Preparation and properties of silicon-containing benzoxazine with high thermal stability

Abstract

A silicon-containing benzoxazine (PDpsp-a) was synthesized from bis( p-hydroxyphenyl)diphenylsilane, aniline, and paraformaldehyde. The structure of the monomer was supported by 1H-NMR and FTIR spectra. The curing behavior of benzoxazine was evaluated by differential scanning calorimetry and in-situ FTIR spectra. The thermal properties were studied by MDSC, TGA, and Py-GC/MS. The results indicated that the characteristic peak of oxazine ring began to disappear when the temperature was heated to 180°C and completely disappeared at 260°C. The polybenzoxazine (PDpsp-a) possessed a high glass transition temperatures (174°C) and had good thermal stability (T10 = 420°C). In the pyrolysates of polybenzoxazine (PDpsp-a), no silicon-containing compounds, no phenol species, and more benzene were detected, we speculated that the Ar-Si bond would fracture with the increase of temperature. The benzene was volatilized from the system as a pyrolysis product and the silicon could react with oxygen to form siloxanes remained in the carbon residue in the form of siloxane compounds. The formed silica layer could endow the silicon-containing polybenzoxazine high thermal degradation stability and high char yield.

Simulation, design and synthesis of polybenzoxazine with different main‐chain structures and properties: A comparative study

“…23 The emergence of the main-chain benzoxazine made the molecular design of benzoxazine more diverse. By adjusting its structure, such as main-chain, [24][25][26] side chain, [27][28][29] end-capping 30,31 or introducing functional groups, 32,33 some unexpected properties could be obtained. 34 Liu et al 35 synthesized PBZ by using the main-chain benzoxazine oligomers with isomerized bisphenol-F and 4,4 0 -diaminodiphenylmethane as raw materials.…”

Integrating Benzoxazine‐PDMS 3D Networks with Carbon Nanotubes for flexible Pressure Sensors

“…[44][45][46] The addition of siloxane to benzoxazine moieties has been a popular option in the literature for improving the polybenzoxazine properties, including its ability to impart excellent flexibility and high thermal stability. [47][48][49] Various studies have integrated distinct siloxanes into benzoxazines, resulting in improved characteristics in the resulting polybenzoxazines, such as enhanced glass transition temperature (Tg) and toughness, [49][50][51][52][53][54][55] better thermal stability, [49,[51][52][53][54][55][56][57][58][59][60][61][62][63][64][65][66][67][68][69] increased flame retardancy, [53,55,66,70] higher surface hydrophobicity, [71] improved mechanical properties, [51,58,62,64,72,73] enhanced shape memory effect, [48] corrosion resistance [74] and lower...…”