Studies of polycyanurates based on phenoxy-substituted cyclic phosphazenes: Synthesis of the monomer and a preliminary study of its thermal properties in binary blends

Organic Crystal Engineering of Thermosetting Cyanate Ester Monomers: Influence of Structure on Melting Point

“…27 These results are in general agreement with other studies. 5, [16][17][18][19][20][28][29][30][31][32][33][34] The siliconcontaining analog of BADCy, bis(4-cyanatophenyl)dimethylsilane, or SiMCy, was synthesized in our laboratory according to a previously published procedure 27 that closely follows the original synthesis reported by Wright. 28,35 SiMCy exhibits a previously reported melting point of 338.2 ± 0.1 K, heat of fusion of 93 ± 1 J/g, and purity of 99.4 ± 0.1% after purification using chromatography.…”

Cyanate Esters

“…12% of bromine are required with cyanate esters, and in unmodified cyanate resin formulations lower levels of brominated additives are usually required as well to achieve a UL94 V-0 rating [88]. Due to the inherent temperature stability of cyanate esters, generally, lower bromine levels are required as for other polymers.…”

“…Due to the inherent temperature stability of cyanate esters, generally, lower bromine levels are required as for other polymers. However, incorporation of bromine into cyanate esters not only improves polymer performance but has some drawbacks as well, such as the potential corrosion of metal components in composites due to halide ion liberation, a decrease in glass transition temperature leading to a softening at already lower temperatures, a possible reduction of the thermo-oxidative stability, a deterioration of the dielectric loss properties, and, due to the high atomic weight of bromine, an increase in the specific weight of the polycyanurates [88]. 12% of bromine are required with cyanate esters, and in unmodified cyanate resin formulations lower levels of brominated additives are usually required as well to achieve a UL94 V-0 rating [88].…”

“…For example, Hamerton et al [88] in a four-step synthesis prepared 2,2,4-tri(4-cyanatophenoxy)-4,6,6-trisphenoxy-2λ 5 ,4λ 5 ,6λ 5 -[1,3,5,2,4,6]-triazatriphosphine (compound x, Figure 11.11), a new monomer containing a six-membered ring consisting of phosphorous and nitrogen atoms that confers improved flame retardancy to the cured cyanate ester network and simultaneously avoids the aforementioned drawbacks caused by bromine substituents. For example, Hamerton et al [88] in a four-step synthesis prepared 2,2,4-tri(4-cyanatophenoxy)-4,6,6-trisphenoxy-2λ 5 ,4λ 5 ,6λ 5 -[1,3,5,2,4,6]-triazatriphosphine (compound x, Figure 11.11), a new monomer containing a six-membered ring consisting of phosphorous and nitrogen atoms that confers improved flame retardancy to the cured cyanate ester network and simultaneously avoids the aforementioned drawbacks caused by bromine substituents.…”

“…For example, one approach recently described uses epoxidized soybean oil (ESO) as a bio-based modifier for commercial cyanate ester monomers [95]. The nanocomposites thereby accessible are Figure 11.11 Chemical structure of 2,2,4-tri (4-cyanatophenoxy)-4,6,6-tris-phenoxy-2λ 5 , 4λ 5 , 6λ 5 -[1,3,5,2,4,6]-triazatriphosphine [88]. The nanocomposites thereby accessible are Figure 11.11 Chemical structure of 2,2,4-tri (4-cyanatophenoxy)-4,6,6-tris-phenoxy-2λ 5 , 4λ 5 , 6λ 5 -[1,3,5,2,4,6]-triazatriphosphine [88].…”