under an inert atmosphere, and then rolling to obtain the functionalized high-strength polyethylene film material.
2. The continuous forming method of the functionalized high-strength polyethylene film according to claim 1, wherein the photosensitizer is one or more of 2,4,6 (trimethyl benzoyl) diphenyl phosphine oxide, methyl o-benzoyl benzoate, benzophenone, 4-chlorobenzone, 4-phenylbenzophenone and thioxanthone.
3. The continuous forming method of the functionalized high-strength polyethylene film according to claim 1, wherein the grafting monomer is one or more of methacrylic acid, trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, vinyltriethoxysilane, vinyltriacetoxysilane and vinyltriisopropoxysilane.
4. The continuous forming method of the functionalized high-strength polyethylene film material according to claim 1, wherein the polyethylene is polyethylene with a viscosity average molecular weight of more than or equal to 150 ten thousand, and the enthalpy value delta H of the polyethylene is more than or equal to 205J/g.
5. The continuous forming method of the functionalized high-strength polyethylene film material according to claim 1, wherein the mass ratio of the photosensitizer to the grafting monomer to the polyethylene is (0.1-1): (0.5-5): (94-99.4).
6. The continuous forming method of the functionalized high-strength polyethylene film material according to claim 1, wherein in S2, the highest temperature in the extrusion process is 2-20 ℃ below the melting point of the polyethylene, and the thickness of the obtained thick sheet film material is less than or equal to 2mm.
7. The continuous forming method of the functionalized high-strength polyethylene film material according to claim 1, wherein in S2, the pressure of continuous isostatic pressing is more than or equal to 10Mpa, the temperature is lower than the melting point by 2-20 ℃, and the thickness of the obtained sheet is less than or equal to 0.5mm.
8. The continuous forming method of the functionalized high-strength polyethylene film according to claim 1, wherein in the step S2, the continuous isostatic pressing process is performed in a continuous isostatic pressing device, and the continuous isostatic pressing device comprises an upper sprocket belt and a lower sprocket belt, wherein the upper sprocket belt is formed by splicing upper sprocket blocks, the lower sprocket belt is formed by splicing lower sprocket blocks, the upper sprocket blocks are provided with protrusions, the lower sprocket blocks are provided with grooves, the protrusions of the upper sprocket blocks are matched with the groove widths of the lower sprocket blocks when the upper and lower sprocket belts drive, and the protrusion height of the upper sprocket blocks is larger than the groove depth of the lower sprocket blocks.
9. The continuous forming method of the functionalized high-strength polyethylene film material according to claim 1, wherein in the step S3, the temperature of multiple hot drawing is 125-melting point, and the drawing rate is more than or equal to 5.5 times.
10. The continuous forming method of the functionalized high-strength polyethylene film material according to claim 1, wherein in the step S3, the ultraviolet irradiation process is performed in an inert atmosphere, the ambient temperature is controlled to be less than or equal to 70 ℃, the irradiation time is controlled to be more than or equal to 10 minutes, and the ultraviolet irradiation intensity is 20-100 mW/cm 2 .

Description

Continuous forming method of functionalized high-strength polyethylene film material Technical Field The invention belongs to the technical field of advanced polymer material preparation, and relates to a continuous forming method of a functionalized high-strength polyethylene film material. Background The high-strength ultra-high molecular weight polyethylene (Ultra High Molecular Weight Polyethylene Fiber is abbreviated as UHMWPE) nonporous membrane material has the excellent performances of high tensile strength, high modulus, impact resistance, high wear resistance, light weight, small dielectric constant, large heat conductivity and the like, has various use forms, can be directly attached to a wear-resistant self-lubricating film for use on one hand, can be cut into strips/bands/flat wires through membrane splitting fibers for use as high-strength fibers on the other hand, does not need to directly layer a spinning cloth for preparing a high-impact-resistance light composite material product, and has a very wide application range in the field of armies and civilians. The high strength and high modulus properties of UHMWPE products are derived from the highly oriented extended chain crystal structure, but the extremely high molecular weight without solvent causes the molecular chains to be very easy to be entangled during the molding process, and the highly extended orientation of the molecular chains is difficult to achieve. The film material is molded at low temperature to maintain the original low entanglement state of molecular chains in primary particles as much as possible, but on one hand, the material at low temperature is in a sandwich state and has no fluidity, the sheet extruded by the screw is easy to be brittle broken due to weak binding force among incompletely plasticized particles, and has no stretchability, so that the oriented extension of the molecular chains cannot be realized. For example, chinese patent application CN113481723A provides a modified ultra-high molecular weight polyethylene fiber cloth, which is prepared by 1) uniformly spreading ultra-high molecular weight polyethylene fiber, irradiating with an electron accelerator, then freezing and preserving, 2) uniformly spreading the frozen and preserved ultra-high molecular weight polyethylene fiber again, then soaking a grafting monomer for grafting reaction, and drying, and 3) uniformly spreading the modified ultra-high molecular weight polyethylene fiber, soaking glue, drying, and then laminating and pressing. However, the patent is a post-treatment modification process for ultra-high molecular weight polyethylene fibers, and the patent is implemented by a method that firstly prepares fibers and then graft-modifies the fibers according to the formed ultra-high molecular weight polyethylene fibers or cloth, and a gel spinning process using a conventional commercial solvent is used in the process of preparing the fibers, and the fibers are still fibrous after modification according to the patent and cannot be directly attached for use, and when the fibers are used as composite material products, a method that firstly prepares UD cloth and then laminates the UD cloth is still required. Chinese patent CN105949484B provides a method for preparing antistatic polyethylene by ultraviolet irradiation, which comprises the steps of uniformly mixing 100 parts of polyethylene, 3-25 parts of polyethylene glycol and 0.1-4.0 parts of photosensitizer to obtain a mixed material, adding the mixed material into an extruder, arranging a light through hole on a charging barrel of the extruder, starting the extruder to extrude, and simultaneously starting an ultraviolet lamp at the light through hole to perform irradiation reaction, wherein the extruded product is the polyethylene glycol grafted antistatic polyethylene. The patent aims to prepare antistatic polyethylene products, and high-strength polyethylene film materials cannot be prepared through the patent, wherein irradiation grafting reaction is carried out in a charging barrel of an extruder, the irradiation time of the materials is controlled by the extrusion speed, and the production efficiency of the original products is influenced if a certain grafting rate is ensured. And only the irradiated materials can undergo grafting reaction, the method cannot ensure that all the materials undergo grafting reaction, and is more difficult to control molecules undergoing grafting reaction to be concentrated on the surface of the product, and meanwhile, the performance of the body can be influenced, so that the grafting rate is possibly high, but the polarity of the surface of the product is very low because the quantity of the molecules undergoing grafting on the surface of the product is small. Disclosure of Invention The invention aims to provide a continuous forming method of a functionalized high-strength polyethylene film material, which is used for realizing continuous forming of the func