Synthesis and characterization of a novel bisphthalonitrile containing benzoxazine

Abstract

Abstract. The novel bisphthalonitrile containing benzoxazine (BPNBZ) has been synthesized using bisphenol-A, 4-aminophenoxylphthalonitrile and paraformaldehyde. The structure of the monomer was supported by FTIR spectroscopy, 1 H-NMR, and 13 C-NMR spectra, which have exhibited that the reactive benzoxazine ring and cyano groups exist in molecular structure of BPNBZ. The cure reaction of BPNBZ was monitored by the disappearance of the nitrile peak and the tri-substituted benzene ring that is attached with oxazine ring peak at 2231, 951 cm -1 . The thermal polymerization of the BPNBZ was studied by differential scanning calorimetry (DSC) and dynamic rheometer. It was shown that the bisphthalonitrile containing benzoxazine had completely cured with two-stage polymerization mechanisms according to oxazine ring-opening and phthalonitrile ring-forming. The thermal decomposition behaviors of the polymer were examined by thermogravimetry analysis (TGA) in nitrogen and in air. The materials achieve char yields above 73% under nitrogen at 800°C and above 78% under air at 600°C, which exhibited the cured resin has good thermal stability and thermo-oxidative stability.

Effect of bisphenol-A on the structures and properties of phthalonitrile-based resin containing benzoxazine

“…The reason was that the ring-opening reaction reinforced by BPA monomer and the formation of the Mannich bridge structures via ringopening polymerization was the first priority [11,14,16]. The second exothermic peak corresponded to the polymerization of nitrile groups catalyzed by the extra hydrogen provided from the ring-opening of oxazine rings and BPA.…”

“…To solve these problems, phthalonitrile-based monomers with additional polymerisable groups such as amino, carboxyl, propargyl, oxazine, allyl, etc. were designed and synthesized to pursue self-promoted polymerization and a broad processing window for advanced applications [7][8][9][10][11]. It is well known that a simple and effective method is the incorporation of hydroxyl or amino groups into the reactive phthalonitrile units.…”

Characterizations of polybenzoxazine modified with isomeric biphenyltetracarboxylic dianhydrides

“…Polybenzoxazine, synthesized by the ring-opening polymerization reaction of cyclic benzoxazine resin only by thermal treatment without the need of catalyst and without producing any harmful by-products during the polymerization process, is recognized as an interesting new class of phenolic resin [1][2][3][4][5]. Moreover, polybenzoxazine provides some characteristics such as excellent dimension stability, high heat resistance, flame retardance and low moisture absorption as well as good dielectric properties in which cannot be found in traditional phenolic resins [6,7].…”

Active diluents effects of 4-nonylphenoxy-1, 2-dinitrilbenzene on phthalonitrile containing benzoxazine and their copolymerization behaviors

“…The curve showed the curing exotherm of the BA-ph monomer exhibited two characteristic exothermic peaks: a peak maximum of about 220°C and the other about 260°C, which was characteristic of the thermal curability of the resin [7,8]. On the contrary, the NP-ph resin showed no sign of a curing reaction in this temperature range without added initiators or catalysts.…”

“…All the chemicals and reagents were used without further purification. Phthalonitrile containing benzoxazine (BA-ph) was synthesized and purified according to the procedure reported before [7].…”