CN-121975051-A - Preparation method and application of self-reinforced high-performance resin special for polyolefin wiredrawing

CN121975051ACN 121975051 ACN121975051 ACN 121975051ACN-121975051-A

Abstract

The invention discloses a preparation method and application of a self-reinforced high-performance polyolefin wiredrawing special resin, and belongs to the field of high-performance fiber preparation. The low fiber strength of the existing High Density Polyethylene (HDPE) fiber commercial materials has limited their use in high strength applications. According to the invention, the molecular chain structure of the resin is regulated and controlled by a melt blending method and an in-situ self-reinforcing method, so that the special resin for the high-performance polyolefin fiber with the melt index range higher than that of commercial materials is prepared, the tensile breaking strength of the obtained high-performance polyolefin fiber is more than or equal to 6 cN/dtex, and the tensile breaking strength of the obtained high-performance polyolefin fiber is more than 20% higher than that of the fiber prepared by the commercial fiber materials, and the requirements of application scenes such as marine fishery and industrial manufacturing on the high-performance HDPE fiber can be met.

Inventors

LI WEI
CHENG YANQING
DI YUTAO
SHI XUANYU
WANG JINGDAI
YANG YONGRONG

Assignees

浙江大学

Dates

Publication Date: 20260505
Application Date: 20260130

Claims (10)

1. A self-reinforced high-performance polyolefin wiredrawing special resin is characterized in that the melt index of the self-reinforced high-performance polyolefin wiredrawing special resin is in the range of 0.6-1.9 g/10min measured under the load of 2.16kg at 190 ℃, the density is in the range of 0.940-0.960 g/cm 3 , the weight average molecular weight is in the range of 6-15X 10 4 g/mol, the alpha-olefin insertion rate of short-branched chain distribution is 0.1-1.0/1000C in the weight average molecular weight range of 10 3.5 ~10 4.0 g/mol, the alpha-olefin insertion rate of short-branched chain distribution is 0.2-2.0/1000C in the weight average molecular weight range of 10 4.1 ~10 4.5 g/mol, the alpha-olefin insertion rate of short-branched chain distribution is 1.0-10.0/1000C in the weight average molecular weight range of 10 4.6 ~10 5.0 g/mol, and the alpha-olefin insertion rate of short-branched chain distribution is 3-20/1000C in the weight average molecular weight range of 10 5.1 ~10 5.5 g/mol.
2. The self-reinforced high-performance resin special for polyolefin wiredrawing according to claim 1, wherein the resin is formed by blending a high-molecular-weight polyethylene component and a low-molecular-weight polyethylene component, wherein the blending method is melt blending or in-situ blending, the content of the high-molecular-weight polyethylene component is 0.1-50 wt%, the weight average molecular weight of the high-molecular-weight polyethylene component is 30-1000 x10 4 g/mol, and the weight average molecular weight of the low-molecular-weight polyethylene component is 1-20 x10 4 g/mol.
3. A method for preparing the self-reinforced high-performance polyolefin wiredrawing special resin according to claim 1 or 2 by in-situ blending, which is characterized by comprising the following steps: (1) Sequentially adding solvent, cocatalyst, catalyst, hydrogen and ethylene into a reaction kettle, wherein the total polymerization pressure is in the range of 3-10 bar, the hydrogen partial pressure is in the range of 0-2 bar, and the polymerization temperature is in the range of 60-85 ℃, controlling the polymerization time to ensure that the ethylene consumption accumulated amount reaches m 1 , and obtaining the high molecular weight polyethylene component; (2) Releasing residual ethylene monomer and hydrogen in the reaction kettle in the step (1), sequentially adding a comonomer, hydrogen and ethylene into the reaction kettle, wherein the total polymerization pressure is in the range of 6-15 bar, the partial pressure of the comonomer is in the range of 0.1-1 bar, the partial pressure of the hydrogen is in the range of 1.5-3 bar, the polymerization temperature is in the range of 80-90 ℃, and controlling the polymerization time to ensure that the ethylene consumption accumulation amount is m 2 , so as to obtain the low molecular weight component polyethylene; (3) Collecting a polymerization product, and drying to obtain the self-reinforced high-performance polyolefin wiredrawing special resin.
4. The method according to claim 3, wherein the catalyst is one or more of a metallocene catalyst, a chromium-based catalyst, an FI catalyst, a Ziegler Natta catalyst, and a post-transition metal catalyst, and the cocatalyst is one or more of triethylaluminum, triisopropylaluminum, trimethylaluminum, diethylaluminum chloride, ethylaluminum dichloride, tributylaluminum, trihexylaluminum, and trioctylaluminum.
5. A process according to claim 3, wherein the comonomer blended in situ is one or more of a C3-C9 alpha-olefin, cyclic olefin, diene.
6. A method according to claim 3, wherein the high molecular weight polyethylene component (m 1 ) obtained in step (1) accounts for 0.1 to 50 wt% of the self-reinforced high performance polyolefin drawing-dedicated resin (m 1 +m 2 ).
7. The high-performance polyolefin fiber is characterized in that the high-performance polyolefin fiber is prepared from the self-reinforced high-performance polyolefin wiredrawing special resin according to claim 1 or 2 through melt spinning and hot orientation drawing.
8. The high performance polyolefin fiber according to claim 7, wherein the melt spinning is any one of the following a-d processes: a, directly feeding a low-entanglement high-molecular-weight component polyethylene homopolymer and a low-molecular-weight component polyethylene copolymer which form the self-reinforced high-performance polyolefin wiredrawing special resin into a single-screw extruder for melt spinning after physical blending; b, carrying out melt blending granulation after physical blending on a low-entanglement high-molecular-weight component polyethylene homopolymer and a low-molecular-weight component polyethylene copolymer which form the self-reinforced high-performance polyolefin wiredrawing special resin, and then feeding the low-entanglement high-molecular-weight component polyethylene homopolymer and the low-molecular-weight component polyethylene copolymer into a single-screw extruder for melt spinning; c, directly feeding the self-reinforced high-performance polyolefin wiredrawing special resin prepared by in-situ blending into a single screw extruder for melt spinning; And d, blending and granulating the self-reinforced high-performance polyolefin wiredrawing special resin prepared by in-situ self-reinforcement, and then feeding the resin into a single screw extruder for melt spinning.
9. The high-performance polyolefin fiber according to claim 8, wherein in the single screw extruder adopted by the melt spinning, the highest temperature of a screw is 200-260 ℃, the rotating speed of the screw is 5-300 rpm, and the winding speed is 10-2000 m/min; and the hot orientation drawing is to carry out hot drawing on the primary fiber of the high-performance polyolefin fiber, wherein the drawing temperature is 80-130 ℃, the drawing multiple is 8-20 times, and the drawing series is 1-3 stages, and finally the high-performance polyolefin fiber is obtained.
10. The high performance polyolefin fiber according to claim 7, wherein the high performance polyolefin fiber has a tenacity at break of not less than 6 cN/dtex and a young's modulus of not less than 120 cN/dtex.

Description

Preparation method and application of self-reinforced high-performance resin special for polyolefin wiredrawing Technical Field The invention belongs to the field of high-performance fiber preparation, and particularly relates to a preparation method of a special resin for high-performance polyolefin fibers. Background High Density Polyethylene (HDPE) is a common polyolefin material and is widely applied to the fields of packaging, construction, medical treatment, agriculture, automobiles and the like, wherein HDPE fibers have good mechanical properties, excellent processability, corrosion resistance and the like, and have important application values in the scenes of fishing nets, ropes, packaging materials and the like. The density of the existing HDPE fiber commercial material is 0.948-0.954 g/cm 3, the melt index is 0.62-1.90 g/10min, the melt index range is favorable for the industrial production of melt spinning fibers, the melt fracture condition of the fibers is reduced while the melt strength of the materials is ensured, but the breaking strength of the current commercial material fibers is only 4.5-5.2 cN/dtex. The strength of the HDPE fibers is derived from the formation of cross crystals in the drawing process, the molecular chains of the fibers are oriented in the drawing direction to form cross crystals in the drawing process, and longer molecular chains are beneficial to the formation of larger-scale cross crystal structures, so that the van der Waals force between the crystals is improved, and higher tensile breaking strength is provided. However, the commercial materials of the existing HDPE fiber have few high molecular weight polyethylene components, the strength is improved by increasing the content of the high molecular weight polyethylene, and the melt viscosity is increased by increasing the long molecular chain, so that the melt spinning fluidity is poor. Thus, the current challenge is to increase the fiber strength while ensuring melt flow. Disclosure of Invention The invention aims to overcome the defects of the prior art and provide a novel high-performance polyolefin fiber special resin, and the high-performance polyolefin fiber prepared from the high-performance polyolefin fiber special resin has excellent tensile breaking strength and knotting strength. Another object of the present invention is to provide a high-performance polyolefin fiber prepared from the above-mentioned resin for high-performance polyolefin fiber. In order to achieve the above purpose, the invention adopts the following technical means: According to a first aspect of the present invention, there is provided a self-reinforced high-performance polyolefin drawing-dedicated resin having a melt index in the range of 0.6 to 1.9 g/10min, a density in the range of 0.940 to 0.960 g/cm 3, a weight average molecular weight in the range of 6 to 15×10 4 g/mol, an alpha-olefin insertion rate of short-chain distribution in the weight average molecular weight range of 10 3.5~104.0 g/mol of 0.1 to 1.0/1000C, an alpha-olefin insertion rate of short-chain distribution in the weight average molecular weight range of 10 4.1~104.5 g/mol of 0.2 to 2.0/1000C, an alpha-olefin insertion rate of short-chain distribution in the weight average molecular weight range of 10 4.6~105.0 g/mol of 1.0 to 10.0/1000C, and an alpha-olefin insertion rate of short-chain distribution in the weight average molecular weight range of 10 5.1~105.5 g/mol of 0 to 20/1000C, as measured under a load of 2.16 kg. Further, the resin is formed by blending a high molecular weight polyethylene component and a low molecular weight polyethylene component, wherein the blending method is melt blending or in-situ blending, the content of the high molecular weight polyethylene component is 0.1-50 wt%, the weight average molecular weight of the high molecular weight polyethylene component is 30-1000 multiplied by 10 4 g/mol, and the weight average molecular weight of the low molecular weight polyethylene component is 1-20 multiplied by 10 4 g/mol. Wherein, the melt blending is to subject the high molecular weight polyethylene component and the low molecular weight polyethylene component to physical blending and then melt blending granulation. According to a second aspect of the present invention, the present invention also provides a method for preparing the self-reinforced high-performance polyolefin wiredrawing special resin by in-situ blending, which specifically comprises the following steps: (1) Sequentially adding solvent, cocatalyst, catalyst, hydrogen and ethylene into a reaction kettle, wherein the total polymerization pressure is in the range of 3-10 bar, the hydrogen partial pressure is in the range of 0-2 bar, and the polymerization temperature is in the range of 60-85 ℃, controlling the polymerization time to ensure that the ethylene consumption accumulated amount reaches m 1, and obtaining the high molecular weight polyethylene component; (2) Releasing