On the origin of thermochromism in cross-polymerized diacetylene-functionalized polyamides

Abstract

The thermochromic behavior of a cross-polymerized diacetylene-functionalized polyamide, poly(hexamethylene-10,12-docosadiyne-1,22-diamide) (PADA 6,22), has been investigated with IR and 13 C solid-state NMR spectroscopy. The polymer was rendered thermochromically active by exposure to UV or electron beam radiation which creates polydiacetylene cross-links across the host polyamide chains. The NMR data indicate that the thermochromic transition of this material is associated with a temperature-induced gauche to trans conformational transition of the methylene groups pendant to the polydiacetylene cross-links