Investigation of the polymerization behavior and regioselectivity of fluorene diamine-based benzoxazines

摘要

A series of fluorene diamine-based benzoxazine monomers are prepared from the reaction of 9,9-bis-(4-aminophenyl)-fluorene with paraformaldehyde and unsubstituted or substituted phenols. Unsubstituted and substituted phenol-based benzoxazines show different polymerization behaviors and give polymers with different thermal properties. The ortho and para positions on the phenol for benzoxazines based on phenol and m-cresol could concurrently participate in the crosslinking reaction during thermal ring-opening polymerization to form Mannich and methylene bridges at high temperature. The glass-transition temperature and thermal stability of the resulting polymers are much higher than those of other substituted phenol-based polybenzoxazines and bisphenol fluorene-based polybenzoxazines.