Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes, 748, Cidade Universitária, São Paulo, SP, 05508-000, Brazil.
Department of Chemistry, University of Victoria, P. O. Box 3065, Victoria, BC V8W 3V6, Canada.
Macromol Rapid Commun. 2024 Jan;45(2):e2300470. doi: 10.1002/marc.202300470. Epub 2023 Oct 9.
Herein, an evaluation of the initial step of benzoxazine polymerization is presented by mass spectrometry, with a focus on differentiating the phenoxy and phenolic products formed by distinct pathways of the cationic ring opening polymerization (ROP) mechanism of polybenzoxazine formation. The use of infrared multiple photon dissociation (IRMPD) and ion mobility spectrometry (IMS) techniques allows for differentiation of the two pathways and provides valuable insights into the ROP mechanism. The results suggest that type I pathway is favored in the initial stages of the reaction yielding the phenoxy product, while type II product should be observed at later stages when the phenoxy product would interconvert to the most stable type II phenolic product. Overall, the findings presented here provide important information on the initial step of the benzoxazine polymerization, allowing the development of optimal polymerization conditions and represents a way to evaluate other multifunctional polymerization processes.
本文通过质谱法对苯并恶嗪聚合的初始步骤进行了评估，重点是通过阳离子开环聚合（ROP）机制区分形成聚苯并恶嗪的不同途径形成的酚氧基和酚产物。使用红外多光子解离（IRMPD）和离子淌度谱（IMS）技术可以区分这两种途径，并为 ROP 机制提供有价值的见解。结果表明，在反应的初始阶段，I 型途径有利于生成酚氧基产物，而在后期阶段，当酚氧基产物互变异构为最稳定的 II 型酚产物时，应该观察到 II 型产物。总的来说，这里提出的研究结果提供了有关苯并恶嗪聚合初始步骤的重要信息，有助于开发最佳聚合条件，并代表了评估其他多功能聚合过程的一种方法。
