Intrinsic self‐initiating thermal ring‐opening polymerization of 1,3‐benzoxazines without the influence of impurities using very high purity crystals |
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| Authors: | Lu Han María Laura Salum Kan Zhang Pablo Froimowicz Hatsuo Ishida |
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| Institution: | 1. Department of Macromolecular Science and Engineering, Case Western Reserve University, Cleveland, Ohio;2. CIHIDECAR‐CONICET y Departamento de Química Orgánica, Facultad de Ciencias Exactas y Naturales Institution Universidad de Buenos Aires, Buenos Aires, Argentina;3. School of Materials Science and Engineering, Jiangsu University, Zhenjiang, China;4. Design and Chemistry of Macromolecules Group, Institute of Technology in Polymers and Nanotechnology (ITPN), UBA‐CONICET, School of Engineering, University of Buenos Aires, Buenos Aires, CP, Argentina |
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| Abstract: | A phenol/aniline type monofunctional benzoxazine monomer, PH‐a , is synthesized and highly purified to study the intrinsic thermal ring‐opening polymerization of benzoxazines without the influence of any impurity. The successful synthesis of the monomer and its corresponding chemical structure are confirmed by Fourier transform infrared spectroscopy (FTIR) and 1H nuclear magnetic resonance (1H NMR) spectroscopy. Purity of the compound is evaluated through differential scanning calorimetry (DSC) as well as elemental analysis (EA). Moreover, the thermal behavior of benzoxazine monomer toward polymerization is also studied by DSC, indicating that the highly purified benzoxazine monomer actually polymerize upon heating. The results present evidence of an intrinsic tendency for 1,3‐benzoxazines to undergo thermally induced ring‐opening polymerization upon heating only without any impurity participating during the reaction. This reveals that polybenzoxazines can be obtained by both the traditional thermally accelerated (or activated) polymerization, where impurities or purposefully added initiators are involved in the reaction; or, by the classic thermal polymerization, where only heat is enough to initiate the reaction. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 3434–3445 |
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| Keywords: | benzoxazines mechanisms polybenzoxazines structure– activity relationships thermal polymerizations |
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