Structure-Properties Relationships for Bisphenol A Polycyanurate Network Modified with Polyoxytetramethylene Glycol

Abstract

A series of polycyanurate networks (PCNs), based on the dicyanate of bisphenol A monomer (DCBA), were synthesized in the presence of dierent contents of hydroxylterminated polyoxytetramethylene glycol (PTMG). The chemical structure, T g behaviour, modulus-composition relations and mechanical properties of the modi®ed PCNs were investigated by Fourier transform infrared (FTIR) spectroscopy, dynamic mechanical thermal analysis (DMTA) and mechanical testing. The oligomer modi®er in¯uences the structure of the ®nal networks insofar as it is partly incorporates and partly dissolves in the polycyanurate matrix, and, thus, decreases the ®nal T g of these modi®ed thermosets. All modi®ed polycyanurate networks exhibit a single, broad glass transition that shifted to lower temperature as the modi®er content was increased.

Effect of ionic liquids on kinetic parameters of dicyanate ester polycyclotrimerization and on thermal and viscoelastic properties of resulting cyanate ester resins

“…First, during the mixing procedure, the -OCN groups of DCBE could react with hydroxyl groups of [HEAIm][Cl] with formation of imidocarbonate O-C(=NH)-O fragment ( Figure 6, compound 2), which further reacted with a second DCBE molecule with formation of a stabilized dimer ( Figure 6, compound 3) Figure 6, compound 6) with release of ROH (monocyanate of bisphenol E). According to Grigat and Pütter [36] as well as our previous works [33][34][35], the more acidic phenol compared to alcohol was released, and thus, a substituted triazine ring should be obtained with the release of a monophenol derived from DCBE. Moreover, we presumed that [HEAIm][Cl] could also increase the polarization of the C=N bond in the imidocarbonate (Figure 6, compound 2), thus making the carbon atom of this functional group more electrophilic.…”

“…The spectrum of CER/[OMIm][BF 4 ] showed only characteristic absorbance bands of both individual components (see Figure 4, curve (3) was proposed for the formation of cyanurate cycles from DCBE polymerization being catalyzed by [HEAIm][Cl] ( Figure 6). Our hypothesis was based on the well-known mechanisms of polycyclotrimerization of CERs in the presence of hydroxy [1,[32][33][34][35] and amino [36,37] compounds. First, during the mixing procedure, the -OCN groups of DCBE could react with hydroxyl groups of [HEAIm][Cl] with formation of imidocarbonate O-C(=NH)-O fragment ( Figure 6, compound 2), which further reacted with a second DCBE molecule with formation of a stabilized dimer ( Figure 6, compound 3) Figure 6, compound 6) with release of ROH (monocyanate of bisphenol E).…”

“…Obviously enough, Figure 10 shows the temperature dependence of storage modulus (E′) and loss factor (tan δ) for neat CER and CER/IL networks. All the samples were characterized by high α relaxation temperature values (T α > 240°C, Table 4), as typically found for thermostable cross-linked polymers, due to high temperature resistance of cross-links and high cross-linking density of polymer networks [1][2][3][4][5][6][32][33][34][35]. Unpredictably, a significant effect of the low IL content (i.e., 1.0 wt%) on the viscoelastic properties of all CER/IL networks was found compared to those of pure CER ( Figure 10, Table 4).…”

Synthesis and characterization of polycyanurate networks modified by oligo(ϵ‐caprolactone) as precursors of porous thermosets

“…[1][2][3][4][5][6][7] Recently, we have published several papers dealing with the modification of PCNs by dihydroxy-telechelic polyethers or polyesters. [8][9][10][11] It was found that the modifiers were partly chemically incorporated into the PCN structure through the reaction of their terminal hydroxyl groups with cyanate groups of growing PCN network.…”

Curing behavior and network formation of cyanate ester resin/polyethylene glycol

“…(3) Application of reactive elastomers, for instance, thermoplastic resin and rubber with active functional groups . (4) Block copolymerization with polyhydric alcohol, including polyether or polyester polyol . The main aim of the above modifications is to control the molecular structure or morphological structure, which is necessary to achieve significant toughening.…”