Synthesis, Characterization and Ultrasonic Determination of Certain Copolyesters Containing Bis (Arylidene) Acetone Moiety in the Main Chain

Six copolyesters were prepared from bis(4-hydroxybenzylidene)acetone (HBAC) and bis(4-hydroxy-3- methoxybenzylidene)acetone (MBAC) (as varying diol, diol-1) with adipoyl chloride, azelaic acid dichloride and sebacoyl chloride and 4-(4-nitrophenylazo)resorcinol (as a common diol, diol-2) by phase transfer catalysed condensation. These copolyesters were characterized by viscometry and spectrometry. DSC thermograms were recorded for all the copolyesters to determine the glass transition temperatures (T_g). The acoustical parameters of all the copolyesters were calculated from the measured ultrasonic velocity (U) and density (ρ) values at different temperatures in N,N-dimethylacetamide (DMAc) solution. The glass transition temperature values were determined from the trend in few calculated acoustical parameters with temperature and compared with those obtained from thermograms taken using differential scanning calorimetry. The molecular interactions at T_g in the copolyester solutions have been investigated from these studies.