asymmetric polidiacetileni with property termocromiche irreversible

摘要

we describe the asymmetric polidiacetileni of general formula (i): (formula i) in which: r = ch3 - (ch2) m - (r = - (ch2) p - oh, - m is a whole number equal to 2, 4, 9, - p is a whole number equal to 1. 2, 3.4: - n is a whole number greater than 20.these polymers have the property of color changing irreversibly when crossing a temperature of different threshold for each member: this can be used as indicatorthe supermarket of the threshold temperature.these polymers exhibit absorption spectra in the range of ultraviolet light or visible with characteristic peaks with values between 570 650 nm.the absorption maximum shifts to the lower wavelength irreversibly when it exceeds the threshold temperature.these compounds are obtained by polymerization of the corresponding monomers led solid state if liquidraffreddandoli at a temperature below their melting point and subsequently irradiated with radiation of wavelength equal to or less than 254 nm.