Design and synthesis of polydiacetylenes, and their low temperature irreversible thermochromic properties

A thermochmmic 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 thermochmmic behavior at below freezing temperatures. The photochromic and thermochmmic 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 degrees C, respectively. Moreover, we prepared a paper test strip and used as a warning indicator for deep freeze products.

Automated summary

Polydiacetylenes functionalized with glycol ester groups were successfully synthesized and used as thermochromic dyes showing irreversible behavior below freezing temperatures. Color-transition temperatures for different polymers were determined in the solid state. Additionally, a paper test strip was prepared as a warning indicator for deep freeze products.