Abstract
We synthesized various cross-linkable prepolymers from castor oil, isocyanates and alkoxysilanes, and evaluated their adhesive property. Influence of the alkoxysilyl group (methoxy or ethoxy) on the adhesion strength was small. On the other hand, adhesion strength of cross-linkable prepolymers synthesized from urethane prepolymer was stronger than those synthesized from isocyanate-silane. It was suggested that the amount of polar groups (urethane group) per castor oil unit had strong influence on the adhesion. Moreover, as compared cross-linkable prepolymers synthesized by usual urethane prepolymer method with those synthesized by via thin film evaporation method, adhesion intensity of cross-linkable prepolymer synthesized by via thin film evaporation method of urethane prepolymer exhibited much higher adhesion strength. Thus, it was suggested that adhesion strength of the prepolymer which had regular distances between cross-linking points was stronger than those with irregular distances.
