Improved performance of polybenzoxazines through a mechanistic understanding of polymerization.

摘要

A class of phenolic resins, polybenzoxazines, is described. Benzoxazine resins have a wide range of mechanical and physical properties that can be tailored to various needs. Good thermal, chemical, electrical, mechanical, and physical properties make polybenzoxazines attractive alternatives to existing materials.;Effective initiators/catalysts aimed at lowering the polymerization temperature and reducing the product cycle time have been examined. The benzoxazine-initiator systems exhibit new polymerization mechanisms and kinetics, leading to polybenzoxazines with highly improved properties. By tailoring the benzoxazine chemistry and utilizing a new synthetic route, both hydrophilic and hydrophobic thermoplastic polybenzoxazines with high molecular weight are synthesized for the first time. A novel type of low cost yet high performance benzoxazine resins, mono-oxazine-based low viscosity benzoxazines, has been developed. Various characterization techniques including proton (1H) and carbon (13C) nuclear magnetic resonance spectroscopy (NMR), Fourier transform infrared spectroscopy (FT-IR), pyrolytic gas chromatography/mass spectrometry (GC/MS), size exclusion chromatography (SEC), static light scattering (SLS), wide angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and dynamic mechanical analysis (DMA) have been used to determine the polymer structures and demonstrate their improved properties.