The influence of montmorillonite concentration and solvent polarity on the synthesis of benzoxazine monomers in the presence of montmorillonite

The synthesis of 3,3′-(hexane-1,6-diyl)bis-(3,4-dihydro-2H-1,3-benzoxazine) was done in the absence and in the presence of 10, 30, 50 and 100 wt.% montmorillonite (MMT). The MMT exhibits a significant catalytic effect on the ring-opening reaction of the benzoxazine monomer, increasing of MMT amount influences the oligomeric structures in the polybenzoxazine precursor composition according to 1H NMR, 13C NMR and SEC data. The influence of solvent polarity and temperature was also studied especially in correlation with possible interactions between solvent and MMT. The influence of the polybenzoxazine precursor composition on the polymerization behaviour was investigated by DSC. The thermostability of the obtained polybenzoxazines was studied by TGA and DMA method was involved to determine the glass transition temperature.