Dispersion and preparation of polyurethane/carbon nanotubes composites

In the paper, the polyurethane/carbon nanotubes composites were prepared by solution-blending method. The polyurethane dissolution, carbon nanotubes dispersion agent, dispersion method and preparation of composites were analyzed. The results showed that the tetrahydrofuran and N-N-dimethylfomamide could used as the dissolution of polyurethane. The dissolution is most even with the ratio of tetrahydrofuran and N-N-dimethylfomamide of 1:1, and 1g polyurethane grains were resolved with 20ml solutions about 72 h. The N-N-dimethylfomamide was used as dispersion agent of carbon nanotubes by ultrasonic dispersion about 2h. The producing process of polyurethane/carbon nanotubes composites was successively heating, drying, and solidifing in the air, so the smooth surface could be received. The results indicated that the dispersion effect from good to poor is ultrasonic dispersion, magnetic dispersion and machining dispersion. With extension in time and increasing disperse frequency, the dispersion effect is better and better. But it also presented that the carbon nanotubes were reunited by magnetic and ultrasonic dispersion after the certainly scattered time, their best dispersion time were respectively two hours and one and a half hours.