Science and Technology Production
Book Chapter
Authorship
Seishi Ohashi
;
Kan Zhang
;
Qichao Ran
;
Carlos R. Arza
;
FROIMOWICZ, PABLO
;
Hatsuo Ishida
Date
2017
Publishing House and Editing Place
Elsevier
Book
Advanced and Emerging Polybenzoxazine Science and Technology
(pp. 1053-1082)
Elsevier
Elsevier
ISBN
9780128041703
Summary
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SIGEVA
As the interest in benzoxazine becomes wide spread, the number of papers published increased exponentially every year in the past twenty years and this trend still continues. Multiple papers have been published on the same benzoxazine monomer, yet the results vary from paper to paper, due in part to the variation of the purity of samples prepared. In order to further advance the fundamental understanding of benzoxazine chemistry, it is important that researchers share common data or information...
As the interest in benzoxazine becomes wide spread, the number of papers published increased exponentially every year in the past twenty years and this trend still continues. Multiple papers have been published on the same benzoxazine monomer, yet the results vary from paper to paper, due in part to the variation of the purity of samples prepared. In order to further advance the fundamental understanding of benzoxazine chemistry, it is important that researchers share common data or information so that quantitative comparison of the results is possible and helps to establish reliable standard data. For this purpose, this chapter is prepared with high purity compounds only, mostly with single crystals of benzoxazine monomers, in order to provide standard structural and spectral information. For a specific case, a sample preparation method, including synthesis to minimize the impurity that interferes with the purification, is provided. Based on this method, we have prepared the largest single crystal of the bisphenol A/ aniline based benzoxazine (abbreviated as BA-a) ever reported. Quite often different papers provide rather similar NMR spectra for the same monomer they studied. Yet, their differential scanning calorimetric (DSC) results vastly differ. This is the reflection of very strong effect of a small amount of cationic impurities on the polymerization process. The effect of such cationic impurities is amplified by the autocatalytic polymerization mechanism of benzoxazine resins. Therefore, this chapter also discusses the effect of varying purity on DSC thermograms, highlighting the strong effect of the impurity on polymerization kinetics. Finally, this chapter presents the Raman and Fourier transform infrared (FT-IR) as well as 1H and 13C NMR spectra, and DSC thermograms of benzoxazine monomer single crystals, with the exception of a few samples being multiple crystals, which are identified as such for clarity.
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