Abstract
Resorcinol formaldehyde resins are synthesized by polycondensation of resorcinol with formal-dehyde and have various structures by the condensation type. The influence of polycondensation type on the stability and structure of the resorcinol formaldehyde resin was studied by molecular mechanics and molecular dynamics. The resins formed by 2,6-polycondensation and 4,6-polycondensationwith head-to-tail orientations have structures of intramolecular hydrogen bonds between 1-hydroxyl groups and between outer hydroxyl groups of the adjacent resorcinols, respectively. The resin formed by 2,6-polycon-densation with head-to-head orientation has a structure that inner hydroxyl groups cluster in the center of the molecule. Energetical stability of the resin is affected by both the intramolecular hydrogen bonds and the steric' hindrance by phenyl group.