Novel fluorene based benzoxazines containing allyl group: synthesis and thermal properties.

Abstract

Two novel difunctional fluorene-based benzoxazine monomers were synthesized from the reaction of 9,9-bis-(4-hydroxyphenyl)-fluorene with formaldehyde and amines including allylamine (PB-ABF) and aniline (PB-PBF). Their chem. structures were confirmed by FTIR and 1H NMR analyses. The curing behavior of the precursors was monitored by differential scanning calorimetry (DSC). The thermal stability of cured polymers was evaluated with thermogravimetric anal. (TGA). The fluorene-based polybenzoxazines show the typical curing characteristic of oxazine ring-opening for difunctional benzoxazines centered at around 250°C and better thermal stability than traditional bisphenol A polybenzoxazines. The thermal decompn. temp. of fluorene based polybenzoxazine contg. allyl group is higher than that of aniline based polybenzoxazine, bisphenol A based polybenzoxazines, and bisphenol A based polybenzoxazines contg. allyl group. The char yield of PB-ABF is lower than that of PB-PBF, however, is much higher than that of typical bisphenol A and allyl-bisphenol A based polybenzoxazine. [on SciFinder(R)]