Preparation method for flexible high-molecular PTC material

The invention relates to a preparation method for a flexible high-molecular PTC material. The preparation method comprises the following successive steps: (1) dispersing carbon black in a high density polyethylene (HDPE) resin by using a melt blending process; (2) adding a styrene-butadiene-styrene segmented copolymer (SBS) into the mixture of HDPE and carbon black and carrying out melt mixing; (3) adding waste ground rubber tire powder into a molten mixture of HDPE/carbon black/SBS and carrying out melt blending; and (4) subjecting a blending product to compression molding so as to obtain a sheet-like substance and carrying out cross-linking with gamma rays (Co60). According to the invention, carbon black is dispersed in a continuous phase of a blending-type elastomer, a PTC effect appears under the condition of temperature rise, so the flexible high-molecular material with PTC performance is obtained. The method is simple; product conductivity is easy to control, and the material has good flexibility and can be produced in mass quantities.