Sound velocity and thermodynamic parameters of chloro epoxy resins of bisphenol-C solutions in chlorinated and aprotic solvents at 35°C and 40°C

Sound velocity (2 MHz) and thermodynamic parameters of epoxy resins of 1,1′-bis(R,R′-4-hydroxy phenyl) cyclohexane (R=R′=Cl and R= –CH3 and R′= –Cl) solutions in chloroform, 1,2-dichloro ethane, 1,4-dioxan and tetrahydrofuran at 30°C and 40°C have been determined in order to understand the effect of concentration, solvent, temperature and substituents. The increase in U, Z, R, b, (α/f2)cl and τ and decrease in Ks, r, π and Lf with C suggested the presence of powerful solvent–polymer interactions. The structure forming tendency of both the resins is confirmed on the basis of the positive values of the solvation number, the decrease in apparent molar volume and apparent molar compressibility . The structure forming tendency of both the resins is due to mutual interaction among electronegative (–Cl and ether) and electropositive (methyl, –OH and phenyl ring) groups with solvents. The decrease in Sn especially in DO and THF above 5% concentration suggested the presence of polymer–polymer interaction.