Sound velocity and molecular interaction studies on chloro epoxy resins solutions at 30°C

The sound velocity (2 MHz) and the related parameters of the epoxy resins of 1,1′-bis(R,R′-4-hydroxy phenyl) cyclohexane (RR′Cl and RCH3 and R′Cl) solutions at 30°C have been evaluated in order to understand the effect of methyl and chlorine substituents on the molecular interactions. The increase in U, Z, R, b, (α/f2)cl and τ and decrease in Ks, r and π with the concentration suggested the presence of a strong solvent–solute interaction. The structure forming tendency of both the resins is confirmed on the basis of the positive values of a solvation number. The observed structure forming tendency of the resins is due to the presence of the electropositive (CH3 and OH) and electronegative (Cl and ether) groups in the resins. The dipole–dipole interaction of the opposite type favours the structure forming tendency while of the same type disrupt the structure formed previously. The observed change in the apparent molar volume and the apparent molar compressibility are due to structural changes.