Abstract: An environmentally friendly irreversible temperature indicating material was prepared from a solution of ethylene acrylic acid copolymer and normal heptane at low temperature. The particle size and crystal structure of the material were tested and analyzed by X-ray diffraction. The crystallization, melting point, and melting range of the material were measured by differential scanning calorimetry The effect of the preparation process on the property of the material was discussed by the singlefactor method. Finally, the optimum composition of the experiment was determined. The initial color temperature of EAA580 was 82 ℃, the range of color temperature was 3 ℃, and the initial color temperature of EAA540 was 86 ℃, the range of color temperature was 10 ℃, the indicating temperature patch prepared by EAA580 had the characteristics such as low initial color temperature, narrow color temperature range, and high sensitivity.

Key words: ethylene acrylic acid copolymer, indicating temperature, melting, crystallinity