POLYETHYLENE Russian patent published in 2025 - IPC C08F10/02 

FIELD: chemistry.

SUBSTANCE: invention relates to polyethylene, which is suitable for production of fiber. Polyethylene, which is a copolymer of ethylene and alpha olefin, satisfies the following conditions: 1) melt index (MI) from 15 g to 40 g/10 min, measured at 190 °C at load of 2.16 kg in accordance with ASTM D1238; 2) molecular weight distribution (MWD) from 2.3 to 2.6; 3) crystallinity from 63% to 71%, measured using a differential scanning calorimeter (DSC) in accordance with ASTM F2625; and 4) crystal relaxation transition temperature (Tcr) from 42 °C to 50 °C, measured by dynamic mechanical analysis (DMA), during which polyethylene samples are subjected to pressure at 190 °C, rectangular samples with thickness of 0.5 mm are obtained, 6 mm wide and 30 mm long, each polyethylene sample is installed on a Q800 DMA instrument from TA Instruments, dynamic modulus of elasticity E' is measured and modulus of mechanical losses E'' by applying periodic deformation with temperature increase from −80 °C to 140 °C at speed 5 °C per minute and then tanδ, which is a value obtained by dividing the modulus of mechanical losses at each temperature by the dynamic modulus of elasticity, and temperature at maximum tanδ is defined as the crystal relaxation transition temperature.

EFFECT: creation of polyethylene, which has a narrow molecular weight distribution and low crystallinity within a similar range of melt index (MI), owing to which it has an increased effective number of physical cross-links of molecules and has reduced formation of fluff and dust during the drawing process, as a result of which it acquires improved abrasion resistance.

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