Mechanistic Pathways for the Polymerization of Methylol-Functional Benzoxazine Monomers

作者：Baqar Mohamed; Agag Tarek; Huang Rongzhi; Maia Joao; Qutubuddin Syed^*; Ishida Hatsuo

来源：Macromolecules, 2012, 45(20): 8119-8125.

DOI：10.1021/ma301963d

The polymerization mechanism of methylol-functional benzoxazine monomers is reported using a series of monofunctional benzoxazine monomers synthesized via a condensation reaction of ortho-, meta-, or para-methylol-phenol, aniline, and paraformaldehyde following the traditional route of benzoxazine synthesis. A phenol/aniline-type monofunctional benzoxazine monomer has been synthesized as a control. The structures of the synthesized monomers have been confirmed by H-1 NMR and FT-IR. The polymerization behavior of methylol monomers is studied by DSC and shows an exothermic peak associated with condensation reaction of methylol groups and ring opening polymerization of benzoxazine at a lower temperature range than the control monomer. The presence of methylol group accelerates the ring-opening polymerization to give the ascending order of para-, meta-, and ortho-positions in comparison to the unfunctionalized monomer. Furthermore, rheological measurements show that the position of methylol group relative to benzoxazine structure plays a significant role in accelerating the polymerization.

• 出版日期2012-10-23