Crosslinked polyamide based on main‐chain type polybenzoxazines derived from a primary amine‐functionalized benzoxazine monomer

Abstract

Two types of main-chain type polybenzoxazines with amide and benzoxazine groups as repeating units in the main chain, termed as poly(amide-benzoxazine), have been synthesized. They have been prepared by polycondensation reaction of primary amine-bifunctional benzoxazine with adipoyl and isophthaloyl dichloride using dimethylacetamide as solvent. Additionally, a model reaction is designed from the reaction of 3,3 0 -(4,4 0 -methylenebis(4,1-phenylene))bis(3,4-dihydro-2H-benzo[e][1,3]oxazin-6-amine) with benzoyl chloride. The structures of model compound and polyamides are confirmed by Fourier transform infrared (FTIR) and proton nuclear mag-netic resonance ( 1 H NMR) spectroscopies. Differential scanning calorimetry and FTIR are also used to study crosslinking behavior of both the model compound and polymers. Thermal properties of the crosslinked polymers are also studied by thermogravimetric analysis.

Hydrogen-bonding characteristics and unique ring-opening polymerization behavior ofOrtho-methylol functional benzoxazine

“…Additionally, benzoxazine monomers can be easily synthesized from various phenols, amines, and formaldehyde. This versatile synthetic method has allowed development of various benzoxazines having functional groups such as amide, imide, allyl, nitrile, furyl, and benzoxazole, which were effectively used for various chemical modifications of the benzoxazine monomers and the corresponding polybenzoxazines including cross‐linking reactions.…”

Greatly enhanced thermo‐oxidative stability of polybenzoxazine thermoset by incorporation of m‐carborane

“…They have many fascinating characteristics such as near‐zero shrinkage during polymerization, low water absorption, high thermal stability and wide flexibility concerning the design of molecular structure . In this regard, polybenzoxazines are promising alternative materials for applications where epoxies, bismaleimides and even polyimides are used . Although the stability of polybenzoxazines is rather excellent under inert atmospheres, the thermal degradation of polybenzoxazines under oxidizing atmospheres, like epoxies and polyimides, is still serious .…”

Thermally curable main-chain benzoxazine prepolymers via polycondensation route

“…The aliphatic (poly(diphenylmethanebenzoxazine-adipamide)) showed slightly lower exothermic peak compared to aromatic poly(diphenylmethanebenzoxazine-phtalamide) due to the flexible aliphatic chains. The cured polymers exhibited good thermal stability indicating the applicability of poly(amide-benzoxazine)s as high performance materials [61].…”