Toothbrush filament and preparation method therefor, and toothbrush

A method for preparing a toothbrush filament, comprising the following steps:

• (1) adding a polyvinylidene fluoride piezoelectric polymer having a weight-average molecular weight of 150,000 to 300,000 into a melt spinning machine, heating to a melting temperature of the piezoelectric polymer, and extruding to obtain a filament having a diameter of 175 μm to 265 μm, wherein the piezoelectric polymer has a piezoelectric constant of 10 pC/N to 32 pC/N;
• (2) subjecting the filament to annealing treatment at 120° C. for 1.5 h to 3 h, and then to corona polarization treatment to obtain the toothbrush filament, wherein for the corona polarization treatment, a voltage is 10 kV to 50 kV, a distance between an electrode tip to a sample is 10 mm to 50 mm, a polarization temperature is 25° C. to 50° C., and polarization time is 10 min to 60 min;
• or
• (2′) subjecting the filament to corona polarization treatment, and then to annealing treatment at 120° C. for 1.5 h to 3 h to obtain the toothbrush filament, wherein for the corona polarization treatment, a voltage is 10 kV to 50 kV, a distance between an electrode tip to a sample is 10 mm to 50 mm, a polarization temperature is 25° C. to 50° C., and polarization time is 10 min to 60 min;
• the voltage generated by the toothbrush filament under the action of external force is 0.6V to 1.5V;
• the single-filament bending recovery rate of the toothbrush filament is 60% to 80%;
• the antibacterial rate of the toothbrush filaments is 45% to 80%;
• the toothbrush filament has a piezoelectric constant of equal to or greater than 0.4 pC/N in a standing state.