Abstract:

For the preparation of color-changing materials used for chemical anti-counterfeit, with 10,12-pentacosasiynoic acid as a photo /thermochromic compound, diacetylene-embedded polyurethane/poly (ethylene oxide) (PU/PEO) composite fiber membrane were prepared by electrospinning. The influences of PU/PEO blending mass ratio and spinning solution cimcentration on the microstructure of fiber membrane were analyzed by scanning electron microscope, and the color parameters, K/S values and absorption curves of fiber membrane were measured by color spectrometer to investigate the photo/thermochromic properties at the same time. The results show that the viscosity of the spinning solution increased with the increase of the ratio of PEO and the concentration of spinning solution, which facilitates continuous spinning but causes the increase of the fiber average diameter. Under the radiation of 254 nm ultraviolet light, diacetylene is successfully polymerized, and the color of fiber changes from white to blue. The time required for photochromic discoloration and the discoloration depth of the fiber mimbrane increases with the increase of diacetyl content. Under thermal stimulation, the color of fiber membrane gradually changed from blue (25 ℃) to red (70 ℃), and the transition temperature is 55 ℃. Corresponding, the maximum wavelength of visible light absorbed by the molecule is shifted from 640 nm to 545 nm.

Key words: 10,12-pentacosasiynoicid, polyurethane,  poly (ethylene oxide), electrospun fiber membrane, phototpolymerization, thermochromic, anti-counterfeiting material