Benzoxazines phenol initiated polymerization

For the polymerization of benzoxazine Jx Initiated with phenol, the same kinetic scheme was used to Interpret results. The values corresponding to the pol3mierlzation of benzoxazine J[c at 140°, with 1%, 5%, and 10% 2,4-dl-tert-butylphenol, are given in Figure 5. However, their behavior is completely different from those obtained using benzoxazine lb, as evidenced by the existence of an induction period that becomes prominent at low phenol concentration. Otherwise the slopes of the linear parts of the curves are identical irrespective of phenol concentration. Increasing the concentration of phenol reduces the Induction period but the rate of pol3nnerlzatlon remains... 

Schreiber, for the preparation of phenolic resins with improved thermal, mechanical, and dielectric characteristics. However, no systematic study was reported in Schreiber s patents. Thus, it was of interest to examine in more detail several points such as 1) the synthesis of an homologeous series of benzoxazines, 2) their reaction with phenols, which may be considered as the initiation step of the polymerization by a ring opening mechanism, 3) the pol3nnerization kinetics of benzoxazines, initiated either thermally or with phenols, and 4) the application possibilities of these monomers and polymers. 

The study of the reactivities of benzoxazines has revealed that it is possible to achieve the ring opening of the heterocycle by reaction with phenols, which can be considered as the initiation step of the pol3oneriza-tion. These results led the authors to study, first, the polymerization of... 

As an extension of this study, we established the reaction kinetics for benzoxazine pol3nnerlzation in the presence of phenols by taking into account thermal initiation. Furthermore, it was shown the possibility existed to form segmented oligomers by succussive polymerization of benzoxazine and benzoxazine le. 

---