A thermochromic material that show irreversible color change at or below freezing temperatures has potential utility as a temperature indicator for frozen food and meat products, therefore, the goods transporters and customers would easily recognize when the goods exposed to high temperatures during their storage and delivery. In this study, we have successfully synthesized and used polydiacetylenes functionalized with glycol ester groups as a thermochromic dye, which show irreversible thermochromic behavior at below freezing temperatures. The photochromic and thermochromic properties of diacetylenes were investigated in the solid state, and color-transition temperatures for poly(DCDA-EGME), poly(DCDA-DGME) and poly(DCDA-TGME) were found to be 2, −10 and −16 °C, respectively. Moreover, we prepared a paper test strip and used as a warning indicator for deep freeze products.

在冷冻温度或更低的温度下显示不可逆颜色变化的热致变色材料具有潜在用途，可作为冷冻食品和肉类产品的温度指示器，因此，货物运输者和客户可以轻松识别在存储和运输过程中何时暴露于高温。在这项研究中，我们已经成功地合成和使用了以乙二醇酯基团官能化的聚二乙炔作为热致变色染料，该染料在低于冰点的温度下表现出不可逆的热致变色行为。研究了固态二乙炔的光致变色和热致变色性能，以及聚（DCDA-EGME），聚（DCDA-DGME）和聚（DCDA-TGME）的色变温度分别为2，-10和-16°C。此外，我们准备了纸质测试条，并用作深冻产品的警告指示。