Synthesis of polymers containing coumarin spectroscopic and dielectric properties

In this study, first, the 4-chloro methyl-7-hydroxy coumarin was synthesized by reaction of ethyl 4-chloroacetoacetate with resorcinol. The methacrylate monomers bearing coumarin side group were synthesized from acylation reaction of methacryloyl chloride with 4-methyl-7-hydroxy coumarin and 4-phenyl-7-hydroxy coumarin, which are received commercially. The preparation of homopolymer, copolymer and graft copolymers were prepared by radical polymerization or atom transfer radical polymerization (ATRP) methods.The modification of poly (4-chloromethyl-2-oxo-2H-chromen-7-yl methacrylate), which is one of polymers synthesized was performed with diethanolamin in different ratios.The FT-IR, 1H and 13C-NMR techniques for structural characterization were used mainly. The thermal behavior of polymers was measured by DSC and TGA, results were compared with each other. The average molecular weights and the polydispersities of polymers was measured by GPC technique.Dielectric behavior of polymers was investigated as a function of temperature and frequency and associated with their structures. The spectroscopic properties of polymers were investigated by UV-Vis and fluorescence spectroscopies. The effect of solvent polarity on emission measurements was investigated by fluorescence spectroscopy. The viscosity measurements of copolymers were carried out by using Ubbelohde viscosimeter. Their intrinsic viscosity from experimental results was determined. The activation energy for thermal degradation of macroinitiator and graft copolymers was calculated according to the method of Flynn-Wall-Ozawa by using decomposition curves in different heating rations. Coumarin ended PMMA was dimerized by using photodimerization property of coumarine.The thermal degradation of poly[4-methyl-7-hydroxy coumarin] and poly[4-chloro methyl-7-hydroxy coumarin] was investigated by programmed heating from ambient temperature to 500 oC under vacuum followed by the product collection. The cold ring fraction (CRF) of products volatile at degradation temperature but not at ambient temperature was identified by FT-IR, NMR, GS-MS. Based on degradation, the major products of CRF are 4-methyl-7-hydroxy coumarin, 4-chloro methyl-7-hydroxy coumarin and their monomers.