Molecular association of alkyl methacrylates and alcohols in non-polar solvents: Dielectric study

Abstract

Experimental results of dielectric investigations at 9.84 GHz for alkyl methacrylates (methyl methacrylate, ethyl methacrylate and butyl methacrylate) with alcohols (1-butanol, secbutanol, tert-butanol and 1-decanol) have been studied in carbon tetrachloride and benzene at 298, 303, 313 and 323 K. The relaxation time and the thermodynamical parameters, viz., free energy, enthalpy and entropy of activation have been determined using the measured dielectric data. The results show a linear dependence of relaxation time on alkyl chain length of both alcohols and alkyl methacrylates and also on the nature of the solvent. Comparative study of free energy of activation for the dielectric relaxation and viscous flow suggest the fact that the process of viscous flow involves greater interference by neighbors than does dielectric relaxation, as the latter takes place by rotation only whereas the viscous flow involves both the rotational and translational forms of motion. The thermodynamic parameter shows negative value which indicates that the reaction is forward and exothermic.

FTIR and dielectric studies of molecular interaction between alkyl methacrylates and primary alcohols

“…This is in agreement with the fact that the process of viscous flow, which involves both the rotational and translational forms of motion, faced greater interference from neighbors than dielectric relaxation, which takes place by rotation only [15].…”

“…A perusal of Table 2 shows that the value of relaxation time increases with increasing chain length of alcohols and methacrylates, and offers hindrance to the rotation of the molecule [15]. The increase in relaxation time may be due to the increase in effective radius of the rotating unit.…”

FTIR Study of Molecular Interaction in Butyl Methacrylate–Organic Solvents Mixtures

“…In previous publications, our research group has investigated the complex formation in ternary mixtures of acrylic esters with proton donors (alcohols) in non-polar solvents using FTIR spectroscopic [39][40][41][42][43][44][45][46] and dielectric [47] methods. The complex formation has been interpreted in terms of formation constant.…”

Molecular Associations in Alcohol−Methyl Methacrylate Mixtures

“…A perusal of Table shows that it is noticed that the value of ε‘ and ε‘ ‘ is found to be decreased by increasing the number of carbon atoms in the chain for all the systems studied. This trend could be attributed to the decrease in the number of dipoles in the complex, which may lead to a decrease in the molar volume of the rotated molecule. , …”