▎ 摘　　要

NOVELTY - The preparation method of polyurethane film involves: (S1) adding polyurethane into N,N-dimethylformamide, uniformly mixing to obtain 17-19 wt.% a solution A, carrying out centrifugal spinning on the solution A to obtain polyurethane nanofibers, and collecting the polyurethane nanofibers and pressing the polyurethane nanofibers into polyurethane nanofiber films; (S2) soaking the polyurethane nanofiber film into graphene oxide dispersion liquid, taking out the polyurethane nanofiber film to be dried, and repeating the step (S2) for n times in a circulating manner to obtain a polyurethane film loaded with graphene oxide; (S3) reducing the polyurethane conductive membrane loaded with the graphene oxide by adopting a reducing agent to obtain a polyurethane film loaded with the redox graphene; and (S4) immersing the polyurethane film loaded with the redox graphene into 6-9 wt.% carbon nano tube dispersion liquid, then taking out, cleaning and drying. USE - Preparation method of polyurethane film loaded with redox graphene and carbon nano tubes for a flexible stress sensor. ADVANTAGE - The film has high conductivity, tensile stability, high working sensitivity and good stability. DETAILED DESCRIPTION - The preparation method of polyurethane film loaded with redox graphene and carbon nano tubes involves: (S1) adding polyurethane into N,N-dimethylformamide, uniformly mixing to obtain 17-19 wt.% a solution A, carrying out centrifugal spinning on the solution A to obtain polyurethane nanofibers, and finally collecting the polyurethane nanofibers and pressing the polyurethane nanofibers into polyurethane nanofiber films; (S2) soaking the polyurethane nanofiber film into graphene oxide dispersion liquid, then taking out the polyurethane nanofiber film to be dried, and repeating the step (S2) for n times in a circulating manner to obtain a polyurethane film loaded with graphene oxide; (S3) reducing the polyurethane conductive membrane loaded with the graphene oxide by adopting a reducing agent to obtain a polyurethane film loaded with the redox graphene; and (S4) immersing the polyurethane film loaded with the redox graphene into 6-9 wt.% carbon nano tube dispersion liquid, then taking out, sequentially cleaning and drying, and circularly repeating the step (S4) for m times.