Novel Benzoxazine Monomers Containing p-Phenyl Propargyl Ether:  Polymerization of Monomers and Properties of Polybenzoxazines

Abstract

Novel benzoxazine monomers containing arylpropargyl ether were prepared, and highly thermally stable polybenzoxazines were obtained by the thermal cure of the monomers. One monomer is a monofunctional benzoxazine, 4-propargyloxyphenyl- 3,4-dihydro-2 H -1,3-benzoxazine (P-appe), and the other is a bifunctional benzoxazine, bis(4-propargyloxyphenyl-3,4-dihydro-2 H -1,3-benzoxazinyl)isopropane (B-appe). The chemical structures of these novel monomers were confirmed by IR and 1H NMR. The cure behavior of the monomers, P-appe and B-appe, and the properties of the resulting polymers were studied in comparison with 4-phenyl-3,4-dihydro-2 H -1,3-benzoxazine (P-a) and bis(4-phenyl-3,4-dihydro-2 H -1,3-benzoxazinyl)isopropane (B-a) as typical benzoxazine monomers without propargyl groups. DSC cure of both P-appe and B-appe showed a single exotherm corresponding to the ring-opening polymerization of oxazine ring and cross-linking of arylpropargyl ether group at almost the same temperature range as P-a and B-a. The T g values of polybenzoxazines derived from propargyl-containing monomers, PP-appe and PB-appe, were higher by ca. 100 and 140 °C than those of typical polybenzoxazines without propargyl groups, PP-a and PB-a, respectively. The storage moduli of PP-appe and PB-appe were maintained constant up to higher temperature for ca. 100 °C than that of PP-a and PB-a. The higher thermal stability of the novel polybenzoxazines, PP-appe and PB-appe, than that of the typical polybenzoxazines, PP-a and PB-a, was proved from thermogravimetric analyses.

Structurally diverse benzoxazines: synthesis, polymerization, and thermal stability

“…The presence of oxazine ring in the prepared compounds was further supported by the appearance of new absorption bands due to asymmetric and symmetric stretching of oxazine at 1230 and 1500 cm À1 , respectively. In addition, the oxazine ring frequency [23][24][25] (948 cm À1 ) was observed for all the materials. The presence of a band at 2951 cm À1 in IBPB and a characteristic band at 2962 cm À1 in SBIB confirm the existence of intact indane and spirobiindane nucleus in IBPB and SBIB, respectively.…”

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

“…In Figure 9, the intensity characteristic absorption band at 1478 cm -1 was assigned to the in-plane C-H stretching of the tetra-substituted benzene, indicating that the methylene bridges formed in the free ortho positions of the phenolic structures [26,27]. Meanwhile, the characteristic band of oxazine at around 967 cm -1 did not appear in the spectra, confirming oxazine rings were involved into the polymerization at 160°C.…”

Preparation and properties of bismaleimide resins modified with hydrogen silsesquioxane and dipropargyl ether and their composites

“…[19][20][21][22][23][24] A new kind of thermosetting resin with terminal propargyl groups has recently been developed as a high-performance polymer owing to its good processability, advantageous dielectric and mechanical properties and excellent thermal stability, whether in air or in a nitrogen atmosphere. [25][26][27][28][29][30] This paper presents new modified BMI resins prepared from BMI, HSQ and dipropargyl aryl ethers. We investigated the processability, mechanical properties and heat resistance of the resins and their composites.…”