Temperature Variation Effect on Behavior of Block Copolymer of 2- Isopropenylnaphthalene and Methacrylic Acid in Ethanol

Abstract

Fluorescence spectra of dilute solution of blockcopolymer of 2- Isopropenylnaphthalene and methacrylic acid ( 2- IPN – MA) in ethanol have been measured in temperature range of 9.5 – 50˚C . The fluorescence spectra show two emission bands at 342 nm and 387nm corresponding to monomer and excimer bands, respectively. From temperature dependent fluorescence measurements a plot of excimer to monomer intensity ratio ( IE/IM ) versus temperature was obtained , which shows that ( IE /IM ) value increases linearly in the temperature range of 9.5-25˚C and sharp increasing at a bout 35˚C ,then IE/IM increases smoothly above 35˚C . These results Indicate that the conformational change of the polymer chain from contraction form to expansion form takes place at about 35˚C.