Quantitative studies on thep-substituent effect of the phenolic component on the polymerization of benzoxazines

Abstract

The pure monofunctional benzoxazines substituted by either electron donating or withdrawing groups are synthesized to verify the electronic effect on the polymerization behaviors without any complicated factors of the impurities.

Thermal Insulation Characteristics of Polybenzoxazine Aerogels

“…Benzoxazine resin is a new type of thermosetting resin that has a hexatomic ring containing O and N atoms. Ring‐opened polymerization under heating or catalysis results in a network structure, which is called polybenzoxazine (PBO), similar to that of phenolic resin . Because of the different structural characteristics of phenolic resin, benzoxazine maintains the advantages such as excellent hardness, heat resistance, inner flame retardancy, electrical insulation, and low cost of traditional phenolic resin, but also has a certain degree of toughness, relatively high char yields and near‐zero shrinkage upon polymerization of the monomers .…”

“…Ring-opened polymerization under heating or catalysis results in a network structure, which is called polybenzoxazine (PBO), similar to that of phenolic resin. [1][2][3][4] Because of the different structural characteristics of phenolic resin, benzoxazine maintains the advantages such as excellent hardness, heat resistance, inner flame retardancy, electrical insulation, and low cost of traditional phenolic resin, but also has a certain degree of toughness, relatively high char yields and near-zero shrinkage upon polymerization of the monomers. [5][6][7][8][9][10][11][12][13] Therefore, PBO is the most desirable material for preparing high-strength and flameretardant aerogel thermal insulating materials.…”

Easily Processable Thermosets with Outstanding Performance via Smart Twisted Small‐Molecule Benzoxazines

“…All of the benzoxazine monomers were obtained at good yields, and were carefully purified to remove impurities, which otherwise can significantly affect the polymerization behaviors of benzoxazine monomers and impair the properties of polybenzoxazines. [17] The structures and purities of the benzoxazine monomers were confirmed by FT-IR, 1 H NMR, 13 C NMR, 2D NMR spectroscopy, as well as high-resolution mass spectrometry and elemental analysis (see Figures S2-S4, Supporting Information).…”

“…The ortho ‐maleimide functional benzoxazines were synthesized by Mannich condensation from ortho ‐maleimide phenol ( o HPMI) (see Figure S1, Supporting Information), p ‐toluidine/aniline/3‐aminophenylacetylene/4‐chloroaniline, and paraformaldehyde using toluene as the solvent (see Schemes S1 and S2, Supporting Information). All of the benzoxazine monomers were obtained at good yields, and were carefully purified to remove impurities, which otherwise can significantly affect the polymerization behaviors of benzoxazine monomers and impair the properties of polybenzoxazines 17. The structures and purities of the benzoxazine monomers were confirmed by FT‐IR, 1 H NMR, 13 C NMR, 2D NMR spectroscopy, as well as high‐resolution mass spectrometry and elemental analysis (see Figures S2–S4, Supporting Information).…”

Synthesis and thermally induced structural transformation of phthalimide and nitrile-functionalized benzoxazine: toward smart ortho-benzoxazine chemistry for low flammability thermosets

“…Polybenzoxazines, [16][17][18] as a novel type of thermoset, offer outstanding advantages such as high thermal stability, 19 high char yield, 20 high T g , 21 near-zero volumetric change during polymerization, 22 good mechanical 23 and dielectric properties, 24 low water absorption 25 and low ammability. 26 Various forms of hydrogen-bonding within the nal network structure are observed in polybenzoxazines, contributing greatly to their unique properties.…”