Determination of solution viscosity characteristics of rubber seed oil based alkyds resins

Three medium oil alkyd samples of different oil length [(1) 45%, (II) 50%, and (III) 55%] were synthesized with rubber seed oil. Dilute solution viscosity measurements were carried out on the alkyd in acetone and in toluene. The parameters investigated include intrinsic viscosity [eta], Huggins constant (k(H)), and Mark-Houwink Sakurada constants (K and alpha). The [eta] values for the alkyd samples were found to be larger in acetone than in toluene. The K-H, values showed a regular order in acetone but not in toluene. The K,, values showed no regular order in their variation with the oil content of the alkyd samples and the solvent, but the values obtained are higher in acetone than in toluene. Correlation of molecular weight (M) with [T1] was also examined. [eta] was observed to increase with the increase in the molecular weight of the resins. The a values obtained are in reasonable agreement with the reported ranges of a values in good solvent. The characteristics examined suggest that acetone is a better solvent for rubber seed oil alkyd resin than toluene. (c) 2006 Wiley Periodicals, Inc.