Effect of method of synthesis of unsaturated fatty acid-modified alkyd resin on the crosslinking behavior of prepolymer: Correlation of molecular weight distribution of prepolymer and degree of crosslinking of the derived film

Abstract

The viscoelastic properties of films of unsaturated fatty acid-modified alkyd resins prepared by different synthetic procedures are examined. The films prepared by the fatty acid method have a higher glass transition temperature and greater degree of crosslinking than those prepared by the monoglyceride method. It is suggested the molecular weight distribution of prepolymer prepared by the monoglyceride method would be broader than that prepared by the fatty acid method, and this was verified by the results of [η]/Mn and fractionation of prepolymers. The differences in viscoelastic properties of films is explainable on the basis of the molecular weight distribution and the distribution of crosslinking functional groups of prepolymers.