Understanding the vibrational structure, ring-opening kinetics of oxazine ring, hydrogen bonding system and smart ortho-structure molecular design of higher performance polybenzoxazines

LU HAN; KAN ZHANG; PABLO FROIMOWICZ; DANIELA IGUCHI; PHWEY GIL; TYLER HEYL; VICTORIA SEDWICK; MARÍA LAURA SALUM; CARLOS R. ARZA; SEISHI OHASHI; DANIEL LACKS; HATSUO ISHIDA

New Orleans

Simposio; Third International Symposium on Polybenzoxazines: Towards Diamond Jubilee of Benzoxazine Chemistry; 2018

American Chemical Society - ACS

Polybenzoxazine is a newly developed thermal set resin which shows a lot of excellent properties. A lot of research hasbeen done focusing on a variety new molecular structures. However, much less work has been done on thefundamental study of understanding the vibrational structure, ring-opening kinetics, hydrogen bonding system ofoxazine ring, which will be a great guidance on future molecular design and higher performance materials, resins,composites. Oxazine ring-related vibrational modes of benzoxazine monomers is studied by using fully aromaticallysubstituted, deuterated, N isotope exchanged and oxazine-ring-substituted compounds and theoretical calculations.This study shows that the band in question is a mixture of the O-C stretching of the oxazine ring and the phenolic ringvibrational modes. Intrinsic self-initiating thermal ring-opening polymerization of 1,3-benzoxazines is demonstratedusing single-crystal resins without the influence of impurities. The study reveals that polybenzoxazines can be obtainedby both the traditional thermally accelerated (or activated) polymerization, where impurities or purposefully addedinitiators are involved in the reaction; or, by the classic thermal polymerization, where only heat is enough to initiate thereaction. The effects of intramolecular and intermolecular hydrogen-bonding systems on the polymerization of amidecontainingbenzoxazines is also studied. Based on all the fundamental studies, smart ortho-structure molecular designis proposed. The polybenzoxazine shows many excellent properties including lower polymerization temperature, highthermal stability, low dielectric constant, and latent catalysis.