Synthesis and properties of a novel high-temperature vinylpyridine-based phthalonitrile polymer

Abstract

A novel vinylpyridine-based phthalonitrile monomer, 2,6-bis[3-(3,4-dicyanophenoxy)styryl]pyridine (BDSP), was resoundingly produced by a nucleophilic substitution reaction of 2,6-bis(3-hydroxystyryl)pyridine with 4-nitrophthalonitrile in the presence of potassium carbonate. The chemical structure of the synthesized BDSP was confirmed by proton (1H) and carbon (12C) nuclear magnetic resonance (NMR) as well as Fourier transform infrared (FTIR) analysis. The curing behavior of BDSP was investigated by FTIR and differential scanning calorimetry (DSC) analyses. The resin showed a low complex viscosity in the wide processing window between the monomer melting temperature and the curing temperature of the polymer, as discovered by rheological analysis. In addition, the properties of the polymer were studied by thermal gravimetric analysis (TGA) and dynamic mechanical analysis (DMA). Based on the test results, the BDSP polymer demonstrated superior processing performance, excellent thermal stability, outstanding mechanical properties, and low water uptake, and these advanced performance characteristics are critical to many fields.

A Pyridazine-Containing Phthalonitrile Resin for Heat-Resistant and Flame-Retardant Polymer Materials

“…It is worth noting that although the molecular structure of BCPD and BCPM monomer is similar, the T m of BCPD monomer is much lower than that of the BCPM monomer in our previous study. An analogous phenomenon also appears in other reported monomers [ 11 , 22 ]. However, one of the differences between BCPD and BCPM monomer is that the former is non-crystalline, while the latter is crystalline.…”

“…It is suggested that monomers with low T m are usually amorphous [ 11 , 23 , 25 ], while monomers with high T m are usually crystalline [ 4 , 20 , 22 , 23 ]. In previous studies, increasing the flexibility of molecular segments is the main strategy for reducing the T m .…”

“…Moreover, the DSC curves suggested satisfying processability ( T m : 74 °C; processing window:178 °C), which is obviously superior to previously reported phthalonitrile resins. In order to show the excellent processing performance of BCPD monomer more intuitively, a comparison of T m and the processing window of BCPD with other phthalonitrile is shown in Figure 5 [ 3 , 4 , 11 , 12 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ]. Hence, predictably, the research results greatly expand on the development of phthalonitrile resin in composite materials.…”

Polymerization mechanism of 4-APN and a new catalyst for phthalonitrile resin polymerization

“…At present, researchers basically believe that CN polymerization mainly produces triazine, isoindole and phthalocyanine rings, [31][32][33][34][35][36][37][38][39][40][41][42] does not produce small molecules, and gives the polymerization mechanism of forming the three heterocycles. However, this does not explain the experimental results in this paper very well.…”

A Phthalonitrile Resin with a Low Melting Point and High Storage Modulus Containing High‐Density Aromatic Ether Bonds

“…The bulk addition polymerization of aromatic compounds at high temperatures using compounds containing amino or hydroxyl groups as curing agent is usually the method to prepare phthalonitrile resin. Common curing agents are 4,4′‐diaminodiphenyl (ODA), bis[4(4‐aminophenoxy)phenyl] sulfone (p‐BAPS), APPH and other complex curing agents …”