Silane‐functional benzoxazine: synthesis, polymerization kinetics and thermal stability

Abstract

A benzoxazine with siloxane and phenyl sulfone units (BS‐b) was synthesized by using aminopropyltriethoxysilane, 4,4'‐dihydroxydiphenylsulfone and paraformaldehyde as precursors via Mannich condensation. Then the hydrolysis and polycondensation reactions of siloxane units were performed and benzoxazine bearing polysiloxanes (BS‐PSO) were obtained. The ring‐opening polymerization reactions of both BS‐b and BS‐PSO were studied by Fourier transform IR spectroscopy and DSC in non‐isothermal conditions. The kinetics of the polymerization of BS‐b were found to be well described by using an nth‐order kinetic model for n = 0.7 (activation energy 141 kJ mol−1). The BS‐PSO was also used to modify bisphenol‐A‐based benzoxazines (BA‐a), and the morphological structure and thermal properties of the copolymer were investigated. The TGA results indicate that the silane‐functional polybenzoxazines display enhanced initial decomposition temperature and char yields in comparison with poly(BA‐a). These results are believed to be important for the development of new flame‐retardant laminates. © 2017 Society of Chemical Industry

Synthesis and properties of a novel bio‐based benzoxazine resin with excellent low‐temperature curing ability

“…Benzoxazine monomer is prepared through dehydration to a ring by a Mannich condensation reaction based on a phenol source, an amine source and a formaldehyde solution or paraformaldehyde. Benzoxazine resin is a kind of phenolic resin; furthermore it has better heat resistance, dielectric properties, low surface energy, low water absorption and no release of small molecules during processing compared with traditional phenolic resin, in addition to zero shrinkage and structure design flexibility …”

Optical, electrochemical, and thermal behavior of polybenzoxazine copolymers incorporated with tetraphenylimidazole and diphenylquinoline

“…FTIR spectra of cross linked polymer are shown in Figure . The disappearance at 938 cm −1 band was noted in IR spectrum of polymer which confirms that the polymerization reaction has taken place through ring opening reaction of benzoxazine ring . The band around 1123 cm −1 is assigned to C―N―C asymmetric stretching vibration.…”

“…The disappearance at 938 cm −1 band was noted in IR spectrum of polymer which confirms that the polymerization reaction has taken place through ring opening reaction of benzoxazine ring. [34][35][36] The band around 1123 cm −1 is assigned to C-N-C asymmetric stretching vibration. The band around 1471 cm −1 is attributed to tetra-substituted benzene ring with methylene amine methylene bridge at the ortho position.…”

Synthesis of siloxane‐containing benzoxazine and its synergistic effect on flame retardancy of polyoxymethylene

“…Benzoxazine monomer itself has an ultrahigh residual carbon yield, can be used as a carbon source for the IFR system, and acts as a skeleton of the carbon layer during combustion . Meanwhile, various types of benzoxazine monomer can be synthesized using various phenols and amines with different substitution groups attached; its superb molecular design flexibility allows to tailor properties of the polymerized materials in a wide range for the specific requirements of individual applications …”

“…14,15 Meanwhile, various types of benzoxazine monomer can be synthesized using various phenols and amines with different substitution groups attached 16 ; its superb molecular design flexibility allows to tailor properties of the polymerized materials in a wide range for the specific requirements of individual applications. 17 Silane-coupling agents can promote the adhesion between inorganic filler and polymeric resin, which is beneficial to improve the mechanical properties of the composites. 18 A benzoxazine-containing silane structure maybe both benefit to the flame-retardant efficiency and mechanical properties of flame-retardant POM.…”